scholarly journals Placodont remains (Sauropsida, Sauropterygia) from the Triassic of Hungary (Transdanubian Range and Villány Mountains)

2020 ◽  
Vol 100 (4) ◽  
pp. 1047-1063
Author(s):  
Kinga Gere ◽  
Torsten M. Scheyer ◽  
László Makádi ◽  
Attila Ősi
Keyword(s):  
Sedimentary Basins ◽  
Passive Margin ◽  
Dental Morphology ◽  
Transdanubian Range ◽  
European Plate

AbstractNew placodont remains from the Triassic of Hungary are described here. They come from two different tectonic units: the Transdanubian Range Unit representing Alpine type sedimentary basins and the Villány-Bihar Unit that was part of the southern passive margin of the European Plate during the Triassic. The fossils came from four stratigraphic levels with the oldest specimen, a maxilla fragment found in the upper Anisian of Forrás Hill, near Felsőörs (Transdanubian Range). Based on dental morphology, the specimen is referred to here as Paraplacodus broilii. This site is similar in age to the Monte San Giorgio (Switzerland and Italy) locality. A Carnian occurrence of placodonts from this tectonical unit is a dentary fragment and two isolated teeth referred to here as Placochelys placodonta. The youngest specimen from this unit is a placochelyid tooth fragment from the Rhaetian of the Keszthely Mountains (Transdanubian Range). The richest assemblage of new placodont remains is from the Ladinian of the Villány Mountains, southern Hungary. Cranial elements are referred to here as Cyamodus sp. Teeth from this site are similar to that of Cyamodus sp. described from Slovenia, and both assemblages are among the last occurrences of the genus in the European Triassic. The Villány site is considered as a gap locality because of the rarity of Ladinian placodont occurrences in the German-Alpine sedimentary basins.

Evolution of Antarctic prospective sedimentary basins

1989 ◽  
Vol 1 (1) ◽  
pp. 51-56 ◽  
Author(s):  
V.L. Ivanov
Keyword(s):  
Sedimentary Basins ◽  
Passive Margin ◽  
Mobile Belt ◽  
Continental Shelves ◽  
The Pacific ◽  
Different Types ◽  
Tectonic Features ◽  
Stratigraphic Evolution ◽  
Continental Glaciation ◽  
The Antarctic

No less than 15–20 sedimentary basins are now known on the Antarctic continental landmass and surrounding continental shelves. Reconstruction of their tectonic and stratigraphic evolution is a specialized task. Owing to the polar position of the continent, the Pacific and Atlantic global geostructures are closely spaced there and the interplay between them is strong enough to result in hybridization of the characteristic tectonic features of the various basins. The present morphostructure of the southern polar region of the Earth is characterized by a prominent circumpolar zoning. Therefore, the sedimentary basins form a gigantic ring along the continental margin, including both the shelf proper and the edge of the continent. Within the ring, the basins are associated with different types of margins successively replacing each other, from the Mesozoic magmatic are in the Pacific segment to the classic passive margin off East Antarctica. The formation of the sedimentary basins in the Antarctic segment of the Pacific mobile belt was a part of a single process of geosynclinal development, whereas on the craton flank the process was superposed on the continental structures by rifting during Gondwana fragmentation. During post-break-up tectonism, continental glaciation played an important part in the formation of the sedimentary basins.

scholarly journals Geochemical evaluation of Campanian-Maastritchian clay-shale sediments of Patti formation, Southern Bida and Mamu Formation, northern Anambra basins

2020 ◽  
Vol 18 ◽  
pp. 97-118
Author(s):  
Nathaniel Odoma Atabo ◽  
Ojochogwu Idakwo Sunday
Keyword(s):  
Source Rock ◽  
Tectonic Setting ◽  
Source Area ◽  
Sedimentary Basins ◽  
Passive Margin ◽  
Clay Shale ◽  
Clay Shales ◽  
Geochemical Evaluation ◽  
Clay Deposits ◽  
Chemical Index

Two basins (Southern Bida and Northern Anambra Basins) were investigated to deduce weathering, paleooxygenation, provenance, depositional environment and tectonic setting, as well as to establish a relationship between the two basins. The obtained high values of calculated weathering indices such as Chemical index of alteration (CIA > 90), Chemical Index of Weathering (CIW > 90), Plagioclase Index of Alteration (PIA > 90) and the Al2O3-(CaO + Na2O)-K2O ternary relationship for the clay – shale sediments from both basins indicate intense weathering in the source area. Important geochemical ratios such as V/Cr, Cu/Zn, Ni/Co, (Cu+Mo)/Zn, revealed predominantly oxic conditions for the clay – shale sediments from both basins, although, a more reducing or an anoxic condition cannot be ruled out for the clay – shale sediments from the Southern Bida basin due to high ratios of U/Th (1.93-5.67) and Cu/Zn (0.19-5.00). In addition, the Sr/Ba ratios (0.16–3.50) for the clay-shales from the Southern Bida basin indicated an alternated marine and continental paleo-depositional settings and only continental setting (Sr/Ba ratios = 0.22 – 0.50) for the Northern Anambra basin. The Th/Sc, La/Sc, Th/Co and the LREE/HREE ratios showed a derivation of the shale and clay deposits from similar felsic-rich source rock while the log of (K2O/Na2O) vs SiO2, revealed a Passive Margin tectonic setting for the two Basins. There is insignificant differences between the geochemical classifications, weathering, source rock/provenance and tectonic settings of clay-shale sediments of both sedimentary basins, however, there exist slight disparity in their salinity conditions and redox settings. Keywords: Geochemistry, Clay-shale, Provenance, Tectonic Setting, Northern Anambra and Southern Bida Basins

scholarly journals Contrasting transform and passive margin subsidence history and heat flow evolution: insights from 3D thermo-mechanical modelling

2021 ◽  
pp. SP524-2021-94
Author(s):  
Attila Bálazs ◽  
Taras Gerya ◽  
Dave May ◽  
Gábor Tari
Keyword(s):  
Heat Flow ◽  
Plate Tectonics ◽  
Temporal Dynamics ◽  
Sedimentary Basins ◽  
Passive Margin ◽  
Surface Processes ◽  
Continental Rifting ◽  
Zone Formation ◽  
First Order ◽  
Supplementary Material

AbstractTransform and passive margins developed during the continental rifting and opening of oceanic basins are fundamental elements of plate tectonics. It has been suggested that inherited structures, plate divergence velocities and surface processes exert a first order control on the topographic and bathymetric evolution and thermal history of these margins and related sedimentary basins. Their complex spatial-temporal dynamics have remained controversial. Here, we conducted 3D magmatic-thermo-mechanical numerical experiments coupled with surface processes modelling to simulate the dynamics of continental rifting, continental transform fault zone formation and persistent oceanic transform faulting and zero-offset oceanic fracture zones development. Numerical modelling results allow to explain the first order observations from passive and transform margins, such as diachronous rifting, heat flow rise and cooling in individual depocenters and contrasting basin tectonics of extensional and transtensional origin. In addition, the models reproduce the rise of both marginal ridges and transform marginal plateaus and their interaction with erosion and sedimentation. Comparison of model results with observations from natural examples yield new insights into the tectono-sedimentary and thermal evolution of several key passive and transform continental margins worldwide.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5756555

scholarly journals Application of seismic stratigraphy in reservoir characterisation: a case study of the passive margin deposits of the northern Orange Basin, South Africa

2020 ◽  
Author(s):  
Chris Adesola Samakinde ◽  
Jan Marinus Van Bever Donker ◽  
Ray Durrheim ◽  
Musa Manzi
Keyword(s):  
South Africa ◽  
Mass Transport ◽  
Gamma Ray ◽  
Sedimentary Basins ◽  
Seismic Stratigraphy ◽  
Passive Margin ◽  
Seismic Facies ◽  
Depositional Sequences ◽  
Seismic Reflectors ◽  
Mass Transport Deposits

AbstractThe Barremian-Cenozoic depositional sequences in the northern Orange Basin, SW, South Africa, were investigated using the principles of seismic stratigraphy to understand the interplay of tectonics and sedimentary processes in the distribution of potential hydrocarbon reservoirs. A seismic stratigraphic workflow (seismic sequence, seismic facies and lithofacies analysis) was completed by utilising three seismic lines (L1, L2 and L3) tied to Wireline data (gamma, checkshots and sonic) in two exploration wells (A1 and A2). Seven depositional sequences were mapped followed by the creation of lithofacies log interpreted from the gamma-ray log (GR) by setting maximum GR value at 60 API for Sandstone, 60–100 API for Siltstone and above 100 API for Shale. Six seismic facies units are recognised based on internal geometry and configurations of the seismic reflectors; Tangential-Oblique (SF1), Hummocky (SF2), Wavy-Parallel (SF3), Chaotic (SF4), Sub-parallel/parallel (SF5) and Divergent (SF6). SF4 is dominant within the Barremian-Aptian sequence and expressed in an incised valley fill, suggesting mass transport deposition accompanied by strong hydrodynamic conditions. Evidence of sedimentary basins progradation is seen within the Late-Albian-Turonian sequences, because of the occurrences of SF2, SF6 and SF 4 facies. SF5 facies is prominent in the Maastrichtian/Campanian sequence, indicating that the deposition of sediments may have been accompanied by uniform margin subsidence after the Late-Cretaceous uplift of the Africa margin. The occurrence of SF1 and SF4 facies within the Cenozoic sequence indicates terrigenous pro-deltaic deposits and mass transport deposits, respectively. Further results from seismic-lithofacies modelling reveal that sand deposits of Barremian-Aptian (SF4 facies unit) and Albian sequences (SF2 and SF6 facies units) are potential stratigraphic reservoirs in this part of the basin.

The Influence of lithosphere and basement properties on the stretching factor and the development of extensional faults across the Otway Basin and eastern Bight Basin

2020 ◽  
Author(s):  
nasim kharazizadeh
Keyword(s):  
Sedimentary Basins ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Major Influence ◽  
Normal Faults ◽  
Basement Faults ◽  
Stretching Factor ◽  
Minor Influence ◽  
Basement Structures ◽  
A Minor

<p>The Influence of lithosphere and basement properties on the stretching factor and the development of extensional faults across the Otway Basin and eastern Bight Basin</p><ol><li><strong> KHARAZIZADEH*, W.P. SCHELLART, J.C. DUARTE </strong></li> </ol><p>School of Earth, Atmosphere and Environment, Monash University, Clayton, VIC 3800, Australia</p><p>Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands</p><p>Instituto Dom Luiz (ILD) and Geology Department, Faculty of Sciences of the University of Lisbon, Campo Grande, Lisbon, Portugal  </p><p> </p><p>*[email protected]</p><p>*[email protected]</p><p> </p><p><strong>Abstract</strong></p><p>The large southern continental margin of Australia, with a wide variety of sedimentary basins, formed during Mesozoic rifting. The evolution of sedimentary basins is mainly controlled by plate tectonic activity and the mechanism of continental extension. This work presents a comparative study between two main depocentres of the Bight Basin (Ceduna, Duntroon sub-basins) and the Otway Basin. Here, the total amount of extension (∆L) and stretching factor (β) have been measured across the Otway Basin and eastern Bight Basin. The results show significant variation in extensional stretching along the basins, with the smallest stretching factors in the Ceduna and Duntroon sub-basins (1.2<β<1.4), and the largest amount of extension (~ 177 km) and the largest stretching factor (β=1.85) in the eastern part of the passive margin. The regions with the lowest β factor are underlain mostly by thicker lithosphere, while the regions with the largest β factor and amount of extension are related to younger and thinner lithosphere. The main basement structures have been mapped throughout South Australia and Victoria to examine the possible relationships between the new pattern of extensional faults and old basement fabrics. The distribution pattern of normal faults varies considerably along onshore and offshore components of basins. It is proposed that in some regions fault strike varies due to changes in orientation of pre-existing structures in the basement. For example, the north-south Coorong Shear Zone seems to affect the geometry of normal faults by changing their strike from E-W to NW-SE and also, in the easternmost part of the basin, the Bambra Fault changes the strike of normal faults to the NE-SW. Also, the NE-SW basement structures in the western part of the Gawler Craton have some control on normal faults in the western Ceduna sub-basin. Normal faults in the easternmost and westernmost parts of the Otway Basin have a similar orientation to the basement faults. However, in most regions basement faults are perpendicular to the normal faults and there is a minor influence on the new pattern of faulting. Our results imply that the properties of the continental lithosphere (age, thickness and strength of lithosphere) exert a major influence on the β factor and amount of crustal extension but only a minor influence on the geometry of extensional faults.</p><p><strong>Keywords:</strong> Otway Basin, Ceduna and Duntroon sub-basins, rifting, total amount of extension, β factor, normal faults, lithosphere properties</p><p> </p>

scholarly journals Seismic analysis of igneous systems in sedimentary basins and their impacts on hydrocarbon prospectivity: examples from the southern Australian margin

2012 ◽  
Vol 52 (1) ◽  
pp. 229 ◽  
Author(s):  
Simon Holford ◽  
Nick Schofield ◽  
Justin MacDonald ◽  
Ian Duddy ◽  
Paul Green
Keyword(s):  
Seismic Analysis ◽  
Sedimentary Basins ◽  
Hydrocarbon Exploration ◽  
Passive Margin ◽  
Continental Margins ◽  
3D Seismic ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Exploration Risk ◽  
Igneous Activity

The increasing availability of 3D seismic data from sedimentary basins at volcanic and non-volcanic continental margins has provided fundamental new insights into both the storage and transport of magma in the continental crust. As global hydrocarbon exploration increasingly focuses on passive margin basins with evidence for past intrusive and extrusive igneous activity, constraining the distribution, timing and pathways of magmatism in these basins is essential to reduce exploration risk. Producing and prospective Australian passive margin basins where igneous systems have been identified include the Bight, Otway, Bass, Gippsland and Sorell basins of the southern margin. This paper reviews both the impacts of volcanic activity on sedimentary basin hydrocarbon prospectivity (e.g. advective heating, reservoir compartmentalisation and diagenesis), and the styles, distribution and timing of late Cretaceous–Recent extrusive and intrusive igneous activity along basins of the southern Australian margin, providing illustrative examples based on 2D and 3D seismic reflection data.

scholarly journals Recent deeper geophysical results better account for the tectonics in the Italian area

1997 ◽  
Vol 40 (5) ◽  
Author(s):  
C. Morelli
Keyword(s):  
Oceanic Crust ◽  
Sedimentary Basins ◽  
Tyrrhenian Sea ◽  
Geological Data ◽  
Ligurian Sea ◽  
Po Plain ◽  
Adriatic Plate ◽  
The Alps ◽  
Tectonic Features ◽  
European Plate

Results from extended DSS profiles (1956-1986) in Italy and surrounding land and sea areas offer good constraints for other geophysical and geological data. Integrated interpretations outline the main tectonic features. Collisional tectonics is predominant in the Alps, for which the Adriatic plate acted as hinterland against the European plate foreland. Main results: W-wards, NW- and N-wards oriented overthrusting on the European crust, bending of the lower European crust, European Moho to 70 km depth with the Adriatic mantle indented above, crustal doubling (Adriatic over the European one). In the Apennines, on the contrary, the Adriatic plate acted as a foreland, against the overthrusts generated by the Tuscanian and Tyrrhenian mantellic bodies, heated, elevated and migrated NE-wards and SE-wards, respectively. Also the Adriatic plate bends under this load-centripetally towards the Tyrrhenian sea, so that the Adriatic Moho from 35 km depth is presumed to descend through a flexure till 40-50 km below the Tuscanian and Tyrrhenian land areas. The external peri-Apenninic area is still in compression and includes thick sedimentary basins, from the Po-plain to Sicily. The internal area is in extension, overlapped by thin, stretched crusts of Ligurian and Tyrrhenian origin, whose remnants occupy most of both seas areas, with two areas of oceanic crust in the SE-Tyrrhenian. Rifting and opening is in action also in the Ligurian Sea and Sicily Strait.

scholarly journals Structural evolution and tectonic setting of the Porongos belt, southern Brazil

2006 ◽  
Vol 143 (1) ◽  
pp. 59-88 ◽  
Author(s):  
K. SAALMANN ◽  
M. V. D. REMUS ◽  
L. A. HARTMANN
Keyword(s):  
Continental Crust ◽  
Tectonic Setting ◽  
Structural Evolution ◽  
Sedimentary Basins ◽  
Passive Margin ◽  
Ductile Deformation ◽  
Geochemical Data ◽  
Northwestern Part ◽  
Metavolcanic Rocks ◽  
Significant Contamination

The SW–NE-striking Porongos belt, located between juvenile Neoproterozoic rocks in the west and the Dom Feliciano belt, characterized by intense reworking of older crust, in the east, comprises a greenschist to amphibolite-facies metavolcano-metasedimentary succession (Porongos sequence) of unknown age with some exposures of Palaeoproterozoic gneisses (Encantadas gneisses). High-temperature ductile deformation of the basement gneisses comprises at least two magmatic events followed by three deformational phases including folding and shearing (DT1–DT3) and can be attributed to the Palaeoproterozoic Trans-Amazonian orogeny. The deformation of the Porongos sequence occurred during the Neoproterozoic Brasiliano orogeny and comprises four ductile deformation phases (DB1–DB4), including two phases of isoclinal folding associated with shearing recorded in mylonitic layers, followed by closed NW-vergent folding and thrusting leading to formation of a thrust stack. Uplift of the basement and formation of late tectonic sedimentary basins occurred as a result of semi-ductile to brittle block faulting in a sinistral strike-slip regime. The Porongos sequence can be subdivided into a southeastern and a northwestern part. Trace element analyses as well as Sm–Nd and Rb–Sr geochemical data indicate partial melting and significant contamination by old continental crust for the metavolcanic rocks. The metavolcanic rocks show εNd(t=780 Ma) values of −20.64 and −21.72 (northwestern units) and −6.87 (southeastern sequence). The metasedimentary rocks were derived from late Palaeoproterozoic to Archaean sources, and the data indicate different sources for the northwestern and southeastern rock units of the Porongos sequence. εNd(t=780 Ma) are −6.25 and −6.85 in the southeastern units, with TDM model ages between 1734 and 1954 Ma, and vary between −14.72 and −17.96 in the northwestern parts, which have TDM model ages between 2346 and 2710 Ma. High 87Sr/86Sr(t) values between 0.7064 and 0.7286 confirm reworking of older crust. Isotopic signatures of the Porongos sequence do not show indications for a significant contribution from a Neoproterozoic juvenile source. A passive margin or continental rift environment is suggested for the tectonic setting of the Porongos belt, which is compatible with both deposition of shallow marine to deep marine sediments and stretching of continental crust leading to volcanism which is characterized by significant contamination by old continental crust.

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