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1
Parkinson, D. Neil. "The sequence stratigraphy of the Lower Jurassic of Western Europe." Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:cddbc521-f687-41dd-a9ad-f70621012555.
Abstract:
The Lower Jurassic stratigraphy of seven contrasting areas in western Europe is compared in order to seek evidence for a pan-Western European stratigraphic forcing mechanism. Sequencestratigraphic models are discussed and emphasis is placed upon the differing response of sedimentary systems in "accommodation space-dominated" and "supply-dominated" settings. Spectral gamma-ray data from clastic successions in the Wessex and Cleveland basins (England) are used to elucidate vertical trends. A proximal-distal model for control of Th/K ratios is advanced. Stage-frequency regressive-transgressive cycles in the two areas are shown to be closely correlative. Sedimentolgical logs and spectral gamma-ray data are presented for the carbonate ramp into turbidite sequence of Peniche (Portugal) and for a new exposure of the Pliensbachian-Toarcian in southern Germany. Systematic variation in clay mineralogy across Europe is suggested. Cycles in the Lower Jurassic of the North Viking Graben (Norwegian North Sea) are examined using wireline log correlation and the stratigraphic evolution of the Tethyan Rift in the Western and Southern Alps is reviewed. X-ray diffraction studies of the Pliensbachian-Toarcian interval in the Southern Alps are presented in order to elucidate sediment supply to the pelagic realm. The cycles observed in the English sections appear to be manifest widely across western Europe in a variety of tectonic and sedimentary settings. Sharp basinward facies shifts (candidate sequence boundaries) do not appear to be synchronous between basins. 87SR/86SR analysis of belemnites from the Portuguese and German sections confirms the regional applicability of the results of Jones (1992) and the utility of this technique in long range correlation. Carbon and oxygen analysis of the same material supplements the data of other workers and a direct relationship is suggested between relative sea level and organic carbon burial in the Early Jurassic.
2
Ahmadi, Ziad M. "Sequence stratigraphy using wireline logs from Upper Jurassic of England." Thesis, Durham University, 1997. http://etheses.dur.ac.uk/1644/.
3
Al-Mojel, Abdullah. "Sedimentology and sequence stratigraphy of the Jurassic, Jabal Tuwaiq, Central Saudi Arabia." Thesis, Bordeaux 3, 2017. http://www.theses.fr/2017BOR30037/document.
Abstract:
Cette étude porte sur l’analyse des séries jurassiques du Shaqra Group (Toarcian to Kimmeridgian) qui affleurent de manière continue en Arabie centrale le long d’un transect de plus de 1000 km de long. Ces séries se sont accumulées sur une vaste plate-forme épicontinentale peu profonde, en contexte tropical. Ces affleurements permettent ainsi d’observer la partie occidentale des séries renfermant des systèmes pétroliers prolifiques exploités en subsurface en Arabie Saoudite. L’analyse sédimentologique de nombreuses coupes et la réalisation de corrélations stratigraphiques de haute résolution sur un transect de 600 km au sud de Riyad, complété par des corrélations avec les données de forage plus à l’est (entre Riyadh et le Rimthan Arch), permettent de distinguer une organisation séquentielle à différents ordres de fréquence et de reconstituer l’évolution de la plate-forme au sein de ces séquences. La plate-forme jurassique évolue d’une plate-forme horizontale caractérisée par des systèmes mixtes à la transition continental-marin du Toarcien au Callovien moyen (formations Marrat et Dhruma) vers un système de type rampe - bassin intrashelf du Callovien au Kimméridgien inférieur (formations Tuwaiq et Hanifa) pour finir par une plate-forme aggradante carbonatée et silico-clastique (Fm. Jubaila) puis carbonatée et évaporitique en contexte aride (Fm. Arab) au Kimméridgien. Les cycles tectono-stratigraphiques de 2ème ordre du Jurassique inférieur et moyen sont limités à la base et au sommet par des discontinuités régionales. Ils occupent un dépôt-centre stationnaire et décrivent un onlap côtier de grande ampleur avec un maximum transgressif au Callovien moyen (Upper Tuwaiq Mb.). Durant le Jurassique supérieur, les dépôts de rampe carbonatée de la Formation Hanifa passent progressivement vers l’ouest à des dépôts plus profonds de bassin intrashelf relativement riches en matière organique (Khurais - Rimthan Arch). La séquence Jubaila – Arab-D montre des variations d’épaisseur qui indiquent une déformation de grande longueur d’onde de la plate-forme arabe à cette période. Les faciès récifaux du membre Arab D sont interprétés comme représentant le maximum d’inondation de ce cycle qui se termine par le développement de systèmes carbonatés – évaporitiques à la fin du JurassiqueThey serve as westernmost reference for adjacent prolific reservoirs and source-rock bearing intrashelf basins. Several hierarchical sequences (second to fourth order) have been recognized in outcrops sections (600 km long south of Riyadh) and correlated with gamma-ray logs of subsurface wells (550 km long from Riyadh to Rimthan Arch). The Jurassic platform evolved from very-flat continental-to-nearshore mixed carbonate-siliciclastic platform (Marrat-Dhruma; Toarcian to Middle Callovian) to differentiated ramp with deep intrashelf basins (Tuwaiq-Hanifa; Callovian to Early Kimmeridgian) to a lowstand followed by flat aggraded platform (Jubaila-Arab-D; Kimmeridgian). Tectonic related siliciclastic influx took place in arid condition during the Kimmeridgian (Jubaila Fm.). The Jurassic platform ends with the mixed carbonate-evaporite systems of the Arab Fm. A first second-order tectono-eustatic cycle (Marrat to Tuwaiq) is bounded at the base and top by regional unconformities. It has a stationary depocenter, and show long-term coastal onlap and marine transgression that reached its maximum extent during the upper Tuwaiq (Middle Callovian). The Hanifa Fm. consists of four 3rd-order sequences aggraded flat-toped platform (outcrops to Khurais) marked at the base by argillaceous limestone and top by pure high-energy carbonates with localized reef buildups. The Jubaila Arab-D is two 3rd-order sequences begin with low-stand deposits followed by long-term transgression. These formed flat successions with lateral thickness variations controlled by differential subsidence increased in the Arabian Basin. The transgression is marked by storm-influenced inner-platform with sandstone quartz, grainstones and restricted lime-mudstone. The Maximum marine transgression is placed in the Arab-D with reef buildups in the westernmost inner-platform. During highstand, the reefs are gently prograding out into Rimthan Arch leaving behind restricted lagoon and sabkhah/salina anhydrite
4
Ceglar, Nathan. "Late Jurassic to Early Cretaceous sequence stratigraphy, Northern Bonaparte Basin, Timor Sea /." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09SB/09sbc389.pdf.
5
Groecke, Darren Richard. "Isotope stratigraphy and ocean-atmosphere interactions in the Jurassic and Early Cretaceous." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393117.
6
Maxwell, Gregor. "The sedimentology and sequence stratigraphy of the Middle Jurassic Beryl Formation, Quad 9, U.K.C.S." Thesis, University of Aberdeen, 1999. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=236949.
Abstract:
Quad 9 of the U.K.C.S., North Sea is located 215 miles NE of Aberdeen. It contains four producing fields with over 400 mmbbls of oil and NGL's and 5.1 TCF of gas initially in place. The major reservoir unit is the Middle Jurassic (Bajocian to Bathonian) Beryl Formation, a marginal to shallow marine deposit which varies in thickness from 150' to 1100' across the studied area. It was deposited within the Beryl Embayment, a transfer zone between two actively extending basin bounding faults of the South Viking Graben, prior to the onset of the major rifting phase during the Callovian to Ryazanian. The objectives of the thesis were to provide a revised sedimentological model for the area accounting for the contrasting sedimentary styles present within the Beryl Formation and to unify the different correlation schemes used by the different operating companies in the area. It was based on well data from 58 cored and a further 79 uncored sections spreading nine licence blocks within Quad 9. Reservoir engineering, biostratigraphic and structural data has also been used for a fully integrated study. Initial core logging identified 32 facies and 10 trace fossil assemblages which were subsequently integrated into 14 facies associations. These were then extrapolated further into the uncored sections by wireline facies associations. Correlation was initially driven by comparison of cored sections but finalised by an integration of the reservoir engineering and biostratigraphic data. Outcrop work on the Middle Jurassic of Skye and Companian of eastern Utah provided an analogue study to accompany the downhole data. Quad 9 can be split up into three main areas distinguished by different stratigraphic histories, the southern area consisting of the Buckland and Sorby Fields, the central area consisting of the Beryl, Nevis, Ness and Linnhe Fields and a northern area consisting the Bruce and Keith Fields.
7
Zerezghi, Simret Ghirmay. "Sedimentology and Stratigraphy of the Lower Jurassic Portland Formation, Newark Supergroup, Hartford Basin." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1181233653.
8
Cole, David Charles. "Sequence palynology of the lower jurassic (Sinemurian - Toarcian) strata of N W Europe." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342883.
9
Molgat, Marianne Patricia. "Sedimentology, stratigraphy, and shallow burial alteration of the Upper Jurassic Swift Formation, southeastern Alberta." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ57146.pdf.
10
James, D. P. "Stratigraphy, sedimentology and diagenesis of Upper Jurassic and Lower Cretaceous (Mannville) strata, Southwestern Alberta." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371509.
11
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.
Abstract:
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.
12
Cook, Preston Scott. "Sedimentology and Stratigraphy of the Middle Jurassic Preuss Sandstonein Northern Utah and Eastern Idaho." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6206.
Abstract:
The purpose of this study is to analyze the sedimentology and stratigraphy of the Middle Jurassic Preuss Sandstone and re-evaluate past sedimentological interpretations. The Preuss is located in northern Utah, western Wyoming and eastern Idaho and is stratigraphically equivalent to the Entrada Sandstone, which is Callovian in age (Dossett et al., 2014). This study is the first attempt at 1) a sequence stratigraphic framework, 2) a petroleum system analysis and 3) an extraterrestrial analog study for the Preuss. This study frames the Preuss within three broad facies groups: marine, coastal and terrestrial. The marine group includes the open marine and restricted marine facies with associated subfacies, the coastal group includes coastal sabkha and associated subfacies, and the terrestrial group includes alluvial, inland sabkha and eolian facies with associated subfacies. Three sections in northern Utah and one section in eastern Idaho compromise the focus of this study. The three Utah sections were measured and described, and samples were collected from two Utah sections and the Idaho section. The Preuss Sandstone was deposited in an asymmetrical retroarc basin, consequently the Preuss thickens from the east towards west-central Utah and the Jurassic Elko highlands. The deposits are mostly terrestrial, which is in accord with recent sedimentological interpretations, but at odds with the old paradigm, which postulates that the Entrada and Preuss were largely tidal in origin. There are marine transgressions within the trough of the retroarc basin, and the transgressions affect terrestrial sedimentary patterns. During marine incurstions, alluvium shed off the highlands is confined west of the seaway, and does not prograde east of the trough until all the available accommodation is filled. The Preuss was deposited during a complete third-order sequence-stratigraphic cycle that lies within the Lower Zuni II second-order lowstand. The Preuss Sandstone can be used as an outcrop analog for ancient and modern environments both here on Earth and on other planetary bodies. The petroliferous Norphlet Formation along the U.S. Gulf Coast was deposited in an environment very similar to the Preuss, but the Waltherian succession of facies might be slightly different. Likewise, the facies present in the Preuss are analogous to modern arid environments, such as the Persian Gulf. Furthermore, the alluvial, sabkha, eolian and shallow marine facies of the Preuss are highly similar to facies observed in ancient Martian environments and modern environments on Saturn's moon, Titan.
13
Altemimi, Khalaf O. "Sequence Development and Dolomitization of a Late Jurassic Giant Oil Reservoir, Arab-D Reservoir, Hawiyah (GHAWAR) and Harmaliyah Fields, Saudi Arabia." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77079.
Abstract:
Thirty cores from the Late Jurassic uppermost Jubaila, Arab-D reservoir and Arab-D anhydrite in Hawiyah (Ghawar) and Harmaliyah fields, eastern Saudi Arabia were studied to document the detailed facies stacking and high resolution sequence stratigraphy. The Jubaila-Arab-D interval is a shallowing upward succession of two composite sequences, in which the Arab-D reservoir and overlying anhydrite have up to twelve higher frequency sequences.
Both fields are strikingly similar in terms of facies, parasequences, and vertical stacking of facies. The direction of the progrodaion is east and northeast and that is supported by northeast thickening of the Arab-D reservoir and by the stromatoporoid and Cladocoropsis facies progrodation. This suggests that the Arab-D reservoirs in both fields may represent part of a single carbonate ramp with subtle syndepositional highs. The scarcity of exposure surfaces with caliche in the Arab-D reflects the relatively high subsidence rate (~6 cm/k.y.) relative to the small sea level oscillations that formed the succession coupled with the long term shallowing trend up through the section.
Dolomites from the Arab-D reservoir zones 1 to 4, in both fields were studied to better understand their origin. The dolomites are dominantly fabric destructive medium to coarse grained types, and much less common fabric retentive finer grained dolomites in the uppermost Arab-D reservoir. The δ¹³C values are rock buffered while the δ¹⁸O values have been greatly shifted toward negative values relative to unaltered early dolomite, and dolomite crystal rims generally have lighter δ¹⁸O values than cores.
The dolomites were initiated at different times during shallowing phases on the Arab-D platform, with the bulk of the fabric destructive dolomites forming under near normal salinities, while the fabric preserving dolomites formed as a result of dolomitizing aragonitic sediments from more evaporated waters. With increasing burial and increasing temperature, the early dolomites re-equilibrated with the increasingly warm basinal brines resulting in replacement of cores, and dolomite cementation by rim overgrowth. Progressive plugging of higher dolomites earlier, caused some of these to retain slightly heavier δ¹⁸O values and marine seawater Sr isotope values while those that remained permeable developed very light δ¹⁸O values and more radiogenic Sr values, shifting them toward the field of late stage baroque dolomite.Ph. D.
14
Jennings, George R. III. "Facies Analysis, Sequence Stratigraphy and Paleogeography of the Middle Jurassic (Callovian) Entrada Sandstone: Traps, Tectonics, and Analog." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4083.
Abstract:
The late Middle Jurassic (Callovian) Entrada Sandstone has been divided into two general facies associations consisting primarily of eolian sandstones in eastern Utah and "muddy" redbeds in central Utah. Sedimentary structures within the redbed portion are explained by the interfingering of inland sabkha, alluvial, and eolian depositional systems. A complete succession from the most basinward facies to the most terrestrial facies in the Entrada Sandstone consists of inland sabkha facies overlain by either alluvial or eolian facies. Where both alluvial and eolian facies interfinger, alluvial facies overlain by eolian facies is considered a normal succession. Sequence boundaries, often identified by more basinward facies overlying more landward facies, are observed in the Entrada Sandstone and are extrapolated for the first time across much of Utah, including both the eolian-dominated and redbed-dominated areas. Using these sequence boundaries as well as recent tephrochronologic studies, three time correlative surfaces have been identified in the Entrada. Based on the facies interpretations at each surface, five paleogeographic reconstructions and five isopach maps have been created, illustrating two major intervals of erg expansion and the location of the Jurassic retroarc foreland basin's potential forebulge. Eolian (erg-margin) sandstones pinch-out into muddy redbeds creating combination traps, as evidenced by dead oil (tar) and bleached eolian sandstone bodies within the Entrada. The Entrada Sandstone is a world-class analog for similar systems, such as the Gulf of Mexico's Norphlet Sandstone, where eolian facies grade into muddy redbed facies.
15
Wulff, Keiran. "Upper Jurassic of the Barrow sub-basin: sedimentology, sequence stratigraphy and implications for reservoir development." Thesis, Curtin University, 1991. http://hdl.handle.net/20.500.11937/1177.
Abstract:
A chronostratigraphic subdivision of the Upper Jurassic synrift sediments in the eastern Barrow Sub-basin was developed from the integration of core logging, petrography, well log sequence analyses and seismic stratigraphy. From this basis, the Callovian to base Cretaceous sediments may be subdivided into five depositional sequences. The development of the sequence boundaries, in most part, is closely related to periods of major changes in basin configuration associated with the sequential breakup of eastern Gondwanaland. Initiation of the Upper Jurassic rift complex occurred during late Callovian early Oxfordian associated with the development of a northeast-southwest trending spreading centre on the Argo Abyssal Plain. The spreading centre propagated southwards during the Late Jurassic. This resulted in active rifting in the Barrow Sub-basin and ultimately led to the separation of the Indian and Australian plates during Valanginian time.Upper Jurassic synrift sediments in the eastern Barrow Sub-basin consist of detached basin floor fan complexes, channelised and canyon fed fan systems, slump deposits, prograding outer shelfal to slope deposits and deep marine claystones. Post-depositional uplift of the eastern shelfal areas during the Late Jurassic resulted in erosion of the transgressive and highstand fluvial-deltaic to shelfal deposits. These periods of uplift and erosion provided much of the sediment redeposited in the basinal areas during the lowstand periods. Seven sandstone facies were recognised in the Upper Jurassic sedimentary section based on core control. Each sandstone has unique reservoir characteristics which can be related to the depositional setting.The abundance of glauconite and belemnites combined with ichnology and biostratigraphic assemblages associated with marine environments, indicate that deposition of all the sandstone facies occurred within an outer shelfal - deep marine environment. Reservoir quality was best developed in the dominantly medium grained, moderate - well sorted sandstones, (facies 7), which were deposited as detached, basin floor submarine fan sands or interbedded turbidites. In contrast, reservoir quality was relatively poorly developed in the remaining facies which were deposited as slope fans, slumps, or distal turbidite deposits.The abundance of quartz and presence of banded iron, jasper, and potassic feldspar grains support the provenance for the basinal sandstone facies being the Precambrian alkyl granites and banded iron formation of.the Pilbara Shield and Hammersley Ranges. These Precambrian igneous rocks and metasediments mark the eastern boundary of the Barrow Sub-basin study area. To predict the distribution of sedimentary facies in the Upper Jurassic synrift sediments of the eastern Barrow Sub-basin, the interplay between the major controlling depositional processes, namely tectonics, sediment supply and eustasy must be understood. Subdivision of the synrift sedimentary section on the basis of lithostratigraphy can be misleading and does not adequately resolve the facies relationships observed in the well intersection. The results of this research form the basis for a regional sequence analysis and seismic stratigraphic study.
16
Wulff, Keiran. "Upper Jurassic of the Barrow sub-basin: sedimentology, sequence stratigraphy and implications for reservoir development." Curtin University of Technology, National Drug Research Institute, 1991. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17024.
Abstract:
A chronostratigraphic subdivision of the Upper Jurassic synrift sediments in the eastern Barrow Sub-basin was developed from the integration of core logging, petrography, well log sequence analyses and seismic stratigraphy. From this basis, the Callovian to base Cretaceous sediments may be subdivided into five depositional sequences. The development of the sequence boundaries, in most part, is closely related to periods of major changes in basin configuration associated with the sequential breakup of eastern Gondwanaland. Initiation of the Upper Jurassic rift complex occurred during late Callovian early Oxfordian associated with the development of a northeast-southwest trending spreading centre on the Argo Abyssal Plain. The spreading centre propagated southwards during the Late Jurassic. This resulted in active rifting in the Barrow Sub-basin and ultimately led to the separation of the Indian and Australian plates during Valanginian time.Upper Jurassic synrift sediments in the eastern Barrow Sub-basin consist of detached basin floor fan complexes, channelised and canyon fed fan systems, slump deposits, prograding outer shelfal to slope deposits and deep marine claystones. Post-depositional uplift of the eastern shelfal areas during the Late Jurassic resulted in erosion of the transgressive and highstand fluvial-deltaic to shelfal deposits. These periods of uplift and erosion provided much of the sediment redeposited in the basinal areas during the lowstand periods. Seven sandstone facies were recognised in the Upper Jurassic sedimentary section based on core control. Each sandstone has unique reservoir characteristics which can be related to the depositional setting.The abundance of glauconite and belemnites combined with ichnology and biostratigraphic assemblages associated with marine environments, indicate that deposition of all the sandstone facies occurred within an outer shelfal - deep marine environment. Reservoir quality was best developed in the dominantly medium grained, moderate - well sorted sandstones, (facies 7), which were deposited as detached, basin floor submarine fan sands or interbedded turbidites. In contrast, reservoir quality was relatively poorly developed in the remaining facies which were deposited as slope fans, slumps, or distal turbidite deposits.The abundance of quartz and presence of banded iron, jasper, and potassic feldspar grains support the provenance for the basinal sandstone facies being the Precambrian alkyl granites and banded iron formation of.the Pilbara Shield and Hammersley Ranges. These Precambrian igneous rocks and metasediments mark the eastern boundary of the Barrow Sub-basin study area. To predict the distribution of sedimentary facies in the Upper Jurassic synrift sediments of the eastern Barrow Sub-basin, the interplay between the major controlling depositional processes, namely tectonics, sediment supply and eustasy must be understood. Subdivision of the synrift sedimentary section on the basis of lithostratigraphy can be misleading and does not adequately resolve the facies relationships observed in the well intersection. The results of this research form the basis for a regional sequence analysis and seismic stratigraphic study.
17
Ayers, James D. "Lithologic Evidence of Jurassic/Cretaceous Boundary Within the Nonmarine Cedar Mountain Formation, San Rafael Swell, Utah." Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1097256637.
18
Perkes, Tyson L. "Integrating Facies Analysis, Terrestrial Sequence Stratigraphy, and the First Detrital Zircon (U-Pb) Ages of the Twist Gulch Formation, Utah, USA: Constraining Paleogeography and Chronostratigraphy." Diss., CLICK HERE for online access, 2010. http://contentdm.lib.byu.edu/ETD/image/etd3409.pdf.
19
Hou, Pengfei. "Sinemurian (Early Jurassic) stratigraphy at Last Creek, British Columbia and Five Card Draw, Nevada : paleontology and environmental implications." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50066.
Abstract:
Over 400 ammonite specimens were collected from the Last Creek Formation in Last Creek, British Columbia and the Sunrise Formation in Five Card Draw, Nevada. A detailed taxonomic study from the Involutum Zone to the lower part of the Harbledownense Zone of the Sinemurian is presented. At least 38 species are identified and described, distributed amongst 15 genera and 5 families. Three species are introduced as new: Tipperoceras n. sp. A, Tmaegoceras obesus n. sp., Arnioceras n. sp. A. Also, Echioceratidae gen. et sp. indet. is tentatively introduced as a new species and genus. The following zones of the current Sinemurian zonation for western North America (Taylor et al., 2001) can be recognized, based on the stratigraphical distribution of the taxa identified, namely the Involutum, Leslei, Carinatum and Harbledownense zones in ascending order. The Jamesi Zone placed between the last two by Taylor et al. (2001) cannot be recognized in the study areas in either Canada or the United States and therefore it is removed from the current zonation scheme. A revised zonation and definition of the zones, with precise correlation to the primary standard northwest European zonation, are provided. The transgressive and regressive events in both Last Creek and Five Card Draw are calibrated with the revised Sinemurian zonation. Their relationships with eustatic changes as well as ammonite biodiversity and faunal turnover are also investigated. The Early Sinemurian transgression proposed by Hallam (1981, 1988) is well represented in both the Last Creek and Five Card Draw sections, and co-occurs with ammonite diversity maxima and a possible global positive CIE (carbon isotope excursion). The mid-Late Sinemurian regression and Late Sinemurian transgression are represented by facies and palebathymetric changes in Five Card Draw. The contrast in paleobiodiversity and faunal turnover as well as in carbon and osmium isotope profiles of the two study areas suggest significant differences in depositional environment, relative connection to the open ocean, and differences in terrestrial sediment input.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
20
Ross, C. Elizabeth. "Palynofacies, palaeoenvironmental change and sequence stratigraphy of the Middle Jurassic, Cleveland Basin and Brent Group of the UK." Thesis, University of Oxford, 1999. https://ora.ox.ac.uk/objects/uuid:f6e7c4a2-a4e0-49bb-b897-b500d74ce371.
Abstract:
Palynofacies analysis, which is the study of microscopic organic matter can, in association with sedimentological and palaeoecological data, provide temporal and spatial resolution in the characterisation of sedimentary environments and potentially, vegetation and climate. However, the reliability of palynofacies analysis as a tool for environmental reconstruction has been questioned recently. This uncertainty is due a number of factors, including the lack of standardisation in the processing and counting of organic matter, subjective and vague terminology used to classify organic matter, and existence of numerous classification schemes. These have all restricted comparison between studies and hence hampered the advance of palynofacies analysis. The most important factor is, however, limited understanding of the controls which govern the genesis of particular associations of particulate organic matter. These issues were addressed using a two-fold approach. Firstly, the particulate organic matter classification scheme created by Lewis in 1995 was tailored to produce a robust hierarchical classification scheme. Secondly, multivariate statistical analysis was applied to a Middle Jurassic data set. This revealed that the primary control upon the nature of the organic matter associations is preservation potential which is affected by redox status, and to a lesser extent by the degree and duration of transportation and disturbance to which the organic-matter has been subjected. The secondary influence was determined to be a change in the nature of organic matter through time. Following this analysis 19 different organic-matter assemblage groups were defined to decipher palaeoenvironmental changes during the Middle Jurassic. Variations in the associations of organic matter through the Aalenian to Bathonian reflect changes in the redox status, proximity to source, salinity and hydrodynamics. This investigation suggests that aridity and/or pronounced seasonality commenced during the early Bajocian of the region which is earlier than the findings of previous investigations. This is based principally on the concomitant increase in black fragments (charcoal) and acme of Classopollis pollen in both the Cleveland Basin and Brent Group. The black fragments are probably charcoal rather than post-depositionally altered fragments because they occur in a range of oxic and anoxic environments, in conjunction with brown fragments, and in a range of lithofacies. These results not only permit the characterisation of the environment of deposition but also illustrate that palynofacies yields a discernible climatic signal.
21
Wilborn, Brooke K. "Two New Dinosaur Bonebeds From the Late Jurassic Morrison Formation, Bighorn Basin, Wy: an Analysis of the Paleontology and Stratigraphy." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35709.
Abstract:
Vertebrate fossils have been discovered at several locations in the Bighorn Basin (Wyoming). The Virginia Museum of Natural History's (VMNH) digsite is located in the eastern part of the Bighorn Basin, in the Coyote Basin. Many scientists have worked within these basins trying to describe the stratigraphy. One question specifically asked is where the boundary between the Morrison Fm. (Jurassic) and the Cloverly Fm. (Cretaceous) lies. This new study attempted to show if the current method (Kvale, 1986) of determining the boundary is appropriate. The stratigraphy of the area was examined using Kvale, 1986, Ostrom, 1970, and Moberly, 1960's work in order to see which model was more robust. The fossils in the VMNH digsite were used to supplement the stratigraphic data in determining the age of specific beds.
All of Ostrom's units were identified throughout the study area. There is some doubt as to whether the units would be acceptable outside of the Coyote Basin because of laterally discontinuity. Nevertheless, his description of units is satisfactory for the study area, and is more appropriate than other methods. The geologic age of the dinosaurs uncovered in the VMNH quarry is in agreement with the age determined stratigraphically. The VMNH site is below Ostrom's Unit II, which would place it in the Late Jurassic. The determination of the Jurassic/Cretaceous stratigraphic boundary has not been resolved. However, since the Pryor Conglomerate member of the Cloverly Fm. can be identified throughout this area, it is proposed as the Morrison Fm./Cloverly Fm. boundary.Master of Science
22
Hesthammer, Jonny. "Stratigraphy and structural geology of Upper Triassic and Jurassic rocks in the central Graham Island area, Queen Charlotte Islands, British Columbia." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29872.
Abstract:
Upper Triassic and Jurassic rocks in the central Graham Island area comprise shale, siltstone, sandstone, and conglomerate of the Kunga, Maude, and Yakoun Groups. Volcanic rocks are common in the Middle Jurassic Yakoun Group. The oldest unit exposed within the study area is the Lower Jurassic Sandilands Formation of the Kunga Group, a more than 250 metre thick sequence of interbedded organic-rich shale, tuff, siltstone, and sandstone. The Lower Jurassic Maude Group conformably overlies the Kunga Group and is divisible into four formations. The Ghost Creek Formation is an organic-rich black fissile shale, and is overlain by calcareous sandstone of the Fannin Formation. The Whiteaves Formation consists of fissile calcareous grey shale that grades upwards into fossil-rich medium- to coarse-grained, sandstone of the Phantom Creek Formation. The base of the Middle Jurassic Yakoun Group is marked by an angular unconformity. The unit is more than 1500 metres thick and is divided into four lithofacies. The lowermost shale and tuff lithofacies is a sequence of interbedded shale, tuff, siltstone, and sandstone, with shale dominating. The sandstone lithofacies overlies and partly interfingers with the shale and tuff lithofacies and comprises medium- to thickly-bedded lithic arenite interlayered with thinly-bedded shale. The conglomerate lithofacies exists within the sandstone lithofacies and consists mostly of thickly-bedded pebble and cobble conglomerate. The volcanic lithofacies interfingers with, and overlies the sedimentary rocks of the Yakoun Group, and includes lava flows, pyroclastic rock deposits, and lahars.
The Kunga and Maude Groups record several relative changes in sea level. They formed in a progressively deepening basin. In Pliensbachian time, the basin shallowed and deposition, represented by the upper Fannin Formation of the Maude Group, was near-shore. Toarcian time is marked by an abrupt transgression. The upper part of the Whiteaves Formation and the Phantom Creek Formation of the Maude Group indicate a subsequent regression.
The sedimentary rocks of the Yakoun Group were deposited in local shallow marine basins. Volcanic rocks are most abundant in the eastern parts of the map area, and indicate that an igneous source is located in that direction.
All rock units in the map area are deformed by major northwest-trending faults and folds, reflecting at least four northeast-southwest oriented deformational events. The angular unconformity at the base of the Yakoun Group restricts one compressional phase to mid-Jurassic time. Abundant southwest-verging folds suggest development of northeast-dipping thrust faults during this compressional event. Northeast-trending normal faults cut through the thrust faults, postdating them and indicating a period of extension. Rocks of the Sandilands Formation are observed thrust on top of the Yakoun Group, thus indicating a second compressional event. Several small-scale strike-slip faults cut through all described rock units and overlying Tertiary sections, suggesting a late Tertiary deformational event.
The Middle Jurassic compressional event may be a result of collision of Wrangellia with North America, or could have been caused by changes in relative plate motion between the North American and Pacific plates during the break-up of Pangaea.
Lithologic similarities between the Jurassic and older units of Wrangellia on the Queen Charlotte Islands and coeval rocks of the Alexander terrane in southeastern Alaska suggest that there are no clear differences between the two, and that they were contiguous since Upper Paleozoic time.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
23
Matos, José Esteves de. "Stratigraphy, sedimentation and oil potential of the Lower Jurassic to Kimmeridgian of the United Arab Emirates : outcrop and subsurface compared." Thesis, University of Aberdeen, 1997. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=120500.
Abstract:
The Jurassic litho-biostratigraphy is reviewed and Jurassic depositional models are defined in order to clarify some regional stratigraphic uncertainties and to evaluate the hydrocarbon potential of the Jurassic of the United Arab Emirates (UAE). A thick succession of Triassic-Cretaceous shallow-marine carbonates is exposed in Wadi Naqab, southeast of Ras Al Khaimah in the UAE, Musandam Peninsula. The Jurassic, 1310 m thick, is examined using biostratigraphy, sedimentology and sequence stratigraphy and compared with the Abu Dhabi subsurface. Direct composition of the Jurassic foraminiferal biozones and algal assemblages can be made between Wadi Naqab and the South-Tethyan realm. Palynological data from the subsurface demonstrate that much of the Liassic, which is well represented in the Musandam Peninsula, is missing over most of the Emirates. A ca. 50 Ma time gap was defined within the Abu Dhabi clastic Minjur Formation (previously assigned to the Triassic). The age of the palynoflora of the upper Minjur is Bajocian, while the lower Minjur yielded Late Carnian palynomorphs. The Upper Toarcian and most of the Aalenian is also probably missing in the Musandam Peninsula, as in the subsurface of the Emirates and Saudi Arabia. A new Bajocian foraminifera Pseudodictyopsella jurassica, n. gen., n. sp., was recognised, and the inception of some stromatoporoids was earlier than previously thought. The Liassic of Wadi Naqab is dominantly a metre-scale 5th-order Milankovitch-driven succession composed of peritidal cycles. Cycle tops are commonly marked by corrosion zones and/or karsts. Stacked paleokarsts are found particularly in the Sinemurian and Lower Pliensbachian. In Wadi Naqab, the Middle and Upper Jurassic seem to comprise one shallowing-upward 3rd-order cycle built of abundant 5th-order cycles. As a result of comparisons in this study, the Bajocian Izhara Formation is redefined and a new type-section proposed. Most of the Kimmeridgian and Tithonian are absent in Wadi Naqab, and eastern onshore and offshore Abu Dhabi, as the result of uplift and erosion before deposition of the Lower Cretaceous. Possible major Jurassic (Liassic-Early Kimmeridgian) hydrocarbon plays of Abu Dhabi are: the Marrat lowstand wedge of eastern onshore, the Jurassic onlap of Triassic high blocks in offshore areas, the Minjur lowstand clastics, the offshore Uweinat and Upper Araej and the Upper Jurassic Hadriya and Hanifa reservoirs.
24
Jensen, Paul H. Jr. "Piecing Together the Triassic/Jurassic Stratigraphy Along the South Flank of the Uinta Mountains, Northeast Utah: A Stratigraphic Analysis of the Bell Springs Member of the Nugget Sandstone." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/649.
Abstract:
Nomenclature for the Upper Triassic and Lower Jurassic strata along the south flank of the Uinta Mountains has been somewhat confusing because of the position of the study area between southern Wyoming, where one set of names is used, and central/southern Utah where a different set of formation names is used. The Nugget Sandstone or Glen Canyon Sandstone of the eastern Uinta Mountains overlies the Upper Triassic Popo Agie or Chinle Formation. The nature of the contact between these two formations is unclear both in stratigraphic location and conformability. The Chinle Formation consists, in ascending order, of the Gartra Member, the purple unit, the ocher unit, and the upper red unit. The overlying Nugget Sandstone consists of two members, the lower Bell Springs Member and the overlying unnamed cross-bedded member, typically believed to be Navajo Sandstone equivalent. These two units of the Nugget Sandstone are thought to represent the Glen Canyon Group of the Colorado Plateau, although no obvious Wingate or Kayenta Formation equivalents have been recognized. The Bell Springs Member contains abundant fine-grained, ripple-laminated sandstones, red and green mudstones, occasional mudcracks and salt casts, evidence of burrowing and exposure, and some medium- to coarse-grained sandstones with small-scale (30-40 cm high) cross-beds. This member was deposited in a marine tidal flat environment, quite different from the mainly eolian environment of the rest of the Nugget Sandstone. The Bell Springs Member appears to be entirely Upper Triassic, based upon dinosaur tracks, while the upper windblown unit's age is unknown, but probably straddles the Triassic-Jurassic boundary. During mapping in the Donkey Flat, Steinaker Reservoir, Dry Fork, and Lake Mountain quadrangles, the Bell Springs Member of the Nugget Sandstone was mapped as a separate unit.
25
Thomson, Robert Charles. "Lower to middle Jurassic (Pliensbachian to Bajocian) stratigraphy and Pliensbachian Ammonite fauna of the northern Spatsizi area, North Central British Columbia." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25059.
Abstract:
The lithostratigraphy and Pliensbachian ammonite fauna of a sequence of Pliensbachian to Bajocian sedimentary rocks, informally referred to here as the Spatsizi Group, from the Spatsizi map-area (104 H) in north-central British Columbia are examined in this thesis. Twenty Five species of ammonites representing fifteen genera from Pliensbachian rocks of the Spatsizi Group are described and their stratigraphic ranges in the thesis area determined. The Spatsizi fauna is comprised primarily of ammonites of Tethyan aspect and also contains elements endemic to the East Pacific faunal realm. The Spatsizi fauna is located on the northern half of the Stikine terrane of the western Cordilleran eugeocline, and is surrounded by biogeographically related faunas containing ammonites of Boreal affinity in addition to Tethyan and East Pacific forms, indicating that northern Stikinia occupied a position within the mixed Boreal/Tethyan zone of the eastern Pacific region during the Pliensbachian. Subsequent tectonic displacement of Stikinia transported it northward to its present position.
The Spatsizi Group is informally defined and is divided into five informal formations; the Joan, Eaglenest Gladys, Groves, and Walker Formations. Each formation reflects deposition in a different sedimentary environment affected by varying degrees of volcanic (epiclastic or pyroclastic) input Rocks of the Spatsizi Group represent the basinward sedimentary equivalents to the coeval Toodoggone volcanics that formed along the southern flank of the Stikine Arch. Facies transitions from the Stikine Arch in the north to the sedimentary basin in the south are best developed in sediments deposited during Pliensbachian and Early Toarcian times, when epiclastic sands and conglomerates accumulating on the southern flank of the arch graded southward into silts and muds in the basin.
Two phases of non-coaxial deformation folded and faulted the rocks in the thesis map area. Deformation was probably related to interaction between the Stikinia and the North American continental margin during accretion.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
26
Cummings, Donald I. "Sedimentology and stratigraphy of an ancient progradational terrigenous clastic shelf margin, Missisauga Formation (Upper Jurassic-Lower Cretaceous), offshore Nova Scotia, Canada." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/29092.
Abstract:
Large-scale stratal architecture, structure, and commonly hydrocarbon distribution in the Mississauga Formation, Sable Subbasin, offshore Nova Scotia, can be satisfactorily explained by shelf margin progradation. Using an integrated subsurface dataset (2-D and 3-D seismic data, biostratigraphy, geophysical well logs, core), the physical characteristics and depositional history of the Missisauga Formation (Tithonian-Barremian) were studied on both local and regional scales. These data suggest that during deposition of the Missisauga, the shelf margin prograded southward from an initial position just basinward of the Venture Field (Tithonian) to a final position just basinward of the Glenelg and Alma fields (Barremian). Growth-faulted, storm-dominated deltaic sandstones deposited at or near the shelf margin during this process are interpreted to contain over half of the discovered in-place gas reserves offshore Nova Scotia. Because shelf-margin delta sand-bodies are typically shore-elongate, tend to occur in groups along a shelf margin and commonly correlate downdip to turbidite sand-bodies, recognition of the shelf-margin delta play-type will not only improve hydrocarbon exploitation strategies offshore Nova Scotia, but will provide an important framework to guide the identification of new exploration opportunities in genetically related parts of the stratigraphic section.
In the Venture Field, Tithonian shelf-margin delta lobes are stacked vertically, suggesting that growth-fault related subsidence at the shelf margin negated depositional topography and created topographic lows through which fluvio-deltaic systems preferentially flowed. Over several relative sea level cycles, the positive feedback between sediment supply and subsidence at the shelf margin potentially focused enough sediment to have constructed slope turbidite systems downdip, which in turn represent new exploration targets.
In the Glenelg Field, Barremian shelf-margin deltas were initially tide-influenced (dominated?) and then changed to a storm-dominated state, possibly because the shoreline initially prograded into a tidally resonant topographic depression, which upon being filled was converted to a wave-dominated setting. Along depositional strike of the main hydrocarbon-bearing sandstones at Glenelg, Barremian sandstone reservoirs in the Alma Field are interpreted to be storm-dominated shelf-margin delta deposits. However, unlike Glenelg, incised valleys were not identified at Alma, suggesting that downdip depocenters were fed by sediment that bypassed Glenelg during the Barremian.
Transgression at the end of the Barremian deposited mudstone of the Naskapi Member throughout the Sable Subbasin, forming a regional seal. Sharp-based, bioturbated shallow marine sandstones deposited locally during this transgression are an important play type in the western Sable Subbasin (e.g., Alma and Panuke fields).
27
Jensen, Paul H. "Mapping and piecing together the Triassic/Jurassic stratigraphy along the south flank of the Uinta Mountains, Northeast Utah : a stratigraphic analysis of the Bell Springs Member of the Nugget Sandstone /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd983.pdf.
28
Andrieu, Simon. "Lien entre diagenèse des discontinuités, faciès sédimentaire et stratigraphie séquentielle : exemple de la plateforme carbonatée de l'ouest de la France (Aalénien-Oxfordien)." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS514/document.
Abstract:
Les objectifs de cette thèse sont (1) de définir les facteurs contrôlant le développement à grande échelle des plateformes carbonatées intracratoniques et (2) de relier la diagenèse précoce des discontinuités avec les paléoenvironnements et les modèles de stratigraphie séquentielle. L’évolution de la plateforme carbonatée de l’ouest de la France a été reconstituée de l’Aalénien à l’Oxfordien (17 millions d’années). La topographie du socle contrôle la répartition latérale des bathymétries jusqu’au Bathonien moyen. La tectonique régionale favorise ou empêche localement la production carbonatée. À l’échelle des bassins ouest-téthysiens, des phases généralisées de disparition et de croissance des plateformes carbonatées sont contrôlées par les variations du climat d’une période de 9 millions d’années. La production carbonatée est faible pendant les périodes humides et importante au cours des périodes sèches perturbées par de courtes moussons. Des analyses isotopiques (δ18O et δ13C) à haute résolution ont été réalisées sur des ciments précoces variés localisés sous des discontinuités, permettant de reconstituer l’histoire paléoenvironnementale aboutissant à leur formation. Les ciments en dents de chien ainsi que les ménisques et enveloppes micritiques analysées ont précipité directement en calcite faiblement magnésienne dans l’eau de mer. Un nouveau modèle reliant architecture, stratigraphie séquentielle, faciès et diagenèse précoce est proposé pour une bordure de plateforme oolithique. Sur la plateforme interne, les discontinuités passent latéralement de surfaces subaériennes à des hardgrounds marins, dont l’érosion aboutit au dépôt de niveaux à intraclastes sur la bordure de plateforme. La cimentation précoce est uniquement localisée sous les discontinuités et est absente dans la bordure de plateforme où la sédimentation est continueThe objectives of this thesis are (1) to characterize the factors controlling the large-scale development of intracratonic carbonate platforms and (2) to link early diagenesis of discontinuities with palaeoenvironments and sequence stratigraphy models. The evolution of the western France carbonate platform is reconstructed from the Aalenian to the Oxfordian (17 million years). The basement topography controls bathymetries until the mid-Bathonian. Regional tectonics promotes or prevents locally carbonate production. General stages of carbonate platform growth and demise in western Tethyan basins are controlled by 9 million years’ climatic variations. Carbonate production is low during humid intervals and high during dry intervals disturbed by short periods of intensive rainfall. High resolution isotopic analyses(δ18O and δ13C) were performed on various early cements located below discontinuities to reconstruct the palaeoenvironmental conditions leading to their formation. Dogtooth cements, micritic meniscus and envelopes precipitated in low-magnesium calcite directly in seawater. A new model, linking architecture, facies, sequence stratigraphy and early diagenesis is proposed for an oolitic platform wedge. On the inner platform, discontinuities change laterally from subaerial surfaces to marine hardgrounds, whose erosion leads to the deposit of an intraclasts level on the platform wedge. Early cements are only located under discontinuities and are absent in the platform wedge because of a continuous sedimentation rate
29
Downs, Drew Tyler. "In search of the Triassic-Jurassic boundary : palynostratigraphy and carbon-isotope stratigraphy of the lower Dinosaur Canyon Member on the Colorado Plateau (Kanab, Utah) /." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1879993731&sid=4&Fmt=2&clientId=1509&RQT=309&VName=PQD.
30
Storm, Marisa. "Carbon-isotope stratigraphy, geochemistry and geochronology of the Lower Jurassic of the Cardigan Bay Basin (Llanbedr (Mochras Farm) borehole), UK, and the Neuquén Basin, Argentina." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:def18cfa-597d-4a1f-8aa2-1ee1dba635c8.
Abstract:
The lack of a continuous high-resolution carbon-isotope (δ13C) record based on a single material, and thus a single carbon reservoir, has so far inhibited investigation on the secular evolution of the Early Jurassic (~201-175 Myr) carbon cycle. The existing δ13C records for the Lower Jurassic Series tend to cover short stratigraphic intervals, originate from a variety of different sedimentary basins and different carbon reservoirs, or are of relatively low stratigraphic resolution. New δ13CTOC data from the continuous strata of the stratigraphically expanded Llanbedr (Mochras Farm) drill-core provides the most expanded Lower Jurassic δ13CTOC record to date. The record aggregates several δ13CTOC excursions of different stratigraphical extent and magnitude. Based on stratigraphic correlations, several of these excursions appear approximately coeval in several NW European sedimentary basins, in multiple carbon reservoirs. Geochemical characterization reveals an organic-lean character of the Lower Jurassic sediments, dominated by terrestrial organic matter. Changes in the relative admixture of marine vs terrestrial organic matter appear as a likely subordinate mechanism driving changes in δ13C. Consecutively appearing small-amplitude fluctuations (~0.5-2 ‰) of comparable magnitude and stratigraphic thickness, including those recorded elsewhere, and hitherto unrevealed excursions, appear to be largely orbitally paced, corresponding to long (405-kyr) eccentricity cycles. Orbital tuning of the continuous Hettangian to Pliensbachian record allows an astronomical timescale to be established, which closely agrees with previous timescales for the Hettangian and Pliensbachian stages, and provides the basis for a Sinemurian chronology. Furthermore, a stratigraphical framework is developed on Lower Jurassic sections in the Neuquén Basin, Argentina, providing the grounds for future work on the radioisotopic dating of the onset of the Toarcian oceanic anoxic event (T-OAE). A chemostratigraphic dataset allows the correlation to same-age records. Coeval appearance of siderite in the lower Toarcian of the Mochras core and the Neuquén Basin suggests a disturbance of the global sulphur cycle (possible low sulphate ocean) during the T-OAE.
31
McArthur, Adam D. "Temporal and spatial relationships of syn-rift, deep-marine hangingwall stratigraphy : examples from the Upper Jurassic of the Inner Moray Firth and the Central North Sea." Thesis, University of Aberdeen, 2012. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=191932.
Abstract:
Sedimentological and palynological datasets have been integrated to improve the understanding of syn-rift, deep-marine hanging wall strata. Upper Jurassic fault scarps were examined from Inner Moray Firth (IMF) outcrops and subsurface data from the Central Graben. Reduced sand supply recorded in IMF sediments, comprising siltstones, sandstones and breccias with Devonian clasts, was investigated by logging of 970 m of outcrop, provenance and palynological analysis, identifying three factors: exhumation of resistant footwall strata; climate change and sea-level rise. Sedimentation rates and lithofacies distribution identified an initial turbidite prone syn-rift phase; MTC dominated rift climax and late stage rifting when sedimentation declined. Thirty-two palynological samples determined palaeoclimate and palaeoenvironment variations; documenting change from humid-temperate to semi-arid. The nature of debris flows implies trigger by earthquakes and their frequency describes three phases of tectonism; turbidites are not distal MTC expressions but correlate with sea-level falls. Temporal and spatial relationships of MTCs and sandstones adjacent to the Josephine Ridge were investigated. One hundred and twenty one palynological samples were used to indicate subaerial exposure of the Judy Horst; Jade remained submerged, with implications for Central Graben palaeogeography. Seismic studies suggest footwall collapse of the horsts provided MTCs. Wireline signatures from sixteen wells and 116.7 m of core demonstrate a Triassic provenance for the MTCs. Distally the massive Freshney Sandstone is interpreted as gravity flow deposits; petrographic and HM studies indicate it was not sourced from the Josephine Ridge. Biostratigraphy shows sandstones were deposited during initial rifting; pre-dating MTCs, which are not predicted to have damaged the reservoir interval due to their non-erosive nature. This study has disentangled the effects of relative sea-level change and growth faulting in rift basins. Rift stages have been identified independently from multiple datasets. The effect of climate change on rift basin stratigraphy has been highlighted and changing footwall lithology has been shown to have a major impact on the development of siliciclastic sediments.
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Salazar, Soto Christian Andrés [Verfasser], and Wolfgang [Akademischer Betreuer] Stinnesbeck. "The Jurassic-Cretaceous Boundary (Tithonian - Hauterivian) in the Andean Basin of Central Chile: Ammonites, Bio- and Sequence Stratigraphy and Palaeobiogeography / Christian Andrés Salazar Soto ; Betreuer: Wolfgang Stinnesbeck." Heidelberg : Universitätsbibliothek Heidelberg, 2012. http://d-nb.info/1177040891/34.
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Schneider, Anton Christoph [Verfasser], Jörg [Gutachter] Mutterlose, and Ulrich [Gutachter] Heimhofer. "Stratigraphy, palaeoenvironment, and hydrocarbon potential of a non–marine sedimentary sequence : the Jurassic-cretaceous boundary interval in northern Germany / Anton Christoph Schneider ; Gutachter: Jörg Mutterlose, Ulrich Heimhofer ; Fakultät für Geowissenschaften." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1202608744/34.
34
Williford, Kenneth Hart. "Biogeochemistry of the Triassic-Jurassic boundary /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/6708.
35
Salloum, Mohamad Ali. "Analyse et modélisation stratigraphique du bassin sédimentaire onshore du Liban." Electronic Thesis or Diss., Université de Lorraine, 2022. http://docnum.univ-lorraine.fr/public/DDOC_T_2022_0098_SALLOUM.pdf.
Abstract:
Dans cette dernière décennie, des découvertes pétrolières importantes ont été faites au large du Liban dans les eaux est-méditerranéennes. Des études géologiques nombreuses en offshore (bassin du Levant) avec des acquisitions sismiques (2D et 3D) ont révélé des réservoirs d'hydrocarbures d'âge Miocène et suggèrent des perspectives prometteuses pour l'exploration. Par ailleurs, des modélisations de systèmes pétroliers à l'échelle de toute la région ont été réalisées, et montrent que les formations du Trias-Jurassique sont des roches-mères potentielles entrées à maturité thermique grâce à un fort contrôle tectonique à certaines périodes. Si celles-ci ont été très étudiées dans le Moyen Orient (Syrie, Jordanie, …) et ont permis de mettre en évidence leur potentialité pétrolière, la zone onshore libanaise a été quant à elle peu étudiée. L'approche stratigraphique complète et l'analyse du bassin sédimentaire onshore libanais font encore défaut sur certains aspects, ne permettant pas encore de définir parfaitement le rôle de la tectonique sur la géométrie, la nature et le calendrier des évènements sédimentaires et diagénétiques. Cette thèse a ainsi pour objectif de caractériser la géométrie des dépôts sédimentaires du bassin onshore et d'expliciter le contrôle tectonique sur son enregistrement stratigraphique. Un ensemble de données géologiques issues de la littérature sur la région (calages profondeurs, stratigraphie, etc.) est synthétisé dans un modeleur géologique 3D (SKUA-GoCad®). A partir de ces données géo-modelées, une approche interprétative permet de visualiser : i) les dépôts sédimentaires du bassin libanais ; ii) les structures tectoniques majeures le contrôlant ; iii) les surfaces d'érosion majeures et iv) les pièges pétroliers potentiels. Cette approche permet ensuite de générer des courbes de subsidence tectonique du bassin sédimentaire dans l'onshore libanais et une partie de l'offshore (sous PetroMod®) et de les interpréter. L'ensemble des résultats décrit les relations entre sédimentation et évolution tectonique à l'échelle régionale du Liban, de définir les failles majeures contrôlant l'enregistrement sédimentaire, d'identifier certaines phases clés dans l'évolution géodynamique et donc de retracer l'histoire tectonique du pays. D'une échelle régionale à une échelle plus locale, cette thèse se focalise sur une famille de failles ayant un rôle de contrôle sur l'enregistrement sédimentaire, en étudiant l'une d'entre-elles dans la région de Nahr Ibrahim. Ce travail se concentre sur la période initiale du Mésozoïque (Jurassique) présent sur le territoire libanais et d'un système structural peu étudié qui l'affecte : le système de failles normales mésozoïques NE-SO réactivées lors de la structuration du système de failles du Levant. Afin de caractériser le contrôle tectonique de ces failles sur la sédimentation (géométrie et diagenèse), une étude de terrain a été réalisée dans cette région, avec une approche sédimentaire, géochimique et diagénétique. Ainsi, trois coupes stratigraphiques dans la formation de Kesrouane (Jurassique) sont présentées. Une étude des faciès et de la diagenèse permet d'identifier les variations d'environnements, puis les principales phases diagénétiques qu'a subi cette formation jurassique. Par une approche chimio-stratigraphique (isotopes du strontium notamment), un calage par des âges absolus est proposé qui permet de corréler les coupes stratigraphiques et de mettre en évidence un rejet vertical de la faille régionale de Nahr Ibrahim de l'ordre de 800 m. Les résultats permettent de mettre en évidence le rôle important de ces failles sur le contrôle de la sédimentation jurassique, la structuration géométrique des formations mésozoïques et leur rôle potentiel joué sur la diagenèse. Aussi, cette approche locale a permis de revenir sur le modèle 3D régional et de l'améliorer en prenant en considération le rôle majeur de ces failles NE-SO réactivées (rejets de 800m) affectant la stratigraphieIn the last decade, important oil discoveries have been reported offshore Lebanon in the eastern Mediterranean waters. Numerous offshore geological studies (Levant Basin) with seismic acquisitions (2D and 3D) have revealed hydrocarbon reservoirs of Miocene age and suggest promising exploration prospects. In addition, petroleum system modeling has been carried out on the scale of the entire region and shows that the Triassic-Jurassic formations are potential source rocks that have reached thermal maturity due to strong tectonic control at certain periods. While these formations have been extensively studied in the Middle East (Syria, Jordan, ...) and have allowed highlighting their petroleum potential, the Lebanese onshore area has been little studied. The complete stratigraphic approach and the analysis of the Lebanese onshore sedimentary basin are still lacking in some aspects, not allowing to define perfectly the role of tectonics on the geometry, the nature, and the timing of sedimentary and diagenetic events.The objective of this thesis is to characterize the geometry of the sedimentary deposits of the onshore basin and to explain the tectonic control on its' stratigraphic record. A set of geological data from the literature on the region (depth settings, stratigraphy, etc.) is synthesized in a 3D geological modeler (SKUA-GoCad®). From these geo-modeled data, an interpretative approach allows to visualize: i) the sedimentary deposits of the Lebanese basin; ii) the major tectonic structures controlling this basin; iii) the major erosion surfaces and iv) the potential oil traps as elements of petroleum systems. This approach allows then to generate tectonic subsidence curves of the sedimentary basin in the Lebanese onshore and part of the offshore (using PetroMod®) and to interpret them. The results describe the relationships between sedimentation and tectonic evolution at the regional scale of Lebanon, define the major faults that controlled the sedimentary record, identify some key phases during the geodynamic evolution and thus trace the tectonic history of the country.From a regional to a more local scale, this thesis focuses on a fault set having a controlling role on the sedimentary record, by studying one of them in the Nahr Ibrahim area. This work focuses on the early Mesozoic (Jurassic) period present in the Lebanese territory and a little-studied structural system that affects it: the NE-SW Mesozoic normal fault system reactivated during the structuring of the Levantine Fault System. In order to characterize the tectonic control of these faults on sedimentation (geometry and diagenesis), a field study was carried out in the Nahr Ibrahim region, with a sedimentary, geochemical and diagenetic approach. Thus, three stratigraphic sections in the Kesrouane Formation (Jurassic) are presented. A study of the facies and of the diagenesis allows to identify the variations of environments, then the main diagenetic phases that this Jurassic formation underwent. Using a chemo-stratigraphic approach (strontium isotopes in particular), a calibration by absolute ages is proposed which allows the correlation of the stratigraphic sections and highlights a vertical rejection of the regional Nahr Ibrahim fault of about 800 m. The results highlight the important role of these faults in the control of Jurassic sedimentation, the geometric structuring of the Mesozoic formations, and their potential role in diagenesis. Also, this local approach has allowed us to revisit and improve the regional 3D model by considering the major role of these reactivated NE-SW faults (800m fault vertical offset) affecting the stratigraphy
36
MAY, STEVEN ROBERT. "PALEOMAGNETISM OF JURASSIC VOLCANIC ROCKS IN SOUTHEASTERN ARIZONA AND NORTH AMERICAN JURASSIC APPARENT POLAR WANDER." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/184199.
Abstract:
Jurassic volcanic rocks in southeastern Arizona provide an opportunity to study the paleomagnetism of an autochthonous segment of the Mesozoic Cordilleran magmatic arc. The Corral Canyon sequence in the Patagonia Mountains is a 650 meter thick homoclinal sequence consisting of interbedded volcaniclastic red-beds, welded ash-flow tuff, and lavas. Rb/Sr isotopic analysis of eight whole rock tuff samples yields an isochron age of 171 ± 3 Ma. Welded tuffs in the Corral Canyon sequence possess a stable, primary magnetization carried in both magnetite and hematite that defines a paleomagnetic pole at 61.8°N, 116.0°E, alpha₉₅= 6.2°. This pole is considered to be a reliable Middle Jurassic reference pole for cratonic North America. Paleomagnetic study of the Canelo Hills volcanics welded tuff member also yields a stable, primary magnetization throughout a stratigraphic thickness of 600 meters. However, results from this formation are enigmatic and the mean pole is discordant with respect to Middle Jurassic reference poles. Various aspects of the paleomagnetic data indicate that discordance of the Canelo Hills volcanics pole is probably due to acquisition of remanent magnetization during a period of non-dipole behavior of the geomagnetic field. Dispersion of paleomagnetic directions suggests that the welded tuff member represents at most two cooling units and can be interpreted as a caldera-fill sequence. A revised Jurassic APW path differs significantly from available paths and has important implications for North American plate motion and paleolatitude. The spatio-temporal progression of reliable Jurassic paleopoles, in conjunction with Triassic and Early Cretaceous poles, is well described by paleomagnetic Euler pole analysis. The APW path is divided into three tracks, separated by two cusps. These cusps represent changes in the direction of North American absolute plate motion and can be correlated with global plate motion and intraplate deformation events at approximately 200-210 Ma and 150 Ma. Finally, the APW path presented herein predicts more southerly Late Triassic and Jurassic paleolatitudes for North America than have been suggested by previous authors. Using revised reference poles, there are no inclination anomalies within paleomagnetic data from Late Triassic and Early Jurassic rocks of Stikinia and Quesnellia (B.C., Canada).
37
Woodfine, Richard Gareth. "Chemostratigraphy of Jurassic-cretaceous Italian carbonate platforms." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:03c84d34-a27d-46fd-89b0-d69a1501d888.
Abstract:
Samples of shallow-water carbonates were collected from Jurassic and Cretaceous Italian carbonate platforms and subjected to petrographic, diagenetic and chemostratigraphic analyses (87Sr/86Sr, δ13Ccarb, δ13Corg, δ18O). In general, the new chemostratigraphic data generated reflect trends established by previous work, some of which has been carried out on biostratigraphically calibrated reference sections. Consequently, chemostratigraphic correlations (87Sr/86Sr, δ13Ccarb) of isotope profiles taken from platform carbonates with well-dated reference sections have allowed the application of high-resolution dating frameworks to the biostratigraphically poorly constrained carbonate platforms. The increased resolution in dating of the Italian carbonate platforms has, furthermore allowed a detailed investigation into the facies response of these carbonate platforms to major geological events. In particular, platform responses to oceanic anoxic events and other periods of major perturbation in the global carbon cycle are analysed (early Toarcian, Aalenian-Bajocian, Oxfordian-Tithonian, Valanginian-Hauterivian, Aptian-Albian, Cenomanian-Turonian, Coniacian-Santonian). Lower Jurassic levels of the Trento Platform record platform devastation in the early Toarcian synchronous with a major negative δ13Ccarb excursion, followed by platform recovery synchronous with a pronounced δ13Ccarb positive excursion and return to background values. The Campania-Lucania Platform shows negligible response to the oceanographic events of the early Toarcian even though the characteristic carbon-isotope profile is readily identifiable. The Trento Platform drowned at approximately the Aalenian-Bajocian Stage boundary, synchronously with a reproducible negative followed by positive δ13Ccarb excursion, whereas the Campania-Lucania Platform underwent a facies transition from oolite to cyclically bedded micrite. The Friuli Platform showed negligible depositional response to the carbon-cycle perturbations of the Kimmeridgian-Tithonian, Valanginian-Hauterivian, Aptian-Albian and Cenomanian- Santonian (as registered in the δ13Ccarb record). The Campania-Lucania Platform registered flooding and increased levels of organic-matter preservation coincident with pronounced positive δ13Ccarb excursions at Cenomanian-Turonian and Coniacian-Santonian levels. Observations on the responses of carbonate platforms to oceanographic conditions during periods of global carbon burial lead to the conclusion that temperature excess is a hitherto neglected control on global carbonate accumulation rates.
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Jones, Charles Edward. "Strontium isotopes in Jurassic and Early Cretaceous seawater." Thesis, University of Oxford, 1992. http://ora.ox.ac.uk/objects/uuid:fe3733bd-8e31-4bba-a78b-6d8275a0075f.
Abstract:
The collection and analysis of a large number of belemnites and oysters with excellent biostratigraphic and diagenetic control has resulted in a highly detailed determination of the seawater Sr-isotope curve through the Jurassic and Early Cretaceous. The new data confirm the broad trends established by previous work, but the much sharper resolution of the new data allows the application of Sr-isotope stratigraphy with an optimal stratigraphic resolution of ± 1 to 4 ammonite subzones (± 0.5 to 2 Ma). The data show a general decline from the Hettangian (Early Jurassic) to a minimum in the Callovian and Oxfordian (Middle/Late Jurassic). This is followed by an increase through the Kimmeridgian (Late Jurassic) to a plateau reached in the Barremian (Early Cretaceous). In addition, there are major negative excursions in the Pliensbachian/Toarcian (Early Jurassic) and Aptian/Albian (Early Cretaceous). Stable isotope data collected from belemnites and oysters have resulted in the most extensive Jurassic δ13C and δ18O database to date. While both the carbon and oxygen data appear to give reasonable marine signals, the scatter in the data suggests that future research must document possible biological fractionation effects and develop better indicators for the diagenetic alteration of 613C and 6i 8O. The final chapter documents an unexpected correlation between sudden shifts in the Sr-isotope curve, the occurrence of positive 513C excursions, and the eruption of flood basalts. In the Jurassic and Cretaceous there is a correlation in time between sudden downward shifts in the Sr-isotope curve (Pliensbachian, Aptian, Cenomanian/Turonian), the occurance of positive 613C excursions, and the eruption of flood basalts. Each of these major downward shifts in the Sr-isotope curve is followed by a sudden upward shift, which although associated with a positive 613C excursion is not associated with an episode of flood basalt volcanism. In the Cenozoic the Sr-isotope curve no longer displays downward shifts, but the correlation continues between the occurrence of flood basalts and positive 513C excursions. Several lines of evidence suggest that the eruption of flood basalts is associated with pulses of hydrothermal activity, and that this hydrothermal activity brings about the conditions necessary for the genesis of carbon-burial events.
39
O'Brien, Jennifer Ann. "Jurassic biostratigraphy and evolution of the Methow Trough, southwestern British Columbia." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/558073.
40
Morgans, Helen Sarah. "Early to middle Jurassic stratigraphic development, vegetation and climate change in north-western Europe." Thesis, University of Oxford, 1997. http://ora.ox.ac.uk/objects/uuid:4b5cae3c-7562-45b9-b2a2-543b2649b24f.
Abstract:
The aim of work presented in this thesis was to explore the inter-relationships of cyclic sedimentation, relative sea-level change, and palaeoclimate as inferred from plant megafossils. To this end, the investigation focused on the classic plant-bearing Middle Jurassic succession of Yorkshire. The Middle Jurassic (Aalenian-Bathonian) Ravenscar Group of the Cleveland Basin (Yorkshire) comprises a predominantly fluvio-deltaic succession intercalated between thinner, laterally persistent marine units. There is a pronounced lateral facies change across the basin, from mainly alluvial sediments in the north to more marine deposits in the south. Although variable in character, the facies composing the sequence are described by four principal environments of deposition: alluvial, estuarine, lagoonal and marine. In an attempt to achieve a more accurate stratigraphic control on the succession, sequence-stratigraphic concepts are applied to outcrop exposures and subsurface cores. The identification of 'key surfaces' in the sequence resolves a series of lithological cycles which reflect relative sea-level fluctuations. Using this approach the Aalenian-Bathonian sequence can be subdivided into two large-scale (second-order) transgressive-regressive cycles onto which six medium-scale (thirdorder) cycles of transgression and regression are superimposed. The potential for correlating these lithological cycles regionally has been assessed by comparing coeval sections from southern Scandinavia. Plant-bearing fluvio-deltaic sequences from Bornholm and Scania were chosen as a means for appraising the lateral continuity of the cycles, and assessing what factors might have controlled their development. Study of floral remains from the Ravenscar Group within the context of this stratigraphic framework yields valuable palaeoclimatic information. Growth-ring analysis of fossil wood of Late Pliensbachian to Late Bathonian age indicates a distinctly seasonal climate with low to moderate interseasonal variation in tree growth. Significant intraseasonal influences on wood production are implicit in the abundance of false rings. Consideration of these results within a stratigraphic context suggests that conditions during the Bathonian were comparatively hostile: a finding which is interpreted to be due to more frequent and extended water shortages associated with a drier climate. These palaeoclimatic inferences are substantiated by evidence obtained from the examination of the flora using Correspondence Analysis (CA). This approach verifies the presence of a temporal fluctuation in the flora found by previous investigations and, furthermore, highlights physiognomic trends in the flora with time. The results from CA also indicate adverse growing conditions during the Bathonian, emphasized by the prevalence of xeromorphic taxa.
41
Williams, Carolyn Jane. "Integrated stratigraphic correlation of the Upper Jurassic : links to sea-level and climate change." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249195.
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Carmeille, Mehdi. "Faciès, architecture et diagenèse des carbonates du Jurassique moyen et supérieur dans la chaîne du sud-ouest Gissar (Ouzbékistan)." Thesis, Bordeaux 3, 2018. http://www.theses.fr/2018BOR30053.
Abstract:
Cette étude transdisciplinaire incluant sédimentologie, stratigraphie séquentielle, chimiostratigraphie, et géochimie organique et inorganique, examine la série carbonatée du Jurassique moyen-supérieur dans la chaîne du sud-ouest Gissar. Cette série représente l’affleurement le plus complet de la marge nord du Bassin d’Amu-Darya, une province gazière majeure d’Asie Centrale. La production de carbonates commence au début du Callovien, lors d’un ralentissement de la subsidence tectonique régionale associé à un réchauffement climatique. Un changement majeur dans la production carbonatée et la configuration de la plate-forme est enregistré à la fin du Callovien. Ce changement se caractérise par le passage (i) d’une rampe carbonatée avec un gradient proximal-distal bien contrasté du Callovien à (ii) un lagon à faciès péritidaux probablement protégé par des récifs de grande dimension à l’Oxfordien. La surface stratigraphique séparant ces deux séquences est interprétée comme une surface d'émersion régionale, enregistrant une chute du niveau marin entraînée par la tectonique et le climat. Durant la partie terminale de l’Oxfordien moyen, un ou plusieurs bassins intrashelfs sont localisés au sud-ouest de la plate-forme carbonatée. Des carbonates fins nodulaires ou laminés se déposent dans des eaux stratifiées, légèrement hypersalées et anoxiques à dysoxiques, où des tapis microbiens produisent de la matière organique et des carbonates. Ces faciès enregistrent l’initiation de la restriction du Bassin d’Amu Darya, qui se poursuit avec la progradation d’une sabkha et le dépôt de séries anhydritiques et salifères. La comparaison des séries sédimentaires met en évidence des évènements stratigraphiques communs entre le sud-ouest Gissar et les autres bassins des marges nord téthysienne et sud téthysienne : initiation de la plate-forme carbonatée, excursions isotopiques du carbone, âge et mode de formation des roches mères organiques (etc.), impliquant des contrôles climatiques et/ou tectoniques à grande échelle. L’étude pétrographique et géochimique de la diagenèse des carbonates révèle une paragenèse complexe. Certains faciès sont influencés par la fabrique sédimentaire lors de la diagenèse précoce. La succession des phases diagénétiques est reliée à la stratigraphie et à la subsidence des carbonates. Après leur dépôt, les sédiments de la série du Kugitang ont été enfouis à plus de 2 km de profondeur. Des phases liées à des fluides chauds et possiblement à la réduction thermochimique des sulfates se mettent en place durant la Mésogenèse. Finalement, les données stratigraphiques à haute résolution obtenues sur les affleurements du sud-ouest Gissar sont utilisées pour aider à la prédiction de la répartition des réservoirs d’hydrocarbures en subsurface du Bassin d’Amu-DaryaThis transdisciplinary study including sedimentology, sequence stratigraphy, chemostratigraphy, and organic and inorganic geochemistry examines the Middle-Upper Jurassic carbonates series located in the southwestern Gissar range. These carbonates, also known as the Kugitang series, represent the most complete outcrop of the northern margin of the Amu-Darya Basin, a gas-producing province of Central Asia. Carbonate production begins in the late Early Callovian during a regional slowing of the tectonic subsidence, coeval with a climate warming. A major change in the carbonate production and platform configuration is recorded at the end of the Callovian: (i) a carbonate ramp with a well-contrasted proximal-distal gradient develops during the Lower to Middle or Upper Callovian. It is overlain by (ii) a vast low energy lagoon dominated by peritidal facies, probably protected by large reefs, during the Lower and Middle Oxfordian. The stratigraphic surface separating the two depositional sequences is associated with a hiatus (Upper Callovian-Lower Oxfordian) and interpreted as a regional exposure surface recording a sea-level drop caused by tectonics and/or climate. During the Middle Oxfordian, one or several intrashelf basins develop southwestwards of the studied carbonate platform. Laminated and nodular carbonates rich in organic matter predominate in these basins. They are interpreted to have formed through the mineralization of microbial mats colonizing the stratified, slightly hypersaline, anoxic to dysoxic basin floor. Large scale reefs may have favored the isolation of these basins. These deposits record the initiation of the tectonic isolation of the Amu Darya Basin, which culminates with the progradation of a large-scale sabkha and the deposition of a thick anhydrite and salt series. The comparison of stratigraphic series highlights common events in several basins of the northern Tethyan margin, but also with the Arabian Plate: initiation of the carbonate platform, carbon isotope excursions, age and depositional conditions of organic-matter rich rocks, etc. The petrography and geochemistry of carbonates reveal a complex diagenetic history. Some facies are strongly controlled by the sedimentary fabric. The diagenetic succession is tentatively linked with the stratigraphy and the subsidence history. Following deposition, the Kugitang series was buried at more than 2 km. Some cements are interpreted to have formed through the circulation of hot fluids in the rocks during the mesogenesis and possibly due to thermochemical sulfate reduction, especially in the Callovian Sequence. Finally, the high-resolution stratigraphy established in this study is used to help improving the prediction of carbonate reservoirs in the subsurface Amu Darya Basin
43
Geesaman, Patrick J. "Structural observations and stratigraphic variability in Jurassic strata, Upheaval Dome, Canyonlands National Park, Utah, USA." Thesis, Colorado School of Mines, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1549082.
Abstract:
Upheaval Dome is a structurally deformed topographic depression located in Canyonlands National Park, southeast Utah. Multiple hypotheses for its origin have been proposed by various scientists over many years of research. The two remaining viable hypotheses are at opposite ends of the geologic spectrum, one proposing long-term deformation of the structure, while the other proposes a catastrophic meteorite impact. (1) The seminal paper by Jackson et al. (1998) suggests that Upheaval Dome was created due to the growth and subsequent pinch-off of a salt diapir sourced from the Pennsylvanian Paradox Formation. Their conclusions were based on various growth geometries in Jurassic age strata. (2) Perhaps the most influential paper proposing a meteorite impact at Upheaval Dome is by Buchner and Kenkmann (2008), titled "Upheaval Dome, Utah, USA: Impact origin confirmed". In this paper only two grains of shocked quartz are identified, out of 120 standard thin sections. Based on these thin sections comprising medium-coarse sand grains, only ~0.00043% of grains displayed evidence of high-pressure deformation. For shocked quartz to confirm a meteorite impact there must be abundant shocked grains (2-5%), and ~0.00043% cannot be considered abundant (French and Koeberl, 2010).
Prior to this study there has been no attempt made to combine an in depth stratigraphic investigation of exposed, accessible formations with structural and lithologic observations in the Upheaval Dome area. Analysis of stratigraphic field data for Triassic to Jurassic-aged strata reveals: (1) stratigraphic thicknesses from measured sections range from 7 meters to 224 meters in the Kayenta Formation, and projected thicknesses in cross sections can exceed 400 meters; (2) distinct changes in facies distributions in relation to mapped structural features; (3) localized angular discordances, such as angular unconformities and onlaps, at the contact between formations or within individual formations.
Analysis of structural features at Upheaval Dome reveals: (1) synclinal axes and associated depositional centers shift throughout the Jurassic; (2) stratigraphic thicknesses across normal faults from hanging to footwall blocks are unequal on the scale of meters to tens of meters; (3) thrust faults verge dominantly to the southeast regardless of the side of the dome they are located on; (4) blocks of Triassic Chinle Formation encased in the younger Jurassic Wingate Sandstone adjacent to dog tongues suggests the involvement of a brief period of allochthonous salt break out after the deposition of the Chinle. Petrographic analysis was inconclusive, as there were no shocked grains, nor any clasts of the Paradox Formation present in younger formations.
The research presented in this study strongly indicates that long-term deformation occurred at Upheaval Dome during the Early Jurassic and possibly in older less well exposed units. Evidence supporting long-term deformation includes growth strata, changes in facies distributions, shifting formation depocenters, angular discordances, and growth faults. Sparse indicators of catastrophic are also present in the form of sparse shocked quartz grains and poorly developed shatter cones. To accommodate these juxtaposing deformational regimes an evolution of Upheaval Dome is presented here that relies on an early meteorite impact to initiate active diapirism leading eventually to a passively growing salt diapir. This explanation would account for the petrographic evidence supporting meteorite impact, as well as the growth geometries in the Triassic-Jurassic aged strata surrounding Upheaval Dome.
Upheaval Dome has historically been one of the most controversial geologic features in the United States. It is important for geologists to understand the genesis for this structure as it is an extremely well exposed field example of a meteorite impact, pinched-off salt diapir, or a combination of the two, and can help further understand similar structures found around the world at the Earth's surface, or in the subsurface.
44
Ejembi, John Idoko. "SEDIMENTOLOGY AND STRATIGRAPHIC EVOLUTION OF THE PARADOX BASIN IN THE MIDDLE-LATE JURASSIC, WESTERN UNITED STATES." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/dissertations/1624.
Abstract:
The Middle-Upper Jurassic sedimentary rocks (i.e., the Entrada Sandstone, Wanakah Formation, and Morrison Formation) in western Colorado were mostly deposited in the Paradox Basin and form part of the modern-day Colorado Plateau in the Cordilleran foreland region. These rocks were deposited in the Mesozoic during periods of active tectonic processes in western and eastern Laurentia due to the Cordilleran magmatism and continued rifting of Pangaea, respectively. The Middle-Late Jurassic sedimentary record in the Paradox Basin shows rapid transition in depositional environments, pulses in sedimentation, post-depositional alteration, and changes in provenance. This dissertation project utilizes three main scientific tools to address pertinent geologic questions regarding the stratigraphic evolution of these units in the Paradox Basin. U-Pb detrital zircon geochronology of sandstones from these units show local and distal provenance sources. The anisotropy of magnetic susceptibility (AMS) of sediments and rock magnetism attribute the post-depositional alteration to percolation of ferruginous fluids driven by an adjacent regional uplift. Multi-geochemical proxies in paleosols suggest variable redox conditions, and a sub-humid to humid paleoclimate with seasonal precipitation during sedimentary hiatus in the Paradox Basin.
45
Hesketh, Richard A. P. "Biostratigraphic calibration and sequence stratigraphic interpretation of the Upper Jurassic of Scotland and the North Sea." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/15016.
Abstract:
Biostratigraphic analysis of the lower part (Oxfordian-Kimmeridgian) of the Upper Jurassic Humber Group in the Outer Moray Firth of the North Sea and coeval onshore Scottish sections has resolved a long-standing controversy regarding the stratigraphic range of key dinoflagellate cyst (‘dinocyst’) taxa. The biostratigraphic ranges of these key species can now be shown to be comparable for Scotland, the North Sea and the classic Upper Jurassic English sections, indicating that the former North Sea Dome did not represent a barrier to faunal migration in Kimmeridgian times. Causes behind previously reported biostratigraphic anomalies can now be demonstrated to result from a combination of erroneous identification of cored material, inconsistent taxonomy and past failures to adhere to the codes of taxonomic nomenclature. The resolution of these reported biostratigraphic anomalies enables a new, robust, chronostratigraphically calibrated dinocyst biozonation to be proposed for the Regulare to Mutabilus Standard Ammonite Zones of Scotland and the North Sea. The application of the unified biostratigraphic scheme enables a revision of the lithostratigraphy, and therefore depositional history, of the Piper and Kimmeridge Clay Formations of the Humber Group in the Outer Moray Firth. The results from the Ivanhoe, Rob Roy and Hamish fields of United Kingdom Continental Shelf (U.K.C.S.) block 15/21 indicate that the Mid Shale Member, a component part of the Piper Formation, was deposited from Oxfordian, Rosenkrantzi Zone times to basal Kimmeridgian, Baylei Zone times. This conclusively demonstrates its strategraphic equivalence to the I-shale Member of the Piper field for the first time, thus necessitating redefinition but simplification of the lithostratigraphic terms used in the basin. Deposition of the Supra Piper Sands was terminated by a transgressive event which was initiated in Mutabilis Zone times, with Kimmeridge Clay Formation mudstone deposition occurring in response to a major transgression which reached its maximum extent in the Eudoxus Zone.
46
Ahmed, Sirwan Hama. "Tectonostratigraphic evolution of the northeastern Arabian Plate in Kurdistan since the Jurassic." Paris 6, 2013. http://www.theses.fr/2013PA066625.
Abstract:
La zone étudiée est située dans le nord de l’Irak dans la Région Autonome du Kurdistan. Cette région correspond géographiquement à la partie nord-ouest de la chaîne du Zagros. La chaîne du Zagros est une chaîne plissée de couverture longue d’environ 1800 km. Elle résulte du plissement de la couverture sédimentaire de la marge et de la plate-forme de la plaque arabe pendant la collision cénozoïque entre la plaque arabe et l’Eurasie. Ce travail s’appuie sur une étude tectono-stratigraphique des série jurassique à cénozoïque du Kurdistan. La période antérieure à la collision a principalement été étudiée, en particulier les relations entre les principaux évènements tectoniques et la sédimentation. The principaux domaines développés sont (1) la biostratigraphie à partir de l’étude des assemblages de nannofossiles, (2) l’analyse de la tectonique cassante et (3) l’étude stratigraphique de la séquence d’âge jurassique à cénozoïque (plus particulièrement crétacée). Les séries de la chaîne du Zagros montrent de nombreux changements latéraux et verticaux de facies et d’environnement, plus particulièrement pendant le Crétacé. Au cours du Jurassique le Kurdistan était occupé par le bassin de Gotnia qui s’ouvrait vers le sud-ouest vers le bassin de Kermansha. Du Berriasien au Barrémien le Kurdistan était couvert par les carbonates des formations de Balambo et de Sarmord. Dans l’est et le sud-est du Kurdistan la formation de Sarmord passe latéralement graduellement aux facies de bassin de la formation de Balambo. De l’Aptien au Cénomanien une épaisse série de carbonates d’origine récifale constituant la formation de Qamchuqa s’est déposé. Un premier épisode extensif peu marqué est enregistré à l’Aptian. Il est associé à des changements latéraux de facies abrupts entre les formations de Qamchuqa et de Balambo. Pendant la période allant du Cénomanien au Turonien inférieur un graben apparait dans la région du Lac de Dokan dans l’est du Kurdistan où se déposent des facies plus profonds (formations de Dokan et Gulneri) entourés de dépôts de plate-forme. Pendant le Turonien se déposent les facies de bassin constitués des calcaires fins à silex de la formation de Kometan qui couvrent le nord-est du Kurdistan. Ces calcaires sont absents dans le centre et l’ouest du pays notamment dans les anticlinaux de Safeen, Shakrok et Harir où cette formation a été totalement ou partiellement érodée pendant la période Coniacien à Campanien inférieur. La sédimentation est très hétérogène pendant le Crétacé supérieur avec une lacune du Coniacien et Santonian. Un bassin associé à une tectonique extensive se développe au Campanien avec le dépôt des marnes et des calcaires marneux de la formation de Shiranish. La première apparition au Kurdistan des facies flyschoïdes de la formation de Tanjero a été précisément datée du Campanien supérieur au Kurdistan. La formation de Tanjero, d’âge Campanien supérieur à Maastrichtien recouvre en concordance la formation de Shiranish. La formation de Tanjero se dépose dans le bassin d’avant-fosse associé à l’obduction des ophiolites téthysienne sur la plate-forme arabe. Le Campanien est une période de non-dépôt dans la partie centrale du Kurdistan (région de Safeen, Shakrok et Harir) alors qu’à l’ouest se développe une vaste plate-forme carbonatée (la plate-forme de Bekmeh). Cette sédimentation carbonatée disparait pendant le Campanien supérieur quand les calcaires marneux de la formation de Shiranish transgressent la plate-forme de Bekmeh. Dans le secteur d’Aqra la formation de Tanjero passe latéralement aux facies récifaux maastrichtiens de la formation d’Aqra. Cette dernière est recouverte en discordance par les carbonates de lagons de la formation de Khurmala. Pendant une grande partie du Campanien la sédimentation est contrôlées par des failles normales orientées NE-SW qui structures les grabens de Dokan, Spilk et Soran. Au cours du Maastrichtien dans l’extrême nord-est du pays des extensions NE-SW et NNW-SSE se développent dans le bassin d’avant-fosse et sont à l’origine des structures en horsts et grabens. Les dépôts clastiques de la formation de Tanjero sédimentent dans les grabens tandis que des lentilles des calcaires récifaux se déposent sur les horsts. Ces lentilles calcaires intercalées dans la série clastique flyschoïde peuvent atteindre quelques dizaines de mètres d’épaisseur et plusieurs kilomètres de long. L’étude des déformations cassantes dans ces corps carbonatés du Maastrichtien moyen-supérieur a montré que l’extension liée à la formation des structures en horsts et grabens était associée, par permutation des axes principaux de contraintes σ1 et σ2, à des régimes décrochants. Cependant l’essentiel des paléo-tenseurs reconstruits dans le Zagros kurde à partir de l’analyse des populations de failles à stries est associé à l’orogénèse du Cénozoïque supérieur du Zagros, donc à la collision entre l’Arabie et l’Eurasie. Le champ de contrainte néogène lié à cet évènement majeur est caractérisé par une alternance de régimes compressifs et décrochants avec des axes de la contrainte principale σ1 orientés NNE-SSW à ENE-WSW avec une pic principal orienté NE-SWThe studied area is located in Northern Iraq in the Kurdistan Region, which approximately corresponds to the North-Western part of the Zagros belt. The Zagros belt is an active fold and thrust belt approximately 1800 km long, mainly resulting from the deformation of the sedimentary sequence of the Arabian margin and shelf during the Cenozoic Arabian-Eurasia collision. This study concentrates on the tectono-stratigraphy evolution of Kurdistan from Jurassic up to present. However we mainly investigated the evolution of the pre-collision period, focusing on the relationship between tectonics and sedimentation. In this study we developed (1) a biostratigraphic approach using nannofossil analysis, (2) a fault tectonic analysis, and (3) a stratigraphic study of the Jurassic to Neogene sequences (more particularly the Cretaceous series). The Zagros fold belt in Kurdistan exhibits many lateral and vertical environmental and facies changes, especially during the Cretaceous times. During the Jurassic period the Kurdistan is occupied by the restricted Gotnia Basin. This basin disappeared and the Kurdistan area changed to open marine of a southwest Kermanshah Basin during the Cretaceous. During the Berriasian to Barremian the Kurdistan was covered by the carbonates of the Balambo and Sarmord formations. In the east and southeast the neritic Sarmord Formation gradationally and laterally passes to the basinal facies of the Balambo Formation. In the Aptian to Cenomanian period shallow massive reefal limestone of the Qamchuqa Formation deposited. The normal faulting that initiates during the Aptian is associated with an abrupt lateral change of the reefal Qamchuqa Formation to the Aptian-Cenomanian part of the Balambo Formation. During the Cenomanian-Early Turonian periods the graben formed in the Dokan Lake in eastern Kurdistan, where developed a deeper restricted environment (Dokan and Gulneri formations) surrounded by a shallow marine platform. During the Turonian the marine pelagic micritic cherty limestones of Kometan Formation covered northeast of Kurdistan, whereas in the Safeen, Shakrok and Harir anticlines the formation was totally, or partially, weathered during the Coniacian-Early Campanian period. The deposition during the Late Cretaceous is very heterogeneous with a gap in the Coniacian-Santonian times probably related to a non-deposition. Associated with extensive tectonics a basin developed during the Campanian with the deposition of shales, marls and marly limestones of the Shiranish Formation. The first appearance is the Kurdistan of the flysch facies of the Tanjero Formation was precisely dated of the Upper Campanian in northeastern Kurdistan. The Tanjero Formation conformably overlaying the Shiranish Formation and was deposited in the foredeep basin associated with the obduction of Tethyan ophiolites onto the Arabian Platform. The Early to Late Campanian period is a time of non-deposition in Central Kurdistan (Safeen, Shakrok and Harir anticlines). During the Late Campanian the Bekhme carbonate platform in the north disappeared when the marly limestones of the Shiranish Formation transgressed over the Bekmeh Platform. In the Aqra area the Maastrichtian Tanjero Formation laterally changed to the thick reefal sequence of the Aqra Formation that unconformably overlies by the Late Paleocene-Early Eocene lagoonal carbonate of the Khurmala Formation. The Campanian sedimentation is mainly controlled by NE- oriented normal faults forming Grabens in Dokan, Spilk and Soran areas. During the Maastrichtian in the extreme northeastern Kurdistan the NE-SW and NNW-SSE normal faults developed in the foredeep basin and originated horsts and grabens. Clastic sediments accumulated in the grabens and the reefal carbonate developed on the horsts. These bars are several tens of meters thick and commonly several kilometres long. The study of the brittle deformations in these Middle-Upper Maastrichtian carbonate bodies showed that the strike-slip faults associated with the extension, formed by permutation of the orientation of σ1 and σ2 axes. However most of the paleotensors reconstructed (compressional and strike-slip regimes) in the Kurdish Zagros from analysis of fault populations are associated with the Late Cenozoic Zagros orogeny, which results from the collision between Arabia and Eurasia. The Neogene stress field related to this major event is characterized by alternating compression with the principal stress axes σ1 oriented NE-SW to ENE -WSW with a main peak oriented NE-SW
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MARCHIONDA, ELISABETTA. "Facies analysis and stratigraphic-sedimentological modelling of the Upper Jurassic Arab Formation (onshore field, Abu Dhabi, UAE)." Doctoral thesis, Università degli studi di Pavia, 2018. http://hdl.handle.net/11571/1214853.
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Wall, Gavin Richard Tod. "The origin and tectonic significance of sediment-filled fissures in the Mendip Hills (SW England)." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670287.
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Porter, John Richard. "Stratigraphic analysis of the Jurassic Ellis Group and paleotectonics in North-Central Montana: deciphering the historically enigmatic 'Belt Island'." Thesis, Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/porter/PorterJ0811.pdf.
Abstract:
"Belt Island", an influential positive structure during the Jurassic, is widely represented in the geologic literature from 1948 to present. Introduced as primarily a stratigraphic anomaly in isopach maps of the Ellis Group, the inherent spatial and temporal context was loosely constrained. In subsequent literature, it is widely referenced in a structural context, though support is lacking for originating paleotectonics and stratigraphic data is minimal. Do the stratigraphy, sedimentology, and regional tectonics support the theory of a paleogeographic/paleotectonic high in north-central Montana during the Middle to Late Jurassic during the deposition of the Ellis Group? What are the tectonic explanations for such a feature if one did persist throughout said time? This project looked at outcrops and cores of the Ellis Group from around the project area. A lithofacies characterization was assembled based on rock properties. Utilizing previous work on lithostratigraphy, biostratigraphy, and regional unconformities and integrating these data with the lithofacies characterization a sequence stratigraphic framework was assembled. This sequence stratigraphic framework was applied to an extensive subsurface well database to generate a geologic framework over the project area. The distributions of lithofacies do support the theory of a large feature in the project area during the deposition of the Ellis Group. The stratigraphic architecture as well supports this theory, and additionally adds a spatial and temporal constraint to the feature. With the integrated sequence stratigraphic framework, it is apparent there was regional syntectonic activity influencing deposition. With the ability to put a temporal and spatial constraint on the paleotectonic feature it is possible to understand through time how this feature behaved. This allows the research to state that the feature originally known as "Belt Island" was the paleogeographic area of non-deposition and erosion of a larger peripheral bulge. This lithospheric flexure would have been the reaction to the crustal loading to the west during the Western North America Cordilleran Orogeny.
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Greenhalgh, Brent W. "A Stratigraphic and Geochronologic Analysis of the Morrison Formation/Cedar Mountain Formation Boundary, Utah." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1392.pdf.