Journal articles on the topic 'Mississippian Geologic Period'
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1
Woods, Mark T., David R. Russell, and Robert B. Herrmann. "Dispersion of Short Period Rayleigh Waves Within The Ozark Uplift and Illinois Basin." Seismological Research Letters 60, no. 3 (July 1, 1989): 111–18. http://dx.doi.org/10.1785/gssrl.60.3.111.
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Abstract We use data recorded by four arrays of portable instruments to investigate the propagation of short period (0.2≤T ≤2.0 sec) surface waves within the Ozark Uplift and Illinois Basin. At the regional scale, we construct group velocity dispersion curves for five suites of propagation paths, and invert them for shear velocity structure. The best model in each case consists of a single layer above a halfspace, and we can correlate the model units with geologic formations. The upper layer in the two Ozark Uplift models represents Ordovician and Cambrian carbonate strata, the halfspace corresponds to the Precambrian crystalline basement. Differences between our new models and an earlier one reflect the different parts of uplift that were sampled, and show the thickening of the Paleozoic section away from the uplift core. In the Illinois Basin models, the upper layer represents Pennsylvanian age elastics and the halfspace represents older Paleozoic carbonates. This interpretation is substantiated by a velocity log from a nearby deep well. Again, differences between our new models and earlier efforts result from different passband data that sample different parts of the basin. We also extract interstation phase velocities from array data recorded at the western edge of the Illinois Basin, over Mississippian age outcrop. By comparing this local dispersion curve with one calculated from the appropriate regional scale model, we conclude that the local structure can also be modeled as a single layer above a halfspace. Local shear velocities are, however, 30% faster than the regional average, which reflects the absence of the slow Pennsylvanian elastic strata around the basin’s periphery.
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Vanden Berg, Beth, Christophe Nussbaumer, Amy Noack, John Thornton, Ralf J. Weger, Gregor P. Eberli, and G. Michael Grammer. "A comparison of the relationship between measured acoustic response and porosity in carbonates across different geologic periods, depositional basins, and with variable mineral composition." Interpretation 6, no. 2 (May 1, 2018): T245—T256. http://dx.doi.org/10.1190/int-2017-0108.1.
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Recent work has shown that there is a predictable inverse relationship between laboratory-measured sonic velocity response and porosity in carbonates, which can be reasonably approximated using the empirical Wyllie time-average equation (WTA). The relationship was initially identified in late Cretaceous to Cenozoic age samples collected from the Great Bahama Bank and the Maiella Platform, an exhumed Cretaceous carbonate platform in Italy. We have compared older carbonate samples from different basins and different geologic ages to determine the applicability of this relationship and subsequent correlations to key petrophysical properties to other carbonate basins and other geologic time periods. The data set used for the comparison shows this relationship to be relatively consistent in other depositional basins (Michigan Basin, Paradox Basin) and with samples from older geologic periods (Pennsylvanian, Ordovician, and Mississippian). However, this basic relationship is also observed to vary significantly within a reservoir system and within a depositional basin in samples from different geologic periods (e.g., Silurian- versus Ordovician-age rocks in the Michigan Basin). Although the empirical WTA can generally be applied as a first-order estimate across a wide range of sample ages in carbonates, limited data suggest the relationship between velocity and porosity to be moderately more complex. For instance, in unconventional carbonate reservoirs characterized by predominantly micro- to nanoscale porosity, it is observed that the WTA should be applied as an upper data boundary. In addition, this study has shown that the relationship to the dominant pore type is less direct than in a macropore system in which it can be assumed that the dominant pore type also has the greatest effect on the effective permeability.
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Hashash, Youssef M. A., Norman A. Abrahamson, Scott M. Olson, Steve Hague, and Byungmin Kim. "Conditional Mean Spectra in Site-Specific Seismic Hazard Evaluation for a Major River Crossing in the Central United States." Earthquake Spectra 31, no. 1 (February 2015): 47–69. http://dx.doi.org/10.1193/033113eqs085m.
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Current seismic design practice often relies on the use of the uniform hazard response spectrum (UHRS), which implicitly includes motions from multiple earthquake sources and envelops possible spectra, yet does not represent a single event. Seismic hazard analyses at the site of a major Mississippi River crossing near St. Louis, Missouri, showed bimodal seismic hazard dominated by small, nearby earthquakes at short periods and large, distant earthquakes in the New Madrid seismic zone at long periods. UHRS motions resulted in large seismic demands and predictions of pervasive liquefaction that were inconsistent with historical and geologic records. UHRS-compatible conditional mean spectra (CMS) were developed to bridge deterministic and probabilistic seismic hazard evaluations, and used to evaluate liquefaction, lateral spreading, and settlement potential. The computed response was consistent with the historical and geologic record. CMSs offer hazard-compatible alternatives to the UHRS and result in seismic demand consistent with historical and geologic evidence.
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Jirásek, Jakub, Lenka Petrušková, and Martin Sivek. "Geotouristic attractions of the Ostrava part of the Upper Silesian Basin: geological and environmental sites." Acta Geoturistica 8, no. 2 (December 20, 2017): 50–57. http://dx.doi.org/10.1515/agta-2017-0005.
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Abstract In the Ostrava part of the Upper Silesian Basin there are many geotouristic sites connected with the underground mining of Carboniferous bituminous coal. Text is focused on those related to the geology of the Basin and environmental issues connected to coal mining. Of great intrest are outcrops of Mississippian sediments of the paralic Ostrava Formation, as well as two most important museums with permanent geological exhibitions. Some interesting geological features conncted to younger periods of Quarternary glaciation are also mentioned. Two types of publicly accessible sites related to the environmental burdens (burning coal heaps, saline mine water drainage system) are also described.
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Koehl, Jean-Baptiste P., and Jhon M. Muñoz-Barrera. "From widespread Mississippian to localized Pennsylvanian extension in central Spitsbergen, Svalbard." Solid Earth 9, no. 6 (December 21, 2018): 1535–58. http://dx.doi.org/10.5194/se-9-1535-2018.
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Abstract. In the Devonian–Carboniferous, a rapid succession of clustered extensional and contractional tectonic events is thought to have affected sedimentary rocks in central Spitsbergen, Svalbard. These events include Caledonian post-orogenic extensional collapse associated with the formation of thick Early–Middle Devonian basins, Late Devonian–Mississippian Ellesmerian contraction, and Early–Middle Pennsylvanian rifting, which resulted in the deposition of thick sedimentary units in Carboniferous basins like the Billefjorden Trough. The clustering of these varied tectonic settings sometimes makes it difficult to resolve the tectono-sedimentary history of individual stratigraphic units. Notably, the context of deposition of Mississippian clastic and coal-bearing sedimentary rocks of the Billefjorden Group is still debated, especially in central Spitsbergen. We present field evidence (e.g., growth strata and slickensides) from the northern part of the Billefjorden Trough, in Odellfjellet, suggesting that tilted Mississippian sedimentary strata of the Billefjorden Group deposited during active (Late/latest?) Mississippian extension. WNW–ESE-striking basin-oblique faults showing Mississippian growth strata systematically die out upwards within Mississippian to lowermost Pennsylvanian strata, thus suggesting a period of widespread WNW–ESE-directed extension in the Mississippian and an episode of localized extension in Early–Middle Pennsylvanian times. In addition, the presence of abundant basin-oblique faults in basement rocks adjacent to the Billefjorden Trough suggests that the formation of Mississippian normal faults was partly controlled by reactivation of preexisting Neoproterozoic (Timanian?) basement-seated fault zones. We propose that these preexisting faults reactivated as transverse or accommodation cross faults in or near the crest of transverse folds reflecting differential displacement along the Billefjorden Fault Zone. In Cenozoic times, a few margin-oblique faults (e.g., the Overgangshytta fault) may have mildly reactivated as oblique thrusts during transpression–contraction, but shallow-dipping, bedding-parallel, duplex-shaped décollements in shales of the Billefjorden Group possibly prevented substantial movement along these faults.
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Kemp, G. Paul, Elizabeth C. McDade, John W. Day, Robert R. Lane, Nancye H. Dawers, and Jason N. Day. "Recovery and Restoration of Biloxi Marsh in the Mississippi River Delta." Water 13, no. 22 (November 10, 2021): 3179. http://dx.doi.org/10.3390/w13223179.
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The State of Louisiana is leading an integrated wetland restoration and flood risk reduction program in the Mississippi River Delta. East of New Orleans, Biloxi Marsh, a ~1700 km2 peninsula jutting 60 km north toward the State of Mississippi is one of few Delta wetland tracts well positioned to dissipate hurricane surge and waves threatening the city’s newly rebuilt hurricane flood defenses. Both its location on the eastern margin of the Delta, and its genesis as the geologic core of the shallow water St. Bernard/Terre aux Boeuf sub-delta, which was the primary Mississippi outlet for almost 2000 years, make Biloxi Marsh attractive for restoration, now that the Mississippi River Gulf Outlet deep-draft ship channel has been dammed, and 50 years of impacts from construction and operation have abated. Now, the cascade of ecosystem damage it caused can be reversed or offset by restoration projects that leverage natural recovery and increased access to suspended sediment from the Mississippi River. Biloxi Marsh is (1) geologically stable, (2) benefiting from increased input of river sediment, and (3) could be restored to sustainability earlier and for a longer period than most of the rest of the submerging Mississippi Delta. The focus of this review is on the Biloxi Marsh, but it also provides a template for regional studies, including analysis of 2D and 3D seismic and other energy industry data to explore why existing marshes that look similar on the ground or from the air may respond to restoration measures with different levels of success. Properties of inherent durability and resilience can be exploited in restoration project selection, sequencing and expenditure. Issues encountered and investigative methods applied in the Biloxi Marsh are likely to resonate across initiatives now contemplated to sustain valuable river deltas worldwide.
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Blum, Mike. "Organization and reorganization of drainage and sediment routing through time: the Mississippi River system." Geological Society, London, Special Publications 488, no. 1 (2019): 15–45. http://dx.doi.org/10.1144/sp488-2018-166.
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AbstractIt has been said that large rivers are the bloodlines of continents, and the Mississippi River system is the most prominent bloodline in North America. The Mississippi drainage stretches from the Rocky Mountains in the western USA to the Appalachian Cordillera in the east, and sediment from this vast area is then routed to the alluvial–deltaic plain of south Louisiana and the basin-floor fan in the deep Gulf of Mexico (GoM). Origins of the Mississippi system can be traced to the Late Cretaceous–Early Paleocene reorganization of North American drainage. However, integration of a continental-scale Mississippi drainage is a Late Neogene phenomenon, and sediment routing to the GoM has changed significantly over multiple timescales in response to a variety of large-scale natural forcing mechanisms and to human activities. This paper reviews large-scale change in drainage, sediment routing and sediment storage for the Mississippi system over timescales of 150 myr, where tectonic and geodynamic processes dominate, the last 150 kyr, where Milankovitch climate and sea-level changes dominate, and the 150 year period of the twentieth and twenty-first centuries when human activities have fundamentally altered the sediment routing and dispersal system.
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O’Sullivan, Jay A. "Population Dynamics of Archaeohippus blackbergi (Mammalia; Equidae) from the Miocene Thomas Farm Fossil Site of Florida." Bulletin of the Florida Museum of Natural History 45, no. 4 (December 31, 2005): 449–64. http://dx.doi.org/10.58782/flmnh.yixb8525.
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The Thomas Farm fossil site, Gilchrist County, Florida, is the most fossiliferous Hemingfordian terrestrial site east of the Mississippi River. Taphonomy indicates that the formation of the fossil deposit occurred over a period of at most thousands of years, a geologic instant. Thomas Farm contains one of the earliest and numerically largest populations of the small equid Archaeohippus. Although the sample of mandibles is small (MNI=30), I was able to recognize nine age grades for Archaeohippus blackbergi. As the age at which a female Equus gives birth to her first offspring (3-3.5 years) approximately correlates with eruption of the third molar (3.5-4 years), it is estimated from tooth eruption data that a female A. blackbergi yielded her first foal between 1.5-2 years of age. A mortality spike for individuals with m3 coming into occlusion is interpreted as representing mortality due to intraspecific combat between males. Potential longevity for A. blackbergi is estimated at about 5 years.
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Wood, Clinton M., and Ethan R. B. Baker. "Cost Savings of Implementing Site-Specific Ground Motion Response Analysis in the Design of Short-Period Mississippi Embayment Bridges." Earthquake Spectra 34, no. 3 (August 2018): 1155–75. http://dx.doi.org/10.1193/120517eqs247m.
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Deep dynamic site characterization and a site-specific ground motion response analysis (SSGMRA) were conducted for a bridge site in Monette, Arkansas. The SSGMRA indicated the design acceleration response spectrum determined using the American Association of State Highway and Transportation Officials (AASHTO) general seismic procedure could be reduced by one third for the short-period range due to attenuation of the short-period ground motions. The steel girder pile-bent bridge, originally designed using the AASHTO general seismic design procedure, was redesigned using the updated seismic demands estimated from SSGMRA. A cost-savings analysis was then conducted to determine the potential savings associated with conducting the SSGMRA. By designing based on the results of the SSGMRA, a potential gross savings of $205,000, or 7% of the original bridge construction cost, could be achieved for the study bridge. Items that contributed most to the cost savings were the pile and embankment construction.
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Mizens, G. A., and S. A. Dub. "Geochemistry of limestones of the Mid-Carboniferous boundary interval in the Southern and Middle Urals." LITHOSPHERE (Russia) 22, no. 3 (July 2, 2022): 300–326. http://dx.doi.org/10.24930/1681-9004-2022-22-3-300-326.
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Research subject. Limestones of 11 sections of the Mid-Carboniferous boundary interval in the Southern and Middle Urals were studied. Sections of the western slope of the Urals (2 sections) refer to the East European platform, while the eastern Urals carbonate strata (9 sections) are fragments of the carbonate platform formed in the residual basin of the Ural Ocean. Material and methods. The lithological features of limestones of all considered sections were identified, the distribution and main characteristics of 28 trace (rare and scattered) elements, as well as Al and Fe, were studied and analyzed. Results and conclusions. The main characteristics of sedimentary basins, including the redox state, terrigenous material provenances, climatic conditions and the influence of endogenous processes, primarily volcanism, were clarified and evaluated. The results confirm the point of view about the short-duration hiatus at the Mid-Carboniferous boundary and the absence of a catastrophic drop in the World Ocean level. There are also no evidences of a significant cooling period. Geochemical and lithological data indicate local unconformities, transformations of sedimentary environments and sources of siliciclastic admixtures, as well as some climate humidization at the Mississippian-Pennsylvanian boundary.
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Courtois, Andrew, Samuel Bentley, Jillian Maloney, Kehui Xu, Jason Chaytor, Ioannis Y. Georgiou, Michael D. Miner, Jeffrey Obelcz, Navid H. Jafari, and Melanie Damour. "Short-Term Sediment Dispersal on a Large Retreating Coastal River Delta via 234Th and 7Be Sediment Geochronology: The Mississippi River Delta Front." Water 16, no. 3 (January 31, 2024): 463. http://dx.doi.org/10.3390/w16030463.
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Many Mississippi River Delta studies have shown recent declines in fluvial sediment load from the river and associated land loss. In contrast, recent sedimentary processes on the subaqueous delta are less documented. To help address this knowledge gap, multicores were collected offshore from the three main river outlets at water depths of 25–280 m in June 2017 just after the peak river discharge period, with locations selected based on 2017 U.S. Geological Survey seabed mapping. The coring locations included the undisturbed upper foreset, mudflow lobes, gullies, and the undisturbed prodelta. Nine multicores were analyzed for Beryllium-7 activity, and four cores were analyzed for excess Thorium-234 activity via gamma spectrometry, granulometry and X-radiography. Our results indicate a general trend of declining 7Be and 234Th activities and inventories with increasing distance from sources and in deeper water. The core X-radiographs are graded from the predominantly physically stratified nearshore to the more bioturbated offshore, consistent with the sedimentation patterns. Sediment focusing assessed via the 7Be and 234Th sediment inventories shows preferential sedimentation in gully and lobe environments, whereas the upper foreset and prodelta focusing factors are relatively depleted. Overall, short-term sediment deposition from the main fluvial source remains active offshore from all three major river outlets, despite the overall declining river load.
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Dagg, M. J., T. Bianchi, B. McKee, and R. Powell. "Fates of dissolved and particulate materials from the Mississippi river immediately after discharge into the northern Gulf of Mexico, USA, during a period of low wind stress." Continental Shelf Research 28, no. 12 (July 2008): 1443–50. http://dx.doi.org/10.1016/j.csr.2006.12.009.
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Bettenay, Leigh. "Geological and Mining Constraints on Historical Mine Production: The Case of Early Medieval Lead-Silver Mining at Melle, France." METALLA 26, no. 2 (August 15, 2022): 67–86. http://dx.doi.org/10.46586/metalla.v26.2022.i2.67-86.
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Early Medieval silver production for the Melle Pb-Ag deposit in western France has been estimated up to 15 tonnes per year over hundreds of years (Téreygeol, 2013) which would place it amongst the top silver mines of all times prior to the New World discoveries. However, this deposit has geological and mining characteristics economically unsuitable for substantial production, because it is thin, sub-horizontal and comprised of discontinuous pods. Furthermore, it is a Mississippi Valley type (MVT) base metal deposit, which are typically not major silver producers. There is no geological evidence for primary or secondary enrichment to generate silver-rich ore. Inaddition, the fact that Melle remained unmined in all later historical periods is enigmatic compared to the almost ubiquitous reworking of significant ore deposits elsewhere.In this paper, I discuss the geological characteristics, mining parameters, documented historical mining rates and workforce considerations, all of which can be used to constrain production estimates for Melle. The largest uncertainty for production estimates is the workforce size, which reflects scarce information about Carolingian Melle and its surroundings. A model employing realistic mining parameters and a workforce appropriate for a small mining village (100 miners/fire-setters, within a workforce of 250-300, from a settlement of at least 400-500) yields 52 tonnes of lead metal and 150 kg of silver per year. Doubling the workforce would double this estimate. Conversely, it could be half or less if mining was a seasonal activity between agricultural priorities such as harvesting and seeding.The previously claimed production rates require improbable mining assumptions together with at least 500 dedicated full-time miners and a population in the thousands. Furthermore, it would yield per capita silver productivity more than four times higher than in well-documented Early Modern operations that were leading silver deposits of their time. This seems unlikely. However, even at the much lower production levels, favoured here, Melle still might have been a major factor in the Carolingian economy, with its lead production perhaps as important as its silver.
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Liang, Xingyu, Bo Li, Chengnan Zhang, Huaikun Qin, Gao Li, and Xinyue Zhang. "Mineralogical and Geochemical Characteristics of Carbonates and Their Geological Significance to the Fuli Pb-Zn Deposit, Yunnan Province." Minerals 12, no. 10 (October 19, 2022): 1317. http://dx.doi.org/10.3390/min12101317.
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Mississippi Valley-Type (MVT) deposits are among the main types of Pb-Zn deposits that feature carbonate minerals as the main gangue minerals; their formation runs through the entire metallogenic process of MVT deposits. Therefore, carbonate minerals contain rich information on metallogenic fluid evolution and are thus important prospecting indicators. The Fuli Pb-Zn deposit in eastern Yunnan is located in the southeast of the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province, which is the biggest producer of zinc and lead in China and contains more than 400 deposits and over 20 million tons of Pb + Zn reserves. The ore occurs in the interlayer fracture zone of Middle Permian Yangxin Formation Dolomite, and the orebody shape is generally stratiform. The main metal-bearing minerals of this deposit are sphalerite, galena, and pyrite; the gangue minerals mainly comprise dolomite and calcite. Three mineralized stages are observed (the early metallogenic period, the main metallogenic period, and the late metallogenic period) according to the characteristics of stratigraphic output, the intercalated contact relationship of gangue minerals, and the alteration characteristics of the wall rock. To determine the source and properties of the ore-forming fluid and the ore-forming process of the Fuli Pb-Zn deposit, different stages of mineralogy and trace element geochemical characteristics of hydrothermal dolomite were systematically studied. The minerals were observed under microscope and subjected to in situ analysis by LA-ICP-MS and C–O isotope test. The δ18OSMOW value of the dolomite in the metallogenic period was between 13.29‰ and 20.55‰, and the δ13CPDB value was between −4.13‰ and 3.5‰. Dolomite of the metallogenic period mainly came from the dissolution of carbonate wall rocks, while C in the ore-forming fluid came from the wall rocks. A few dolomites showed a trend of depleting δ13CPDB and δ18OSMOW at the same time, implying the influence of sedimentary rock contamination in the mantle multiphase system. The lower δ18O was due to the exchange of O isotopes between the wall rocks and the depleted δ18O in ore-forming fluids. From the early to the later stage of mineralization, the ore-forming fluid changed from alkaline to neutral to weakly acidic due to a decrease in the oxygen fugacity and temperature of the fluid; this change resulted in the precipitation of sulfide and dolomite in the deposit. From the early to the late stages of mineralization, Fe and Mn showed a downward trend. Fe and Mn entered the alkaline environment of the carbonate minerals, while Fe and Mn were released into the acidic fluid, indicating that due to the metasomatism from strong to weak, their metallogenic environment evolved from alkaline to acidic. From the early to the late stage of mineralization, Sr showed an upward trend, which might indicate that the continuous reaction between the hydrothermal fluid and the wall rock continuously released Sr into the fluid. The Fe-Sr and Mn-Sr diagrams show that two kinds of fluid mixing occurred in the ore-forming process. The Fuli Pb-Zn deposit may have formed from mineral precipitation caused by the mixing of the metal-rich, oxidized acidic fluid and the sulfur-rich, reduced alkaline fluid. The results show that the Fuli Pb-Zn deposit belongs to MVT deposits.
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Harris, J. B., R. L. Street, J. D. Kiefer, D. L. Allen, and Z. M. Wang. "Modeling Site Response in the Paducah, Kentucky Area." Earthquake Spectra 10, no. 3 (August 1994): 519–38. http://dx.doi.org/10.1193/1.1585787.
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Site conditions at 37 locations in Paducah, Kentucky, and the surrounding area were modeled using seismic refraction and reflection data to determine site response to a suite of Canadian strong-motion records and a hypothetical central United States earthquake. The seismic data, integrated with local borehole information, indicated that depths to bedrock range from less than 300 to more than 500 ft. The site-response analysis shows that the study area can be subdivided into three zones and the highest spectral amplifications are associated with thick alluvial and lake-bed deposits. The magnitude of spectral ratios ranges from less than five to more than 20 times, and dynamic site periods range from 0.7 to 1.5 sec. Although this study relates directly to the Paducah area, the methods and types of data collected are applicable for other Upper Mississippi Embayment communities for land-use planning and the design of critical structures.
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Hashash, Youssef MA, Okan Ilhan, Halil Uysal, Jonathan P. Stewart, Sissy Nikolaou, Ellen M. Rathje, Kenneth W. Campbell, and Walter J. Silva. "Application of empirical and simulation-based site amplification models for Central and Eastern North America to selected sites." Earthquake Spectra 37, no. 1_suppl (June 18, 2021): 1516–33. http://dx.doi.org/10.1177/87552930211020770.
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The Next Generation Attenuation Relationships for Central & Eastern North-America (NGA-East) Geotechnical Working Group (GWG) has presented models for site amplification in Central and Eastern North America that represent a significant change from past practice, which was based on models developed for active tectonic regions. The GWG models are ergodic in their formulation, meaning that they produce an average level of amplification conditional on VS30 and other the site parameters. We illustrate the application of these models to four sites in Texas, South Carolina, Mississippi, and New York City, and compare results with site-specific ground response analyses. The results indicate that substantial advantage is possible when ergodic models conditioned only on VS30 are supplemented with a modular term that produces a peak at one or more site natural periods ( Tnat). The article demonstrates features and limitations of the GWG models for sites in Central and Eastern North America and provides useful recommendations for coupling ergodic and non-ergodic (site-specific) modeling as part of seismic hazard studies.
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Ielpi, Alessandro, Martin R. Gibling, Arden R. Bashforth, and Chinemerem I. Dennar. "Impact of Vegetation On Early Pennsylvanian Fluvial Channels: Insight From the Joggins Formation of Atlantic Canada." Journal of Sedimentary Research 85, no. 8 (August 1, 2015): 999–1018. http://dx.doi.org/10.2110/jsr.2015.50.
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Abstract: Riparian vegetation profoundly influences modern fluvial channels in a variety of ways, depending on the life-history strategies of different plant types, disturbance frequency, and drainage conditions of available habitats. Direct evidence for these dynamic relationships is usually cryptic in ancient deposits. We report evidence for interactions between rivers and in situ vegetation for selected sites in the lower Pennsylvanian Joggins Formation of Atlantic Canada, encompassing fixed, meandering, and distributary channels originally up to 6 m deep. Channel bodies are associated with a suite of fossilized plant remains, specifically lycopsids that preferred stable wetland settings, disturbance-tolerant calamitaleans, and slow-growing, long-lived cordaitaleans. Vegetation was effective in stabilizing banks and bars and promoting aggradation. Lycopsids and calamitalean groves colonized the channel bed during periods of reduced flow, drawing on the groundwater table, and mounds around upright trunks indicate that they formed bar nuclei after flow resumed. Bank-attached bars with lateral-accretion sets contain upright trees, which may have stabilized inclined sediment surfaces, and trees present between small distributary channels may have formed vegetated islands. Erect lycopsids rooted below the channel base project up into the channel fill, where they formed obstacles and nucleated sediment mounds in active channels. On channel cutbanks, upright lycopsids are tilted towards the channel, and early formed rhizoconcretions are associated with deep cordaitalean root systems in the tops of channel fills. These features imply that vegetation contributed to stabilization of sediment surfaces. The predominance of in situ over transported plant remains suggests that these low-flow-strength rivers had limited ability to erode and entrain large woody debris, especially for small channels with strengthened banks. We infer that patterns of interaction between vegetation and rivers with a range of fluvial style broadly resembled those of today. By the early Pennsylvanian, rivers had moved from a geomorphic and biogeomorphic mode of operation into a fully ecological mode with prominent feedback loops between vegetation and fluvial processes. Vegetation is commonly poorly preserved in fluvial systems but should be incorporated into facies models for Pennsylvanian and younger strata, possibly also for some Devonian and Mississippian formations.
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Raczynski, Krzysztof, and Jamie Dyer. "Variability of Annual and Monthly Streamflow Droughts over the Southeastern United States." Water 14, no. 23 (November 26, 2022): 3848. http://dx.doi.org/10.3390/w14233848.
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Understanding the patterns of streamflow drought frequency and intensity is critical in defining potential environmental and societal impacts on processes associated with surface water resources; however, analysis of these processes is often limited to the availability of data. The objective of this study is to quantify the annual and monthly variability of low flow river conditions over the Southeastern United States (US) using National Water Model (NWM) retrospective simulations (v2.1), which provide streamflow estimates at a high spatial density. The data were used to calculate sums of outflow deficit volumes at annual and monthly scales, from which the autocorrelation functions (ACF), partial autocorrelation functions (PACF) and the Hurst exponent (H) were calculated to quantify low flow patterns. The ACF/PACF approach is used for examining the seasonal and multiannual variation of extreme events, while the Hurst exponent in turn allows for classification of “process memory”, distinguishing multi-seasonal processes from white noise processes. The results showed diverse spatial and temporal patterns of low flow occurrence across the Southeast US study area, with some locations indicating a strong seasonal dependence. These locations are characterized by a longer temporal cycle, whereby low flows were arranged in series of several to dozens of years, after which they did not occur for a period of similar length. In these rivers, H was in the range 0.8 (+/−0.15), which implies a stronger relation with groundwater during dry periods. In other river segments within the study region the probability of low flows appeared random, determined by H oscillating around the values for white noise (0.5 +/−0.15). The initial assessment of spatial clusters of the low flow parameters suggests no strict relationships, although a link to geologic characteristics and aquifer depth was noticed. At monthly scales, low flow occurrence followed precipitation patterns, with streamflow droughts first occurring in the Carolinas and along the Gulf Coast around May and then progressing upstream, reaching maxima around October for central parts of Mississippi, Alabama and Georgia. The relations for both annual and monthly scales are better represented with PACF, for which statistically significant lags were found in around 75% of stream nodes, while ACF explains on average only 20% of cases, indicating that streamflow droughts in the region occur in regular patterns (e.g., seasonal). This repeatability is of greater importance to defining patterns of extreme hydrologic events than the occurrence of high magnitude random events. The results of the research provide useful information about the spatial and temporal patterns of low flow occurrence across the Southeast US, and verify that the NWM retrospective data are able to differentiate the time processes for the occurrence of low flows.
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Wang, Jiong, and Toshiro Tanimoto. "Estimating Near-Surface Rigidity from Low-Frequency Noise Using Collocated Pressure and Horizontal Seismic Data." Bulletin of the Seismological Society of America 110, no. 4 (June 23, 2020): 1960–70. http://dx.doi.org/10.1785/0120200098.
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ABSTRACT We propose a single-station approach to estimate near-surface elastic structure using collocated pressure and seismic instruments. Our main result in this study is near-surface rigidity (shear modulus) structure at 784 EarthScope Transportable Array (TA) stations in operation from mid-2011 to the end of 2018 using coherent horizontal seismic and pressure signals at 0.02 Hz. We isolate time periods for which surface pressure change is the dominant excitation source for seismic signals by searching for data windows with large pressure variations and high-seismic-pressure coherence. We emphasize the importance of using horizontal seismic components for two reasons: first, horizontal seismic signals are significantly higher than vertical signals at 0.02 Hz due to ground tilt, and second, we can analytically compute the predicted horizontal signals without an assumption of atmospheric pressure wavespeed (which is required for predicting the vertical excitation). Sensitivity kernels from 0.01 to 0.05 Hz show that this pressure–seismic coupling is mostly dependent on rigidity shallower than 50 or 100 m. Our estimates of shallow elastic structure show good spatial agreement with large-scale surface geological features. For instance, stations in the Appalachian Mountains mostly have high rigidity, whereas low-rigidity sites dominate the Mississippi Alluvial Plain. Because of the lack of measured velocity profiles, we quantitatively validate our approach by comparing with VS30 models that are based on proxies such as topographic slopes and large-scale surface geology. We estimate near-surface rigidity at 784 TA stations, where these locations have no prior structure information. Our method provides independent information for seismic hazard studies.
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Marchesini, Pierpaolo, Jonathan B. Ajo-Franklin, and Thomas M. Daley. "In situ measurement of velocity-stress sensitivity using crosswell continuous active-source seismic monitoring." GEOPHYSICS 82, no. 5 (September 1, 2017): D319—D326. http://dx.doi.org/10.1190/geo2017-0106.1.
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The ability to characterize time-varying reservoir properties, such as the state of stress, has fundamental implications in subsurface engineering, relevant to geologic sequestration of [Formula: see text]. Stress variation, here in the form of changes in pore fluid pressure, is one factor known to affect seismic velocity. Induced variations in velocity have been used in seismic studies to determine and monitor changes in the stress state. Previous studies conducted to determine velocity-stress sensitivity at reservoir conditions rely primarily on laboratory measurements of core samples or theoretical relationships. We have developed a novel field-scale experiment designed to study the in situ relationship between pore-fluid pressure and seismic velocity using a crosswell continuous active-source seismic monitoring (CASSM) system. At the Cranfield, Mississippi, [Formula: see text] sequestration field site, we actively monitored seismic response for five days with a temporal resolution of 5 min; the target was a 26 m thick injection zone at approximately 3.2 km depth in a fluvial sandstone formation (lower Tuscaloosa Formation). The variation of pore fluid pressure was obtained during discrete events of fluid withdrawal from one of the two wells and monitored with downhole pressure sensors. The results indicate a correlation between decreasing CASSM time delay (i.e., velocity change for a raypath in the reservoir) and periods of reduced fluid pore pressure. The correlation is interpreted as the velocity-stress sensitivity measured in the reservoir. This observation is consistent with published laboratory studies documenting a velocity ([Formula: see text]) increase with an effective stress increase. A traveltime change ([Formula: see text]) of 0.036 ms is measured as the consequence of a change in pressure of approximately 2.55 MPa ([Formula: see text]). For [Formula: see text] total traveltime, the velocity-stress sensitivity is [Formula: see text]. The overall results suggest that CASSM measurements represent a valid technique for in situ determination of velocity-stress sensitivity in field-scale monitoring studies.
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Manor, Matthew J., Stephen J. Piercey, Corey J. Wall, and Nikola Denisová. "High-Precision CA-ID-TIMS U-Pb Zircon Geochronology of Felsic Rocks in the Finlayson Lake VMS District, Yukon: Linking Paleozoic Basin-Scale Accumulation Rates to the Occurrence of Subseafloor Replacement-Style Mineralization." Economic Geology 117, no. 5 (August 1, 2022): 1173–201. http://dx.doi.org/10.5382/econgeo.4910.
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Abstract Felsic igneous complexes and associated volcano-sedimentary rocks in continental back-arc environments host large-tonnage and/or high-grade volcanogenic massive sulfide (VMS) deposits. The emplacement mechanisms, style, and preservation of these deposits is thought to be partially dependent on depositional rates of the host lithofacies (i.e., discrete volcanic eruptions) relative to the setting of massive sulfide genesis on the seafloor as mounds and/or via subseafloor replacement of existing strata. The localization and occurrence of subseafloor replacement-style VMS deposits is therefore strongly influenced by the characteristics of the volcano-sedimentary facies in the hosting basin and the rates of their emplacement; the latter are poorly constrained in the literature due to the difficulty of obtaining high-precision dates that make this possible in Phanerozoic and older rocks. New high-resolution U-Pb geochronology and detailed regional stratigraphic investigation indicate that Devonian-Mississippian volcanic rocks and associated VMS mineralization in the Yukon-Tanana terrane in the Finlayson Lake district, Yukon, Canada, were erupted or emplaced during distinct time periods (ca. 363.3, 362.8, and 355.2 Ma) in two discrete submarine basins: the Kudz Ze Kayah formation and the Wolverine Lake group. The VMS deposits in both settings are contained within intrabasinal rocks that accumulated at rapid rates of ~350 to 2,000 m/m.y. over 0.6 to 1.4 m.y. Locally, these rates reach peak rates up to 7,500 m/m.y. in the Wolverine Lake group, which are interpreted to reflect facies deposition by mass transport complexes or turbidity currents. These new dates indicate that rapid accumulation of volcanic rocks in the back-arc basins was critical for localizing subseafloor replacement-style mineralization and the development of the Zn-enriched GP4F, Kudz Ze Kayah, and Wolverine VMS deposits. Rapid depositional processes observed in these deposits and their host basins are interpreted to have an important role in developing highly porous and permeable, water-saturated lithofacies that provide optimal conditions for enhancing zone refining processes and subsequent preservation of massive sulfide mineralization, which are key in the development of high-grade and large-tonnage VMS deposits. It is herein suggested that quantitative basin-scale accumulation rates, as a result of new U-Pb geochronological methods and increased precision combined with detailed stratigraphic and facies analysis, may provide important perspectives on the formation of continental back-arc basins and the localization of VMS deposits in other continental margin environments globally.
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Amininia, Karim, and Seyed Mahdi Saghebian. "Uncertainty analysis of monthly river flow modeling in consecutive hydrometric stations using integrated data-driven models." Journal of Hydroinformatics 23, no. 4 (February 5, 2021): 897–913. http://dx.doi.org/10.2166/hydro.2021.142.
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Abstract The flow assessment in a river is of vital interest in hydraulic engineering for flood warning and evacuation measures. To operate water structures more efficiently, models that forecast river discharge are desired to be of high precision and certain degree of accuracy. Therefore, in this study, two artificial intelligence models, namely kernel extreme learning machine (KELM) and multivariate adaptive regression splines (MARS), were applied for the monthly river flow (MRF) modeling. For this aim, Mississippi river with three consecutive hydrometric stations was selected as case study. Using the previous MRF values during the period of 1950–2019, several models were developed and tested under two scenarios (i.e. modeling based on station's own data or previous station's data). Wavelet transform (WT) and ensemble empirical mode decomposition (EEMD) as data processing approaches were used for enhancing modeling capability. Obtained results indicated that the integrated models resulted in more accurate outcomes. Data processing enhanced the model's capability up to 25%. It was observed that the previous station's data could be applied successfully for MRF modeling when the station's own data were not available. The best-applied model dependability was assessed via uncertainty analysis, and an allowable degree of uncertainty was found in MRF modeling.
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Roushangar, Kiyoumars, Nasrin Aghajani, Roghayeh Ghasempour, and Farhad Alizadeh. "The potential of ensemble WT-EEMD-kernel extreme learning machine techniques for prediction suspended sediment concentration in successive points of a river." Journal of Hydroinformatics 23, no. 3 (February 22, 2021): 655–70. http://dx.doi.org/10.2166/hydro.2021.146.
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Abstract Sediment transport is one of the most important issues in river engineering. In this study, the capability of the Kernel Extreme Learning Machine (KELM) approach for predicting the river daily Suspended Sediment Concentration (SSC) and Discharge (SSD) was assessed. Three successive hydrometric stations of Mississippi river were considered and based on the sediment and flow characteristics during the period of 2005–2008. Several models were developed and tested for SSC and SSD modeling. For improving the applied model efficiency, two post-processing techniques, namely Wavelet Transform (WT) and Ensemble Empirical Mode Decomposition (EEMD), were used. Also, two states of modeling based on stations' own data (state 1) and previous stations' data (state 2) were considered. The single and integrated KELM model results comparison indicated that the integrated WT and EEMD-KELM models resulted in more accurate outcomes. Results showed that data processing with WT was more effective than EEMD in increasing the models' efficiency. Data processing enhanced the models' capability by up to 15%. The results showed that the state 1 modeling led to better results, however, using the integrated KELM approaches the previous stations data could be applied successfully for SSC and SSD modeling when the stations' own data were not available. HIGHLIGHT The suspended sediment concentration (SSC) and suspended sediment discharge (SSD) were predicted via artificial intelligence approach in successive hydrometric stations. The data pre-processing impacts on models' efficiency improvement was assessed. The sensitivity analysis showed the most effective subseries was obtained from pre-processing models.
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Yang, Changbing, Katherine Romanak, Susan Hovorka, Robert M. Holt, Jeff Lindner, and Ramon Trevino. "Near-Surface Monitoring of Large-Volume CO2 Injection at Cranfield: Early Field Test of SECARB Phase III." SPE Journal 18, no. 03 (January 30, 2013): 486–94. http://dx.doi.org/10.2118/163075-pa.
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Summary An early field project of the Southeast Regional Carbon Sequestration Partnership (SECARB) was conducted in Cranfield oil field, western Mississippi. Carbon dioxide (CO2) was injected into coarse-grained fluvial deposits of the Cretaceous lower Tuscaloosa formation, forming a gentle anticline at depths of 3300 m. CO2 injection started in July 2008, increasing to 23 wells (as of May 2011), with total injection rates greater than 1 million tons/yr. Focused monitoring programs of the deep subsurface and near surface have been implemented in different study areas. Here we present results of the near-surface monitoring program over a 3-year period, including shallow groundwater monitoring and soil-gas monitoring. A general methodology of detecting CO2 leakage into shallow groundwater chemistry is proposed. A set of geochemical indicator parameters was identified on the basis of the characterization of groundwater geochemistry, and these were further tested and validated using numerical modeling approaches, laboratory experiments, and field experiments. For soil-gas monitoring, a site (P-site) containing a plugged and abandoned well, a nearby open pit, and an engineered pad (representing a typical industrial near-surface environment for soil-gas monitoring) was selected for detailed study. The site was heavily instrumented with various sensors for measuring soil-gas concentrations at different depths, soil-water content, matric potential, and weather information. Three monitoring technologies were assessed: soil CO2 concentration measurements, CO2 flux measurements on the land surface, and multiple soil-gas component measurements. Results indicate that soil-gas-component measurements provide reliable information for gas-leakage detection. Methodologies of near-surface monitoring developed in this study can be used to improve CO2-leakage monitoring at other CO2 sequestration projects. This early field project was funded by the US Department of Energy, National Energy Technology Laboratory, as part of the Regional Carbon Sequestration Partnerships (RCSP) program. SECARB is led by the Southern States Energy Board (SSEB).
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Güyagüler, Baris, Roland N. Horne, Leah Rogers, and Jacob J. Rosenzweig. "Optimization of Well Placement in a Gulf of Mexico Waterflooding Project." SPE Reservoir Evaluation & Engineering 5, no. 03 (June 1, 2002): 229–36. http://dx.doi.org/10.2118/78266-pa.
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Summary In this study, a hybrid optimization technique based on the genetic algorithm (GA), polytope algorithm, kriging algorithm, and neural networks is proposed to optimize a waterflooding project. Hybridization of the GA with these helper methods introduces hill climbing into the stochastic search and makes use of proxies created on the fly. It was observed that the number of simulations required was reduced significantly, as compared to conventional approaches. This reduction in the number of simulations reduced the computation time, enabling the use of full-scale simulation for optimization even for this full-scale field problem. It was also seen that the optimization technique was able to prevent convergence to local maxima owing to its stochastic nature. Introduction Determination of the location of new wells is a complex problem that depends on reservoir and fluid properties, well and surface equipment specifications, and economic criteria. Various approaches have been proposed for this problem. Among those, direct optimization using the simulator as the evaluation function, although accurate, is in most cases infeasible due to the number of simulations required. Optimal placement of up to four water-injection wells was studied for Pompano, an offshore field in the Gulf of Mexico. Injection rate was also optimized. The net present value (NPV) of the waterflooding project was used as the objective function. Profits and costs during the time period of the project were taken into consideration. Numerical models are detailed and powerful predictive tools in reservoir management. While not perfect, they are often the best representation of the subsurface available. Optimization methodologies run these numerical models perhaps thousands of times, searching for the most profitable solution to reservoir management questions. Because of the computational time involved, optimization methodologies are not used as much as they could be. Various researchers have explored speeding up optimization either by using a speedier evaluation of the objective function (i.e., a simpler model or a proxy for the full numerical model) or by improving the efficiency of the optimization search itself. This paper uses the latter approach (focusing on search improvement), yet it harnesses some of the techniques often used in proxy development to allow the search to step toward optimality more skillfully. Researchers have looked into the optimization of well placement and rate using numerical simulation. Beckner and Song1 formulated the problem as a traveling-salesman problem and used simulated annealing to optimize well location and drilling schedule. Bittencourt and Horne2 investigated optimization of well placement using a hybrid of the GA and the polytope method. Güyagüler and Gümrah3 optimized production rates for a gas storage field using GAs. Aanonsen et al.4 coupled a CPU-efficient reservoir simulator with an optimization algorithm and made use of a kriging proxy to find optimum well locations. Pan and Horne5 also used kriging to decrease the necessary number of simulations required to optimize well location. Rogers and Dowla6 and Centilmen et al.7 used neural networks as a substitute for numerical simulation. We have been exploring search improvements in GA8 to decrease the total number of individual simulations required for convergence of the optimization problem. The GA is popular for its strengths in avoiding suboptimal solutions, freedom from requiring derivatives, and ease of parallelization. The GA was chosen over other popular heuristic search algorithms, such as simulated annealing, because of the concept of population and the greater ease of parallelization. Parallelization obviously has the potential to speed calculations. The concept of population integrates well with the formulation of the search improvements of this work. Some of the same traits that make the GA robust and powerful also make it slow and inexact in refining the solution. The GA typically has rapid initial progress during the search, but it has problems locating the final optimal solution. Because of these limitations, this work investigated specific helper methods that can significantly improve the efficiency, speed, and exactness of the GA search. The two helper methods integrated into the GA search are the polytope method9 and the proxy method. The two types of proxies explored are derived from kriging10 and neural-network11 estimates. Other proxies, such as simple analytical models, could be considered. These helper methods were integrated into a hybrid GA and applied to a waterflood management problem for the Pompano field in the Gulf of Mexico. This field is a complex turbidite sequence with anticlinal structure and a bottom drive aquifer. It was thought that the addition of one or more injection wells could increase overall field production and profitability significantly. We considered well placement and well pumping rates to be decision variables. Maximizing NPV was the overall objective. Again, note that the searches ultimately relied on the full numerical model; however, the number of function evaluations required for the search was reduced with the guidance of the helper methods. Reservoir Description The Pompano field extends over five Gulf of Mexico blocks [Mississippi Canyon (MC) 27, 28, and 72 and Viosca Knoll (VK) 989 and 990] located approximately 24 miles southeast of the Mississippi River Delta. Operations for the Pompano field have been investigated previously in the literature.12,13 BP plc and Kerr Mc- Gee hold 75% and 25% equity, respectively. The Pompano platform sits in VK 989 in 1,290 ft of water and is a 40-slot, fixed-leg platform. It is the second-tallest fixed structure in the Gulf of Mexico. The platform receives production from three reservoirs: upthrown Pliocene, downthrown Pliocene, and Miocene. In this paper, we focus on the Miocene reservoir, which comprises two thirds of the field reserves. The Miocene sands are located in MC 28 and 72. Developing these sands has proved challenging, given the large distance from the platform. The longest drillable platform wells (approximately 18,000 ft of lateral step out) can only reach the northern one-third of the reservoir. Thus, the remaining two-thirds in the south were developed from a 10-slot subsea template located in MC 28 in 1,800 ft of water. The template is tied back to the VK989 platform by two 8-in. flowlines approximately 4.5 miles in length.
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Gutierrez, Dubert, Archie R. Taylor, Vinodh Kumar, Matthew G. Ursenbach, Robert G. Moore, and Sudarshan A. Mehta. "Recovery Factors in High-Pressure Air Injection Projects Revisited." SPE Reservoir Evaluation & Engineering 11, no. 06 (December 1, 2008): 1097–106. http://dx.doi.org/10.2118/108429-pa.
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Summary High-pressure air injection (HPAI) is an improved-oil-recovery (IOR) process in which compressed air is injected into a deep light-oil reservoir with the expectation that the oxygen in the injected air will react with a fraction of the reservoir oil at an elevated temperature to produce carbon dioxide. The resulting flue-gas mixture provides the main mobilizing force to the oil downstream of the reaction region, sweeping it to production wells. The combustion zone itself may provide a critical part of the sweep mechanism. In 1994, Fassihi et al. proposed a method for estimating recovery factors of light-oil air-injection projects on the basis of the performance of two successful HPAI projects. Their suggested method relies on the extrapolation of the field gas/oil ratio (GOR) up to an economic limit. In other words, it treats HPAI as an immiscible gasflood and neglects any potential oil that could be recovered by the combustion front. The truth is that, although early production during an HPAI process is caused mostly by repressurization and gasflood effects, once a pore volume of air has been injected, the combustion front becomes the main driving mechanism. Moreover, one of the unique features of air injection is the self-correcting nature of the combustion zone, which promotes good volumetric sweep of the reservoir. This paper presents laboratory and field evidence of the presence of a thermal front during HPAI operations and evidence of its beneficial impact on oil recovery. An analysis of the three HPAI projects in Buffalo field, which are the oldest HPAI projects currently in operation, shows that only a small fraction of the reservoir has been burned and, if time allows and the projects are managed appropriately, burning of more reservoir volumes could result in much higher oil recoveries than those predicted by the gasflood approach. Introduction HPAI is an emerging technology for the recovery of light oils that has proved to be a valuable IOR process, especially in deep thin low-permeability reservoirs (Erickson et al. 1994; Kumar and Fassihi 1995; Kumar et al. 2007a, 2007b; Fassihi et al. 1996, 1997). The first extended field test of HPAI began in 1963 on the Sloss field in Nebraska (Parrish et al. 1974a, 1974b), where Amoco's Combination of Forward Combustion and Waterflooding (COFCAW) process was applied as a tertiary-recovery process to a deep (6,200 ft), thin (11 ft), light-oil (38.8°API), watered-out reservoir. This COFCAW pilot recovered 83,992 bbl of oil, which is equivalent to 43% of the oil remaining in the five-spot pattern after waterflood. In 1967, the pilot was expanded from an 80- to a 960-acre project and recovered 527,000 bbl of incremental oil. However, it proved to be uneconomical, with crude-oil prices at less than USD 3/bbl. The second application of HPAI was the West Heidelberg pressure-maintenance project (Huffman et al. 1983) in the US state of Mississippi, which started in 1971 as a secondary-recovery project in the deep (11,400 ft) Cotton Valley sands. Even though oil prices were less than USD 4/bbl during the early period of the air-injection operations, payout of the project occurred at approximately 2.5 years, and the project continued to be a successful air-injection project. One interesting aspect of this project was the simulation work presented by Kumar (1991), which showed that, although the early production was mainly because of pressure maintenance, more than half of the cumulative oil production was mainly a result of thermal effects. An important milestone in the advance of HPAI was the implementation of commercial secondary HPAI projects in the North and South Dakota portions of the Williston basin, which started in 1979 and continues to be a technical and economic success (Erickson et al. 1994; Kumar and Fassihi 1995; Kumar et al. 2007a, 2007b; Fassihi et al. 1996, 1997). The estimation of ultimate recovery in HPAI projects is subject to a high level of uncertainty and requires history matching. Nevertheless, in 1994, Kumar and Fassihi (1995) proposed a method for estimating recovery factors of light-oil air-injection projects on the basis of the performance of two HPAI projects. Their suggested method relies on the extrapolation of the field GOR up to an economic limit. In other words, it considers HPAI as an immiscible gasflood. This paper intends to challenge that "gasflood" approach with a "combustion" approach, on the basis of laboratory results and field data gathered mostly from the Buffalo field, which comprises the three oldest HPAI projects currently in operation.
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JPT staff, _. "E&P Notes (October 2022)." Journal of Petroleum Technology 74, no. 10 (October 1, 2022): 16–20. http://dx.doi.org/10.2118/1022-0016-jpt.
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CNOOC Turns Taps on Bohai Bay Fields Volumes are flowing from two new CNOOC-operated field developments in the Bohai Sea, offshore China. Production began at the Luda 5-2 oil field north phase 1 project in Liaodong Bay. The field is in an average water depth of around 32 m. CNOOC installed one thermal recovery wellhead platform and one production platform, and connected processing facilities serving the Suizhong 36-1 oil field. The company plans to drill a total of 26 production and two water-source wells, with peak crude oil production of 8,200 B/D targeted for 2024. Oil also is flowing at the Kenli 6-1 oil field 4-1 block development in the southern Bohai Sea. A new wellhead platform in about 17 km of water is connected to processing facilities at the Bozhong 34-9 oil field. CNOOC plans a total of seven producer and five water-injector wells at Kenli 6-1, with peak oil production later this year of around 4,000 B/D. CNOOC holds a 100% stake in both projects. Sailaway for GTA FPSO Expected by Year-End A BP executive told conference goers in Senegal recently that the FPSO destined for that country’s Greater Tortue Ahmeyim (GTA) gas project is expected to leave China prior to year-end. BP Executive Vice President for Production and Operations Gordon Birrell added that the first phase of the GTA project is 80% complete. The main function of the FPSO will be to remove water and condensate and reduce impurities in the gas stream before exporting processed gas to a nearby FLNG facility and domestic gas offtake. BP and Kosmos Energy are leading the development of GTA and Yakaar-Teranga, Senegal’s first natural gas projects. GTA straddles the border between Senegal and Mauritania. Phase 1 of the planned development is expected to start delivering gas by the end of 2023. Birrell added that BP is in discussions with Senegal and Mauritania about GTA’s second phase and other projects in both countries, but did not get into specifics, according to Reuters. Phase two should double expected production from 2.5 to 5.0 mtpa. ReconAfrica, NAMCOR Reach Target Depth on Namibia Well Reconnaissance Energy Africa and its joint venture partner NAMCOR, the state oil company of Namibia, confirmed the third stratigraphic test well in the Kavango basin of northeast Namibia, 1819/8-2, reached target depth. The well was drilled to a total depth of 2056 m reaching all geological targets. However, the duo did not reveal what was found in the well. Instead, the pair said current operations were focused on well data capture and initiating analysis of the data. Company-owned rig Jarvie-1 will remain on site until logging and coring operations are completed. A vertical seismic profile tool will also be run to total depth to tie into the 2D seismic program. Processing of the second phase of 761 km of 2D seismic is near completion, where early results are being used to refine drilling locations for the upcoming stratigraphic wells. The next well of this planned continuous drilling program was scheduled to have the rig on location by the end of last month. Pantheon Resources Alaska Discovery Deemed “World Class” Pantheon Resources has uncovered a “world-class” oil discovery on its Theta West acreage in Alaska, according to independent consultants brought in to assess the area’s potential. Baker Hughes Advanced Hydrocarbon Stratigraphy (AHS) was charged with compiling a report based on data collated after a successful appraisal well drilled early this year. The firm believes there is a continuous column of oil-bearing cuttings of at least 1,360 ft that is host to a light crude in the order of 37–39 °API. The AHS report concluded there are “abundant good-quality reservoirs” with an “ultimate, nonpermeable seal” at 7,070 ft. Pantheon said the results are supportive of analyses of cuttings from previous work on the acreage on Alaska’s prolific North Slope. The company estimated the project, which is close to infrastructure, is host to 17 billion bbl of which 10%, or 1.7 billion bbl, is deemed recoverable. Invictus Well in Zimbabwe a “Game Changer” The Mukuyu-1 exploration well being drilled in Zimbabwe by Australian firm Invictus Energy in partnership with the government is being called “a game changer” for the country by President Emmerson Mnangagwa. The well is in license SG 4571, which covers 250,000 acres located in the most prospective portion of the Cabora Bassa Basin in northern Zimbabwe. The license is currently in the second exploration period which runs to June 2024. Invictus entered into an agreement with the Zimbabwe government in March 2022 to increase the license area sevenfold to 1.77 million acres. Previously explored by Mobil Oil, the project contains the largest undrilled structure in onshore Africa. The Muzarabani anticline feature has more than 200 km2 under closure and up to 1500 m vertical relief at favorable depths for conventional oil and gas. Invictus completed the acquisition of 840 km of high-resolution infill 2D seismic data ahead of spudding the well using Exalo Rig 202 in August. Drilling Results a Mixed Bag for APA Offshore Suriname APA Corporation has made an oil discovery offshore Suriname with its Baja-1 well in Block 53 but came away empty with a probe in Block 58. Baja-1 was drilled to a depth of 5290 m and encountered 34 m of net oil pay in a single interval within the Campanian. Preliminary fluid and log analysis indicates light oil with a gas/oil ratio (GOR) of 1,600 to 2,200 scf/bbl, in good-quality reservoir. The discovery at Baja-1 is a down-dip lobe of the same depositional system as the Krabdagu discovery, 11.5 km to the west in Block 58. Evaluation of openhole well logs, cores, and reservoir fluids is ongoing. The success at Baja marks the sixth oil discovery in which APA has participated in offshore Suriname and the first on Block 53. The company said the result confirms its geologic model for the Campanian in the area and helps to de-risk other prospects in the southern portion of both Blocks 53 and 58. APA recently received regulatory approval regarding an amendment to the Block 53 production-sharing contract, which provides options to extend the exploration period by up to 4 years. The company is currently proceeding with formalizing the first one-year extension, for which all work commitments are complete. APA is operator and holds a 45% working interest in Block 53; partners Petronas and CEPSA hold 30% and 25% stakes, respectively. Baja-1 was drilled using drillship Noble Gerry de Souza in water depths of approximately 1140 m. The rig will mobilize to Block 58 following the completion of current operations, where it will drill the Awari exploration prospect, approximately 27 km north of the Maka Central discovery. APA was not as fortunate with its Dikkop exploration well in Block 58. The well encountered water-bearing sandstones in the targeted interval and has been plugged and abandoned. Operator TotalEnergies holds a 50% working interest, while APA holds the remaining 50% stake. The drillship Maersk Valiant will be moving to the Sapakara field to drill a second appraisal well at Sapakara South, where the joint venture conducted a successful flow test late last year. Helix Energy Solutions Secures Production, P&A Work With Thunder Hawk Buy Helix Energy Solutions Group subsidiary Deepwater Abandonment Alternatives (DAA) acquired all of MP GOM’s 62.5% interest in Mississippi Canyon Block 734, comprising three wells and related subsea infrastructure, collectively known as the Thunder Hawk field. MP GOM is a subsidiary of Murphy Oil. Financial terms of the deal were not disclosed. “This acquisition furthers Helix’s energy transition business model by taking on decommissioning obligations in exchange for production revenues,” said Owen Kratz, president and chief executive of Helix. “We have long communicated our unique position as a qualified offshore field operator that can also assume and efficiently discharge decommissioning obligations. We continue to pursue opportunities that enable us to enhance and extend the life of existing reserves and safely perform the related decommissioning of the infrastructure in transactions that allow producers to remove noncore assets from their balance sheets.” Under the terms of the transaction, Helix receives the benefit of ownership of MP GOM’s interest, with a 1 November 2021 effective date purchase price adjustment resulting in nominal cash paid by MP GOM at closing, in exchange for the assumption of MP GOM’s abandonment obligations at the Thunder Hawk Field. In addition to anticipated future production revenue, DAA will operate the Thunder Hawk field with Helix eventually expected to perform the required plug and abandonment operations. Kolibri Continues Tishamingo Program in Oklahoma Kolibri Global Energy has completed the location work for the Glenn 16-3H and Brock 9-3H wells, which are the third and fourth wells in its 2022 drilling program. A fifth location is also being prepped. All three wells in the Tishamingo area of the SCOOP play are planned to be drilled back-to-back, and the completion operations for the Glenn 16-3H and Brock 9-3H wells have been tentatively scheduled for the first week of October. Neptune Energy Confirms New Discovery in the Gjøa Area Neptune Energy and its partners announced a new commercial discovery at the Ofelia exploration well (PL 929), close to the Gjøa field in the Norwegian sector of the North Sea. Neptune has completed drilling of the Ofelia well, 35/6-3 S, and encountered oil in the Agat formation. The preliminary estimate of recoverable volume is in the range of 16 to 39 million BOE. In addition to the Agat volumes, north of the well there is an upside of around 10 million BOE recoverable gas in the shallower Kyrre formation, which brings the total recoverable volume to approximately 26 to 49 million BOE. Located 15 km north of the operated Gjøa platform, at a water depth of 344 m, Ofelia will be considered for development as a tieback to Gjøa, in parallel with the company’s recent oil and gas discovery at Hamlet. The Ofelia well, drilled by Odfjell-operated semisubmersible Deepsea Yantai, confirmed an oil/water contact at 2639 m total vertical depth. It is the third discovery by Neptune Energy in the Agat formation, a reservoir which until recently was not part of established exploration models on the Norwegian Shelf. The first was at the Duva field, which is now onstream and being operated by Neptune. The second was the company’s discovery at Hamlet, with estimated recoverable volumes between 8 and 24 million BOE.
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Sawin, Robert S., Evan K. Franseen, W. Lynn Watney, Ronald R. West, and Greg A. Ludvigson. "New Stratigraphic Rank for the Carboniferous, Mississippian, and Pennsylvanian in Kansas." Current Research in Earth Sciences, October 22, 2009, 1–4. http://dx.doi.org/10.17161/cres.v0i256.11846.
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A new classification for the Carboniferous System/Period is formally adopted by the Kansas Geological Survey (KGS), and Zeller (1968) is modified accordingly. The Carboniferous is the system/period between the Devonian and Permian, and the Mississippian and Pennsylvanian are subsystems/subperiods of the Carboniferous. The Mississippian is subdivided into Lower, Middle, and Upper Mississippian Series and the Pennsylvanian is subdivided into Lower, Middle, and Upper Pennsylvanian Series. Regional stage names remain unchanged.
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Sawin, Robert S., Evan K. Franseen, W. Lynn Watney, Ronald R. West, and Greg A. Ludvigson. "New Stratigraphic Rank for the Carboniferous, Mississippian, and Pennsylvanian in Kansas." Current Research in Earth Sciences, October 22, 2009, 1–4. http://dx.doi.org/10.17161/cres.v0i256.11846.
Full textAbstract:
A new classification for the Carboniferous System/Period is formally adopted by the Kansas Geological Survey (KGS), and Zeller (1968) is modified accordingly. The Carboniferous is the system/period between the Devonian and Permian, and the Mississippian and Pennsylvanian are subsystems/subperiods of the Carboniferous. The Mississippian is subdivided into Lower, Middle, and Upper Mississippian Series and the Pennsylvanian is subdivided into Lower, Middle, and Upper Pennsylvanian Series. Regional stage names remain unchanged.
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Albert, Lois E. "The Norman Site: Descriptions." Index of Texas Archaeology Open Access Grey Literature from the Lone Star State, 2000. http://dx.doi.org/10.21112/.ita.2000.1.19.
Full textAbstract:
The Norman site (34WG2) lay on a terrace on the west side of the Neosho (Grand) River in Wagoner County, Oklahoma. Throughout much of its course within Oklahoma, this river flows along the western boundary of the Ozark Uplift. East of the river, the limestones, shales, and sandstones deposited during the Upper Mississippian and Pennsylvanian geological periods form the Boston Mountains and the Springfield Plateau. Several of these formations contain knappable cherts, often of good quality. West of the river, the Mississippian and Pennsylvanian deposits thin and dip under the surface to form the Prairie Plains Province, characterized by low, east-facing escarpments. Sandstone and shale bedrocks underlie the Prairie-Plains Province. The streams flowing eastward across these are muddy and sluggish.
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Ouyang, Ying, Theodor D. Leininger, Sudhanshu S. Panda, Wayne C. Zipperer, and Timothy L. Stroope. "Contributions to groundwater from National Forest lands in the Mississippi Embayment: a century-long simulation." Water Practice and Technology, October 29, 2020. http://dx.doi.org/10.2166/wpt.2020.098.
Full textAbstract:
Abstract Very little effort has been devoted to analyzing the contributions of National Forests to groundwater resources in the US and around the world. In this study, the US Geological Survey's MERAS (Mississippi Embayment Regional Aquifer Study) model was used in the ModelMuse simulating system to estimate more than a century of subsurface hydrologic processes, groundwater budgets, and spatial-temporal groundwater level distributions in three forests in Mississippi, US. The results showed that groundwater recharge and stream leakage are important for groundwater storage in this region. All three forests served as groundwater sinks at times and sources at others, but the volume changes were relatively small. Groundwater levels declined over the simulation period – 1900 to 2014 – beneath all three forests, especially around the DNF (Delta National Forest) where groundwater abstraction is relatively intense. Knowledge gained from long-term hydrologic simulations and water budgets is useful when managing forest land groundwater resources.
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Battiau-Queney, Yvonne, Alain Préat, Alain Trentesaux, Philippe Recourt, and Viviane Bout-Roumazeilles. "Late Mississippian limestone sedimentary environment in southern Pembrokeshire (Bullslaughter Bay, Wales): evidence of meteoric diagenesis and hypersaline features." Geological Magazine, September 9, 2020, 1–28. http://dx.doi.org/10.1017/s0016756820000758.
Full textAbstract:
Abstract Bullslaughter Bay in southern Pembrokeshire, UK, exposes sections of Upper Mississippian limestone strata. In many places, the rock suffered an isovolumetric alteration during a period of sea-level oscillations. We used multiple approaches to study the weathered rocks, combining sedimentological, petrographic and isotopic compositions (δ18O and δ13C values). Two main microfacies are recognized: (i) packstones/grainstones, characteristic of an open marine shallow subtidal/intertidal environment, with a high degree of agitation, slightly elevated salinity and temporary subaerial exposure; and (ii) mudstones/wackestones in a lagoonal setting and intertidal or supratidal environments, with a pedogenetic influence. In both cases, a complex diagenetic story, which started early in a meteoric environment, induced a strong alteration producing loose sediments in place of the parent rock. Calcretization, at or near the sediment surface in the vadose zone, was one of the most widespread diagenetic modes. It could be associated with beachrocks. Carbon and oxygen stable isotope analyses from more or less weathered limestones support the petrographic data: they show non-marine values with δ13C ranges of from −2.13 ‰ to 1.75 ‰ and δ18O from −6.05 ‰ to −4.66 ‰. These values are systematically lower than those of the middle Carboniferous seawater. Some periods of low sea level and subaerial exposure allowed gypsum to form. Neoformation of euhedral quartz by probable replacement after sulfate, and halite pseudomorphs after gypsum in a hypersaline environment are documented for the first time in southern Pembrokeshire. The studied weathered limestones present a complex diagenetic evolution related to sea-level oscillations in a range of hot and contrasting seasonal climates.
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Cramer, Chris H., Roy B. Van Arsdale, David Arellano, Shahram Pezeshk, Stephen P. Horton, Taylor Weathers, Nima Nazemi, et al. "Seismic and Liquefaction Hazard Maps for Five Western Tennessee Counties." Seismological Research Letters, September 22, 2023. http://dx.doi.org/10.1785/0220230036.
Full textAbstract:
Abstract A five-year seismic and liquefaction hazard mapping project for five western Tennessee counties began in 2017 and supported natural hazard mitigation efforts in Lake, Dyer, Lauderdale, Tipton, and Madison counties. Additional geological, geotechnical, and geophysical information has been gathered in all five counties to improve the base northern Mississippi Embayment hazard maps of Dhar and Cramer (2017). Information gathered includes additional geological and geotechnical subsurface exploration logs, water table level data collection, new measurements of shallow shear-wave velocity (VS) profiles, and the compilation of existing VS profiles in and around the counties. Improvements have been made in the 3D geological model, water table model, the geotechnical liquefaction probability curves, and the VS correlation with lithology model for these counties. The resulting updated soil response amplification distributions on a 0.5 km grid were combined with the 2014 U.S. Geological Survey seismic hazard model (Petersen et al., 2014) earthquake sources and attenuation models to add the effect of local geology for Lake, Dyer, Lauderdale, Tipton, and Madison Counties. The resulting products are similar to the Memphis and Shelby County urban seismic hazard maps recently updated by Cramer, Dhar, and Arellano (2018). Generally, the effect of local geology is to reduce seismic hazard at short periods and increase it at long periods. Liquefaction hazard is high only in the alluvial lowlands, but not in the loess covered uplands.
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Dunne, Kieran, Sylvia Dee, Joeri Reinders, Samuel Munoz, and Jeffrey Nittrouer. "Examining the impact of emissions scenario on lower Mississippi River flood hazard projections." Environmental Research Communications, August 26, 2022. http://dx.doi.org/10.1088/2515-7620/ac8d53.
Full textAbstract:
Abstract The Mississippi River is the largest commercial waterway in North America and one of the most heavily engineered rivers in the world. Future alteration of the river's hydrology by climate change may increase the vulnerability of flood mitigation and navigation infrastructure implemented to constrain 20th century discharge conditions. Here, we evaluate changes in Lower Mississippi River basin hydroclimate and discharge from 1920-2100 C.E. by integrating river gauge observations and climate model ensemble simulations from CESM1.2 under multiple greenhouse gas emissions scenarios. We show that the Lower Mississippi River's flood regime is highly sensitive to emissions scenario; specifically, the return period of flood discharge exceeding existing flood mitigation infrastructure decreases from approximately 1000 years to 33 years by the year 2100 under RCP8.5 forcing, primarily driven by increasing precipitation and runoff within the basin. Without aggressive reductions in greenhouse gas emissions, flood mitigation infrastructure may require substantial retrofitting to avoid disruptions to industries and communities along the Lower Mississippi River.
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Ouyang, Ying, Yongshan Wan, Wei Jin, Theodor D. Leininger, Gary Feng, and Yuguo Han. "Impact of climate change on groundwater resource in a region with a fast depletion rate: the Mississippi Embayment." Journal of Water and Climate Change, March 3, 2021. http://dx.doi.org/10.2166/wcc.2021.326.
Full textAbstract:
Abstract Mississippi Embayment (ME) is one of the fastest groundwater depletion regions around the world, while the impacts of climate change on groundwater resources in the region are complex and basically unknown. Using the U.S. Geological Survey's Mississippi Embayment Regional Aquifer Study (MERAS) model, such a challenge was addressed through the base, wet, and dry simulation scenarios. Over the 137-year simulation period from 1870 to 2007, the cumulative aquifer storage depletions were 1.70 × 1011, 1.73 × 1011, and 1.67 × 1011 m3, respectively, for the base, dry, and wet scenarios. As compared with that of the base scenario, the aquifer storage depletions were only 1.76% more for the dry scenario and 1.8% less for the wet scenario. A multiple regression analysis showed that the aquifer storage depletion rate was controlled more by the groundwater pumping and stream leakage rates and less by the groundwater net recharge rate. Groundwater table variation in the forest land was much smaller than in the crop land. Results suggested that groundwater pumping rather than climate change was a key driving force of groundwater depletion in the ME. Our findings provide a useful reference to water resource managers, foresters, and farmers in the ME and around the world when developing their groundwater supply strategies.
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Sherman, Simon P., Ryan M. Parish, Youngsang Kwon, Steven Meredith, and David Johnson. "Non‐destructively characterizing sandstones, orthoquartzites, agates, and petrified wood for provenance research: Perspectives from the Southeastern Coastal Plain, United States." Geoarchaeology, July 23, 2024. http://dx.doi.org/10.1002/gea.22018.
Full textAbstract:
AbstractSiliceous sandstone (including quartzites), petrified wood, and agates located in Alabama and Mississippi were utilized as a toolstone resource during every recognized cultural period in the Lower Mississippi Valley region of the Southeastern United States. Regrettably, these materials have not been the focus of many provenance‐related investigations. Recent analyses of quartzite and sandstone from other regions in North America and from the Pyrenees were successful in discriminating sources using petrographic techniques. The current study examines the application of visible/near‐infrared reflectance and Fourier transform infrared reflectance (FTIR) spectroscopy on sourcing siliceous materials besides chert, particularly sandstones, orthoquartzites (quartz sandstone), petrified woods, and agates. This source characterization investigation focuses on a case study involving materials gathered from eight distinct collection sites, encompassing nine different siliceous resources collected in Alabama and Mississippi. These materials were sourced from two distinct geological formations: the Hattiesburg and Tallahatta. Results demonstrate the ability of non‐destructive reflectance spectroscopy and introduces a new outlier modeling method that detects, clusters, and separately models outliers with their own set of basis vectors. Principal component analyses, least absolute shrinkage and selection operator regression, linear discriminant function analysis (LDA), and random forest classification are used in this paper to better identify outlier elements as well as discriminate for stone materials accurately (between 67% and 100%). Although this is the first reflectance spectroscopy investigation used to characterize these materials for provenance applications, the preliminary results compare favorably with other provenance techniques whose aim is to quantify between‐formation (inter) and within‐formation (intra) outcrop variation. The quantified and differentiated sources, based on the hyperspectral signatures of the material, will provide a better understanding of prehistoric reliance on these lithic resources and produces a proxy to determine mobility, social interaction, and other past behavior.
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Neubeck, Nikki, Andrew Carter, Tammy Rittenour, and Peter D. Clift. "Climate and anthropogenic impacts on North American erosion and sediment transport since the Last Glacial Maximum: Evidence from the detrital zircon record of the Lower Mississippi Valley, USA." GSA Bulletin, February 7, 2023. http://dx.doi.org/10.1130/b36565.1.
Full textAbstract:
The Mississippi River provides an opportunity to examine models of sediment transport in large alluviated floodplain systems. We test the idea that sources of sandy sediment in such settings are invariable on timescales <104 y because of storage and recycling in the floodplains. To reconstruct the development of the Mississippi sediment load over the past 2500 years we collected sediment from an abandoned point bar complex nearby at False River, Louisiana, USA. We also took annual samples from the lower reaches between 2015 and 2021 to assess changes on that timescale. Optically stimulated luminescence dating indicated that the point bar accreted between 2460 and 860 years ago. Detrital zircon U-Pb dating was used to assess sediment source and variability over time. We confirm a dominant sediment flux from the Rocky Mountain foreland but with higher relative erosion from the Superior Province during the Last Glacial Maximum (LGM) based on existing data from the Gulf of Mexico. There have been resolvable changes in the sources of sediment particularly since the LGM and after 860 years ago, but also over shorter, even sub-annual timescales in the recent past. These changes may reflect seasonal weather or storm events in the headwater regions and imply limited floodplain buffering of the sand load. In recent times this may reflect the installation of levees in the lower reaches, suppressing reworking. Changes over 102−103 y time periods may be related to changes in climate (e.g., the Medieval and Roman warm periods) and to the development of agriculture across North America after ∼2000 years ago. Detrital zircon dating is an effective provenance tool and does not appear to be strongly biased by the grain size of the sediment in this setting.
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Koperna, G., D. Riestenberg, J. Leierzapf, B. Roth, R. Esposito, and K. Sams Gray. "Building an EPA Class VI Permit Application." SPE Reservoir Evaluation & Engineering, April 1, 2023, 1–16. http://dx.doi.org/10.2118/210198-pa.
Full textAbstract:
Summary To accelerate the commercialization of carbon capture and storage (CCS), the US Department of Energy (US DOE) is building on decades of characterization efforts and pilot-scale projects through their CarbonSAFE program. Administered through their National Energy Technology Laboratory, this program seeks to bring fully integrated projects to the sector that can store more than 50 million tonnes of CO2 over a 30-year period. The program, which was enacted before the enhancement of Internal Revenue Code Section 45Q, is in the capture assessment, characterization, and permitting phase. The objectives of this paper are to discuss (a) the injection permitting requirements of the CarbonSAFE projects; (b) information gathering in support of the permit; (c) the timelines of field development and permit-related activities; (d) the major technical components of the field development plan; and (e) early feedback from the regulators toward acceptance of the permit. In Mississippi, more than 30,000 acres have been characterized by six deep characterization wells, a deep groundwater well, and 92 line miles of 2D seismic as part of the CarbonSAFE Project ECO2S. During the acquisition of seismic data, all receiver lines were live, which resulted in the generation of a pseudo-3D seismic design. The incorporation of a 3D seismic survey was not included as part of this project due to logistical difficulties presented by the undulating, wooded surface terrain. A suite of openhole geophysical logs was taken from each well, allowing for a detailed interpretation of prospective storage reservoirs and confining intervals to complement the analysis carried out on the 290 ft of a whole core that was cut through the prospective confining zone and storage reservoir. The detailed geologic and reservoir data were assembled and entered into a 3D model to assess the injection capacity and the area of review (AoR). This information fed into the detailed corrective action, monitoring, testing, and postinjection site care (PISC) modeling. The results have been exceptional. The geologic assessment has revealed three primary storage targets, ranging in depth from 3,500 ft to 6,000 ft. These storage reservoirs net 1,300 ft of sandstone, with mean porosity and permeability of 29% and 3.6 darcies, respectively. Together, these reservoirs have storage capacities that may exceed 20 million tonnes per square mile, making this a gigatonne prospect. Forward modeling of the project resulted in an AoR of 16 sq miles, injecting about 8000 t/d, for 30 years, via two deep injection wells. The excellent confining characteristics of the caprock, relatively simple geologic structure, and lack of historical well drilling activity in this area provide excellent containment of the injected CO2. Based on this work, the project has proposed 20 years of PISC. To date, only two US CO2 injection permits have been granted. These projects relied on a singular capture point feeding a singular sequestration point (source to sink), and considerations have not been made to garner CO2 emissions from other industrial sources. The Kemper County Storage Complex is a first-of-its-kind storage hub concept that looks to develop an area capable of storing significant quantities of CO2 from the region. Also, this work will show how characterization efforts, geological and numerical modeling efforts, and plan development were constructed in support of permit and incentives acceptance.
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del Strother, Peter, Andrew Giże, Cathy Hollis, and Duncan McLean. "Bituminous coals on emergent surfaces in an Asbian, lower Carboniferous (Mississippian) limestone succession on the North Wales carbonate platform, UK, and implications for palaeoclimate." Proceedings of the Yorkshire Geological Society, July 14, 2021, pygs2020–006. http://dx.doi.org/10.1144/pygs2020-006.
Full textAbstract:
Emergent surfaces in the Mississippian (Asbian to Brigantian) carbonate platform succession of North Wales record periods of plant colonisation and peat formation that led ultimately to the local development of coals. Examination of bituminous coals on three emergent surfaces within Cefn Mawr Quarry reveals information on palaeoclimate that is not available from study of the limestones alone. Three coal seams in the Asbian Loggerheads Limestone Formation were identified and the lowest one studied in detail. Vitrinite reflectance data from alternating bands of vitrite and duroclarite microlithotypes, the distribution of pyrite within them, and the sharp contacts between them, suggest that there were abrupt changes in marine influence during the development of the peats that formed the coals. It is inferred that local palaeoclimate alternated between periods of high and low rainfall, the amount of rainfall influencing the extent to which seawater encroached into the peats, with higher rainfall suppressing the ingress of saline waters into groundwater. On the basis of modern peat growth rates, the timescale of the alternation indicated by each duroclarite-vitrite couplet is suggestive of an annual cycle, such as would arise in a monsoonal climate. The low proportion of ash in the three coals, the preservation of internal lamination, the low diversity of spore species in the lowest coal compared with the over- and underlying mudrock, and the presence of rhizoconcretions in palaeokarstic limestone beneath the lowest and highest coals, demonstrate that the peat swamps were isolated from the hinterland and autochthonous. This study demonstrates that a wider application of palynology and coal petrology is an important contribution to the study of marine carbonate successions of any age where terrestrial organic matter, formed during emergence, has been preserved.
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Angiolini, Lucia, Gabriela A. Cisterna, Bernard Mottequin, Shu-Zhong Shen, and Giovanni Muttoni. "Global Carboniferous brachiopod biostratigraphy." Geological Society, London, Special Publications, April 9, 2021, SP512–2020–225. http://dx.doi.org/10.1144/sp512-2020-225.
Full textAbstract:
AbstractWe present an updated look at the Carboniferous brachiopod biozonation from most of the world framed into a revised Carboniferous palaeogeography, based on a selection of the literature published on Carboniferous brachiopods since the Nineteenth century. The biostratigraphic significance of the most important brachiopod taxa is synthetized in seven geographic correlations.The Mississippian is characterized by rich brachiopod faunas, with widespread taxa with a good potential for global correlation, such as Rugosochonetes, Delepinea, Buxtonia, Antiquatonia, Spinocarinifera, Marginatia, Fluctuaria, Ovatia, Rhipidomella, Lamellosathyris, Unispirifer, Tylothyris, and Syringothyris. From the mid–Viséan to the late Serpukhovian, taxa of gigantoproductidines are biostratigraphically significant, and occur everywhere except for South America and Australia, which remain as distinct faunal successions for most of the period. A major turnover occurs at the beginning of the Pennsylvanian, characterized by a higher degree of provincialism. Pennsylvanian brachiopod faunas are diverse in China, Russia and North America, but otherwise they are less developed and they are characterized mostly by endemic taxa, hampering long–distance correlation. An exception is the rapid diversification of taxa of the Choristitinae, which were widespread from the Bashkirian to the Moscovian, allowing long–distance correlation.
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Franseen, Evan K. "Mississippian (Osagean) Shallow-Water, Mid-Latitude Siliceous Sponge Spicule and Heterozoan Carbonate Facies." Current Research in Earth Sciences, July 10, 2006, 1–23. http://dx.doi.org/10.17161/cres.v0i252.11790.
Full textAbstract:
Mixtures of biosiliceous and heterozoan-dominated carbonate deposits are commonly interpreted as recording cold-water polar or deep basinal conditions. However, a growing body of literature is documenting examples from the rock record that show these deposits accumulated in shallow-water middle- to low-latitude environments. The continued recognition of ancient neritic heterozoan carbonate and biosiliceous accumulations is broadening our understanding of the various paleoenvironmental controls on their development.
Early-Middle Mississippian time was characterized by the development of biosiliceous and carbonate accumulations in North America. This study focuses on Osagean cherty dolomitic strata in cores from the Schaben field in Kansas, which is located in Ness County on the southwest flank of the Central Kansas uplift (CKU). During the Osagean, Kansas was located at approximately 20° S latitude, within the tropical to subtropical latitudinal belt. Study area strata are characterized by shallow-water inner-shelf carbonates that were deposited on a gently southward-sloping shelf (ramp). Two depositional sequences (DS1 and DS2) are identified in cores and are separated by a sequence boundary (SB1) that evidences subaerial exposure. The primary facies in the two depositional sequences include 1) Mudstone-Wackestone (MW); 2) Sponge Spicule-Rich Wackestone-Packstone (SWP); 3) Echinoderm-Rich Wackestone-Packstone-Grainstone (EWPG); and 4) Dolomitic Siltstones and Shale facies. Other features identified in cores include 1) Silica Cementation and Replacement; 2) Silica Replaced Evaporites; 3) Brecciation and Fracturing; and 4) Calcite Cementation and Replacement.
The abundance of echinoderm facies with other diverse fauna, evidence of extensive reworking by burrowing organisms, and only rare occurrence of evaporites suggest subtidal deposition in a normal to slightly restricted marine inner-shelf setting for DS1. After the SB1 subaerial exposure event, marine conditions returned but the depositional environment over the study area changed compared to that for much of DS1 deposition. The volumetric increase of sponge-spicule wackestone and packstone (SWP) with less diverse fauna, abundance of early evaporites (replaced by silica), and evidence for shallowest water to subaerially exposed conditions throughout DS2 suggest deposition in more restricted environments that likely ranged from restricted inner shelf/protected embayment to evaporative lagoon and possibly supratidal flat.
One of the more significant characteristics in DS2 is the dominance of siliceous sponge spicule facies and heterozoan carbonates that were deposited in shallow-water and restricted environments. This study and others from numerous periods in the geologic record are indicating that shallow-marine, mid-latitude biosiliceous and heterozoan carbonates may be more common than previously thought. Especially interesting are the examples from Mississippian (Osagean-Meramecian) strata in North America that show similar facies associations with DS2 strata of this study.
The predominance of Early-Middle Mississippian heterozoan carbonate and biosiliceous (spiculitic) deposits, and lack of photozoan deposits, in the mid-latitude shallow-shelf setting in Kansas and surrounding areas was likely due to abundant nutrients and dissolved silica derived from basinal and/or terrestrial sources. Based on available evidence, upwelling of basinal waters rich in nutrients and dissolved silica appears to have been a primary control on shelf margin and shelf facies. Upwelling even may have had a primary imprint on shallow-water, inner-shelf areas, especially during transgression(s). Nutrients and dissolved silica from terrestrial sources may have contributed to the facies associations in shallowest water, inner-shelf areas. However, the available evidence suggests that terrestrial sourced nutrients and dissolved silica were not the dominant control.
The results of this study have implications from a petroleum reservoir standpoint. The DS2 sponge spicule, heterozoan carbonate, and silica-replaced evaporite facies in this study form reservoirs in Schaben field and another nearby field composed of similar facies. Because regional upwelling is likely to have had at least some control, facies similar to DS2 strata may form important reservoirs in Lower-Middle Mississippian strata that were deposited in shallow-water inner shelf/ramp settings elsewhere in Kansas and North America.
Continuing studies of the controls on biosiliceous and heterozoan carbonate deposition and diagenesis in mid-latitude neritic settings will improve our understanding and predictive capabilities.
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Franseen, Evan K. "Mississippian (Osagean) Shallow-Water, Mid-Latitude Siliceous Sponge Spicule and Heterozoan Carbonate Facies." Current Research in Earth Sciences, July 10, 2006, 1–23. http://dx.doi.org/10.17161/cres.v0i252.11790.
Full textAbstract:
Mixtures of biosiliceous and heterozoan-dominated carbonate deposits are commonly interpreted as recording cold-water polar or deep basinal conditions. However, a growing body of literature is documenting examples from the rock record that show these deposits accumulated in shallow-water middle- to low-latitude environments. The continued recognition of ancient neritic heterozoan carbonate and biosiliceous accumulations is broadening our understanding of the various paleoenvironmental controls on their development.
Early-Middle Mississippian time was characterized by the development of biosiliceous and carbonate accumulations in North America. This study focuses on Osagean cherty dolomitic strata in cores from the Schaben field in Kansas, which is located in Ness County on the southwest flank of the Central Kansas uplift (CKU). During the Osagean, Kansas was located at approximately 20° S latitude, within the tropical to subtropical latitudinal belt. Study area strata are characterized by shallow-water inner-shelf carbonates that were deposited on a gently southward-sloping shelf (ramp). Two depositional sequences (DS1 and DS2) are identified in cores and are separated by a sequence boundary (SB1) that evidences subaerial exposure. The primary facies in the two depositional sequences include 1) Mudstone-Wackestone (MW); 2) Sponge Spicule-Rich Wackestone-Packstone (SWP); 3) Echinoderm-Rich Wackestone-Packstone-Grainstone (EWPG); and 4) Dolomitic Siltstones and Shale facies. Other features identified in cores include 1) Silica Cementation and Replacement; 2) Silica Replaced Evaporites; 3) Brecciation and Fracturing; and 4) Calcite Cementation and Replacement.
The abundance of echinoderm facies with other diverse fauna, evidence of extensive reworking by burrowing organisms, and only rare occurrence of evaporites suggest subtidal deposition in a normal to slightly restricted marine inner-shelf setting for DS1. After the SB1 subaerial exposure event, marine conditions returned but the depositional environment over the study area changed compared to that for much of DS1 deposition. The volumetric increase of sponge-spicule wackestone and packstone (SWP) with less diverse fauna, abundance of early evaporites (replaced by silica), and evidence for shallowest water to subaerially exposed conditions throughout DS2 suggest deposition in more restricted environments that likely ranged from restricted inner shelf/protected embayment to evaporative lagoon and possibly supratidal flat.
One of the more significant characteristics in DS2 is the dominance of siliceous sponge spicule facies and heterozoan carbonates that were deposited in shallow-water and restricted environments. This study and others from numerous periods in the geologic record are indicating that shallow-marine, mid-latitude biosiliceous and heterozoan carbonates may be more common than previously thought. Especially interesting are the examples from Mississippian (Osagean-Meramecian) strata in North America that show similar facies associations with DS2 strata of this study.
The predominance of Early-Middle Mississippian heterozoan carbonate and biosiliceous (spiculitic) deposits, and lack of photozoan deposits, in the mid-latitude shallow-shelf setting in Kansas and surrounding areas was likely due to abundant nutrients and dissolved silica derived from basinal and/or terrestrial sources. Based on available evidence, upwelling of basinal waters rich in nutrients and dissolved silica appears to have been a primary control on shelf margin and shelf facies. Upwelling even may have had a primary imprint on shallow-water, inner-shelf areas, especially during transgression(s). Nutrients and dissolved silica from terrestrial sources may have contributed to the facies associations in shallowest water, inner-shelf areas. However, the available evidence suggests that terrestrial sourced nutrients and dissolved silica were not the dominant control.
The results of this study have implications from a petroleum reservoir standpoint. The DS2 sponge spicule, heterozoan carbonate, and silica-replaced evaporite facies in this study form reservoirs in Schaben field and another nearby field composed of similar facies. Because regional upwelling is likely to have had at least some control, facies similar to DS2 strata may form important reservoirs in Lower-Middle Mississippian strata that were deposited in shallow-water inner shelf/ramp settings elsewhere in Kansas and North America.
Continuing studies of the controls on biosiliceous and heterozoan carbonate deposition and diagenesis in mid-latitude neritic settings will improve our understanding and predictive capabilities.
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Manor, Matthew J., Stephen J. Piercey, Donald C. Murphy, and Corey J. Wall. "Age and Chemostratigraphy of the Finlayson Lake District, Yukon: Implications for Volcanogenic Massive Sulfide (VMS) Mineralization and Tectonics along the Western Laurentian Continental Margin." Lithosphere 2022, no. 1 (June 20, 2022). http://dx.doi.org/10.2113/2022/4584611.
Full textAbstract:
Abstract The Yukon-Tanana terrane in the Finlayson Lake district, Yukon, represents one of the first arc–back-arc systems that formed adjacent to the Laurentian continental margin in the mid-Paleozoic. Back-arc rocks contain many large and high-grade volcanogenic massive sulfide (VMS) deposits. This study integrates U-Pb zircon geochronology, lithogeochemistry, and Hf-Nd isotopes to establish precise controls on tectonomagmatic activity adjacent to the western Laurentian margin in the Late Devonian to Early Mississippian. High-precision chemical abrasion- (CA-) ID-TIMS U-Pb zircon geochronology defines coeval arc (ca. 363.1 to 348 Ma) and back-arc (ca. 363.3 to 355.0 Ma) magmatism in the Finlayson Lake district that intruded continental crust of Laurentian affinity (e.g., Snowcap assemblage). Mafic and felsic rocks display geochemical and isotopic characteristics that are consistent with being formed from mixtures of depleted asthenosphere and enriched lithospheric mantle sources. These melts variably entrained Laurentian continental crust via high-temperature crustal melting due to basaltic underplating. The high-temperature back-arc felsic magmatism occurs at specific time periods coinciding with VMS deposits and supports previous genetic models for VMS mineralization that suggest elevated heat flow and hydrothermal circulation were due to regional-scale rift-related magmatism rather than from local subvolcanic intrusions. The short timescales and transient nature of tectonomagmatic events in the Finlayson Lake district suggest that rapid and complex subduction initiation of oceanic and continental crust fragments facilitated coeval compression, extension, and magmatism in the arc and back-arc regions. We thus reevaluate the presently accepted tectonostratigraphic framework of the Finlayson Lake district and suggest revised interpretations that shed light on VMS depositional environments and a possible broader association with the ca. 358 Ma Antler Orogeny. Results of this study have implications for incipient tectonics, magmatism, and mineralization along the western Laurentian continental margin and other orogenic belts globally.
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Joon, Shams, Ismael Dawuda, Eugene Morgan, and Sanjay Srinivasan. "Rock Physics-Based Data Assimilation of Integrated Continuous Active-Source Seismic and Pressure Monitoring Data during Geological Carbon Storage." SPE Journal, February 1, 2022, 1–15. http://dx.doi.org/10.2118/209585-pa.
Full textAbstract:
Summary There has been substantial controversy concerning the role of geological carbon storage (GCS) in sequestering anthropogenic carbon emissions to mitigate climate change and global warming. Arguments center on the inability to monitor a geological storage site precisely and continuously, especially highlighting the associated costs and spatiotemporal trade-offs when using conventional subsurface monitoring techniques (well logs, core samples, chemical tracers, and 4D seismics). Active surveillance of GCS sites is essential for managing and mitigating potential leaks but is also required by regulation. With the goal of enhancing the monitoring capability at GCS sites, we present a rock physics-based joint data assimilation model to study a popular GCS site at Cranfield, Mississippi, USA. Synthetic continuous active-source seismic monitoring (CASSM) data (in the form of Vp and Qp measurements) and wellbore pressure monitoring data are assimilated with an ensemble of reservoir realizations to monitor gas saturation and reservoir pressure changes over a period of 100 years. Synthetic seismic attributes are generated using rock physics models (RPMs) and wellbore pressure monitoring data are extracted from the ground truth. Two assimilation methods, ensemble Kalman filter (EnKF) and ensemble Kalman smoother (EnKS), are tested in an observation system simulation experiment (OSSE) environment to assess the prediction accuracy of the individual and composite observation systems. The joint monitoring system achieves more accurate estimates of gas saturation and pressure, across the time span from start of injection to end of forecast, as compared to a single type of monitoring tool and irrespective of data assimilation algorithm choice. These results indicate that jointly assimilated data from two types of sensors (in this case, crosswell seismic and downhole pressure) may lead to a more risk-reducing monitoring design. One would expect that more data, vis-à-vis inclusion of a new sensor type, will improve the accuracy of any GCS monitoring system. However, from a practical standpoint, one important question is whether such a gain in accuracy is worth the additional cost associated with the new sensor. This paper focuses on quantifying the gain in accuracy, such that a practitioner can answer this question.
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Wang, Weiwei, and Madhu Khanna. "Land Use Effects of Biofuel Production in the US." Environmental Research Communications, May 2, 2023. http://dx.doi.org/10.1088/2515-7620/acd1d7.
Full textAbstract:
Abstract Biodiesel production has been growing in the United States and although its amount is small by comparison with corn ethanol, its addition to existing demands on land can have nonlinear effects on land use, due to an upward sloping and increasingly inelastic supply of land. It is critical to quantify these effects to inform future policies that may expand production. Here we apply a multi-period, partial equilibrium economic model (BEPAM) to determine land use under a validated counterfactual scenario with no biofuel policy or with corn ethanol mandate alone to isolate the extent to which expansion of biodiesel production in the US led to the conversion of Conservation Reserve Program (CRP) acres and other noncropland to crop production, over the 2007-2018 period. We find that the land use change intensity of biodiesel ranged from 0.78 to 1.5 million acres per billion gallons in 2018 which is substantially higher than that of corn ethanol, that ranged from 0.57 to 0.75; estimates at the lower end of these ranges are obtained under the assumption that there is no conversion of permanent pastureland to cropland and better supported by model validation than the upper end of these ranges. The land use change elasticity with respect to changes in land rent was more inelastic for biodiesel than for corn ethanol. The largest levels of expansion in cropland were in Iowa, Minnesota, North Dakota, Kansas, Michigan and Mississippi.
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Xu, Saihua, Yuzhao Hu, Yong Cheng, Jizhan Zhu, Yuan Ping, Qimeng Zhang, and Zixuan Pei. "Genetic relationship between the Maoping Pb-Zn deposit and paleo-oil reservoir in the northern Yunnan-Guizhou depression: Evidence from bitumen trace elements and the in-situ sulfur isotope of pyrite associated with bitumen." Frontiers in Earth Science 10 (January 13, 2023). http://dx.doi.org/10.3389/feart.2022.1109112.
Full textAbstract:
The coexistence of numerous Mississippi Valley-type (MVT) Pb-Zn deposits and oil/gas reservoirs in the world demonstrates that a close genetic link between them. The northern Yunnan–Guizhou depression (NYGD) is a tectonic unit containing Pb–Zn deposits, paleo-oil reservoirs and shale gas. However, previous studies on the relationship between hydrocarbon accumulation and Pb–Zn mineralization have been ignored. The Maoping Pb–Zn deposit is a large-sized MVT deposit in the NYGD where a large amount of solid bitumen (i.e., a paleo-oil reservoir) occurs, and it is an ideal area to study the relationship between hydrocarbon accumulation and lead–zinc mineralization. In this paper, the bitumen and pyrite associated with bitumen from the Xujiazhai (discovered in this study) and Xiaocaoba paleo-oil reservoirs and the Maoping Pb–Zn deposit are researched. Geological observation has revealed that bitumen occurs in dissolution pores, fractures and intercrystalline pores in dolomite of the Upper Devonian and Carboniferous. The bitumen from Xujiazhai, Maoping and Xiaocaoba with high and similar Raman equivalent reflectance (RmcRo%) indicates they are in over-mature level and may be derived from the cracking of early-accumulated crude oils. The bitumen in the Xujiazhai paleo-oil reservoir and Maoping deposit has an abundant Pb and Zn content, indicating petroleum liquids may act as the transporting agents of metallogenic metal elements, carrying them to sites where mineralization may take place. The source rocks may have provided not only the oil for paleo-oil/gas reservoirs, but also a portion of ore metals for the Pb-Zn mineralization. The bacterial sulfate reduction (BSR) and thermochemical sulfate reduction (TSR) processes were recorded by the pyrite in the paleo-oil reservoir, which was consistent with the mechanism of reduced sulfur formation in the Maoping deposit. In addition, the large negative (−27.7‰ to −5.7‰) and positive (.9‰ to 19.2‰) δ34S values of the pyrite associated with the bitumen in the paleo-oil reservoir were similar to those of the sulfide in the Maoping deposit. We believe that the formation and evolution of the paleo-oil reservoirs are closely related to the metallogenic process of the Maoping Pb–Zn deposit, and the sulfides in them have the same sulfur source and formation mechanism as reduced sulfur. BSR phenomena could occur in prior to migration of the hydrocarbons into the reservoir or low mature oil stage in paleo-oil reservoir; a small amount of H2SBSR was combined with metal ions in ancient oil reservoirs and deposits to form early subhedral, xenomorphic granular, fine-grained strawberry aggregate pyrite and/or gelatinous sphalerite. The paleo-gas reservoir formed by the evolution of the paleo-oil reservoir in the main metallogenic period potentially participated in the mineralization; that is, organic gas acted as a reducing agent and transformed SO42− in the upper Devonian Zaige Formation gypsum strata on the periphery of the Maoping lead–zinc mining area into H2STSR through TSR, providing reduced sulfur and creating the environmental conditions for mineralization. During or after the transformation of the paleo-oil reservoir to a paleo-gas reservoir, the decoupling of metals and organic complexes may have provided the ore metals for mineralization. Massive sulfide precipitation may have occurred during or after the paleo-oil reservoir cracked into the paleo-gas reservoir.