Structural evolution of the Early Cretaceous depocentres, Otway Basin, Victoria

The Albula Pass region lies between the Lower Austroalpine Err Nappe and the Middle Austroalpine Silvretta Nappe. They will be treated here as the frame of the non- to gently metamorphic sedimentary units between the two during the Alpide times. Sedimentation started on a metamorphic Hercynian basement during the latest Carboniferous(?) and continued into the Permian. Then a sequence from the Alpine Buntsandstein to the medial Jurassic to early Cretaceous Aptychenkalk (=Maiolica) and radiolarites were deposited in an environment of rifting and subsidence. The succeeding Palombini clastics were laid down after the Aptychenkalk and mark the onset of shortening in the Alpine realm. The initial structures that formed were at least two north-dipping normal faults which formed before the deposition of the Jurassic sedimentary rocks. When shortening set in, the first structure that came into being was the south-vergent Elalbula Nappe, bending the normal faults into close antiforms. It became further dismembered into two pieces creating parts of the future Ela and Albula nappes in the Albula region. This motion was later reversed, when the entire ensemble became bulldozed by the immense body of the Silvretta Nappe along numerous, closely spaced thrust faults, some of which only very locally followed horizontal bits of the old normal faults, but in principle they determined their own course. No evidence for westerly motion could be identified, although microstructures in the structural fabric were not studied. The reason for this may be the pre-orogenic fabric in the bounding tectonic units.

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Tromsø - Bjørnøya Composite Tectono-Sedimentary Element

Geological Society London Memoirs ◽

10.1144/m57-2018-19 ◽

2021 ◽

pp. M57-2018-19

Author(s):

Alf Eivind Ryseth ◽

Dominique Similox-Tohon ◽

Olaf Thieβen

Keyword(s):

Early Cretaceous ◽

Middle Jurassic ◽

Late Jurassic ◽

Barents Sea ◽

Structural Evolution ◽

Primary Source ◽

Source Rocks ◽

Late Paleozoic ◽

The North ◽

Sea Floor Spreading

AbstractThe Tromsø - Bjørnøya composite tectono-sedimentary element in the southwestern Barents Sea comprises strata of Late Paleozoic - Paleocene age. Since the Paleozoic Caledonian orogeny, the structural evolution of the CTSE is mainly related to extension, culminating in Late Jurassic - Early Cretaceous hyperextension. Some compressive deformation observed during Late Cretaceous - Paleogene times may relate to activity in the North Atlantic prior to the Early Eocene onset of sea floor spreading between Norway and Greenland.The sedimentary succession may be up to 14 km thick. It comprises Late Paleozoic continental facies, followed by carbonates, evaporites and eventually cherts and marine clastic material. The overlying Triassic - Paleocene succession is entirely siliciclastic, reflecting Triassic - Middle Jurassic deltaic and shallow marine conditions followed by deeper marine conditions during Late Jurassic - Paleocene times.Primary reservoirs are encountered in the latest Triassic - Middle Jurassic succession, with secondary reservoirs found in Late Jurassic - Early Cretaceous syn-rift succession, and in Paleocene strata. The primary source rock for petroleum is of Late Jurassic - Early Cretaceous age. Other source rocks include strata of Triassic and Barremian age, and a recently observed unit of Cenomanian - Early Turonian age.

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Sedimentological observations on the early Cretaceous sediments in eastern parts of the Nûgssuaq embayment

Rapport Grønlands Geologiske Undersøgelse ◽

10.34194/rapggu.v79.7473 ◽

1977 ◽

Vol 79 ◽

pp. 45-61

Author(s):

E.J Schiener

Keyword(s):

Early Cretaceous ◽

Structural Evolution ◽

Precambrian Basement

The early structural evolution of the embayment is evaluated by interpretation of sedimentary features at the contact between Precambrian basement and the overlying sediments and by interpreting vertical facies relationships within the Cretaceous sediments.

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Structural Evolution Impact on Reservoir Quality Distribution in an Early Cretaceous Carbonate Reservoir, UAE

10.2118/202964-ms ◽

2020 ◽

Author(s):

Alicia McGeer ◽

Christopher Sellar ◽

Ravi Verma ◽

Dhabia Al Naqbi

Keyword(s):

Early Cretaceous ◽

Structural Evolution ◽

Carbonate Reservoir ◽

Reservoir Quality

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Temporal variations in the dynamic evolution of an overriding plate: Evidence from the Wulong area in the eastern North China Craton, China

Geological Society of America Bulletin ◽

10.1130/b35465.1 ◽

2020 ◽

Vol 132 (9-10) ◽

pp. 2023-2042 ◽

Cited By ~ 1

Author(s):

Shuai Zhang ◽

Guang Zhu ◽

Shiye Xiao ◽

Nan Su ◽

Cheng Liu ◽

...

Keyword(s):

Early Cretaceous ◽

North China Craton ◽

North China ◽

Structural Evolution ◽

Shear Zones ◽

Temporal Variations ◽

Normal Faults ◽

Second Phase ◽

Existing Structures ◽

Plate Deformation

Abstract The evolution of overriding-plate deformation, and the mechanisms responsible for this deformation, are debated. One area where these processes can be investigated is the eastern North China Craton (NCC) in China, which was situated in an overriding-plate position relative to the subducting Paleo-Pacific Plate during the Jurassic and Cretaceous. Here we constrain the structural evolution of the Jurassic and Cretaceous using new structural, stress field, and geochronological data from the Wulong area. The results show that the first phase of deformation (D1) produced a series of SE-dipping reverse shear zones and parallel folds in response to NW-SE shortening at 157–146 Ma (Late Jurassic). Based on microscopic observations and quartz c-axis analysis, it is suggested that the temperature during D1 deformation was 500 ± 50 °C. A second phase of contractional deformation (D2) at 146–132 Ma (earliest Early Cretaceous) gave rise to numerous NE-SW–striking sinistral faults and shear zones. The majority of D2 structures display ductile fabrics in the southwest of the Wulong area and brittle deformational features in the northeast, thus indicating enhanced exhumation in the former area. Microstructures of D2 sinistral shear zones indicate deformation temperatures of 300–400 °C. Inversion of fault slip data from the sinistral faults demonstrate that N-S compression was responsible for the D2 structures. The third phase of deformation (D3) was related to WNW-ESE extension during the middle to late Early Cretaceous (132–100 Ma). This extensional phase produced a series of NE-SW–striking normal faults and reactivated pre-existing structures. Dikes and plutons were emplaced during the D3 deformation, synchronous with the peak destruction of the NCC. Our results indicate that the eastern NCC showed temporal variations in stress and strain during the Jurassic and Cretaceous. Consistent with the slab-driven model, we suggest that this behavior represents the response of the overriding-plate to changes in subduction kinematics.

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Jurassic - Lower Cretaceous of the Danish Central Trough; - depositional environments, tectonism, and reservoirs

Danmarks Geologiske Undersøgelse Serie A ◽

10.34194/seriea.v16.7035 ◽

1987 ◽

Vol 16 ◽

pp. 1-45

Author(s):

Olaf Michelsen ◽

Niels Frandsen ◽

Lise Holm ◽

Thorkild Feldthusen Jensen ◽

Jens Jørgen Møller ◽

...

Keyword(s):

Organic Carbon ◽

Early Cretaceous ◽

Late Jurassic ◽

Structural Evolution ◽

Depositional Environments ◽

Density Currents ◽

Sediment Types ◽

Basin Subsidence ◽

Central Trough ◽

Tectonically Active

A revised model for the Jurassic - Early Cretaceous basin development in the Danish Central Trough is described on the basis of new studies of the bio- and lithostratigraphy and sedimentological and seismic data. The trough has been subdivided into a number of areas, each characterized by specific structural evolution. Middle Jurassic fluvio-deltaic and coastal sands follow the mid Cimmerian unconformity and probably cover large parts of the trough. Right-lateral movements, initiated during the Late Jurassic along WNWESE trending faults, caused fault controlled basin subsidence. The Jurassic and early Early Cretaceous sedimentation were dominated and characterized by clay. More than 4000 m of clay were deposited. Organic carbon rich clays were deposited from the Kimmeridgian until the Late Ryazanian, when deposition of organic carbon poor sediments under oxygenated conditions commenced. During the Late Jurassic transgression coastal sands were deposited along tectonically quiet basin margins. Sands deposited from density currents accumulated along tectonically active margins at the Jurassic-Cretaceous transition. More centrally in the basins, more distal turbidite deposits of Late Jurassic age may be present. Early Cretaceous basin expansion caused by elevation of the sea-level led to decreasing siliciclastic deposition rates and hence to more calcareous sediment types. Contemporaneously basin subsidence decreased. At mid Hauterivian time the importance of differential subsidence governed by left-lateral transtensional wrenching along NNW-SSE trending faults decreased. This change was accompanied by a mild inversion controlled by NNW-SSE directed right-lateral transpression, heralding regional subsidence. Following this inversion chalk was deposited in almost the entire trough area. Later, during the Barremian and Aptian anoxia in the basin caused deposition of marls rich in organic carbon, followed by marls deposited under oxygenated conditions during the Albian transgression. The distribution and character of possible reservoir bodies are discussed.

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Tectono-Sedimentary Evolution of the Uranium Deposits of the DASA Graben, Northern Niger

Global Journal of Science Frontier Research ◽

10.34257/gjsfrhvol21is1pg37 ◽

2021 ◽

pp. 37-64

Author(s):

Abdoulwahid Sani ◽

Moussa Konaté ◽

Peter Wollenberg ◽

A. D. Christophe

Keyword(s):

Early Cretaceous ◽

Structural Evolution ◽

Uranium Mineralization ◽

Hydrothermal Fluids ◽

Field Observations ◽

Uranium Deposits ◽

Borehole Data ◽

Sedimentary Evolution ◽

Combined Use ◽

Very High

This study presents the structural evolution of the N70° trending Paleozoic-Mesozoic DASA graben, which is considered a sub-basin of the Tim Mersoï basin, and is located in northern Niger. The DASA graben is a uranium-rich trough discovered in recent exploration surveys. A tectono-sedimentary analysis of the DASA graben was implemented with a combined use of satellite imagery, field observations, borehole data analysis and available literature. This graben was affected from the Carboniferous to the Early Cretaceous by two major tectonic periods. The first period was an uplifting stage, which prevailed during the Carboniferous-Permian times and the second, ranging from the Triassic to the Early Cretaceous, corresponds to a rifting episode. The particularity of the DASA graben is that the sediments contain very high uranium grades. Lithological and tectonic factors controlled the emplacement of the uranium mineralization in the graben. The successive fracturing phases that affected the DASA graben were associated with a greater circulation of hydrothermal fluids and would have favoured higher grades of uranium mineralization.

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CROSS-SECTION BALANCING AND THERMOCHRONOLOGICAL ANALYSIS OF THE MESOZOIC DEVELOPMENT OF THE EASTERN OTWAY BASIN

The APPEA Journal ◽

10.1071/aj96024 ◽

1997 ◽

Vol 37 (1) ◽

pp. 390 ◽

Cited By ~ 11

Author(s):

G.T. Cooper ◽

K.C. Hill

Keyword(s):

Cross Section ◽

Early Cretaceous ◽

Cross Sections ◽

Seismic Data ◽

Vitrinite Reflectance ◽

Geometric Analysis ◽

Structural Evolution ◽

Geometric Constraints ◽

Source Rocks ◽

Structural Style

Recent advances in cross-section balancing software have simplified the application of basic geometric constraints to the analysis of basin development. Geometric analysis of field and seismic data allows the user to verify initial interpretations and also elucidates important information about the structural evolution of a basin. Principally, computerised balancing and restoration of cross-sections assists in constraining:the amount of crustal extension;trap geometries, particularly fault geometries through time;the geometry of key horizons at any time, revealing basin morphology and migration paths;the time and amount of maximum burial and hence hydrocarbon migration; andthe likely mechanisms involved in basin evolution. In turn, these parameters can be used to further assess hydrocarbon prospectivity by providing useful data for lithospheric modelling.This study utilises 2D cross-section balancing software (Geosec™) to decompact, balance and restore a series of regional onshore-offshore cross-sections based on both reflection seismic data in the Torquay Embayment and field mapping in the Otway Ranges. The thickness of eroded strata has been constrained by Apatite Fission Track and Vitrinite Reflectance analyses. The resulting section restoration suggests that the eastern Otway Basin experienced extension of 26 per cent in the Early Cretaceous and that the Otway Ranges were subjected to −8 per cent shortening during mid-Cretaceous inversion and −4 per cent shortening during Mio-Pliocene inversion.The structural style of the Otway Ranges and Torquay Embayment is typified by steep, relatively planar, en echelon, N and NE-dipping Early Cretaceous extension faults that were subsequently inverted and eroded during the Cenomanian and Mio-Pliocene. The structural style of the region shows strong similarities with oblique- rift analogue models suggesting that the extensional history of the region was strongly controlled by prevailing basement fabric.Lower Cretaceous source rocks in the eastern Otway Basin reached maximum maturity prior to mid-Cretaceous inversion with the exception of parts of the Torquay Embayment which may not have experienced significant uplift and erosion at this time. The lack of subsidence in the eastern Otway Basin prevented the deposition of significant amounts of Upper Cretaceous sediments which are proven reservoirs in the western Otway Basin and Gippsland Basin. Subsequent Tertiary burial was insufficient, in most regions, to allow the source rocks re-enter the oil generation window.

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