Relation between structural evolution of the Longmenshan orogenic zone and sedimentation of its foreland basin

Gare Kakheti foothills are located between Lesser Caucasus and Kakheti Ridge and are mainly represented by the series of NEN dipping thrust faults, most of which are associated with fault&#8208;related folds. Gare Kakheti foothills as a part of the Kura foreland fold-and-thrust belt developed formerly as a foreland basin (Oligocene-Lower Miocene) (e.g. Alania et al., 2017). Neogene shallow marine and continental sediments in the Gare Kakheti foothills keep the record on the stratigraphy and structural evolution of the study area during the compressive deformation. Interpreted seismic profiles and structural cross-sections across the Udabno, Tsitsmatiani, and Berebisseri synclines show that they are thrust-top basins. Seismic reflection data reveal the presence of growth fault-propagation folds and some structural wedges (or duplex). The evolution of the Udabno, Tsitsmatiani, and Berebisseri basins is compared with simple models of thrust-top basins whose development is controlled by the kinematics of competing for growth anticlines. Growth anticlines are mainly represented by fault-propagation folds. The geometry of growth strata in associated footwall synclines and the sedimentary infill of thrust-top basins provide information on the thrusting activity in terms of location, geometry, and age. This work was supported by Shota Rustaveli National Science Foundation (SRNSF - #PHDF-19-268).&#160;

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Structural evolution of the Skiddaw Group (English Lake District) on the northern margin of eastern Avalonia

Geological Magazine ◽

10.1017/s0016756800020926 ◽

1993 ◽

Vol 130 (5) ◽

pp. 621-629 ◽

Cited By ~ 28

Author(s):

R. A. Hughes ◽

A. H. Cooper ◽

P. Stone

Keyword(s):

Large Scale ◽

Volcanic Rocks ◽

Structural Evolution ◽

Foreland Basin ◽

Lake District ◽

Complex Deformation ◽

Northern Margin ◽

Marine Strata ◽

Deformation Event ◽

Group Structures

AbstractThe Skiddaw Group comprises a marine sedimentary sequence deposited on the northern margin of eastern Avalonia in Tremadoc to Llanvirn times. It is unconformably overlain by subduction-related volcanic rocks (the Eycott and Borrowdale Volcanic groups) of mid-Ordovician age, and foreland basin marine strata of late Ordovician and Silurian age. The Skiddaw Group has a complex deformation history. Syn-depositional deformation produced soft sediment folds and an olistostrome. Volcanism was preceded (in late Llanvirn to Llandeilo times) by regional uplift and tilting of the Skiddaw Group, probably caused by the generation of melts through subduction-related processes. The Acadian (late Caledonian) deformation event produced a northeast- to east-trending regional cleavage, axial planar to large scale folds, and a later set of southward-directed thrusts with associated minor folds and crenulation cleavages. This event affected the northern Lake District probably in the late Silurian and early Devonian. The Skiddaw Group structures contrast strongly with those formed during the same event in the younger rocks of the Lake District inlier. The contrasts are attributed to differing rheological responses to varying and possibly diachronous stresses, and to possible impedence of thrusting by the combined mass of the Borrowdale Volcanic Group and the Lake District batholith.

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The Cenozoic structural evolution of the northwestern Tarim Basin, China

10.5194/egusphere-egu21-3721 ◽

2021 ◽

Author(s):

Wenhang Liu ◽

Piotr krzywiec ◽

Stanisław Mazur ◽

Fanwen Meng ◽

Zhuxin Chen

Keyword(s):

Tarim Basin ◽

Late Miocene ◽

Seismic Data ◽

Structural Evolution ◽

Foreland Basin ◽

Growth Strata ◽

The North ◽

Kunlun Mountains ◽

Structural Style ◽

West Kunlun

The vast Tarim basin is surrounded by Tian Shan Mountains in the north, West Kunlun Mountains in the southwest, and the Altyn Mountains in the southeast. The southwestern Tarim Basin developed within the foreland of the West Kunlun Mountains and cumulated up to 10 km of Cenozoic strata. Despite several decades of geological studies its structural styles and details of its geological evolution are still being debated. In this study, we used seven regional seismic transects from the Yecheng - Hotan area calibrated by deep wells to assess lateral variations of a structural style and syn-tectonic sedimentation in this part of the basin.The basement of the SW Tarim Basin is covered by Paleozoic and Cenozoic strata, as revealed by several deep calibration wells. The regional north-directed basement thrust together with two evaporitic detachments including the Middle Cambrian evaporites (Awatage Formation) and Paleogene evaporites (Aertashi Formation) controlled the overall tectonic framework and structural evolution of this part of the basin. The visible growth strata on seismic data indicate progressive development of the structural wedge within the frontal W Kunlun Mountains from the Late Miocene to the Present day.Four main Cenozoic evolutionary stages of the W Kunlun Mountains and adjacent SW Tarim Basin have been determined. At the end of Paleogene, evaporites of the Aertashi Formation have been deposited in SW Tarim Basin; their thickness, as indicated by seismic data, increases towards the Kunlun orogenic wedge which suggests their deposition within the flexural foreland basin. Then, during the Early to Middle Miocene, about 4000m of sediments have been deposited in rapidly subsiding foreland basin. Towards the end of Late Miocene-Pliocene, tectonic wedging along thrust front led to significant uplift of the Kunlun Mountains that presently form S margin of the Tarim Basin. Quaternary migration of compressional deformations towards the North, towards the basin interior led to formation of the intra-basinal Jade anticline that was re-interpreted as a thin-skinned syn-depositional &#8220;fish tail&#8221; structure detached within the Paleogene evaporites. Present-day activity along some deeply buried thrusts of the Kunlun Mts. tectonic wedge might be related to current earthquakes.

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Study on Degradation Mechanism of Stress in Generation Process of Coal-Bed Methane

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.1995 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 1995-2000

Author(s):

Xiao Ming Li

Keyword(s):

Degradation Mechanism ◽

Eastern China ◽

Structural Evolution ◽

Foreland Basin ◽

Tectonic Stress ◽

Coal Bed ◽

Generation Process ◽

Transmission Electron ◽

Lattice Images ◽

Diffraction Patterns

In order to discuss the effect of tectonic stress on the structural evolution of coal, given the importance attached to High-resolution Transmission Electron Microscopy and micro-FTIR analysis, we investigated several aspects of material structures of high-rank Carboniferous period coal, located in the northern foreland basin of the Dabie orogenic belt in eastern China. High powered crystal lattice images of Bright Fields (BF) and Selected Area Diffraction patterns (SAD) of different types of metamorphism in coal were obtained. The organic molecular characters of different metamorphism types coal and the effecting factors are studied. The results show that:(1) the Basic Structural Units (BSU) become increasingly more compact as a function of rising temperature and pressure. Under pressure, the local orientation of molecules is strengthened, the arrangement of BSU speeds up and the degree of order is clearly enhanced; (2) tectonic stress is in favor of the chemistry environment transfer of hydrogen in coal, resulting in the decrease of aliphatic hydrocarbon and the increase of aromatic hydrocarbon in content, and accelerating the polycondensation and ordering of large molecules texture of coal.

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Crustal thickening and crustal extension as controls on the evolution of the drainage network of the central Swiss Alps between 30 Ma and the present: constraints from the stratigraphy of the North Alpine Foreland Basin and the structural evolution of the

Basin Research ◽

10.1046/j.1365-2117.1998.00063.x ◽

1998 ◽

Vol 10 (2) ◽

pp. 197-212 ◽

Cited By ~ 37

Author(s):

Fritz Schlunegger ◽

Rudy Slingerl ◽

Albert Matter

Keyword(s):

Structural Evolution ◽

Foreland Basin ◽

Swiss Alps ◽

Crustal Thickening ◽

Drainage Network ◽

Crustal Extension ◽

The North ◽

North Alpine Foreland Basin ◽

Alpine Foreland ◽

Alpine Foreland Basin

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Structural Evolution of Lorestan salient in North Zagros Mountain Belt, Iran

10.5194/egusphere-egu2020-7803 ◽

2020 ◽

Author(s):

Jun Wei Pang ◽

Jyr-Ching Hu

Keyword(s):

Structural Model ◽

Oil And Gas ◽

Active Tectonics ◽

Structural Evolution ◽

Foreland Basin ◽

Late Triassic ◽

Lateral Variation ◽

Zagros Mountain ◽

Oil And Gas Exploration ◽

Mountain Belt

Zagros foreland basin is the most important oil-gas foreland basin in the world. At least 60 oil and gas fields have been found. Therefore, research in this area will enrich the petroleum geological information of the foreland basin as an important basis for oil and gas exploration. First, we conduct 2D restoration of Lorestan salient in North Zagros Mountain Belt with 2DMove to test the rationality of the equilibrium profile and understand the structural evolution of the Lorestan salient. Base on the 2D restoration, faults evolved in the ways of in-sequence and out-of-sequence, many faults have breached the cover layer from basement then produced anticline, in the earlier stage of deformation. Anaran anticline and Kabir Kuh anticline caused by the thrusts that displacement along the thrust are 5769 m and 11496 m, respectively. The Vardalan, Dareh Baneh and Naft Anticline also produced by the basement thrust later, this result suggest that surface topography and anticline are highly associated with basement thrust. Second, using the Move2017-Surface to establish the 3D structural model to observe the lateral variation of the strata, some strata have lateral variation, the Mishan formation is absent in the NW but gradually appear to the SE and the Triassic carbonates thickness decreases from almost 1000 m in the southwest to 200 m in the northeast. This reduction in thickness may associated with late Triassic normal faulting and erosion. Third, we project the earthquake on the cross section to understanding the relation between earthquake distribution and tectonic patterns. Based on the analysis of seismicity and geological profiles, earthquake focal mechanisms are mostly reverse faulting with NW&#8211;SE strikes and the distribution is over whole horizontal Zagros belt but concentrated in depth of 5~16 km. In addition, larger magnitude earthquakes mainly distribute in southwest Lorestan, it implies that it is the main regime of active tectonics.

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