Analysis of structural deformation in the North Dabashan thrust belt, South Qinling, central China

2014 ◽  
Vol 56 (10) ◽  
pp. 1276-1294 ◽  
Author(s):  
Wangpeng Li ◽  
Shaofeng Liu ◽  
Tao Qian ◽  
Guoxing Dou ◽  
Tangjun Gao
2016 ◽  
Vol 155 (4) ◽  
pp. 893-906 ◽  
Author(s):  
CHUANBO SHEN ◽  
DI HU ◽  
CHUN SHAO ◽  
LIANFU MEI

AbstractThe Wudang Complex located in the central part of South Qinling, has been inferred to be a segment of the Yangtze Craton involved in the orogen. In this study, the cooling/exhumation history of the Wudang Complex is revealed through combined published geochronology data and new apatite fission-track results. Three rapid exhumation episodes related to relevant geodynamic events have been identified. Previous40Ar–39Ar and (U–Th)/He data indicate that the most significant exhumation, induced by the collision between the North and South China Blocks, occurred fromc.237 to 220 Ma after long-term subsidence and sedimentation of the passive continental margin. The second exhumation event, related to the long-distance effect of the Pacific subduction, occurred during the period fromc.126 to 90 Ma. Following the late Cretaceous – Eocene peneplanation stage, the final late Cenozoic exhumation sincec.15 Ma may be attributed to the combined effect of the eastward growth of the Tibetan Plateau uplift and the Asian monsoon.


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.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1419-1424
Author(s):  
Jun Feng Qian

The Structural and deformational features of fold-thrust belt in the north margin of Kashi,southern Tian Shan were disclosed based on various data such as two dimensional seismic profile and field geologic survey. The results show that the fold-thrustbelt can be divided into several rows of anticlines, includingKalaboketuoer-Wenguer, Tuopa-Kangxiweier, Atushi and Kashi on plane,and the development of Atushi anticlines and its north side was controlled by the activity of the thrust system originated along the middle Cambrian Awatage Group from north to south. The fold-thrust belt can be divided into two different spatial levels: the shallow tectonic is a large scale imbricate thrust system, the detachment surface is uplifted from Cambrian system to Neogene system; the deep structure is a buried duplex structure system, the fault in floor and fault in roof are located at gypsic horizon in Cambrian and Neogene systemrespectively. Based on structural deformation analyzing and balanced section technology, the distribution of each anticlinal belt and the structure style of the low and deep thrust systems are confirmed. In this area the distance is shortened by 32.64~49.1km from north to south since Pliocene with the scalage of 40.5%~50.51%,and its average crustal shortening rate is 9.11~13.71mm/a.


2021 ◽  
Vol 9 ◽  
Author(s):  
Delong Ma ◽  
Jianying Yuan ◽  
Yanpeng Sun ◽  
Hongbin Wang ◽  
Dengfa He ◽  
...  

Because of the influence of the far field effect of the collision between Euro-Asian and India plates during the Late Cenozoic, the Tian Shan orogenic belt underwent intense reactivation, forming the Southern Junggar fold-and-thrust belt (SJ-FTB) to the north and the Kuqa fold-and-thrust belt to the south. Most previous research focuses on the deformation features and mechanisms during the Late Cenozoic. However, little research has been done on deformation features and mechanisms during the Late Jurassic. In this paper, we conducted geometric and kinematic analyses of seismic profiles and outcrop data to reveal the Late Jurassic deformation characteristics in SJ-FTB. Furthermore, we carried out sandbox modeling experiments to reproduce the regional structural evolution since the Early Jurassic. Angular unconformity between the Cretaceous and Jurassic is well preserved in the Qigu anticline belt. This unconformity also exists in the Huoerguosi–Manasi–Tugulu (HMT) anticline belt, which is the second fold belt of the SJ-FTB, indicating that the HMT anticline belt started to become active during the Late Jurassic. The Qigu anticline belt reactivated intensively during the Late Cenozoic, and the displacement was transferred to the HMT anticline belt along the Paleogene Anjihaihe Formation mudstone detachment. Therefore, the present-day SJ-FTB forms because of the two-stage compressional deformation from both the Late Jurassic and Late Cenozoic (ca. 24 Ma).


Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Xinglin Chen ◽  
Yongjun Shao ◽  
Chunkit Lai ◽  
Cheng Wang

The Longmendian Ag–Pb–Zn deposit is located in the southern margin of the North China Craton, and the mineralization occurs mainly in quartz veins, altered gneissic wallrocks, and minor fault breccias in the Taihua Group. Based on vein crosscutting relations, mineral assemblages, and paragenesis, the mineralization can be divided into three stages: (1) quartz–pyrite, (2) quartz–polymetallic sulfides, and (3) quartz–carbonate–polymetallic sulfides. Wallrock alteration can be divided into three zones, i.e., chlorite–sericite, quartz–carbonate–sericite, and silicate. Fluid inclusions in all Stage 1 to 3 quartz are dominated by vapor-liquid two-phase aqueous type (W-type). Petrographic and microthermometric analyses of the fluid inclusions indicate that the homogenization temperatures of Stages 1, 2, and 3 are 198–332°C, 132–260°C, and 97–166°C, with salinities of 4.0–13.3, 1.1–13.1, and 1.9–7.6 wt% NaCleqv, respectively. The vapor comprises primarily H2O, with some CO2, H2, CO, N2, and CH4. The liquid phase contains Ca2+, Na+, K+, SO42−, Cl−, and F−. The sulfides have δ34S=–1.42 to +2.35‰ and 208Pb/204Pb=37.771 to 38.795, 207Pb/204Pb=15.388 to 15.686, and 206Pb/204Pb=17.660 to 18.101. The H–C–O–S–Pb isotope compositions indicate that the ore-forming materials may have been derived from the Taihua Group and the granitic magma. The fluid boiling and cooling and mixing with meteoric water may have been critical for the Ag–Pb–Zn ore precipitation. Geological and geochemical characteristics of the Longmendian deposit indicate that the deposit is best classified as medium- to low-temperature intermediate-sulfidation (LS/IS) epithermal-type, related to Cretaceous crustal-extension-related granitic magmatism.


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