Journal articles on the topic 'Quantitative dynamic sequence stratigraphy'
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1
Barbee, Olivia, Craig Chesner, and Chad Deering. "Quartz crystals in Toba rhyolites show textures symptomatic of rapid crystallization." American Mineralogist 105, no. 2 (February 1, 2020): 194–226. http://dx.doi.org/10.2138/am-2020-6947.
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Abstract Textural and chemical heterogeneities in igneous quartz crystals preserve unique records of silicic magma evolution, yet their origins and applications are controversial. To improve our understanding of quartz textures and their formation, we examine those in crystal-laden rhyolites produced by the 74 ka Toba supereruption (>2800 km3) and its post-caldera extrusions. Quartz crystals in these deposits can reach unusually large sizes (10–20 mm) and are rife with imperfections and disequilibrium features, including embayments, melt inclusions, titanomagnetite and apatite inclusions, spongy morphologies, hollow faces, subgrain boundaries, multiple growth centers, and Ti-enriched arborescent zoning. Using a combination of qualitative and quantitative analyses (petrography, CL, EBSD, X-ray CT, LA-ICPMS), we determine that those textures commonly thought to signify crystal resorption, crystal deformation, synneusis, or fluctuating P–T conditions are here a consequence of rapid disequilibrium crystal growth. Most importantly, we discover that an overarching process of disequilibrium crystallization is manifested among these crystal features. We propose a model whereby early skeletal to dendritic quartz growth creates a causal sequence of textures derived from lattice mistakes that then proliferate during subsequent stages of slower polyhedral growth. In a reversed sequence, the same structural instabilities and defects form when slow polyhedral growth transitions late to fast skeletal-dendritic growth. Such morphological transitions result in texture interdependencies that become recorded in the textural-chemical stratigraphy of quartz, which may be unique to each crystal. Similar findings in petrologic experimental studies allow us to trace the textural network back to strong degrees of undercooling and supersaturation in the host melt, conditions likely introduced by dynamic magmatic processes acting on short geologic timescales. Because the textural network can manifest in single crystals, the overall morphology and chemistry of erupted quartz can reflect not only its last but its earliest growth behavior in the melt. Thus, our findings imply that thermodynamic disequilibrium crystallization can account for primary textural and chemical heterogeneities preserved in igneous quartz and may impact the application of quartz as a petrologic tool.
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Ainsworth, R. Bruce, Jamie B. McArthur, Simon C. Lang, and Adam J. Vonk. "Quantitative sequence stratigraphy." AAPG Bulletin 102, no. 10 (October 2018): 1913–39. http://dx.doi.org/10.1306/02201817271.
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Agterberg, F. P. "Quantitative Dynamic Stratigraphy." Computers & Geosciences 17, no. 3 (January 1991): 473–74. http://dx.doi.org/10.1016/0098-3004(91)90056-j.
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Herla, Florian, Simon Horton, Patrick Mair, and Pascal Haegeli. "Snow profile alignment and similarity assessment for aggregating, clustering, and evaluating snowpack model output for avalanche forecasting." Geoscientific Model Development 14, no. 1 (January 15, 2021): 239–58. http://dx.doi.org/10.5194/gmd-14-239-2021.
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Abstract. Snowpack models simulate the evolution of the snow stratigraphy based on meteorological inputs and have the potential to support avalanche risk management operations with complementary information relevant for their avalanche hazard assessment, especially in data-sparse regions or at times of unfavorable weather and hazard conditions. However, the adoption of snowpack models in operational avalanche forecasting has been limited, predominantly due to missing data processing algorithms and uncertainty around model validity. Thus, to enhance the usefulness of snowpack models for the avalanche industry, numerical methods are required that evaluate and summarize snowpack model output in accessible and relevant ways. We present algorithms that compare and assess generic snowpack data from both human observations and models, which consist of multidimensional sequences describing the snow characteristics of grain type, hardness, and age. Our approach exploits Dynamic Time Warping, a well-established method in the data sciences, to match layers between snow profiles and thereby align them. The similarity of the aligned profiles is then evaluated by our independent similarity measure based on characteristics relevant for avalanche hazard assessment. Since our methods provide the necessary quantitative link to data clustering and aggregating methods, we demonstrate how snowpack model output can be grouped and summarized according to similar hazard conditions. By emulating aspects of the human avalanche hazard assessment process, our methods aim to promote the operational application of snowpack models so that avalanche forecasters can begin to build an understanding of how to interpret and trust operational snowpack simulations.
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Holland, Steven M. "Quantitative Dynamic Stratigraphy. Timothy A. Cross." Journal of Geology 99, no. 5 (September 1991): 786. http://dx.doi.org/10.1086/629545.
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Borgomano, Jean, Cyprien Lanteaume, Philippe Léonide, François Fournier, Lucien F. Montaggioni, and Jean-Pierre Masse. "Quantitative carbonate sequence stratigraphy: Insights from stratigraphic forward models." AAPG Bulletin 104, no. 5 (May 2020): 1115–42. http://dx.doi.org/10.1306/11111917396.
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Skene, Kenneth I., David J. W. Piper, and Paul S. Hill. "Quantitative analysis of variations in depositional sequence thickness from submarine channel levees." Sedimentology 49, no. 6 (December 2002): 1411–30. http://dx.doi.org/10.1046/j.1365-3091.2002.00506.x.
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Morettini, Elena, Anthony Thompson, Gregor Eberli, Keith Rawnsley, Roeland Roeterdink, Wenche Asyee, Peter Christman, et al. "Combining high-resolution sequence stratigraphy and mechanical stratigraphy for improved reservoir characterisation in the Fahud field of Oman." GeoArabia 10, no. 3 (July 1, 2005): 17–44. http://dx.doi.org/10.2113/geoarabia100317.
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ABSTRACT In the Fahud field of Oman, the integration between hierarchies of sequence stratigraphic units and fracture systems has proven to be crucial to explain the distribution of flow and mechanical units. The study focused on the Upper Cretaceous, Albian to Lower Cenomanian Natih e unit (Natih Formation, Wasia Group), a 170-mthick carbonate sequence/reservoir, which exhibits heterogeneities in both facies and reservoir quality. Based on a core-derived high-resolution sequence stratigraphic analysis, the Natih e reservoir can be subdivided into four orders of depositional cycles (from 6th- to 3rd-order). Each cycle consists of a transgressive and regressive hemicycle with characteristic facies and rock properties. The facies and diagenetic overprint of the higher-order cycles vary according to their position within the 3rd-order sequences. Analysis of core, borehole images, seismic, tracer and production data indicate a hierarchy of fractures and faults that seems to follow the stratigraphic subdivisions. A relationship between depositional and diagenetic architecture of the cycles, and the aforementioned data, led to the identification of mechanical layering and stratigraphy within the reservoir. This finding was validated and supported by the successful history match of the three-phase production data within the dynamic model of the reservoir. The combination of sequence and mechanical stratigraphy provides a framework for the correlation of facies and mechanical units across the field. Furthermore, the facies and mechanical units are related to reservoir quality and fracture distribution for consistent upscaling into large-scale reservoir models. Through close co-operation between geologists and reservoir engineers utilising dynamic data, it was possible to determine the most appropriate scale for flow and ensure that such a scale was then used as input for dynamic modelling and for planning of the future exploitation of the Fahud field. As a result of this study, Petroleum Development Oman (PDO) has evaluated a 20% increase in risked reserves, and a 25% reduction of well costs.
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Aigner, Thomas, and Gerhard H. Bachmann. "Dynamic stratigraphy of an evaporite-to-red bed sequence, Gipskeuper (Triassic), southwest German Basin." Sedimentary Geology 62, no. 1 (March 1989): 5–25. http://dx.doi.org/10.1016/0037-0738(89)90098-5.
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Peters, Shanan E. "Macrostratigraphy and Its Promise for Paleobiology." Paleontological Society Papers 14 (October 2008): 205–31. http://dx.doi.org/10.1017/s1089332600001698.
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Macrostratigraphy is the study and statistical analysis of sediment packages that formed continuously at a specified scale of temporal resolution and that are bound by gaps recognizable at that same scale. The temporal ranges of gap-bound packages, compiled separately for different geographic locations, permit area-weighted, survivorship-based measures of rock quantity and spatio-temporal environmental continuity to be measured. Analytical basin fill models suggest that the parameters controlling sedimentation and sequence stratigraphic architecture, such as base level and sediment supply, can be detected quantitatively by macrostratigraphy.Macrostratigraphic analysis of the marine sedimentary rock record in the United States at a temporal resolution of ~106 years reproduces most of the well-known Sloss sequences, but it also identifies two prominent megasequences, the Paleozoic and Modern megasequences, which are separated by a Permian-Triassic discontinuity and Phanerozoic minimum in rock quantity. Many short- and long-term features of the macroevolutionary history of marine animals are reproduced by macrostratigraphy, including 1) many patterns in genus richness, 2) patterns in rates of genus extinction and, to a lesser degree, rates of origination, and 3) patterns of extinction selectivity and the shifting relative richness of Sepkoski's Paleozoic and Modern evolutionary faunas. The extent to which macrostratigraphy reproduces the macroevolutionary history of marine animals transcends what is expected by geologically-controlled sampling biases. Instead, the processes which control the spatio-temporal dynamics of shelf sedimentation, including expansions and contractions of shallow epicontinental seas, have probably exerted a consistent influence on the macroevolutionary history of marine animals. Exploring the common cause hypothesis by putting fossils back into rocks and rocks into a new quantitative framework for physical environmental change holds considerable promise for paleobiology.
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Pufahl, P. K., S. L. Anderson, and E. E. Hiatt. "Dynamic sedimentation of Paleoproterozoic continental margin iron formation, Labrador Trough, Canada: Paleoenvironments and sequence stratigraphy." Sedimentary Geology 309 (July 2014): 48–65. http://dx.doi.org/10.1016/j.sedgeo.2014.05.006.
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Xing, Zhan Tao, and Kai Yuan Chen. "A New Method for Quantitative Calculation of the Reservoir Thickness." Advanced Materials Research 347-353 (October 2011): 1696–700. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.1696.
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Thickness of reservoir has a direct and close contact with oil and gas exploration and development, reservoir thickness is directly related to success and failure of the exploration and development. The main problem of the Seismic exploration is the limit of the resolution, geophysical workers have done a lot work, but the effect has been not obvious. Mainly to the following questions: 1、it is difficult to determine the boundaries of the reservoir；2、the limits of the resolution still exists. In this paper, through the study of the high-resolution sequence Stratigraphy and fine calibration, we used the sequence boundary and flooding surface to build the initial model, and then the density inversion was done to indentify the oil and gas reservoir. On the basis of the inversion, the density ranges of the sandstone in the sequence were calculated through geostatistics, and then we correctly calculated the thickness of the sandstone in every sequence, in this way we not only solved the problem of reservoir boundaries, but also improved the resolution.
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Day, Michael O., Roger B. J. Benson, Christian F. Kammerer, and Bruce S. Rubidge. "Evolutionary rates of mid-Permian tetrapods from South Africa and the role of temporal resolution in turnover reconstruction." Paleobiology 44, no. 3 (August 2018): 347–67. http://dx.doi.org/10.1017/pab.2018.17.
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AbstractThe Main Karoo Basin of South Africa contains a near-continuous sequence of continental deposition spanning ~80 Myr from the mid-Permian to the Early Jurassic. The terrestrial vertebrates of this sequence provide a high-resolution stratigraphic record of regional origination and extinction, especially for the mid–late Permian. Until now, data have only been surveyed at coarse stratigraphic resolution using methods that are biased by nonuniform sampling rates, limiting our understanding of the dynamics of diversification through this important time period. Here, we apply robust methods (gap-filler and modified gap-filler rates) for the inference of patterns of species richness, origination rates, and extinction rates to a subset of 1321 reliably-identified fossil occurrences resolved to approximately 50 m stratigraphic intervals. This data set provides an approximate time resolution of 0.3–0.6 Myr and shows that extinction rates increased considerably in the upper 100 m of the mid-Permian Abrahamskraal Formation, corresponding to the latest part of theTapinocephalusAssemblage Zone (AZ). Origination rates were only weakly elevated in the same interval and were not sufficient to compensate for these extinctions. Subsampled species richness estimates for the lower part of the overlying Teekloof Formation (corresponding to thePristerognathusandTropidostomaAZs) are low, showing that species richness remained low for at least 1.5–3 million years after the main extinction pulse. A high unevenness of the taxon abundance–frequency distribution, which is classically associated with trophically unstable postextinction faunas, in fact developed shortly before the acme of elevated extinction rates due to the appearance and proliferation of the dicynodontDiictodon. Our findings provide strong support for a Capitanian (“end-Guadalupian”) extinction event among terrestrial vertebrates and suggest that further high-resolution quantitative studies may help resolve the lack of consensus among paleobiologists regarding this event.
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Teixeira, Leonardo, Wagner M. Lupinacci, and Alexandre Maul. "Quantitative seismic-stratigraphic interpretation of the evaporite sequence in the Santos Basin." Marine and Petroleum Geology 122 (December 2020): 104690. http://dx.doi.org/10.1016/j.marpetgeo.2020.104690.
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Hart, Bruce S. "Whither seismic stratigraphy?" Interpretation 1, no. 1 (August 1, 2013): SA3—SA20. http://dx.doi.org/10.1190/int-2013-0049.1.
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Here, I provide an historical summary of seismic stratigraphy and suggest some potential avenues for future collaborative work between sedimentary geologists and geophysicists. Stratigraphic interpretations based on reflection geometry- or shape-based approaches have been used to reconstruct depositional histories and to make qualitative and (sometimes) quantitative predictions of rock physical properties since at least the mid-1970s. This is the seismic stratigraphy that is usually practiced by geology-focused interpreters. First applied to 2D seismic data, interest in seismic stratigraphy was reinvigorated by the development of seismic geomorphology on 3D volumes. This type of reflection geometry/shape-based interpretation strategy is a fairly mature science that includes seismic sequence analysis, seismic facies analysis, reflection character analysis, and seismic geomorphology. Rock property predictions based on seismic stratigraphic interpretations usually are qualitative, and reflection geometries commonly may permit more than one interpretation. Two geophysics-based approaches, practiced for nearly the same length of time as seismic stratigraphy, have yet to gain widespread adoption by geologic interpreters even though they have much potential application. The first is the use of seismic attributes for “feature detection,” i.e., helping interpreters to identify stratigraphic bodies that are not readily detected in conventional amplitude displays. The second involves rock property (lithology, porosity, etc.) predictions from various inversion methods or seismic attribute analyses. Stratigraphers can help quality check the results and learn about relationships between depositional features and lithologic properties of interest. Stratigraphers also can contribute to a better seismic analysis by helping to define the effects of “stratigraphy” (e.g., laminations, porosity, bedding) on rock properties and seismic responses. These and other seismic-related pursuits would benefit from enhanced collaboration between sedimentary geologists and geophysicists.
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Matthews, Robley K., and Cliff Frohlich. "FORWARD MODELING OF SEQUENCE STRATIGRAPHY AND DIAGENESIS: Application to Rapid, Cost-Effective Carbonate Reservoir Characterization." GeoArabia 3, no. 3 (July 1, 1998): 359–84. http://dx.doi.org/10.2113/geoarabia0303359.
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ABSTRACT Dynamic forward modeling of carbonate reservoir sequence stratigraphy and diagenetic overprint can yield rapid, cost-effective reservoir characterization. The common practice in reservoir characterization now relies heavily on massive data accumulation and geostatistics to produce the three-dimensional geocellular static model which is the basis for flow simulation. In dynamic forward modeling, reliance on understanding of geological process allows high resolution prediction of the geometry of permeable and impermeable units and horizons within the reservoir. Data requirements are reduced to state-of-the-art information on a relatively small number of control wells which constrain and calibrate the forward model. Sensitivity-testing among formally-stated competing concepts is encouraged. In the long-term, it is the accurate prediction of reservoir response to future production that will afford choice among competing static models and flow simulations. The goal should be to predict future problems and avoid them, rather than wait to observe problems and react to them.
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Rosenblume, Justin A., and Ross D. Powell. "Glacial sequence stratigraphy of ANDRILL ‐1B core reveals a dynamic subpolar Antarctic Ice Sheet in Ross Sea during the late Miocene." Sedimentology 66, no. 6 (July 17, 2019): 2072–97. http://dx.doi.org/10.1111/sed.12592.
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Lafontaine, Adam T., Bruce J. Mayer, and Kazuya Machida. "Dynalogo: an interactive sequence logo with dynamic thresholding of matched quantitative proteomic data." Bioinformatics 36, no. 5 (October 14, 2019): 1632–33. http://dx.doi.org/10.1093/bioinformatics/btz766.
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Abstract Summary Current web-based sequence logo analyses for studying domain–peptide interactions are often conducted only on high affinity binders due to conservative data thresholding. We have developed Dynalogo, a combination of threshold varying tool and sequence logo generator written in the R statistical programming language, which allows on-the-fly visualization of binding specificity over a wide range of affinity interactions. Hence researchers can easily explore their dataset without the constraint of an arbitrary threshold. After importing quantitative data files, there are various data filtering and visualizing features available. Using a threshold control, users can easily track the dynamic change of enrichment and depletion of amino acid characters in the sequence logo panel. The built-in export function allows downloading filtered data and graphical outputs for further analyses. Dynalogo is optimized for analysis of modular domain–peptide binding experiments but the platform offers a broader application including quantitative proteomics. Availability and implementation Dynalogo application, user manual and sample data files are available at https://dynalogo.cam.uchc.edu. The source code is available at https://github.com/lafontaine-uchc/dynalogo. Supplementary information Supplementary data are available at Bioinformatics online.
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Inichinbia, S., and Halidu Hamza. "Detailed quantitative sequence stratigraphic interpretation for the characterization of Amangi field using seismic data and well logs." Scientia Africana 19, no. 3 (February 24, 2021): 63–82. http://dx.doi.org/10.4314/sa.v19i3.6.
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The sequence stratigraphy of Amangi field of the Niger Delta was studied using seismic data and well logs. The field is a structurally complex one and presents serious challenges to hydrocarbon exploration and production. The main objective of these analyses is to identify sand intervals using the available data. Well log data were used as additional tools to constrain the seismic correlations in order to solve the correlation problem. The well logs were evaluated for the field’s petrophysical properties by combining the gamma ray and resistivity logs to determine reservoir zones with considerable hydrocarbon saturation. Also, the relationship between some basic rock properties/attributes and litho-types were determined for the study area. Next, well-to-seismic ties were produced and two horizons were picked. Acoustic impedance inversion was also performed which revealed “hard sands” due to mixed lithologies (heterolithics). This made it difficult to discriminate the sands from shales in the P-impedance domain alone. So, progress was made to determine the net-to-gross of the field. The analysis revealed that these reservoirs have shaly sand with shale content of 10%, porosity averaging 21%, and hydrocarbon saturation of 90%. The result established a vertical stack of a series of reservoirs in an anticlinal structure of which the H1000 and H4000 stand out for their huge volumes of rich gas condensate accumulation. This discovery provoked the drive for the first phase of development of this field.
Keywords: stratigraphy, facies, net-to-gross, horizon, lithology, well-to-seismic tie, impedance
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Kauffman, Erle G., and Bradley B. Sageman. "Biological patterns in sequence stratigraphy; Cretaceous of the Western Interior Basin, North America." Paleontological Society Special Publications 6 (1992): 158. http://dx.doi.org/10.1017/s2475262200007188.
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High-resolution stratigraphic analysis of Cretaceous strata in the Western Interior Basin (WIB) of North America has allowed definition of numerous disconformity-bounded, eustatically and/or tectonically driven sequences and their systems tracts at 2nd- through 4th-order scale, as well as 5th- to 7th-order climate-induced cycles. Integrated event chronostratigraphy and biostratigraphy allow detailed regional tracing and facies analysis of these sequences, leading to three-dimensional modeling of facies evolution. Whether driven by relative sealevel changes or smaller scale climate cycles, Cretaceous sequences and their bounding disconformities reflect dynamic changes in many factors which moderate biological systems (e.g. sealevel and paleobathymetric changes, changes in current velocity and in erosion/sedimentation rates and patterns, watermass temperature and chemistry, etc). Predictable biological responses (patterns) to varying environmental conditions and different systems tracts are expected in sequence stratigraphy. Once defined within well-studied systems, these patterns can then be used as an independent tool for sequence stratigraphic analysis. To date, our research has focused on the development of paleobiological criteria which aid in the recognition of sequence stratigraphic frameworks, especially in basinal facies where sequence boundaries and systems tracts may be subtly defined in the physical stratigraphy. Such criteria may include the identification of sequence boundaries and other omission surfaces by punctuated character displacement in evolutionary series, by condensation or omission of biostratigraphic zones, by mixed or time-averaged community elements and biozones, and by selective colonization by firm substrate-dependent benthic communities. Gradients within and between systems are characterized by different community composition, biofacies, taxonomic and community diversity patterns, adaptive bauplans among resident taxa, taphonomic signatures, and bioevents that allow predictive biological characterization in sequence stratigraphy. Once established and correlated, sequence stratigraphic systems among different basins provide a chronostratigaphic and environmental framework within which the regional dynamics of ancient populations and communities can be evaluated, leading to the analysis and modeling of relationships between sealevel changes and biogeographic migration patterns, and the rates and patterns of evolution and extinction.
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Farouk, Sherif, Sreepat Jain, Nancy Belal, Mohamed Omran, and Khaled Al-Kahtany. "Quantitative Middle Eocene benthic foraminiferal biofacies from west-central Sinai, Egypt: Implications to paleobathymetry and sequence stratigraphy." Marine Micropaleontology 155 (March 2020): 101823. http://dx.doi.org/10.1016/j.marmicro.2020.101823.
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Zhang, Meng, Tuanfeng Y. Wang, Duygu Ceylan, and Niloy J. Mitra. "Dynamic neural garments." ACM Transactions on Graphics 40, no. 6 (December 2021): 1–15. http://dx.doi.org/10.1145/3478513.3480497.
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A vital task of the wider digital human effort is the creation of realistic garments on digital avatars, both in the form of characteristic fold patterns and wrinkles in static frames as well as richness of garment dynamics under avatars' motion. Existing workflow of modeling, simulation, and rendering closely replicates the physics behind real garments, but is tedious and requires repeating most of the workflow under changes to characters' motion, camera angle, or garment resizing. Although data-driven solutions exist, they either focus on static scenarios or only handle dynamics of tight garments. We present a solution that, at test time, takes in body joint motion to directly produce realistic dynamic garment image sequences. Specifically, given the target joint motion sequence of an avatar, we propose dynamic neural garments to synthesize plausible dynamic garment appearance from a desired viewpoint. Technically, our solution generates a coarse garment proxy sequence, learns deep dynamic features attached to this template, and neurally renders the features to produce appearance changes such as folds, wrinkles, and silhouettes. We demonstrate generalization behavior to both unseen motion and unseen camera views. Further, our network can be fine-tuned to adopt to new body shape and/or background images. We demonstrate our method on a wide range of real and synthetic garments. We also provide comparisons against existing neural rendering and image sequence translation approaches, and report clear quantitative and qualitative improvements. Project page: http://geometry.cs.ucl.ac.uk/projects/2021/DynamicNeuralGarments/
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Paumard, Victorien, Julien Bourget, Tobi Payenberg, Annette D. George, R. Bruce Ainsworth, and Simon Lang. "From quantitative 3D seismic stratigraphy to sequence stratigraphy: Insights into the vertical and lateral variability of shelf-margin depositional systems at different stratigraphic orders." Marine and Petroleum Geology 110 (December 2019): 797–831. http://dx.doi.org/10.1016/j.marpetgeo.2019.07.007.
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Ma, Ming Fu, and Yuan Fu Zhang. "Identifying Parasequence Sets Boundaries by Using Well Logging Data." Advanced Materials Research 356-360 (October 2011): 3038–41. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.3038.
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Logging data, as representations of lithology and physical properties of stratum, hold abundant information related to sedimentary cycles with high vertical resolution. The use of various methods to extract and analyze corresponding information will greatly promote the quantitative level in the study of stratum sequence. SP mirror (spontaneous potential), the ratio of sand and mud, CN (neutron)-GR (natural gamma ray) curve overlay technique and wavelet analyses were comprehensively analyzed in this paper. Application in X block of Algeria that it has a great effect and is a good tool in the parasequence sets study. Continuously improve the level of utilization of logging data, full logging data in sequence stratigraphic analysis of the role and scope of application will be beneficial for the development of sequence stratigraphy.
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Youssef, Abdulkader. "Early – Middle Miocene Suez Syn-rift-Basin, Egypt: A sequence stratigraphy framework." GeoArabia 16, no. 1 (January 1, 2011): 113–34. http://dx.doi.org/10.2113/geoarabia1601113.
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ABSTRACT The analyses of thirteen planktonic and benthonic biozones, paleobathymetry and electric log data were used to interpret the sequence stratigraphy of the Early to early Middle Miocene syn-rift section in the Gulf of Suez. The study area is located in the central province of the Gulf and includes six boreholes located in two half grabens and the October Field. The new framework proposes the Suez Supersequence and Suez Depositional Sequence DS 50 instead of the five paleontological sequences commonly cited in the literature (S10 to S50). The Supersequence starts above the regional unconformity that separates the pre-and syn-rift rocks, commonly referred to as Terrace T00. The shallow-marine deposits of the Aquitanian Nukhul Formation form the lowstand systems tract. The Burdigalian Mheiherrat Formation starts with the Uvigerina costata flooding event and forms the transgressive systems tract deposited in outer-neritic to upper-bathyal settings. The overlying Langhian Hawara Formation was deposited in upper to middle bathyal settings and represents the maximum flooding interval. The Langhian Asl Formation (early falling stage systems tract, upper bathyal to outer neritic) and overlying Langhian Lagia Member of the Ayun Musa Formation (late falling stage systems tract) closed the Supersequence. Suez Depositional Sequence DS 50 lies unconformably on the Supersequence, and represents a major transgression starting with the Praeorbulina glomerosa s.l. flooding event. DS 50 corresponds to the Ras Budran Member of the Ayun Musa Formation (paleontological sequence S50). Its setting is outer neritic and its upper sequence boundary is an unconformable with the Belayim Formation. The Suez Supersequence is interpreted in terms of 35 genetic parasequences and DS 50 by 10 more. The parasequences are interpreted by the coincidence of quantitative paleontological faunal and paleobathymetric breaks with the electric log shifts. The sequences and parasequences are correlated between the six wells to show the evolution of the half-grabens and October Field at different times.
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Kurz, Tobias H., Galo San Miguel, Dominique Dubucq, Jeroen Kenter, Veronique Miegebielle, and Simon J. Buckley. "Quantitative mapping of dolomitization using close-range hyperspectral imaging: Kimmeridgian carbonate ramp, Alacón, NE Spain." Geosphere 18, no. 2 (February 4, 2022): 780–99. http://dx.doi.org/10.1130/ges02312.1.
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Abstract Geological models from outcrop analogues are often utilized as a guide, or soft constraint, for distributing reservoir properties in subsurface models. In carbonate outcrops, combined sequence stratigraphic, sedimentological, and petrographic studies constrain the heterogeneity of geobodies and diagenetic processes, including dolomitization, at multiple scales. High-resolution digital outcrop modeling further aids geometric mapping, geobody definition, and statistical analysis, though its usefulness for detailed mineralogical and lithological mapping is limited. Hyperspectral imaging offers enhanced spectral resolution for mapping subtle mineralogical differences. In both outcrops and subsurface, differences in carbonate composition can provide key information for distributing porosity and permeability, yet this mapping is highly challenging in field studies due to access difficulties, visible material differences, and sampling resolution. Spectral analysis of limestone–dolomite ratios conducted in laboratory studies indicates theoretical measures for quantitative identification and mapping of dolomite degrees within carbonate rocks. In this study, close-range hyperspectral imaging is applied to outcrops of the Alacón Member, Barranco del Mortero, northeastern Spain, to identify exposed limestone–dolomite geobodies and to quantify the degree of dolomitization across outcrop faces. Hyperspectral imaging is supplemented with photogrammetric outcrop modeling, field spectroscopy, and laboratory sample analysis for empirical validation and uncertainty analysis. Hyperspectral mapping shows that earlier fieldwork utilizing visual inspection of difficult to access outcrop surfaces had overestimated the amount of dolomite in the outcrop. Results indicate that hyperspectral imaging identified dolomite bodies more accurately and reliably than conventional field methods and facilitates the mapping of dolomite contribution in areas modified by dedolomitization, where dolomite content changes by more than ~20%.
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Zhu, Hongtao, Hongliu Zeng, and Keyu Liu. "A quantitative simulation study of asymmetrical tectonic subsidence control on non-synchronous sequence stacking patterns of Eocene lacustrine sediments in Bohai Bay Basin, China." Sedimentary Geology 294 (August 2013): 328–41. http://dx.doi.org/10.1016/j.sedgeo.2013.07.002.
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Smith, Michael E., and John F. Doershuk. "Late Postclassic Chronology in Western Morelos, Mexico." Latin American Antiquity 2, no. 4 (December 1991): 291–310. http://dx.doi.org/10.2307/971780.
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Chronology building is an integral part of the archaeological research process, and changing research questions often require the refinement of existing chronologies. This view is illustrated with a description of the derivation, refinement, and confirmation of a ceramic sequence for the Postclassic period in Morelos, Mexico. The joint application of stratigraphy and quantitative ceramic seriation produced a five-phase Postclassic chronology. To deal with problems in distinguishing the stylistically similar ceramics of the final three phases, discriminant-function analysis was employed, resulting in the confident phasing of nearly all excavated contexts at the sites of Capilco and Cuexcomate. Calendar years are assigned to the phases by radiocarbon dating, and the implications of the dated sequence are explored briefly.
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STREEL, Maurice, Michel VANGUESTAINE, Andrés PARDO-TRUJILLO, and Eric THOMALLA. "The Frasnian-Famennian boundary sections at Hony and Sinsin (Ardenne, Belgium): new interpretation based on quantitative analysis of palynomorphs, sequence stratigraphy and climatic interpretation." Geologica Belgica 3, no. 3-4 (October 1, 2001): 271–83. http://dx.doi.org/10.20341/gb.2014.033.
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In the light of recent geochemical and sedimentological investigations, the Frasnian-Famennian Boundary sections at Hony and Sinsin (eastern and central Ardenne, Belgium) are re-evaluated in terms of quantitative analysis of spiny acritarchs and miospores. It is concluded that the shaly interval separating the limestone beds dated Frasnian and Famennian by conodonts corresponds to a transgressive - regressive marine sequence. This interpretation is supported, for the Hony section, by a quantitative analysis of two spiny acritarch groups (Gorgonisphaeridium gr. and Micrhystridium gr.) based on the relationship between their abundance and the depth of the marine environment. It is also corroborated by the frequency distribution of a Prasinophyceae (Maranhites stockmansii) indicative for a maximum flooding surface. A sequence stratigraphic model and the possible causes of the bathymetric changes right at the Frasnian-Famennian Boundary are briefly discussed. It is suggested that these changes are related to a short glacial phase during a "warm mode" period.
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Jaarsma-Coes, Myriam G., Teresa A. Ferreira, Petra J. van Houdt, Uulke A. van der Heide, Gregorius P. M. Luyten, and Jan-Willem M. Beenakker. "Eye-specific quantitative dynamic contrast-enhanced MRI analysis for patients with intraocular masses." Magnetic Resonance Materials in Physics, Biology and Medicine 35, no. 2 (October 13, 2021): 311–23. http://dx.doi.org/10.1007/s10334-021-00961-w.
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Abstract Objective Dynamic contrast enhanced (DCE)-MRI is currently not generally used for intraocular masses as lesions are small, have an inhomogeneous T1 and the eye is prone to motion. The aim of this paper is to address these eye-specific challenges, enabling accurate ocular DCE-MRI. Materials & methods DCE-MRI of 19 uveal melanoma (UM) patients was acquired using a fat-suppressed 3D spoiled gradient echo sequence with TWIST (time-resolved angiography with stochastic trajectories sequence). The analysis consisted of a two-step registration method to correct for both head and eye motion. A T1 map was calculated to convert signal intensities to concentrations. Subsequently, the Tofts model was fitted voxel wise to obtain Ktrans and ve. Results Registration significantly improved the concentration curve quality (p < 0.001). The T1 of melanotic lesions was significantly lower than amelanotic lesions (888 ms vs 1350 ms, p = 0.03). The average achieved B1+ in the lesions was 91%. The average Ktrans was 0.46 min−1 (range 0.13–1.0) and the average ve was 0.22 (range 0.10–0.51). Conclusion Using this eye-specific analysis, DCE of intraocular masses is possible which might aid in the diagnosis, prognosis and follow-up of UM.
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MACNEIL, ALEX J., and BRIAN JONES. "Sequence stratigraphy of a Late Devonian ramp-situated reef system in the Western Canada Sedimentary Basin: dynamic responses to sea-level change and regressive reef development." Sedimentology 53, no. 2 (April 2006): 321–59. http://dx.doi.org/10.1111/j.1365-3091.2005.00767.x.
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Elliott, Colleen G., Christopher R. Barnes, and Paul F. Williams. "Southwest New World Island stratigraphy: new fossil data, new implications for the history of the Central Mobile Belt, Newfoundland." Canadian Journal of Earth Sciences 26, no. 10 (October 1, 1989): 2062–74. http://dx.doi.org/10.1139/e89-173.
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The identification of fossils from 16 new localities on southwestern New World Island has resulted in the refinement and simplification of local stratigraphy and in the correlation of rock units across an intensely deformed area. Complex stratigraphic classifications of earlier workers are replaced by a simpler scheme consisting of four formations: the Summerford Formation (oldest), Rogers Cove Formation, Sansom Formation, and Goldson Formation. Mélange units are fault related and cannot be included in the stratigraphy. Fossil and lithological data provided here confirm previous indications that the rocks of the Summerford Formation are the remains of a long-lived volcanic-island complex. This complex is overlain by a markedly diachronous coarsening-upwards sequence of marine clastic sediments, now represented by the Rogers Cove, Sansom, and Goldson formations.The new stratigraphic data, combined with structural evidence, indicate that the stratigraphy is repeated across several bedding-parallel faults. Significant diachroneity of formation boundaries and the absence of syndepositional high-angle faults suggest deposition in one large mid-Paleozoic basin rather than in a number of small dynamic basins.
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Ning, Zhao, Gao Xia, Huang Jiangqin, Chen Zhongmin, and Zhang Guangya. "Sedimentary Characteristics and Lithological Trap Identification of Distant Braided Delta Deposits: A Case on Upper Cretaceous Yogou Formation of Termit Basin, Niger." E3S Web of Conferences 53 (2018): 03020. http://dx.doi.org/10.1051/e3sconf/20185303020.
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Lithological trap identification in thin sand and thick shale layers is still a challenge for hydrocarbon exploration. Based on the high-resolution sequence stratigraphy theory and the establishment of high-resolution sequence stratigraphy framework with seismic-well tie, the dynamic deposition process of braided delta sands on late Cretaceous Yogou formation has been analyzed on 62 wells in passive rifting Termit basin with multi-stages depressions and reversals. (1) Six kinds of sedimentary microfacies and three major reservoir sands with multi-stages vertical stacking and lateral migration are in late Cretaceous; (2) Based on accommodation space/Sediments supply change and depositional progress, sedimentary facies distribution evolution has been done according to sands thickness statistics of sedimentary micro-facies, and narrow-time seismic attributes and slices analysis, multi-sources braided delta depositional model has been concluded; (3) Based on source rock and caprock evaluation, with reservoir sands distribution and faults impact on Yogou formation of Termit basin, four types of traps, including structure-lithology, Structure-strata, stratigraphic and lithology are concluded. Traps influencing factors, i.e., structure geometry, sands distribution, paleotopography, stratigraphy cycling, sand/shale lateral connection, reservoir quality and so on, have different impacts on these traps, and different lithologic-stratigraphy traps have different exploration risks. Structure geometry and sands distribution are very important for the structure-lithology traps; structure geometry and paleotopography are the key factors in Structure-strata traps. Sands distribution and reservoir quality can be focused on lithology traps. Moreover, paleotopography and sand/shale lateral connection are significant on stratigraphic traps. Therefore, different hydrocarbon accumulation types of lithological traps have been established.
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Tiwari, R. S., and Archana Tripathi. "Marker Assemblage-Zones of spores and pollen species through Gondwana Palaeozoic and Mesozoic sequence in India." Journal of Palaeosciences 40 (December 31, 1991): 194–236. http://dx.doi.org/10.54991/jop.1991.1773.
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Most of the palynozonation schemes so far proposed for the Gondwana sequence of India are based on quantitative representation of spore-pollen genera. These proposals have limited value for interbasinal correlation. The present synthesis deals with a model for species-based stratigraphy. Palynologically well studied Permian and Triassic sequences in the Damodar Graben and Permian, Triassic and Cretaceous sequences in the adjacent Rajmahal Basin have been taken as key regions to establish the zonation scheme. Based on the FADs and LADs and totality of composition of selected species, twenty Species Assemblage-Zones have been recognised. The reorganisation of this data through computer has also resulted in the identification of thirty Species Acme-Zones.
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Mao, Albert H., Nicholas Lyle, and Rohit V. Pappu. "Describing sequence–ensemble relationships for intrinsically disordered proteins." Biochemical Journal 449, no. 2 (December 14, 2012): 307–18. http://dx.doi.org/10.1042/bj20121346.
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Intrinsically disordered proteins participate in important protein–protein and protein–nucleic acid interactions and control cellular phenotypes through their prominence as dynamic organizers of transcriptional, post-transcriptional and signalling networks. These proteins challenge the tenets of the structure–function paradigm and their functional mechanisms remain a mystery given that they fail to fold autonomously into specific structures. Solving this mystery requires a first principles understanding of the quantitative relationships between information encoded in the sequences of disordered proteins and the ensemble of conformations they sample. Advances in quantifying sequence–ensemble relationships have been facilitated through a four-way synergy between bioinformatics, biophysical experiments, computer simulations and polymer physics theories. In the present review we evaluate these advances and the resultant insights that allow us to develop a concise quantitative framework for describing the sequence–ensemble relationships of intrinsically disordered proteins.
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La Croix, Andrew D., Vahab Honari, Sebastian Gonzalez, Jim Underschultz, and Andrew Garnett. "Impact of sequence stratigraphy on static and dynamic reservoir models: examples from the Precipice-Evergreen succession, Surat Basin, Queensland." ASEG Extended Abstracts 2018, no. 1 (December 2018): 1–4. http://dx.doi.org/10.1071/aseg2018abm1_3c.
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Rach, Oliver, Ansgar Kahmen, Achim Brauer, and Dirk Sachse. "A dual-biomarker approach for quantification of changes in relative humidity from sedimentary lipid <i>D</i>∕<i>H</i> ratios." Climate of the Past 13, no. 7 (July 3, 2017): 741–57. http://dx.doi.org/10.5194/cp-13-741-2017.
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Abstract. Past climatic change can be reconstructed from sedimentary archives by a number of proxies. However, few methods exist to directly estimate hydrological changes and even fewer result in quantitative data, impeding our understanding of the timing, magnitude and mechanisms of hydrological changes. Here we present a novel approach based on δ2H values of sedimentary lipid biomarkers in combination with plant physiological modeling to extract quantitative information on past changes in relative humidity. Our initial application to an annually laminated lacustrine sediment sequence from western Europe deposited during the Younger Dryas cold period revealed relative humidity changes of up to 15 % over sub-centennial timescales, leading to major ecosystem changes, in agreement with palynological data from the region. We show that by combining organic geochemical methods and mechanistic plant physiological models on well characterized lacustrine archives it is possible to extract quantitative ecohydrological parameters from sedimentary lipid biomarker δ2H data.
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Ahmadshahi, M. A., Sridhar Krishnaswamy, and S. Nemat-Nasser. "Dynamic Holographic-Electronic Speckle-Pattern Interferometry." Journal of Applied Mechanics 60, no. 4 (December 1, 1993): 866–74. http://dx.doi.org/10.1115/1.2900995.
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The development of a nondestructive, full-field, quantitative optical technique, and its feasibility to study dynamic deformations of opaque and diffusively reflecting solids under transient loads, are discussed. The technique involves recording a sequence of dynamically changing two-beam speckle interference patterns (also called holographic speckle patterns) of a rapidly deforming body which is doubly illuminated by a laser light source. The time sequence of speckle patterns is recorded by means of a high-speed camera on an ultra-sensitive 35-mm film. The developed negatives are then digitized by a CCD camera into an image processing system. An initial speckle pattern corresponding to the undeformed state of the object is taken as the reference, and subsequent speckle patterns are digitally subtracted (reconstructed) from it to produce time- varying fringe patterns corresponding to the relative deformation of the test object. In order to gain confidence that the technique can be used to record truly transient deformation, it is tested here on a vibrating plate at resonance, thereby obtaining the evolution of the fringe pattern during 1/2 cycle of deformation corresponding to 160 μs.
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Schneebeli, Martin, and Jerome B. Johnson. "A constant-speed penetrometer for high-resolution snow stratigraphy." Annals of Glaciology 26 (1998): 107–11. http://dx.doi.org/10.3189/1998aog26-1-107-111.
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A new constant-speed penetrometer for field and laboratory measurement has been developed. The initially independent work of SFISAR and CRREL has been brought together, and a portable field device is now in an advanced stage of testing. The new penetrometer has high rigidity and a high-resolution large dynamic range force sensor. It uses a much smaller sensing head (5 mm) than previous designs and has a constant-speed drive. With this construction, the penetration resistance of very fine layers and the influence of the bonding strength between snow grains can be more accurately determined than is possible with the rammsonde or Pandalp. Artificial foam layers as thin as 2 mm and thin layers in snow have been detected by the penetrometer. Thin snow layers detected from penetration-resistance profiles have been correlated to fine layering as determined from plane-section microphotographs of samples taken adjacent to the profile. The instrument’s measurements are highly repeatable and the lack of subjective decisions when operating the penetrometer makes the penetration resistance a quantitative measure of snow stratigraphy.
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Schneebeli, Martin, and Jerome B. Johnson. "A constant-speed penetrometer for high-resolution snow stratigraphy." Annals of Glaciology 26 (1998): 107–11. http://dx.doi.org/10.1017/s0260305500014658.
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A new constant-speed penetrometer for field and laboratory measurement has been developed. The initially independent work of SFISAR and CRREL has been brought together, and a portable field device is now in an advanced stage of testing. The new penetrometer has high rigidity and a high-resolution large dynamic range force sensor. It uses a much smaller sensing head (5 mm) than previous designs and has a constant-speed drive. With this construction, the penetration resistance of very fine layers and the influence of the bonding strength between snow grains can be more accurately determined than is possible with the rammsonde or Pandalp. Artificial foam layers as thin as 2 mm and thin layers in snow have been detected by the penetrometer. Thin snow layers detected from penetration-resistance profiles have been correlated to fine layering as determined from plane-section microphotographs of samples taken adjacent to the profile. The instrument’s measurements are highly repeatable and the lack of subjective decisions when operating the penetrometer makes the penetration resistance a quantitative measure of snow stratigraphy.
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Srour, Jessy Mouannes, Wanyong Shin, Saurabh Shah, Anindya Sen, and Timothy J. Carroll. "SCALE-PWI: A Pulse Sequence for Absolute Quantitative Cerebral Perfusion Imaging." Journal of Cerebral Blood Flow & Metabolism 31, no. 5 (December 15, 2010): 1272–82. http://dx.doi.org/10.1038/jcbfm.2010.215.
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The Bookend technique is a magnetic resonance imaging (MRI) dynamic susceptibility contrast method that provides reliable quantitative measurement of cerebral blood flow (CBF) and cerebral blood volume (CBV). The quantification is patient specific, is derived from a steady-state measurement of CBV, and is obtained from T1 changes in the white matter and the blood pool after contrast agent injection. In the current implementation, the Bookend technique consists of three scanning steps requiring a cumulative scan time of 3minutes 47seconds, a well-trained technologist, and extra time for offline image reconstruction. We present an automation and acceleration of the multiscan Bookend protocol through a self-calibrating pulse sequence, namely Self-Calibrated Epi Perfusion-Weighted Imaging (SCALE-PWI). The SCALE-PWI is a single-shot echo-planar imaging pulse sequence with three modules and a total scan time of under 2minutes. It provides the possibility of performing online, quantitative perfusion image reconstruction, which reduces the latency to obtain quantitative maps. A validation study in healthy volunteers ( N = 19) showed excellent agreement between SCALE-PWI and the conventional Bookend protocol ( P > 0.05 with Student's t-test, r = 0.95/slope = 0.98 for quantitative CBF, and r = 0.91/slope = 0.94 for quantitative CBV). A single MRI pulse sequence for absolute quantification of cerebral perfusion has been developed.
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Montelli, Aleksandr, Sean P. S. Gulick, Rodrigo Fernandez, Bruce C. Frederick, Amelia E. Shevenell, Amy Leventer, and Donald D. Blankenship. "Seismic stratigraphy of the Sabrina Coast shelf, East Antarctica: Early history of dynamic meltwater-rich glaciations." GSA Bulletin 132, no. 3-4 (July 16, 2019): 545–61. http://dx.doi.org/10.1130/b35100.1.
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Abstract High-resolution seismic data from the Sabrina Coast continental shelf, East Antarctica, elucidate the Cenozoic evolution of the East Antarctic Ice Sheet. Detailed seismic stratigraphic and facies analysis reveal the Paleogene to earliest Pliocene glacial evolution of the Aurora Basin catchment, including at least 12 glacial expansions across the shelf indicated by erosional surfaces and chaotic acoustic character of strata. Differences in facies composition and seismic architecture reveal several periods of ice-free conditions succeeded by glacial expansions across the shelf. A deep (∼100 m), undulating erosional surface suggests the initial appearance of grounded ice on the shelf. Following the initial ice expansion, the region experienced an interval of open-marine to ice-distal conditions, marked by an up to 200-m-thick sequence of stratified sediments. At least three stacked erosional surfaces reveal major cross-shelf glacial expansions of regional glaciers characterized by deep (up to ∼120 m) channel systems associated with extensive subglacial meltwater. The seismic character of the sediments below the latest Miocene to earliest Pliocene regional unconformity indicates intervals of glacial retreat interrupted by advances of temperate, meltwater-rich glacial ice from the Aurora Basin catchment. Our results document the Paleogene to late Miocene glacial history of this climatically sensitive region of East Antarctica and provide an important paleoenvironmental context for future scientific drilling to constrain the regional climate and timing of Cenozoic glacial variability.
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Dans, Pablo D., Alexandra Balaceanu, Marco Pasi, Alessandro S. Patelli, Daiva Petkevičiūtė, Jürgen Walther, Adam Hospital, et al. "The static and dynamic structural heterogeneities of B-DNA: extending Calladine–Dickerson rules." Nucleic Acids Research 47, no. 21 (October 18, 2019): 11090–102. http://dx.doi.org/10.1093/nar/gkz905.
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Abstract We present a multi-laboratory effort to describe the structural and dynamical properties of duplex B-DNA under physiological conditions. By processing a large amount of atomistic molecular dynamics simulations, we determine the sequence-dependent structural properties of DNA as expressed in the equilibrium distribution of its stochastic dynamics. Our analysis includes a study of first and second moments of the equilibrium distribution, which can be accurately captured by a harmonic model, but with nonlocal sequence-dependence. We characterize the sequence-dependent choreography of backbone and base movements modulating the non-Gaussian or anharmonic effects manifested in the higher moments of the dynamics of the duplex when sampling the equilibrium distribution. Contrary to prior assumptions, such anharmonic deformations are not rare in DNA and can play a significant role in determining DNA conformation within complexes. Polymorphisms in helical geometries are particularly prevalent for certain tetranucleotide sequence contexts and are always coupled to a complex network of coordinated changes in the backbone. The analysis of our simulations, which contain instances of all tetranucleotide sequences, allow us to extend Calladine–Dickerson rules used for decades to interpret the average geometry of DNA, leading to a set of rules with quantitative predictive power that encompass nonlocal sequence-dependence and anharmonic fluctuations.
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Bellas, S., D. Frydas, and H. Keupp. "LATE MIOCENE CALCAREOUS NANNOFOSSIL STRATIGRAPHY AND BIOEVENTS CORRELATION: KALIDONIA CASE SECTION (NW CRETE, GREECE)." Bulletin of the Geological Society of Greece 40, no. 1 (June 8, 2018): 1. http://dx.doi.org/10.12681/bgsg.16323.
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Calcareous nannofossils are widely used for biostratigraphic correlations. Quantitative approaches enable better understanding of reliability of bioevents. In order to refine the late Miocene stratigraphy ofNW Crete, the deposits of Kalidonia basin along its type section are here investigated. It was possible to distinguish the Tortonian/Messinian boundary by NNlla & NNllb, CN9a & CN9b, MNNlla & MNNllb biozones. Reticulofenestra pseudoumbilicus PB (Paracme Beginning) and R. rotaria FO (First Occurrence) proved to act as additional significant biohorizons improving the stratigraphie evolution of the studied paleobasin and providing a tight biochronologic framework. The Kalidonia section fully covers an undisturbed marine depositional cycle from the upper Tortonian to upper Messinian, where a predominant deep water fades (DWF) is followed by transitional sediments (TF) and the sequence closes at the top by a reefal-bioclastic fades (RF) relative to the 'Calcare di Base ' in Italy indicating the 'Messinian Salinity Crisis Event.
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Sun, Wenqing, Long Xu, Suli Ma, Yihua Yan, Tie Liu, and Weiqiang Zhang. "A Dynamic Deep-learning Model for Generating a Magnetogram Sequence from an SDO/AIA EUV Image Sequence." Astrophysical Journal Supplement Series 262, no. 2 (September 27, 2022): 45. http://dx.doi.org/10.3847/1538-4365/ac85c0.
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Abstract The solar magnetic field dominates solar activities in the solar atmosphere, such as solar flares and coronal mass ejections (CMEs). The Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) has been in operation from 2010, providing a full-disk photospheric magnetogram. However, with a single view of observation, SDO/HMI cannot provide a global view of the Sun at the same time, so the farside of the Sun is blind to us. The Solar Terrestrial Relations Observatory (STEREO) provides two different views of the Sun with complementary viewing angles relative to SDO/HMI. However, it did not carry a magnetograph, but an extreme-ultraviolet (EUV) imager. Fortunately, deep learning has been proved to generate a solar farside magnetogram from STEREO farside EUV observation. Although a single generated magnetogram is morphologically very similar to ground truth, the sequence of the generated magnetogram has noticeable magnetic field fluctuation, which cannot be ignored when it is displayed as a time series, especially at an active region. This fluctuation is represented by sudden magnetic polarity reversal and drifting of magnetic field distribution. To mitigate this problem, a novel dynamic deep-learning model by integrating a convolutional gated recurrent units (convGRU) model into a pix2pix baseline is proposed in this paper. It can generate a sequence of a magnetogram with smooth transition among consecutive magnetograms by exploring spatio-temporal information of an input EUV image sequence. From both quantitative and qualitative comparisons, the proposed model can generate a magnetogram sequence more close to real observation.
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Al-Fares, Abdul Aziz, Mark Bouman, and Pete Jeans. "A New Look at the Middle to Lower Cretaceous Stratigraphy, Offshore Kuwait." GeoArabia 3, no. 4 (October 1, 1998): 543–60. http://dx.doi.org/10.2113/geoarabia0304543.
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ABSTRACT Offshore exploration in Kuwait commenced in 1961 with the award of a 5,600 square kilometre offshore concession to Shell. Some 6,300 kilometres of 3-fold analogue seismic were acquired in 1961, and 3 wells were drilled during 1962 and 1963. In the same period, Kuwait Oil Company (KOC) also drilled their first 3 offshore exploration wells. In 1981, KOC embarked upon a second offshore exploration campaign, acquiring some 6,000 kilometres of seismic data and, during 1983 and 1984, drilling two wells. None of these wells was a commercial discovery. Between 1995 and 1997, an integrated team of KOC and Shell explorers undertook a review of the hydrocarbon potential of Offshore Kuwait. In order to establish an integrated sequence-stratigraphical framework for the prospective Lower to Middle Cretaceous interval, a quantitative biostratigraphical study was made. Some 790 biostratigraphical analyses (10% core samples; 90% cuttings) from eleven wells were carried out: the nanno-fossil data was particularly important in providing accurate chronostratigraphical calibration, and this data has been used to constrain a “Time-Rock Synopsis”. KOC’s lithostratigraphical nomenclature proved to be basically sound and has been maintained as the basis for the present stratigraphical framework. However, the study revealed the existence of two substantial and hitherto unsuspected hiati: one between the Ratawi and Zubair formations of Early Valanginian to Mid-Hauterivian age; and the other, representing the whole of the Early Albian, within the Burgan Formation. This latter result, if it can be further substantiated by more exhaustive study in the onshore area, would neccessitate a re-definition of the Burgan Formation and the erection of a new formation to describe the clastic sequence of Late Aptian age which lies between the Early Albian hiatus and the top of the Shu’aiba Formation, and which has hitherto been included within the Lower Burgan Formation.
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Scott, R. W. "Are seismic/depositional sequences chronostratigraphic units?" Paleontological Society Special Publications 6 (1992): 264. http://dx.doi.org/10.1017/s2475262200008248.
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Sequence Stratigraphic Analysis is claimed to be a “new globally valid system of stratigraphy … a precise methodology to subdivide, correlate and map sedimentary rocks” (Vail et al., 1991, p. 622). Sequence stratigraphic units, such as depositional sequences, depositional systems tracts, and parasequences, are time-equivalent rocks of specific durations controlled by cyclical changes in sediment supply related to eustasy. These units are bounded by regionally extensive unconformities with erosion beneath and onlapping strata above, or by physical surfaces separating either different patterns of stratal geometry or shoaling-up facies units. According to this school, precise correlations are based upon inferred time relations within depositional models.Several key concepts of sequence stratigraphy have their origins in early geological studies. For many years geologists have separated time-equivalent strata by regional unconformities related to changes in climate or sea level, e.g., J. Woodward, 1695 and T. C. Chamberline, 1909. Stratal surfaces, such as bentonites and limestone markers, have been used in place of fossils for time correlations since the first wells were drilled. Stratigraphic models have strongly influenced how we correlate strata since the time of William Smith.Two developments are, indeed, new and have sparked the current resurgence in stratigraphic research. One is the seismic technology to test the physical continuity of strata on a regional scale (50-100 km), and to test the stratal geometry of genetically related depositional packages. The second is the chart of global coastal onlap events and eustasy (Haq et al., 1988).Some key research problems are: (1) how to identify unique, time-significant stratal surfaces; (2) how to test their physical continuity; (3) how to test the time relations within depositional models; and (4) how to identify the unique, time-significant global events recorded in the stratigraphic record. These stratigraphic concepts can be tested by graphic correlation, which is a powerful technique of high precision, quantitative stratigraphy. Its application in Cretaceous sections of the Gulf Coast and Oman, and in the Plio-Pliestocene of the Gulf Coast aids the distinction between synchronous surfaces and diachronous boundaries.
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Bianchi, Valeria, Troy Smith, and Joan Esterle. "Stratigraphic forward model of Springbok Sandstone sedimentation controlled by dynamic topography." APPEA Journal 56, no. 2 (2016): 600. http://dx.doi.org/10.1071/aj15106.
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After a long history of conventional gas exploration, the eastern Surat Basin in Queensland has developed as an active regional exploration target for coal seam gas, hosting large gas reserves. Interest in understanding basin fill mechanisms for petroliferous basins has grown in response to their economic significance. The Surat Basin is characterised by sedimentary successions with geometric complexity due to difficulty in correlation of coal splitting, interburden facies, and overburden channel belts. The uncertainty increases away from well control, in particular towards the centre where the basin is sparsely drilled. The forward modelling in LECODE (landscape evolution climate ocean and dynamic earth) is an innovative geomorphic and stratigraphic forward modelling code capable of simulating surface evolution and clastic sedimentary processes in 3D through geological time. This numerical tool can be used to test geological scenarios and predict the associated grain size distribution and sediment dispersal as a high-resolution synthetic stratigraphic record. This work focuses on a stratigraphic forward model developed for the Springbok Formation (Late Jurassic) within the Surat Basin. The simulated stratigraphy matches with models proposed by companies, highlighting a depocenter trending northwest–southeast. The formation is divided in two units: lower Springbok, defined by a fining-upward sequence and characterised by high-accommodation space and overfilling processes; and upper Springbok, described as an overall fining-upward sequence, with locally coarsening-upward wedge (conformable with the Weald Sandstone). The 3D basin simulation forecasts high heterogeneity of depositional geometries and stratal termination in depocentral and marginal areas.
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Fuxreiter, Monika. "Towards a Stochastic Paradigm: From Fuzzy Ensembles to Cellular Functions." Molecules 23, no. 11 (November 17, 2018): 3008. http://dx.doi.org/10.3390/molecules23113008.
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The deterministic sequence → structure → function relationship is not applicable to describe how proteins dynamically adapt to different cellular conditions. A stochastic model is required to capture functional promiscuity, redundant sequence motifs, dynamic interactions, or conformational heterogeneity, which facilitate the decision-making in regulatory processes, ranging from enzymes to membraneless cellular compartments. The fuzzy set theory offers a quantitative framework to address these problems. The fuzzy formalism allows the simultaneous involvement of proteins in multiple activities, the degree of which is given by the corresponding memberships. Adaptation is described via a fuzzy inference system, which relates heterogeneous conformational ensembles to different biological activities. Sequence redundancies (e.g., tandem motifs) can also be treated by fuzzy sets to characterize structural transitions affecting the heterogeneous interaction patterns (e.g., pathological fibrillization of stress granules). The proposed framework can provide quantitative protein models, under stochastic cellular conditions.
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Xie, Luke, Anita T. Layton, Nian Wang, Peder E. Z. Larson, Jeff L. Zhang, Vivian S. Lee, Chunlei Liu, and G. Allan Johnson. "Dynamic contrast-enhanced quantitative susceptibility mapping with ultrashort echo time MRI for evaluating renal function." American Journal of Physiology-Renal Physiology 310, no. 2 (January 15, 2016): F174—F182. http://dx.doi.org/10.1152/ajprenal.00351.2015.
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Dynamic contrast-enhanced (DCE) MRI can provide key insight into renal function. DCE MRI is typically achieved through an injection of a gadolinium (Gd)-based contrast agent, which has desirable T1 quenching and tracer kinetics. However, significant T2* blooming effects and signal voids can arise when Gd becomes very concentrated, especially in the renal medulla and pelvis. One MRI sequence designed to alleviate T2* effects is the ultrashort echo time (UTE) sequence. In the present study, we observed T2* blooming in the inner medulla of the mouse kidney, despite using UTE at an echo time of 20 microseconds and a low dose of 0.03 mmol/kg Gd. We applied quantitative susceptibility mapping (QSM) and resolved the signal void into a positive susceptibility signal. The susceptibility values [in parts per million (ppm)] were converted into molar concentrations of Gd using a calibration curve. We determined the concentrating mechanism (referred to as the concentrating index) as a ratio of maximum Gd concentration in the inner medulla to the renal artery. The concentrating index was assessed longitudinally over a 17-wk course (3, 5, 7, 9, 13, 17 wk of age). We conclude that the UTE-based DCE method is limited in resolving extreme T2* content caused by the kidney's strong concentrating mechanism. QSM was able to resolve and confirm the source of the blooming effect to be the large positive susceptibility of concentrated Gd. UTE with QSM can complement traditional magnitude UTE and offer a powerful tool to study renal pathophysiology.