Dissertations / Theses on the topic 'Stratigraphic Miocene'
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1
Chan, On-kee Angel. "Miocene collision related conglomerates, south Tibet." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B30736870.
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Lien, Bon-Hsiang. "Pressuremeter testing in miocene stiff clays." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/39730.
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In geotechnical engineering, it has proven difficult to obtain reliable soil parameters for stiff clays. Laboratory testing results are often scattering due to the fissures and slickensides in these soils. Alternatively, in situ techniques offer a means to test the soils in place. This study focuses on in situ testing in Miocene stiff clays using an advanced nine strain arm self-boring pressuremeter (SBPM). This device was used to test the soils in both a self-boring and a simpler, non-boring mode (pre-bored or PBPM tests). The Miocene stiff clay was unique in that was sensitive and lacked of fissures and slickensides. The pressuremeter results could be compared to a range of other tests previously performed at the site.
It is concluded that the SBPM provides accurate values of modulus and strength. Minor soil disturbance was found to have little effect when it could be anticipated. The simpler PBPM tests were not successful because of disturbance caused by borehole preparation.Ph. D.
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Hall, Donald L. "Origin of dolomite in the Miocene Hawthorn Group, northeastern Florida." [Tampa, Fla.], 1993. http://purl.fcla.edu/fcla/tc/fhp/SF00000317.pdf.
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Hayes, Frederick Glynn. "Paleomagnetics and biostratigraphy of the Pine Ridge Arikaree Group (late Oligocene-early Miocene), Nebraska." [Lincoln, Neb. : University of Nebraska-Lincoln], 2004. http://www.unl.edu/libr/Dissertations/2004/HayesDis.pdf.
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Smith, Alexander Ryan. "Sedimentology and Stratigraphy of Miocene-Age Glacial Deposits, Friis Hills, Antarctica." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29316.
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The Friis Hills is an isolated plateau standing as much as 600 m above surrounding topography in the McMurdo Dry Valleys region or Antarctica.Preserved on the plateau surface is a sequence of early to middle Miocene-aged dritis. At the eastern edge of the plateau, these drifts fill a shallow paleovalley to a depth of at least 35 m. The drills are exposed in a natural cross-section where modern topography crosscuts the paleovalley. Establishing an age and an environmental interpretation for these deposits is important because Antarctic paleoclimate records are lacking from the Mid-Miocene Climate Optimum. Two drifts fill the ancient paleovalley in the eastern Friis Hills. The upper drift is here named Cavendish drift: the lower is here named Friis drift. Cavendish can be subdivided into three units, whereas Friis drift can be subdivided into two units. Each of these units is a horizontal bed that laps on paleovalley sidewalls. The lowest, Friis II, is a compact diamicton that is overlain by a nearly in-situ bedded volvanic ash. Based on [20]Ar/[39]Ar dating, the ash is 19.76 [plus/minus] 0.07 Ma old. A second diamicton, Friis I, conformably blankets Friis II and was discovered to hold fossileferous interbeds. Both Friis I and II contain erratic clasts and both are lodgemont tills deposited from small, locally derived, alpine glaciers. Bedrock striations show ice flow to the northeast at azimuths between 025? to 032?, parallel to the trend of the paleovalley axis. Above these, Cavendish I. II. and III were deposited when thick ice covered the Friis Hills. Where the Cavendish drift laps onto paleovalley sidewalls, bedrock striations show ice flow from 077? to 150?. Cavendish drift was deposited sometime alter 19.8 Ma but before 14 Ma. when the Dry Valleys glacial records show that regional glaciers became cold-based. Downcutting eventually isolated the Friis Hills plateau, resulting in the preservation of the drift sequence. This event was most likely associated with growth or the East Antarctic Ice Sheet 14 Ma ago. This age constraint means that the tills preserved in the Friis Hills date from a time just before the East Antarctic Ice Sheet expanded and became a permanent feature. Based on the age-dated stratigraphy presented in this thesis, future work focusing on fossiliferious interbeds could provide unique and important constraints on Miocene climate change.North Dakota State University. Department of Geosciences
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Burton, Renee. "Miocene to Recent stratigraphy, structural architecture and tectonic evolution of the Adana Basin, Southern Turkey /." Internet access available to MUN users only, 2002. http://collections.mun.ca/u?/theses,28504.
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Hess, Emily Nancy. "Strontium, Lead, and Oxygen Isotopic Signatures of Mid-Miocene Silicic Volcanism in Eastern Oregon." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2079.
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Widespread, mid-Miocene rhyolite volcanism of eastern Oregon that are coeval or slightly postdate flood basalts of the Columbia River Basalt Province allows for mapping crustal domains using radiogenic and stable isotopes. Rhyolites are thought to be derived in large part by partial melting of the crust and thus yield direct information on the composition of the crust. Silicic volcanism is expressed in the form of numerous domes and tuffs exposed over a wide area (~300 km in N-S dimension and ~200 km in E-W dimension) west of the presumed craton boundary, which runs parallel but mostly east of the Oregon-Idaho state border as delineated by geophysical characteristics and isotopic transitions, including the 87Sr/86Sri = 0.7060 line (MSL) and 87Sr/86Sri = 0.7040 (CSL).
87Sr/86Sri of twenty-seven silicic units are variable and some are high. Sr isotopic ratios are inconsistent with the location of the traditional MSL and CSL boundaries. A primary control on the 87Sr/86Sri isotope variations may reflect changes in the crustal make-up of Paleozoic accreted terranes of a particular area rather than arising from a westward-dipping decollement that moved cratonic lithosphere below accreted terranes in eastern Oregon. A secondary control on observed isotopic ratios may be related to the amount and composition of basalt involved in the generation of rhyolites. This could lead to higher or lower 87Sr/86Sri relative to the surrounding crust because de facto coeval mafic magmas of the Columbia River Basalt Group have a wide range of Sr isotopic signatures.
While Pb isotope data is incomplete for all samples of this study, the available data indicate a significant range in Pb isotopes. Yet, data of individual regions tend to plot close to one another relative to the entire data distribution. Comparison of samples from this study in a more regional view indicates the samples generally fall within the previously defined lead isotope boundaries of the main-phase Columbia River Basalt Group lavas.
[lowercase delta]¹⁸O values range from below 2 parts per thousand to above 9 parts per thousand. In addition, there is a crude trend of rhyolites having lower [lowercase delta]¹⁸O and more radiogenic ⁸⁷Sr/⁸⁶Sr[subscript i] ratios. The lowest oxygen ratios (< 2 parts per thousand) are found in rhyolites ~80 km west of the cratonic margin, potentially reflecting remelting or assimilation of hydrothermally altered crust. Low [lowercase delta]¹⁸O of selected rhyolite flows cannot be explained by remelting of Cretaceous plutons of the Idaho Batholith and appear irreconcilable with remelting of altered silicic rocks at centers of multiple, confocal caldera cycles- both processes that have been proposed to explain low [lowercase delta]¹⁸O of rhyolites of the Snake River Plain-Yellowstone area.
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Chan, On-kee Angel, and 陳安琪. "Miocene collision related conglomerates, south Tibet." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30736870.
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Zalinge, Marit Elise van. "Stratigraphic, tectonic and magmatic evolution of the early miocene oxaya formation ignimbrites, Central Andes." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.702270.
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Between 22.7 Ma and 19.7 Ma a series of large volume ignimbrites, collectively known as the Oxaya Formation, covered large parts of the Western Andean Slope, in northernmost Chile, representing the onset of large volume ignimbrite volcanism in the Central Andes. Despite significant Miocene uplift and deformation, the Oxaya Formation is exceptionally well preserved, due to the dry climate of the Atacama Desert. Thorough examination of intact cores recovered from nine drill holes that penetrated the up to 1000 m thick Oxaya Formation enabled detailed reconstruction of the stratigraphic and magmatic evolution of the ignimbrites, as well as the tectonic evolution of the Western Andean Slope in this area. The Oxaya Formation consists of five members: the Poconchile ignimbrite; the volcaniclastic member; the Cardones ignimbrite; the Molinos ignimbrite; and the Oxaya ignimbrite. Medial and distal deposits of the 21.9 Ma Cardones ignimbrite are between 300 and 1000 m thick, . representing one of the thickest outflow sheets on Earth. A line-balanced reconstruction with the uneroded, but deformed, surface of this ignimbrite restores the covered pre-eruptive palaeotopography and constrains post-eruptive deformation. The extreme, but variable thickness of the Cardones ignimbrite results from a highly irregular pre-21.9 Ma palaeo-topography that was characterized by an up to 1700 m high proto-slope that was incised by rivers. After this palaeoslope was inundated by the Cardones ignimbrite, the area experienced up to 2000 m of structural relief of which ca. 80% can be attributed to fault-related folding into the ",40 km wide Huaylillas Anticline and ca. 20% to regional fore-arc tilting. The main folding likely occurred during the mid-and late Miocene and ceased by ca. 6 Ma.
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Rodriguez, Luis Oswaldo. "Tectonic analysis, stratigraphy and depositional history of the Miocene sedimentary section, Central Eastern Venezuela basin /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Tsoukalas, Nikolaos. "Stratigraphy of the Upper Miocene volcanic rocks of the Island of Kos, Greece : geodynamic implications /." Halifax, N.S. : Saint Mary's University, 2008.
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Durogbitan, Abimbola Adewolfe. "Seismic, sequence stratigraphic and structural analysis of ewan and oloye fields (middle Miocene), Northwestern Niger Delta." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.706483.
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Shaw, Neil B. "Biostratigraphy of the Cowlitz Formation in the upper Nehalem River Basin, northwest Oregon." PDXScholar, 1986. https://pdxscholar.library.pdx.edu/open_access_etds/3654.
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Examination of stream and roadcut exposures of the Cowlitz Formation allows the selection of measured representative sections, and collection of fossils, from an area roughly defined by the intersection of the boundaries of Clatsop, Columbia, Tillamook and Washington counties in Oregon. The study defines the features of the local environment of deposition, correlates sections to derive a composite columnar section, and develops a checklist of species for both microfossils and megafossils of the Cowlitz Formation.
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Guzmán, Espinal José Ignacio. "Miocene stratigraphy and depositional framework of northeastern Maracaibo Basin, Venezuela : implications for reservoir heterogeneity prediction in tectonically-active settings /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Diyarbakirli, Ali Can. "Stratigraphic Analysis and Reservoir Characterization of the Late Oligocene-Early Miocene, Upper Yenimuhacir Group, Thrace Basin, Turkey." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73651.
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The Thrace Basin, NW Turkey, is one of the most important basins in Turkey in terms of hydrocarbon potential. Previous studies, starting in the 1930s, focused on tectonics, basin evolution, sedimentation and stratigraphy, depositional systems, and hydrocarbon potential. Eocene turbiditic sandstones and reefal limestones, and Oligocene deltaic sandstones are the major reservoir targets in the basin today. The focus of this research is the Upper Oligocene deltaic sandstones, namely the Danismen and Osmancik formations, which contain potential hydrocarbon reservoirs. The aims of research were to develop a better understanding of the geometric configuration of the Oligocene strata and to identify potential reservoirs within the study area. Accordingly, the geometric configurations of the strata were delineated using 3D seismic reflection data whereas petro-physical properties of the target formations were determined using wireline logs from three wells. A right-lateral strike slip or reverse fault system and associated NW-SE trending asymmetric fold extend across the study area. Both the fault system and the fold are truncated beneath the Miocene unconformity and are thus dated as late Oligocene to early Miocene in age. The Miocene unconformity forms a stratigraphic trap whereas the fault system and associated fold construct a NW-SE trending structural trap. Hydrocarbon-bearing, five main clean sandstone (shale volume less than %10) intervals were identified using wireline logs and evaluated as potential targets. Hydrocarbon concentrations increase through the fold structure. Thus, the fault system and the associated asymmetric fold were the main factors that affected the zonal distribution of hydrocarbons in the study area.Master of Science
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Canalda, Sabrina Michelle. "Magnitude of right-lateral offset on the southern Death Valley fault zone from miocene volcanic assemblages." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Wilson, Doyle Coley. "Post-middle Miocene Geologic History of the Tualatin Basin, Oregon with Hydrogeologic Implications." PDXScholar, 1997. https://pdxscholar.library.pdx.edu/open_access_etds/4711.
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The geologic history and sedimentary till of the Tualatin Basin after Columbia River Basalt Group (CRBG) emplacement is assessed and related to groundwater characteristics. The 334 m deep HBD-1 core from the Hillsboro Airport, provides the primary information for sediment characterization and is supported by over 2400 well logs and cores, and four seismic lines. The sedimentary section above the 26 m thick paleosol on the CRBG in HBD-I is divided into two main groups: a 25 m thick section of Missoula flood sediments called the Willamette Silt overlies a 263 m thick finegrained sequence of fluvial Neogene sediments.
Pollen, diatom and paleomagnetic data support dividing the Neogene sediments into a 230 m thick Pleistocene package and an underlying, 75 m thick Pliocene to upper Miocene unit. Heavy mineral and INAA chemical analyses indicate that the Neogene sediments were primarily derived from local highlands surrounding the Tualatin Valley.
The structure of the top CRBG in the Tualatin Basin exhibits two provinces, a larger northern subbasin with few faults cutting the Neogene sediments above the CRBG and a smaller, more complexly faulted, subbasin south and east of the Beaverton Fault. Neogene sedimentation rates increased ten fold from the late Miocene-Pliocene to the Pleistocene, concomitant with increased basin subsidence. Comparison of Neogene basin evolution among Willamette Valley depositional centers reveals similarities among gravity and seismic reflection characters and subsidence timing between the Tualatin Basin and the northern Willamette Basin and out of phase with the Portland Basin.
The Tualatin River CRBG nickpoint near the river's mouth has remained essentially unchanged since the Missoula floods filled the basin 12,700 years ago. This has kept the river from cutting back into the valley resulting in the low gradient evident today.
Elevated orthophosphate levels in the upper 140 m of the Neogene sediment section indicate that the sediments are a natural source of phosphorus supplied to groundwater. Groundwater conditions in the lower Neogene sediments promote stabilization of phosphorus as vivianite. The unconfined Willamette Silt aquifer and the underlying confined Neogene aquifers are distinct, separate hydrogeologic units and usually yield less than 40 1pm.
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Derman, Hasan Armasan. "Sequence Stratigraphic Architecture Of Mut Basin Along Ramp To Reefal Margin Transition And Its Diagenetic Imprint." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/1259480/index.pdf.
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The whole Mediterranean was a site of carbonate deposition during Miocene. Unlike other Miocene basins in the Mediteranean, the importance of Mut Basin lies in its tectonically undisturbed nature that provides excellent
exposures to study sequence stratigraphic architecture and carbonate sedimentology. Opening of Mut Basin began during Oligocenecarbonate deposition started during Early Miocene. The pre-Miocene rocks are characterized by (from bottom to top), 1. ophiolites and Mesozoic limestones, 2. Eocene lacustrine limestones, 3. Burdigalian fluvial sandstones and conglomerates. The carbonate deposition began in Miocene, settling on the preexisting topography. Carbonates have been deposited in a ramp setting, where several sequences formed. The ramp was partly subaerially exposed during Early Miocene due to relative sea level fall
however, no significant lowstand deposits were developed. The subsequent sea level rise caused transgressive deposits to overlie this ramp sequence. The patch reefs on this ramp exhibit a keep-up type depositional setting. As the transgression continued, the basin topography controlled the type of depositional setting. Hence, a transition from ramp to reefal margin type setting occurred. In landward direction the topographically low areas became back reef lagoonal part of this reefal margin. A mature reefal environment formed during highstand times, which is characterized by a rich coral fauna / algal flora in the basinward side. Some of the patch reefs of the ramp transformed into pinnacle reefs. Diagenetic alterations are mostly related to duration and degree of sea level fall, and therefore related to sequence boundaries. The Miocene carbonates in the study area consist of six sequences which may be used for correlation with other Miocene carbonates of the Mediterranean region.
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Gallardo, Garcia Alejandro. "Middle Eocene-Early Miocene larger foraminifera from Dhofar (Oman) and Socotra Island (Yemen)." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/336096.
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Here, the larger foraminifera found in Middle Eocene-Early Miocene rocks from Dhofar (Oman) and Socotra Island (Yemen) are studied in detail. The architectural analysis leads to the description of four new genera and nine new species: five agglutinated foraminifera, Pseudolituonella roberti n. sp., Socotraella ashawqi n. gen. n. sp., Pseudochrysalidina ayaki n. sp., Barattolites andhuri n. sp. and Dhofarella aydimi n. gen. n. sp.; and four porcellaneous foraminifera, Idalina grelaudae n. sp., Idalina pignattii n. sp., Macetadiscus incolumnatus n. gen. n. sp. and Omanodiscus tenuissimus n. gen. n. sp.
The larger foraminifera identified in a Composite section located in Western Dhofar, in the Shuwaymiyah section located in Eastern Dhofar and in the Wadi Ayak section located on Socotra Island, has facilitated the identification of the following larger foraminifera zones: SBZ 14-SBZ 15 (Middle Lutetian), SBZ 16 (Late Lutetian), SBZ 17 (Bartonian), SBZ 18 (latest Bartonian-earliest Priabonian), SBZ 19-SBZ 20 (Priabonian), SB 21-SB 22A (Rupelian), SB 22B-SB 23 (Chattian) and SB 24 (Aquitanian).
All these data permit stablished the age of the following lithostratigraphic units: Dammam Fm. Andhur Mb Early Lutetian?-Middle Lutetian age (SBZ 13?-SBZ 14 partim), Qara Mb Middle Lutetian (SBZ 14-SBZ 15), Uyun Mb Late Lutetian (SBZ 16). Aydim Fm. Heiron Mb Bartonian (SBZ 17), Moosak Mb upper Bartonian-Priabonian (SBZ 18-SBZ 20), Tagut Mb Priabonian (SBZ 19-SBZ 20), Haluf Mb Priabonian (SBZ 19-SBZ 20) till SBZ 21 on Socotra Island. Ashawq Fm Rupelian (SB 21-SB 22A). Mughsayl Fm Chattian-Aquitanian (SB 23-SB 24).En esta tesis se han estudiado en profundidad los macroforaminíferos encontrados en rocas del Eoceno Medio al Mioceno Inferior de la región del Dhofar (Sultanato de Omán) y de la isla de Socotra (Yemen). Su análisis arquitectural permite la descripción de cuatro géneros nuevos así como de nueve nuevas especies; cinco de macroforaminíferos aglutinados, Pseudolituonella roberti n. sp., Socotraella ashawqi n. gen. n. sp., Pseudochrysalidina ayaki n. sp., Barattolites andhuri n. sp. y Dhofarella aydimi n. gen. n. sp.; y cuatro de macroforaminíferos aporcelanados, Idalina grelaudae n. sp., Idalina pignattii n. sp., Macetadiscus incolumnatus n. gen. n. sp. y Omanodiscus tenuissimus n. gen. n. sp. Los macroforaminíferos identificados en la sección Compuesta, situada en el Dhofar Occidental; en la sección de Shuwaymiyah, situada en el Dhofar Oriental y en la sección de Wadi Ayak, localizada en la isla de Socotra, han facilitado la identificación de las siguientes biozonas de macroforaminíferos: SBZ 14-SBZ 15 (Luteciense Medio), SBZ 16 (Luteciense Superior), SBZ 17 (Bartoniense), SBZ 18 (Bartoniense Superior-Priaboniense Inferior), SBZ 19-SBZ 20 (Priaboniense), SB 21-SB 22A (Rupeliense), SB 22B-SB 23 (Catiense) and SB 24 (Aquitaniense). Todos estos datos permiten establecer la edad de las siguientes unidades litoestratigráficas; Formación Dammam: Miembro Andhur Mb Luteciense Inferior?-Luteciense Medio (SBZ 13? -SBZ 14 partim), Miembro Qara Luteciense Medio (SBZ 14-SBZ 15), Miembro Uyun Luteciense Superior (SBZ 16). Formación Aydim: Miembro Heiron Bartoniense (SBZ 17), Miembro Moosak Bartoniense Superior -Priaboniense (SBZ 18-SBZ 20), Miembro Tagut Priaboniense (SBZ 19-SBZ 20), Miembro Haluf Priaboniense (SBZ 19-SBZ 20) hasta SBZ 21 en la isla de Socotra. Formación Ashawq Rupeliense (SB 21 SB-22A). Formación Mughsayl Catiense-Aquitaniense (SB 23 SB-24).
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Calderone, Gary Jude. "Paleomagnetism of Miocene volcanic rocks in the Mojave-Sonora desert region, Arizona and California." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184554.
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Paleomagnetic directions have been obtained from 190 Middle Miocene (12-20 Ma) mafic volcanic flows in 16 mountain ranges in the Mojave-Sonora desert region of western Arizona and southeastern California. These flows generally postdate Early Miocene tectonic deformation accommodated by low-angle normal faults but predate high-angle normal faulting in the region. After detailed magnetic cleaning experiments, 179 flows yielded characteristic thermal remanent magnetism (TRM) directions. Because of the episodic nature of basaltic volcanism in this region, the 179 flows yield only 65 time-distinct virtual geomagnetic poles (VGPs). The angular dispersion of the VGPs is consistent with the angular dispersion expected for a data set that has adequately averaged geomagnetic secular variation. The paleomagnetic pole calculated from the 65 cooling unit VGPs is located at 85.5°N, 108.9°E within a 4.4° circle of 95% confidence. This pole is statistically indistinguishable (at 95% confidence) from reference poles calculated from similar-age rocks in stable North America and from a paleomagnetic pole calculated from similar-age rocks in Baja and southern California. From the coincidence of paleomagnetic poles from the Mojave-Sonora and adjacent areas, we can conclude that: (1) vertical-axis tectonic rotations have not accompanied high-angle normal faulting in this region; (2) there has been no latitudinal transport of the region since 12-20 Ma; and (3) long-term nondipole components of the Miocene geomagnetic field probably were no larger than those of the recent (0-5 Ma) geomagnetic field. In contrast, paleomagnetic data of other workers indicate vertical-axis rotations of similar-age rocks in the Transverse Ranges, the Eastern Transverse Ranges, and the Mojave Block. We speculate that a major discontinuity in the vicinity of the southeastward projection of the Death Valley Fault Zone separates western areas affected by vertical-axis rotations from eastern areas that have not experienced such rotations.
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Downing, Kevin Francis. "Biostratigraphy, taphonomy, and paleoecology of vertebrates from the Sucker Creek Formation (Miocene) of southeastern Oregon." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185976.
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The Sucker Creek Formation exposures at Devils Gate in southeastern Oregon have yielded a significant small mammal fauna of at least thirty small mammal taxa from five stratigraphic horizons. The mammal-bearing portion of the Devils Gate section is more than 200 m thick. Fossil mammals occur in lacustrine and marginal lacustrine deposits lower in the section and occur in overbank and paleosol deposits higher in the section. ⁴⁰Ar/³⁹Ar single-crystal laser-fusion dates on three Devils Gate ashes shows that the age of the mammal-bearing sequence at Devils Gate spans the late early Barstovian land-mammal age with possible overlap into the late Barstovian, as currently defined. Duration of the entire mammal-bearing portion of the Devils Gate section was less than a million years. Both a new ash date from the type section and biostratigraphic correlations between Devils Gate and the type section support considerable temporal overlap between the two exposures. The Devils Gate Local Fauna includes several new taxa: a phyllostomatid bat; two "flying squirrels", Petauristodon sp. A and Petauristodon sp. B; and an eomyid rodent, Leptodontomys sp. A. Several fossil occurrences represent the first record of a taxon in the northern Great Basin and/or in the Barstovian land-mammal age, including: Blackia sp., Schaubeaumys grangeri, Protospermophilus quatalensis, and Pseudadjidaumo stirtoni. The Stagestop locality produced two new taxa, Copemys sp. aff C. esmeraldensis and Mystipterus sp. The Stagestop local fauna is Clarendonian in age. Concretions are an important source of fossil mammals in exposures of the Sucker Creek Formation. Geochemical analyses show that concretions formed through a complex interaction between bone and surrounding volcaniclastic material. Although some superficial bone was consumed during concretion diagenesis, concretion development reduced the chance of prolonged chemical and physical destruction of bone during later soil development. The broad ecological diversity of small mammals recovered from Devils Gate supports an interpretation of the local paleoecology as a mosaic of grassland, forest, and pond/lake-bank environments. Sequential small mammal faunas across a prominent ash event show a generally stable composition with no pronounced ecomorphic differences in pre- and post-volcanic disturbance intervals. Therefore, small mammals do not show analogous ecological patterns to disturbance-driven plant successions in the Sucker Creek Formation. I infer that the local ecosystem recovered from volcanic blasts at a temporal scale below the resolution of time-averaged, post-disturbance paleosols.
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Sidi, Franciscus Hasan. "Sequence stratigraphy, depositional environments, and reservoir geology of the middle-Miocene fluvio-deltaic succession in Badak and Nilam Fields, Kutai Basin, East Kalimantan, Indonesia." Thesis, Queensland University of Technology, 1998.
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Wiweko, Agung. "Sedimentary facies and depositional geometry of distributary mouth bars in Tunu Field Miocene Kutei Basin and comparison with modern Mahakalm Delta." Thesis, Queensland University of Technology, 1998.
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Cepeda, Raquel. "Three-dimensional seismic stratigraphic interpretation of the upper miocene to lower pleistocene deep-water sediments of the Thunder Horse-Mensa area, southern Mississippi Canyon, northern deep Gulf of Mexico." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/cr/colorado/fullcit?p1427771.
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Belaústegui, Barahona Zain. "Estudio icnológico y tafonómico del Mioceno marino de la cuenca de El Camp de Tarragona (NE España) = Ichnologic and Taphonomic Study from the Middle Miocene of El Camp de Tarragona Basin (NE Spain)." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/129366.
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Esta tesis tiene por objetivo el estudio sobre los paleoambientes, y su evolución, del Mioceno marino de la cuenca de El Camp de Tarragona desde una perspectiva tafonómica e icnológica. En concreto, se han integrado los datos obtenidos a partir del análisis tafonómico de las acumulaciones esqueléticas, tanto de invertebrados como vertebrados, con la información proporcionada por el estudio de las icnoasociaciones e icnofábricas presentes a lo largo de las secciones estudiadas, para finalmente proponer un modelo que explique de la forma más completa posible la evolución sedimentaria y paleoambiental de dichas secciones.
Además de introducir el contexto geológico y geográfico de la cuenca de El Camp de Tarragona, se presenta por primera vez una estratigrafía y una cartografía geológica de detalle de la mayor parte de los depósitos marinos miocenos situados a lo largo de la actual franja costera de la Cuenca de El Camp de Tarragona. En concreto de las secciones de El Miracle, Fortí de la Reina, L’Arrabassada, Sanatori, La Savinosa, Cala Romana, Waikiki, Punta de la Móra, Tamarit, Altafulla y Torredembarra.
Para englobar los diferentes materiales diferenciados en esas secciones, se proponen cuatro asociaciones de facies principales:
A) Facies relacionadas a paleoacantilados, consistentes en conglomerados heterométricos en los que cabe destacar la abundante bioerosión tanto en los litoclastos como en los fósiles. Apareciendo siempre depositadas sobre un sustrato pre-Mioceno, intensamente perforado a techo.
B) Facies de plataforma interna, incluyen una gran variedad de facies carbonáticas. Principalmente, o niveles biocalcareníticos con mayor o menor contenido en macrofósiles, o facies con predominancia de trazas fósiles y estratificación cruzada de gran escala.
C) Facies de plataforma externa, constituidas por niveles calcisiltíticos intensamente bioturbados.
D) Facies siliciclásticas, consistentes en areniscas bioturbadas con estratificación cruzada asociadas a depósitos marinos someros (probablemente asociados a un ambiente estuarino), o niveles de margas relacionados a ambientes de plataforma media o mar abierto.
En la cuenca de El Camp de Tarragona, el análisis tafonómico (centrado principlamente en los procesos bioestratinómicos) de los fósiles de vertebrados y sobretodo de invertebrados se ha mostrado como una herramienta muy útil a la hora de interpretar el ambiente deposicional de esos fósiles, complementando la información inferida a través de la litología, sedimentología y taxonomía.
En cuanto al estudio icnológico, entre estructuras de bioturbación y bioerosión, se han reconocido 15 icnogéneros, de los cuales 10 han sido clasificados a nivel icnoespecífico. Todas estas trazas fósiles han sido atribuidas a la actividad de invertebrados marinos, principalmente crustáceos y anélidos en el caso de las estructuras de bioturbación, y de bivalvos, anélidos y esponjas en el caso de la bioerosión. Describiendo a partir de los diferentes afloramientos, 5 icnoasociaciones principales: A) Icnoasociación de Cylindrichnus, ligada a ambientes de plataforma externa con baja energía y baja sedimentación (probablemente los más distales en la cuenca de El Camp); B) Icnoasociación de Haentzschelinia/Ophiomorpha, ligada a facies terrígenas posiblemente depositadas en ambientes estuarinos; C) Icnoasociación de Ophiomorpha, ligadas a ambientes de plataforma interna sometidos a condiciones energéticas variables, y a mayor o menor tasa de sedimentación; D) Icnoasociación de Thalassinoides, presentes en ambientes de plataforma interna y externa; y E) Icnoasociación de Gastrochaenolites/Entobia, principalmente asociada a facies de paleoacantilado, aunque también es común en sustratos minerales biogénicos.
Finalmente en función de las facies que presentan y de su localización geológica/geográfica, se propone agrupar las secciones estudiadas en dos dominios principales:
A) Dominio periumbral, influenciado por el paleorelieve y el alto estructural existente (unidad Salou-Tarragona), y constituido por facies de paleoacantilado, de plataforma interna y siliciclásticas (secciones de El Miracle, Fortí de la Reina, L’Arrabassada, Sanatori, La Savinosa y Cala Romana).
B) Dominio distal, dominado por una sedimentación carbonática en ambientes de plataforma interna a externa, y sin influencia de altos estructurales cercanos (secciones de Waikiki, Punta de la Móra, Tamarit, Altafulla y Torredembarra).The aim of the present research was the study of the paleoenvironments recorded in the marine Miocene sediments from El Camp de Tarragona Basin, through the taphonomic and ichnological perspectives. In particular, it is intended to integrate the data obtained from the taphonomic analysis of the skeletal accumulations, both from invertebrates as vertebrates, with the information provided by the study of the ichnoassemblages and the ichnofabrics identified along the studied sections, in order to propose a general model to interpret the sedimentary and paleoenvironmental evolution of these sections. In addition to a general overview of the geology of El Camp de Tarragona Basin, detailed geological cartography and stratigraphy of the coastal outcrops of this basin are presented for the first time. In particular, in those sections named as El Miracle, Fortí de la Reina, L’Arrabassada, Sanatori, La Savinosa, Cala Romana, Waikiki, Punta de la Móra, Tamarit, Altafulla and Torredembarra. To include the various materials differentiated in these studied sections, four main facies associations are proposed: a) Facies related to paleocliffs consisting of heterometric conglomerates and complete oysters. Bioerosion is abundant both in lithoclasts and fossils. These deposits usually lay upon the pre-Miocene substrate, which is also intensely bored. b) Inner-platform facies, which include a variety of carbonate deposits. Large-scale, cross-bedded biocalcarenites record the presence of subtidal dune fields, while rhodophyte carbonates, and bivalve and echinoid (clypeasteroid) coquines constitute factory facies in different settings. c) Outer-platform facies are constituted by intensely bioturbated calcisiltites, which are rich in glauconite in most distal settings. d) Siliciclastic facies, which crop out very locally and consist of well-sorted fine- to medium-grained, quartzitic sandstones with large-scale cross-bedding and common bioturbation structures indicative of shallow marine conditions, or marly units related with open marine conditions. Finally, according to the facies identified and their geological/geographical location, the studied sections are enclosed in two main domains: a) Perihorst domain, whose sedimentation is highly influenced by the presence of a Mesozoic high or horst, and constituted by paleocliff, inner-platform and siliciclastic facies. b) Distal domain, dominated by carbonate sedimentation related to inner- and outer-platform facies, and without influence of close structural highs.
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Large, Adam M. "Silicic Volcanism at the Northern and Western Extent of the Columbia River Basalt Rhyolite Flare-up: Rhyolites of Buchanan Volcanic Complex and Dooley Mountain Volcanic Complex, Oregon." PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3122.
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Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.
Previous work at the Buchanan rhyolite complex was limited to regional mapping (Piper et al., 1939; Greene et al., 1972) and brief mention of the possibility of multiple eruptive units (Walker, 1979). Observed stratigraphic relationships and geochemical analysis were used to identify eight distinct eruptive units and create a geologic map of their distribution. Slight differences in trace element enrichment are seen in mantle normalized values of Ba, Sr, P, Ti and Nd-Zr-Hf and are used to differentiate eruptive units. New geochemical analyses are used to correlate the overlying Buchanan ash-flow tuff (Brown and McLean, 1980) and two underlying mafic units to the Wildcat Creek ash-flow tuff (~15.9 Ma, Hooper et al., 2002) and flows of the Upper Steens Basalt (~16.57 Ma, Brueseke et al., 2007), respectively, bracketing the eruptive age of the Buchanan rhyolite complex to between ~16.5 and ~15.9 Ma (Brueseke et al., 2007; Hooper et al., 2002).
The Dooley Mountain rhyolite complex was thoroughly mapped by the U.S. Geological Survey (Evans, 1992) and geochemically differentiated in a previous Portland State University M.S. thesis (Whitson, 1988); however, discrepancies between published interpretations and field observations necessitated modern geochemical data and revisions to geologic interpretations. Field and laboratory studies indicate that the Dooley Mountain rhyolite complex consists of multiple eruptive units that were effusive domes and flows with associated explosive eruptions subordinate in volume. At least four geochemically distinct eruptive units are described with variations in Ba, Sr, Zr and Nb. Picture Gorge Basalt flows and Dinner Creek Tuff units found within the study area both overlay and underlie the Dooley Mountain rhyolite complex. These stratigraphic relationships are consistent with the one existing Ar-Ar age date 15.59±0.04 Ma (Hess, 2014) for the Dooley rhyolite complex, bracketing the eruptive period between ~16.0 and ~15.2 Ma (Streck et al., 2015; Barry et al., 2013).
The findings of this study indicate that the Buchanan rhyolite complex and the Dooley Mountain rhyolite complex are the westernmost and northernmost rhyolite complexes among the earliest (16-16.5 Ma) mid-Miocene rhyolites associated with initiation of Yellowstone hot spot related volcanism.
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NGATSE, LOUIS-RICHARD. "Les ostracodes du post-salifere congolais du cretace inferieur au miocene : systematique, stratigraphie, biogeographie." Paris 6, 1989. http://www.theses.fr/1989PA066714.
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Les ostracodes marins du bassin de pointe-noire (congo) ont ete etudies systematiquement pour montrer leur interet aussi bien stratigraphique, paleoecologique que biogeographique dans le cadre de la tectonique des plaques. 61 especes d'ostracodes ont ete decrites, dont 6 nouvelles. A l'aptien superieur-albien, le bassin du bas congo-gabon ainsi que celui de sergipe alagas (bresil) formaient un seul ensemble comme le montre la faune d'ostracodes. Des relations paleogeographiques avec la tethys sont mises en evidence des l'albien moyen, peut-etre meme a l'albien inferieur. Alors qu'elles n'apparaissent que plus tard (coniacien) avec l'afrique du sud
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Irvine, Janelle Rose Mae. "Sedimentology, stratigraphy and palaeogeography of Oligocene to Miocene rocks of North Canterbury-Marlborough." Thesis, University of Canterbury. Geological Sciences, 2012. http://hdl.handle.net/10092/6826.
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The Cenozoic was a time of climatic, tectonic and eustatic change in the Southern Hemisphere. Cooling at the pole, glaciation and substantial sea ice formation occurred as latitudinal temperature gradients increased and tectonics altered Southern Hemisphere circulation patterns. During this same time frame, the tectonic regime of the New Zealand continental block transitioned from a passive margin to an active plate boundary, resulting in the reversal of a long-standing transgression and an influx of terrigenous sediment to marine basins. In this transition, depositional basins in the South Island became more localized; however, the influence of oceanographic and tectonic drivers is poorly understood on a local scale. Here we apply sedimentological, biostratigraphic and geochemical analyses to revise understanding of the effects of the changing climatic regime and active tectonics on the development of Oligocene and Miocene rocks in the Northern Canterbury Basin.
The Late Oligocene to Middle Miocene sedimentary rocks of the northern Canterbury Basin record oceanographic and tectonic influences on basin formation, sediment supply and deposition. The Palaeocene to Late Eocene Amuri Formation in the basin are micrites and biogenic cherts recording deepwater, terrigenous-starved environments, and do not show any influence of active tectonics. The Early Oligocene development of ice on the Antarctic continent and the associated global sea level response is reflected in this basin as the Marshall Paraconformity, an eroded, glauconitized and phosphatised firm ground and hardground atop the Amuri. Sedimentation above this unconformity resumed in the Late Oligocene-Early Miocene with cleaner, deep-water, bathyal planktic foraminifera packstones and wackestones in eastern areas and Late Oligocene inner shelf volcaniclastic packstones in parts of the western basin. Post-unconformity sedimentation resumed earlier in western areas, as the currents responsible for scouring the sea floor moved progressively to the east. The development of tectonic uplift in terrestrial settings is first seen in the northwestern basin in Lower Miocene fine quartz-rich sandstones, and by the Middle Miocene, bathyal sandstones and quartz-rich wackestones appear in the basin, replacing earlier, more pure carbonates. The uplift caused shallowing to the west, in the form of shelf progradation due to sediment influx. This shallowing is not observed to the east; instead, the palaeoenvironments show a deepening as a result of sea level rise.
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Gardère, Philippe. "Les sables fauves : dynamique sédimentaire et évolution morphostructurale du bassin d'Aquitaine au Miocène moyen /." Toulouse : Laboratoire de dynamique des bassins sédimentaires, Université Paul Sabatier, 2002. http://catalogue.bnf.fr/ark:/12148/cb38956178q.
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Fang, Linhao. "Terrestrial carbon-isotope stratigraphy : an exploration of the method from Miocene and Jurassic examples." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:883ef59a-f3aa-44ac-b539-d0f81317296e.
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Terrestrial carbon-isotope stratigraphy has proven a promising tool for stratigraphic correlation between the different exchangeable carbon-isotope reservoirs, as well as a powerful approach to reconstructing the evolution of δ13C of atmospheric CO2, which is closely associated with the evolution of palaeoenvironment and palaeoclimate. However, the limited understanding of pitfalls in specific application potentially restricts the method’s utility for stratigraphic correlation and palaeoenvironmental reconstruction. This thesis takes advantage of three case studies at two vital geological intervals which are both characterized by the significant carbon-isotope perturbation in the exchangeable reservoirs, to explore the nature of terrestrial carbon-isotope stratigraphy. Two of the case studies focus on the late Early to Middle Miocene, the period of the so called Monterey Event that is marked by remarkable positive carbon-isotope excursions in benthic and pelagic marine carbonate records. There are few terrestrial carbon-isotope records for the Monterey Event. In the present study, shallow marine sediments were collected from boreholes in the New Jersey margin, USA (IODP, Expedition 313) and North Sea Basin, Denmark. Phytoclasts are concentrated from palynological residues as the basis for a terrestrial carbon-isotope stratigraphy from the two locations. The carbon-isotope curves obtained can be correlated in detail locally, and correlated crudely on a global scale. However, there are no definite positive carbon-isotope excursions observed in the terrestrial isotopic stratigraphic records through the biostratigraphically determined Langhian interval equivalent to the Monterey Event. The reasons for the absence of relatively positive carbon-isotope excursions in terrestrial carbon-isotope stratigraphy might be caused by the reworking deposits of woody phytoclasts from older strata or some other process related to reworking. Another case study centres on the Triassic-Jurassic boundary and Early Jurassic fluvial and lacustrine succession in the Kuqa section, Tarim Basin, NW China. Macrofossil wood samples were collected to generate the terrestrial carbon-isotope stratigraphy. On the basis of the biostratigraphy and potential Stage/Age (sub-) boundaries implied by biological overturns, the terrestrial carbon-isotope stratigraphy in the Kuqa section can be well correlated with both terrestrial and marine carbon-isotope stratigraphic records from UK through the Early Jurassic. For the Triassic-Jurassic boundary, more precise correlation was made globally and an exact the position of Triassic-Jurassic boundary is proposed in the Kuqa section. In light of the biostratigraphy and the carbon-isotope stratigraphy obtained in the present study, an updated age assignment of the lithostratigraphic units is proposed to Age/Stage level in the Early Jurassic across the Northern Tarim Basin. The carbon-isotope stratigraphy thus significantly improves the terrestrial stratigraphic resolution. Terrestrial carbon-isotope stratigraphy is a powerful tool for global stratigraphic correlation and unifies stratigraphic correlation over marine and non-marine strata in cases when potential biasing factors are excluded.
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Beard, Linda Sue. "Precambrian Geology of the Cottonwood Cliffs Area, Mohave County, Arizona." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/244095.
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A belt of Early Proterozoic rocks crops out in the Cottonwood Cliffs area, northwest Arizona. The belt contains an eastern and a western assemblage separated by the Slate Mountain fault. The western assemblage consists of mafic to felsic metavolcanic rocks, metapelites, and metaconglomerates. The eastern assemblage consists of phyllites, felsic to intermediate metavolcanic rocks, metagraywackes, and metagabbro bodies. The belt is bounded to the east by foliated granodiorite. The Valentine granite intruded the belt on the west and north. Steeply-plunging lineations and fold axes, and northeast-trending vertical foliation dominate the structural fabric. The regional elongation direction is near-vertical, as indicated by mineral and pebble lineations, and is parallel to fold axes. Although only one deformational event is evident, the intensity of that event may have obliterated evidence of any earlier deformation. Tertiary basalts and the Peach Springs Tuff locally overly the metamorphic rocks. Cenozoic normal faults in the area are mostly of minor displacement.
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Hassan, Meor Hakif Amir. "Sedimentary facies and sequences stratigraphy : Miocene coastal and coastal plain depostional systems, balingian province, sarawak." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529350.
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Levesh, Jarrett Leigh. "Middle Miocene to Holocene History of the Delacroix Island Fault System." ScholarWorks@UNO, 2019. https://scholarworks.uno.edu/td/2623.
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An in-depth field study of the Delacroix Island producing field illustrates the evolution of the east-trending Delacroix Island Fault during the last 13 My. Well log correlations and 3-D seismic interpretation of 22 subsurface bio-stratigraphic horizons across the fault reveal variable stratigraphic thicknesses and displacement. Wells, with well log curve data as shallow as 31 m (100 ft) below the surface, were used to calculate interval thicknesses, expansion indices, sediment accumulation rates, burial history and magnitudes of displacement. Through these analyses, a correlation was found between the positioning of ancient Miocene depocenters over Delacroix Island and a period of increased fault activity. Historic satellite imagery (last 34 yrs) of the field depicts a lineation on the modern marsh surface coincident with the upward projected fault plane. Continuous wetland loss on the downthrown side of the fault trace suggests that recent and continued fault movement may be contributing to marsh submergence.
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Lê, Tuâń Việt. "Stratigraphie sismique et modelisation stratigraphique : application a l'evolution tectonique oligo-miocene du bassin du fleuve rouge (vietnam)." Rennes 1, 1998. http://www.theses.fr/1998REN10066.
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La zone d'etude se situe sur la bordure n-e du bassin du fleuve rouge. Ce bassin se forme pendant l'eocene-oligocene et le miocene inferieur en contexte transtensif senestre, suite au deplacement senestre sur le systeme de failles du fleuve rouge. Le bassin est ensuite inverse durant le miocene superieur en regime de transpression, suite au changement des contraintes sur le systeme de failles du fleuve rouge. Ces changements de cinematique sur le systeme des failles du fleuve rouge sont induits par la collision inde-asie. Les donnees sismiques ont ete utilisees afin d'individualiser des sequences sismiques (limitees par des onlap, toplap, downlap et formant des clinoformes) correlables a l'echelle de l'ensemble du bassin. Les facies sismiques sont cales sur les donnees de trois puits de forage. Ces sequences permettent de definir trois grands cycles retrogradant, aggradant et progradant qui correspondent respectivement a l'extension dans le bassin, a la fin de l'extension et a l'inversion du bassin. Une modelisation numerique stratigraphique deterministe fondee sur des lois de transport de type diffusif a ensuite ete realisee avec le logiciel dionisos (ifp) a partir des donnees sismiques interpretees en terme de stratigraphie sequentielle. Dans le cas du bassin du fleuve rouge, la modelisation stratigraphique se base sur une simulation simplifiee du processus de depot. Les donnees d'entree du modele sont la subsidence, l'eustatisme (sous forme d'epaisseurs decompactees et de paleobathymetrie calculees par subtec), les apports sedimentaires et les coefficients de diffusion pour les grands types d'environnement de depot. La modelisation stratigraphique en trois dimensions permet d'ajuster les flux de sediment afin de retrouver la geometrie des corps sedimentaires. Cette double approche apporte une nouvelle methode d'investigation de la dynamique du remplissage des bassins sedimentaires en relation avec la tectonique. De plus, elle permet de quantifier la variation spatiale et temporelle des apports sedimentaires et de connaitre l'importance de ces flux dans l'architecture des depots.
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Schmidt, Rolf. "Stratigraphy and macrofaunal assemblages of the Oligo-Miocene Mannum Formation, Lower Murray River Cliffs, South Australia /." Adelaide, 1996. http://web4.library.adelaide.edu.au/theses/09SB/09sbs349.pdf.
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Thesis (B. Sc. (Hons.))--University of Adelaide, Dept. of Geology and Geophysics, 1996.One folded chart in pocket on back cover. Australian National Grid reference Adelaide sheet S1 54/9 Renmark sheet S1 54/10 1:250 000. Includes bibliographical references (leaves 38-42).
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Bialkowski, Anne. "Stratigraphie isotopique (carbone et oxygène) des séries continentales d'un bassin d'avant-pays (Oligo-Miocène du bassin de Digne-Valensole) : paléoenvironnements et séquences de dépôt /." Paris : École des mines de Paris, Centre de géotechnique et d'exploitation du sous-sol - sédimentologie, 2004. http://catalogue.bnf.fr/ark:/12148/cb392606585.
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Descote, Pierre-Yves. "Relations architecturales, faciologiques et diagénétiques des carbonates bioclastiques du bassin miocène rhodano-provençal (SE France)." Phd thesis, École Nationale Supérieure des Mines de Paris, 2010. http://pastel.archives-ouvertes.fr/pastel-00563849.
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Situé dans le domaine périalpin à moyenne paléolatitude, le Bassin Molassique Rhodano-Provençal enregistre durant le Miocène, une sédimentation bioclastique particulière. Ces séries miocènes sont caractérisées par un réseau de vallées incisées. Cette thèse se fonde sur l'analyse des séries affleurant dans les secteurs de Vénasque (Aquitanien-Langhien) et de Martigues (Aquitanien-Tortonien). L'objectif est d'étudier les corps bioclastiques (pétrographie, architecture sédimentaire, environnements de dépôt et diagenèse) afin de déterminer leur potentiel pétrolier. Après la formation de vallées fluviatiles en bas niveau marin, les sédiments déposés sont dominés par une dynamique tidale strictement sous aquatique. Ils peuvent être séparés en deux groupes : les intervalles bioclastiques et les intervalles marneux, respectivement transgressifs et de haut niveau marin. Les corps bioclastiques présentent le meilleur potentiel réservoir mais sont caractérisés par une forte hétérogénéité interne. Cette hétérogénéité résulte d'une combinaison de facteurs hydrodynamiques, écologiques et diagénétiques associés aux cycles tectono-eustatiques. L'établissement d'un schéma séquentiel précis en relation avec la diagénèse permet de caractériser le potentiel des réservoirs bioclastiques confinés dans des vallées sous-marines. Les dépôts du Miocène rhodanien constituent un analogue terrain exceptionnel pour la compréhension des réservoirs actuellement impliqués dans des systèmes pétroliers.
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Le, T. V. "Stratigraphie sismique et modélisation stratigraphique : application à l'évolution tectonique oligo-miocène du Bassin du Fleuve Rouge (Vietnam)." Phd thesis, Université Rennes 1, 1998. http://tel.archives-ouvertes.fr/tel-00728242.
Full textAbstract:
La zone d'étude se situe sur la bordure N-E du Bassin du Fleuve Rouge. Ce bassin se forme pendant l'Éocène-Oligocène et le Miocène inférieur en contexte transtensif sénestre, suite au déplacement sénestre sur le système de failles du Fleuve Rouge. Le bassin est ensuite inversé durant le Miocène supérieur en régime de transpression, suite au changement des contraintes sur le système de failles du Fleuve Rouge. Ces changements de cinématique sur le système des failles du Fleuve Rouge sont induits par la collision Inde-Asie. Les données sismiques ont été utilisées afin d'individualiser des séquences sismiques (limitées par des onlap, toplap, downlap et formant des clinoformes) corrélables à l'échelle de l'ensemble du bassin. Les faciès sismiques sont calés sur les données de trois puits de forage. Ces séquences permettent de définir trois grands cycles rétrogradant, aggradant et progradant qui correspondent respectivement à l'extension dans le bassin, à la fin de l'extension et à l'inversion du bassin. Une modélisation numérique stratigraphique déterministe fondée sur des lois de transport de type diffusif a ensuite été réalisée avec le logiciel Dionisos (IFP) à partir des données sismiques interprétées en terme de stratigraphie séquentielle. Dans le cas du Bassin du Fleuve Rouge, la modélisation stratigraphique se base sur une simulation simplifiée du processus de dépôt. Les données d'entrée du modèle sont la subsidence, l'eustatisme (sous forme d'épaisseurs décompactées et de paléobathymétrie calculées par SUBTEC), les apports sédimentaires et les coefficients de diffusion pour les grands types d'environnement de dépôt. La modélisation stratigraphique en trois dimensions permet d'ajuster les flux de sédiment afin de retrouver la géométrie des corps sédimentaires. Cette double approche apporte une nouvelle méthode d'investigation de la dynamique du remplissage des bassins sédimentaires en relation avec la tectonique. De plus, elle permet de quantifier la variation spatiale et temporelle des apports sédimentaires et de connaître l'importance de ces flux dans l'architecture des dépôts .
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Saylor, Joel Edward. "The Late Miocene through Modern Evolution of the Zhada Basin, South-Western Tibet." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194652.
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The uplift history of the Tibetan Plateau is poorly constrained in part due to its complex and extended tectonic history. This study uses basin analysis, stable isotope analysis, magnetostratigraphy, detrital zircon U-Pb dating, and paleoaltimetry, and frequency analysis to reconstruct the tectonic, spatial, and environmental evolution of the Zhada basin in southwestern Tibet since the late Miocene. The Zhada Formation, which occupies the Zhada basin and consists of ~ 850 m of fluvial, alluvial fan, eolian, and lacustrine sediments, is undeformed and lies in angular unconformity above Tethyan sedimentary sequence strata. The most negative Miocene δ¹⁸Opsw (paleo-surface water) values reconstructed from aquatic gastropods are significantly more negative than the most negative modern δ¹⁸O(sw) (surface water) values. In the absence of any known climate change which would have produced this difference, we interpret it as indicating a decrease in elevation in the catchment between the late Miocene and the present. Basin analysis indicates that the decrease in elevation was accomplished by two low-angle detachment faults which root beneath the Zhada basin and exhume mid-crustal rocks. This exhumation results from ongoing arc-parallel extension and provides accommodation for Zhada basin fill. Sequence stratigraphy shows that the basin evolved from an overfilled to an underfilled basin but that further evolution was truncated by an abrupt return to overfilled, incising conditions. This evolution is linked to progressive damming of the paleo-Sutlej River. During the underfilled portion of basin evolution, depositional environments were strongly influenced by Milancovitch cyclicity: particularly at the precession and eccentricity frequencies.
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Davies, Quintin James. "Climatic and tectonic controls on deep water sedimentary cyclicity : evidence from the Miocene to Pleistocene of Cyprus." Thesis, Open University, 2001. http://oro.open.ac.uk/54616/.
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Traditionally, sedimentation at active plate margins is thought to be dominantly controlled by tectonism, with any climatic cyclicity being overprinted. Since the early Miocene, Cyprus has been situated above an active subduction zone, which has strongly influenced the regional tectonics. Global climate change also occurred during the Miocene marking a transition from relative global warmth of the early-Miocene to the Neogene 'icehouse world'. Cyprus has extensive outcrops of Miocene to Pleistocene deep water sediments and provides an ideal setting to test the magnitude of climatic signals in tectonically active areas, and thus deduce the relative roles of climate and tectonics on sedimentation. Detailed sedimentary logging and biostratigraphical dating of the Miocene-age pelagic Pakhna Formation reveals that the formation can be divided into depositional sequences,bounded by hard grounds or erosion surfaces, and contains a distinct pattern of marl-chalk couplets. These sequences correlate, within the constraints of biostratigraphy to European and New Jersey Margin sequence chronostratigraphy. Three smaller scales of cyclicity are identified by stratigraphic time series analysis, and are likely to correspond to the 100 kyr, 41ky and ~20 ky Milankovitch cycles. Stable oxygen and carbon isotope analysis on pelagicforaminifera indicate the following climatic influences; (1) chalk-marl couplets probably record climatically controlled supply of terrigenous material; (2) a strong link between 818O maxima and sequence boundaries; and (3) the globally recognised 813C Monterey ExcursionIS present. The increasing abundance of tectonically derived Troodos material partially masks the climatically controlled sedimentation in the Pakhna Formation south of the Troodos massif. Rapid Troodos uplift during the Pliocene-Pleistocene is demonstrated by the high abundance of ophiolite derived clasts in the Khirokitia-Psematismenos submarine fan-complex. Here,graphic logging, and biostratigraphy suggests that the six cycles observed are likely to correlate to cycles identified in European sequence chronostratigraphy, though higher frequency,climatic cyclicity is obscured by the overprint of tectonic activity.
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Badescu, Adrian Constantin. "Reservoir characterization of the Miocene Starfak and Tiger Shoal fields, offshore Louisiana through integration of sequence stratigraphy, 3-D seismic, and well-log data." Access restricted to users with UT Austin EID, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3108452.
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Besson, David. "Architecture du bassin rhodano-provençal miocène (Alpes, SE France). Relations entre déformation, physiographie et sédimentation dans un bassin molassique d’avant-pays." Paris, ENMP, 2005. https://pastel.archives-ouvertes.fr/pastel-00003284.
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Dans un cadre stratigraphique revu le remplissage miocène du bassin molassique rhodano-provençal (BMRP) a été découper en 10 séquences de dépôt (IIIrd). Trois grandes phases d’érosion fluviatile ont été caractérisées : entre l’Aquitanien et le Burdigalien inférieur et entre le Burdigalien terminal et le Langhien puis à la base du Tortonien. Les transgressions marines miocènes du BMRP sont contrôlées par l’existence de ces réseaux fluviatiles successifs. Un modèle séquentiel haute fréquence du remplissage par des carbonates bioclastiques de faciès « foramol » du premier complexe de vallées incisées est proposé. Ces réseaux miocènes qui alimentent la plate-forme et le talus du golfe du Lion permettent de mieux comprendre comment l'ouverture du Golfe du Lion, son ralentissement puis son arrêt interagissent avec le raccourcissement alpin. Les vallées aquitano-burdigaliennes sont généralement superposées et emboîtées dans les dépôts oligo-aquitaniens. Ils sont en relation direct avec l’héritage morphostructural de ce bassin d’avant-pays et signent une déformation régionale de grande longueur d’onde rapportée à une remise en compression à la base du Miocène. Les réseaux suivant en quasi-conformité avec les structures pyrénéo-provençales sont en relation avec l’activation des plis et des chevauchements et signent une déformation plicative de plus courte longueur d’onde associée pour le réseau du Burdigalien terminal à un soulèvement régional. Leur superposition souligne la pérennité d’un contrôle tectonique. Leur déboîtement est la conséquence de l’activation des plis et des chevauchements provoquant la migration des dépôts-centres et des réseaux successifs de vallées dont cette déformation amplifie le creusementInventory and analysis of incised valleys through the “rhodano-provencal” molassic basin (BMRP) results in re-examining the miocene sea submergence and the tectonic deformations of the alpine chain foreland basin. Three great fluviatile erosion stages have been characterized : between late Aquitanian and early Burdigalian, between late Burdigalian and early Langhian and early Tortonian. These Miocene networks who supply the platform and the slope of Lions Gulf provide some elements for a better geodynamic understanding of this area: in particular how the deceleration and the stop of the opening of the Lion Gulf interact with the alpine shortening. The marine Miocene invasions of the peri-alpine furrow are controlled by these successive fluviatile networks existence. The first fluviatile network filling is composed of bioclastic carbonates of “foramol” facies. A high frequency sequential model of an incised valleys complex is proposed. The identification of the three Miocene incised valleys networks allow a completely new BMRP geomorphological evolution analysis. The Aquitano-Burdigalian valleys are generally superimposed and encased in the Oligo-Aquitanian deposits in direct relation with the tectonic foreland basin morphostructural heritage and sign a regional large wavelength deformation reported to a compression stage of this field at the lower Miocene. The next networks are in quasi-conformity with the septentrional pyreneo-provencal structures. They are in relation with the activation of the folds and thrust. They sign a shorter wavelength folded deformation associated, for the late Burdigalian network, to a regional rising. Their superposition underlines the tectonic control perenniality. Their dismantling is the consequence of the folds and thrust activation causing not only depotcenters migration but also of the successive valleys networks whose deformation amplifies the digging
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Lê, Tuâń Việt. "Stratigraphie sismique et modélisation statigraphique : application à l'évolution tectonique oligo-miocène du bassin du Fleuve Rouge (Vietnam) /." Rennes : Géosciences, Université de Rennes I, 1999. http://catalogue.bnf.fr/ark:/12148/cb37073680n.
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Rakic-El, Bied Kruna. "Stratigraphie à haute résolution et paléo-océanographie au Maroc à la fin du Miocène : apport des foraminifères planctoniques." Bordeaux 1, 1990. http://www.theses.fr/1990BOR10581.
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La precision apportee par la stratigraphie des intervalles (biozones), existante au maroc depuis une vingtaine d'annees, n'a pas ete suffisante pour l'etablissement de correlation entre l'atlantique et la mediterranee et pour controler les evenements pendant la crise de salinite dans le couloir rifain. Le but de cette these a ete de construire un cadre de reference stratigraphique suffisamment precis pour pouvoir suivre les evenements impliques dans la crise de salinite messinienne. Le principe de la stratigraphie a haute resolution (shr) represente une strategie d'analyse provenant des donnees biostratigraphiques, des signaux geomagnetiques et des signatures isotopiques. Cette stratigraphie represente une nouvelle direction dans la recherche du neogene marocain. Les donnees reconnues ont permis de construire un modele paleoceanographique de circulation par effet bernoulli: le siphon, dans le couloir rifain, qui a assure le passage entre l'atlantique et la mediterranee durant le messinien inferieur. Ce modele s'appuie sur divers evenements biologiques coincidant. L'identification du carbon shift a 6,3 ma, avec les evenements biostratigraphiques, ont permis de confirmer la correlation de la limite inferieure du messinien entre l'atlantique et le stratotype en mediterranee. Les nouvelles analyses biostratigraphiques et paleomagnetiques, ont dementi l'attribution de l'age pliocene propose en 1977 par montenat et al. Pour la coupe de cuevas del almonzora (sud-est de l'espagne). Les evenements enregistres dans les bassins de vera coincident avec les evenements qui ont precede la crise de salinite messinienne. La limite inferieure du pliocene est proposee dans la section du bou regred en respectant le principe de la commission internationale de stratigraphie global boundary stratotype section and point (gssp)
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Mavilla, Nicola. "Stratigraphie et analyse des faciès de la succession d'âge oligocène-miocène du bassin tertiaire piémontais (Italie nord occidentale)." Bordeaux 1, 2001. http://www.theses.fr/2001BOR10508.
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Cette étude est consacrée aux aspects sédimentologiques et stratigraphiques des successions oligocènes et miocènes du secteur occidental du bassin tertiaire piémontais (btp). Elle vise à caractériser les dépôts analysés par rapport à leur distribution et géométrie, à leur facies et processus sédimentaires, ainsi qu'à déterminer les facteurs qui contrôlent leurs caractéristiques et distribution dans des bassins tectoniquement actifs. Les unités sédimentaires, confinées dans des petites dépressions structurales qui contraignent la direction des paléo-courants et la distribution des facies, caractérisent la partie basale de la série étudiée. Les lobes sableux de plate-forme, caractérisés par une population de grains de sable très bien triés et par des facies à structures internes distinctes (hcs), s'accumulent dans la partie supérieure de la série étudiée. La succession de facies observée dans les unités qui ont été étudiée, est typique des systèmes de cônes deltaïques dominés par les crues. Les systèmes deltaïques étudiés enregistrent l'augmentation progressive de la taille du bassin et du volume des écoulements en même temps que la diminution des dimensions des grains. L'efficacité des écoulements a augmenté au cours du temps suivant l'augmentation de ces paramètres. Les dépôts fins laminés montrent dans la zone d'étude différents types de motifs sédimentaires en termes de structures internes, d'épaisseur des bancs, de classement, mais la caractéristique la plus évidente de ces dépôts est l'empilement de niveaux lamines qui révèle que ces dépôts sont issus de courants instables générés par des écoulements hyperpycanaux. Certains cônes deltaïques, remplissant plusieurs petits bassins structuraux avec de sources différentes, se sont développés pendant l'oligocène dans la partie est de la zone d'étude. Les données stratigraphiques démontrent clairement comment les failles limitant ces systèmes se sont inverses pendant le dépôt et ont causé le déplacement des dépôts-centres. Les analyses stratigraphiques et sédimentologiques ont permis de proposer un modèle de sédimentation lié aux écoulements bipartite dans un contexte à relief topographique important. Les paramètres contrôlant le dépôt et la localisation du relief topographique en relation avec le déplacement du courant et les transformations de l'écoulement.
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Wolak, Jeannette Marie. "Sedimentology and stratigraphy of a deepwater transient fan on the continental slope: the Late Miocene Isongo Formation, equatorial West Africa." Diss., Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/wolak/WolakJ0511.pdf.
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Deepwater clastic deposits of the Late Miocene Isongo Formation, located 50 km northwest of Bioko Island, characterize a sand-rich transient fan system developed in response to incipient structural growth on the continental slope. Approximately 1200 ft (366 m) of conventional core, 21 wells, 3-D seismic (maximum 40-60 Hz), biostratigraphy, chemostratigraphy and dynamic production data from the 100 km 2 study area are used to: (1) Define process-based sedimentological facies within the Isongo Fan; (2) Characterize porosity and permeability trends at three temporal and spatial scales; (3) Identify sedimentary bodies throughout cored and uncored intervals; and (4) Correlate stratigraphic sequences within a framework of adjustment, initiation, growth and retreat (AIGR). While the former two objectives capture small-scale geologic heterogeneities developed at the time of deposition, the latter two describe changes in fan geomorphology during coeval uplift and sedimentation. Fifteen core-defined sedimentological facies reflect subaqueous depositional processes including turbidity currents, debris flows and pelagic settling. Pore space generated during deposition is correlated to grain size; pore connectivity is correlated to sorting. Sedimentation units and facies assemblages, which characterize depositional processes operating during a single sedimentation event, show patterns of accumulative flow in the confined, narrow portion of the Isongo Fan; depletive flow in the unconfined, southwestern portion. Erosional slope channel-levee systems in the northeast demonstrate very large sedimentation events, likely due to eruptive activity and uplift of Mount Cameroon 50 km updip. Partly confined to unconfined distributary channel-lobe systems in the southwest characterize a change in fan geomorphology off the flank of a growing structure. Core-calibrated petrophysical facies and wireline log thicknesses allow identification of sedimentary bodies in uncored intervals throughout the Isongo Fan, a 2.3 million year episode of sand-rich deposition (3rd order sequence). High frequency 4th and 5th order sequences are used to describe changes in fan morphology over time relative to the growing anticline. A surface of adjustment marks the onset of syn-sedimentary growth, followed by 4th order phases of initial deposition that onlap the structure. Sandrich fan growth, however, is greatest during a period of minimal uplift, followed by retreat of the Isongo depocenter to the north. Post-Isongo deposits suggest that renewed anticline growth resulted in avulsion of the system to the northwest after 8.2 Ma.
'Co-authored by Michael H. Gardner and W. Sebastian Bayer.'
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Dunn, Shane Christopher. "Miocene Contourite Deposition (along-slope) near DeSoto Canyon, Gulf of Mexico: A Product of an Enhanced Paleo-Loop Current." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6494.
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A Neogene contourite depositional system was identified and mapped along the DeSoto Slope in the northeastern Gulf of Mexico, U.S.A. A series of drift deposits comprising the larger contourite depositional system were interpreted from a 2-D industry seismic data set. The now subsurface drift deposits are adjacent to the anomalous seabed feature, the DeSoto Canyon, and these data suggest contourite deposition and ocean currents are in integral part of the canyon’s depositional history. The contourite depositional system is underlain by an extensive, middle Miocene aged, erosional unconformity formed by ocean currents. The timing of this erosional surface is in alignment with the widely accepted premise that the Miocene represented a transitional period in Gulf of Mexico basin circulation. The discovery of this contourite depositional system adds to an established list of Miocene-aged features pointing to the onset of enhanced Loop Current circulation in the Neogene Gulf of Mexico.
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Güiza, Helga Nayibe Niño. "Análise sismoestratigráfica do mioceno medio-inferior: oligoceno superior em uma área da guajira alta na Bacia Da Guajira, Colômbia." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/153270.
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O Caribe Colombiano é o foco da exploração na Colômbia, e a Bacia da Guajira na sua parte offshore tem sido relativamente pouco explorada. O presente trabalho tem como objetivo fazer um estudo sísmico de alta resolução aplicável á áreas sem exploração em blocos novos ou para ter diferentes perspectivas em blocos já explorados, neste caso para o intervalo de tempo compreendido entre o limite do Mioceno médio-inferior e o Oligoceno superior, em uma área da Guajira Alta. A partir da integração de duas seções sísmicas 2D, associadas a seis poços com litologias definidas por amostras de calha, foi realizada: (1) uma análise sismoestratigráfica de alta resolução incluindo a interpretação das terminações dos refletores, definição das unidades sismoestratigráficas e superfícies chave, (2) identificação das sismofácies, (3) a elaboração de uma carta cronoestratigráfica. Como resultado, foram individualizadas cinco unidades sísmicas, seis sismofácies e a carta cronoestratigráfica Todas as unidades sísmicas identificadas correspondem com depósitos de gravidade tipo fluxo de detritos e turbiditos, e depósitos hemipelágicos. As sismofácies caracterizadas como turbiditos (refletores paralelos, subparalelos, hummocky), são geralmente calcáreas, as sismofácies de fluxo de detritos (refletores caóticos), têm mistura de litologias tipo folhelhos, siltitos, lamitos, arenitos e carbonatos, e as sismofácies definidas como depósitos hemipelágicos (refletores paralelos, subparalelos), correspondem em sua maioria com depósitos finos. Na carta cronoestratigráfica indica uma depositacão contínua em esse intervalo de tempo.Colombia Caribbean province is an important hydrocarbon exploration target in Colombia, a Guajira Offshore Basin as part of this province and is a frontier basin today. Main objective of this study is to develop a high resolution seismic stratigraphic study to be applied to unexplored areas on new blocks and/or to have another interpretation in low explored areas, in this case, on the specific time interval upper Oligocene-middle-lower Miocene, selecting a study area in Upper Guajira offshore. Data integration of two seismic sections and lithologic logs from six wells obtained from cuttings made possible to interpret: 1) High resolution seismic stratigraphic analysis including seismic stratigraphic units and key surfaces definition, seismic reflectors pinch outs, 2) seismic facies definition and 3) cronostratigraphic chart. From this analysis were stablished five seismic units, six seismic facies and a chronostratigraphic events chart. All interpreted seismic units correspond to gravity flow deposits debris and turbiditic type and hemipelagic deposits. Turbidite type seismic facies (parallel, subparallel and hummocky reflectors), are usually calcareous in composition, as well as detrital fluxes (chaotical reflectors), are generally a mixture of sandstones, limestones, siltstones, mudstones and shales, and hemipelagic seismic facies (parallel to subparallel reflectors) correspond to thin bedded deposits usually silty and muddy. Chronostratigraphic chart events indicates continuous deposition in this time interval.
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Sorel, Denis. "L'évolution structurale de la Grèce nord-occidentale depuis le miocène, dans le cadre géodynamique de l'arc égéen." Paris 11, 1989. http://www.theses.fr/1989PA112421.
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Cadre stratigraphique: la datation et la durée des phases tectoniques de Grèce nord-occidentale sont précises ainsi que l’âge des formations récentes de cette région et de Corinthie. Les trois dernières phases compressives datent du langhien inferieur (17-16 M. A. Environ), du pliocène inferieur (5-4,2 M. A. Environ), du pléistocène inferieur final (1-0,7 M. A. Environ). Les phases n'ont duré que quelques centaines de milliers d'années. Des périodes calmes dix fois plus longues les séparent. Tectonique: la direction de compression des trois phases, ENE-WSW dans le repère actuel, est restée orthogonale à la marge ionienne de l'arc. La phase du langhien a formé le front ionien de l'arc, celle du pliocène le front préapulien toujours actif. Géodynamique: l'arc égéen serait apparu au langhien (17-16 M. A. ), assez rectiligne. Une pliure (déchirure?) De la lithosphère plongeant sous l'arc aurait permis sa courbure (anguleuse) par les rotations opposées de ses deux branches. Les phases du langhien et du pliocène inferieur résulteraient d'une subduction continentale. Celle du pléistocène inferieur, accompagnée d'une surrection de l'arc externe, viendrait de la rupture sous son propre poids de la lithosphère subduction. Une seule subduction aurait produit le magmatisme orogénique égéen depuis l'oligocène au moins. La traction de la lithosphère subduction serait une force majeure du développement de la courbure de l'arc égéen. Elle en explique les principaux caractères, qui se retrouvent dans d'autres arcs alpins méditerranéens (tyrrhénien, alpes, Carpates). La convergence Afrique/Eurasie résulterait dans une certaine mesure de cette traction des subductions océaniques et continentales sous la chaine alpine
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Frouté, Jean-Yves. "Le rôle de l'accident d'Estella dans l'histoire géologique crétacé supérieur à miocène des bassins navarro-alavais (Espagne du Nord)." Pau, 1988. http://www.theses.fr/1988PAUU3019.
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L'accident d'Estella d'orientation sub-méridienne a constitue un trait majeur de l'histoire géologique de la région d'Estella (Pyrénées SW). En réponse a l'évolution du schéma des contraintes, ce trait structural majeur a donc constamment guide l'évolution géologique (subsidence, paléogéographie, déformations. . . ). C'est par l'analyse des séries sédimentaires et notamment par des approches paléogéographiques que le rôle de cet accident est mis en évidence. Subsidence du compartiment occidental cantabrique au crétacé supérieur. Effacement progressif de ce schéma paléogéographique a partir du maestrichtien en liaison avec le développement des raccourcissements Pyrénées (NNE-SSW). Subsidence du compartiment oriental au biarritzien (bassin de Pampelune). Subsidence du bassin de l'ebre au sannoisien sous l'effet du contraste isostatique croute sud-pyrénéenne épaissie par les raccourcissements pyrénéens croute normale de l'Ebre. Subsidence différentielle de part et d'autre de l'accident d'Estella. Accentuation des phénomènes compressifs (raccourcissements n 160#oe) au chattien, responsables d'un mouvement senestre et de montées halocinétiques le long de l'accident d'Estella