Tectonic Development of the Bengal Basin in Relation to Fold-Thrust Belt to the East and to the North

Author(s):  
Md. Sakawat Hossain ◽  
Md. Sharif Hossain Khan ◽  
Rashed Abdullah ◽  
Khalil R. Chowdhury
2021 ◽  
pp. M57-2021-31
Author(s):  
Harald Brekke ◽  
Halvor S. S. Bunkholt ◽  
Jan I. Faleide ◽  
Michael B. W. Fyhn

AbstractThe geology of the conjugate continental margins of the Norwegian and Greenland Seas reflects 400 Ma of post-Caledonian continental rifting, continental breakup between early Eocene and Miocene times, and subsequent passive margin conditions accompanying seafloor spreading. During Devonian-Carboniferous time, rifting and continental deposition prevailed, but from the mid-Carboniferous, rifting decreased and marine deposition commenced in the north culminating in a Late Permian open seaway as rifting resumed. The seaway became partly filled by Triassic and Lower Jurassic sediments causing mixed marine/non-marine deposition. A permanent, open seaway established by the end of the Early Jurassic and was followed by the development of an axial line of deep marine Cretaceous basins. The final, strong rift pulse of continental breakup occurred along a line oblique to the axis of these basins. The Jan Mayen Micro-Continent formed by resumed rifting in a part of the East Greenland margin in Eocene to Miocene times. This complex tectonic development is reflected in the sedimentary record in the two conjugate margins, which clearly shows their common pre-breakup geological development. The strong correlation between the two present margins is the basis for defining seven tectono-sedimentary elements (TSE) and establishing eight composite tectono-sedimentary elements (CTSE) in the region.


AAPG Bulletin ◽  
1964 ◽  
Vol 48 ◽  
Author(s):  
Frank C. Armstrong, Steven S. Oriel

2020 ◽  
Vol 90 (9) ◽  
pp. 1175-1197
Author(s):  
Anne C. Fetrow ◽  
Kathryn E. Snell ◽  
Russell V. Di Fiori ◽  
Sean P. Long ◽  
Joshua W. Bonde

ABSTRACT Terrestrial sedimentary archives record critical information about environment and climate of the past, as well as provide insights into the style, timing, and magnitude of structural deformation in a region. The Cretaceous Newark Canyon Formation, located in central Nevada, USA, was deposited in the hinterland of the Sevier fold–thrust belt during the North American Cordilleran orogeny. While previous research has focused on the coarser-grained, fluvial components of the Newark Canyon Formation, the carbonate and finer-grained facies of this formation remain comparatively understudied. A more complete understanding of the Newark Canyon Formation provides insights into Cretaceous syndeformational deposition in the Central Nevada thrust belt, serves as a useful case study for deconvolving the influence of tectonic and climatic forces on sedimentation in both the North American Cordillera and other contractional orogens, and will provide a critical foundation upon which to build future paleoclimate and paleoaltimetry studies. We combine facies descriptions, stratigraphic measurements, and optical and cathodoluminescence petrography to develop a comprehensive depositional model for the Newark Canyon Formation. We identify six distinct facies that show that the Newark Canyon Formation evolved through four stages of deposition: 1) an anastomosing river system with palustrine interchannel areas, 2) a braided river system, 3) a balance-filled, carbonate-bearing lacustrine system, and 4) a second braided river system. Although climate undoubtedly played a role, we suggest that the deposition and coeval deformation of the synorogenic Newark Canyon Formation was in direct response to the construction of east-vergent contractional structures proximal to the type section. Comparison to other contemporary terrestrial sedimentary basins deposited in a variety of tectonic settings provides helpful insights into the influences of regional tectonics, regional and global climate, catchment characteristics, underlying lithologies, and subcrop geology in the preserved sedimentary record.


2011 ◽  
Vol 182 (4) ◽  
pp. 337-346 ◽  
Author(s):  
Stéphane Molliex ◽  
Olivier Fabbri ◽  
Vincent Bichet ◽  
Herfried Madritsch

Abstract This study presents new constraints for Plio-Quaternary (post-2.4 Ma to present-day) anticline growth along the frontal zone of the Jura fold-and-thrust belt, in the Forêt de Chaux area, located 30 km SW of Besançon. The Forêt de Chaux area consists of a N080°E-elongated depression bordered by the Doubs and Loue rivers to the north and south respectively, and filled with Sundgau-type Pliocene alluvial deposits. The upper surface of the Pliocene deposits between the Loue and Doubs rivers is marked by a N065°E-trending ridge crossing the depression in a median position. A differential uplift along this ridge, post-dating the deposition of the gravels (2.4 Ma), is suggested by several geomorphological observations such as the opposite river migration on each side of the ridge as well as variations of drainage geometry and incision intensity. Geological and geophysical subsurface data indicate that the ridge roughly coincides with the axis of an anticline hidden beneath the Pliocene deposits. The observed uplift is presumably related to a post-2.4 Ma anticline growth. The fact that the azimuth of the hidden anticline axis is parallel to the strike of deep-seated Late Paleozoic basement faults and not to the local strike of the thin-skinned Jura structures indicates that the inferred post-Pliocene deformation could possibly be an expression of a recent thick-skinned deformation of the basement of the northern Alpine foreland. The focal depth (15 km) of the February 24th, 2004, Besançon earthquake supports the hypothesis of a basement fault reactivation.


2014 ◽  
Vol 56 (10) ◽  
pp. 1276-1294 ◽  
Author(s):  
Wangpeng Li ◽  
Shaofeng Liu ◽  
Tao Qian ◽  
Guoxing Dou ◽  
Tangjun Gao

1988 ◽  
Vol 25 (8) ◽  
pp. 1161-1174 ◽  
Author(s):  
H. G. Miller

New gravity data from the northeastern portion of the Gander Terrane of Newfoundland are analysed in association with existing gravity data. These are combined with the digitized and filtered aeromagnetic and geochemical data to produce an interpretation of the subsurface geology.Interpretation of these data suggests that there are two extensive areas underlain at depth by rocks similar to the Dunnage Terrane mafic and ultramafic rocks that outcrop at the Gander River ultrabasic belt. These regions of ultramafic and mafic rocks extend in two north–south belts throughout the study area, and both may have tongues continuing seaward beneath the Deadman's Bay pluton. The western belt, the Ocean Pond belt, probably consists of a series of granitic plutons underlain by mafic and ultramafic rocks. Geophysical modelling corroborates an earlier geological interpretation that the eastern belt, the Indian Bay Big Pond thrust belt, is a thrust sheet. The lateral extent of the thrust belt is accurately determined by new geophysical data. The presence of these two subsurface units composed of material similar to typical Dunnage Terrane rocks demonstrates that the Gander River ultrabasic belt is neither the most eastward extent of the Dunnage Terrane nor the sole thrust upon which Dunnage Terrane material was transported eastward. The two belts have associated diagnostic geochemical signatures and are bounded on the north and south by linear patterns in both the geophysical and geochemical patterns. The block defined by these geophysical and geochemical patterns is the same as that upon which the classic Gander Terrane was defined. The evidence presented in this paper suggests that this block may be allochthonous, which implies that the nature of the Gander Terrane may need to be reconsidered.


2020 ◽  
Vol 25 (2) ◽  
pp. 64
Author(s):  
Ayyed Hussein Ward ◽  
Thair Mudhir Fahmi ◽  
Hasnaa Saleh Khalaf

Folds of northern Iraq are considered integral part for the Western Zagros Fold – Thrust Belt. The growth of these folds was due to inversion displacement on inherited listric faults. This research deal with the relationship between the folds vergency and the faults that propagated folds, where that the dip of the back limb (gentle limb) for the fold is parallel to the thrust fault surface that propagated the fold, and the vergency of the fold determined by the forelimb (steep limb) situation. As a results, the folds of the high folded zone and of the western part of the low folded zone showed suture ( N and NE) vergency and foreland (S and SW) vergency, while the eastern part of the low fold zone showed foreland (S and SW) vergency only. The appearance of the suture and foreland vergency within the high folds considered as indication to the high tectonic development conformable with the location of these folds in the Iraqi Zagros Fold Belt, while the appearance of the suture and foreland vergency in the western part of the low folded zone attributed to the more tectonic development of this part in comparison with the eastern part of the zone that there folds appeared foreland vergencies only, or to the influence of the evaporite beds for Fatha formation in this part.          http://dx.doi.org/10.25130/tjps.25.2020.031


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