Mineralogy and element geochemistry of salinized lacustrine organic-rich shale in the Middle Permian Santanghu Basin: Implications for paleoenvironment, provenance, tectonic setting and shale oil potential

2020 ◽  
Vol 120 ◽  
pp. 104569 ◽  
Author(s):  
Bo Liu ◽  
Yu Song ◽  
Kai Zhu ◽  
Peng Su ◽  
Xiang Ye ◽  
...  
Author(s):  
Henrik Rasmussen ◽  
Lars Frimodt Pedersen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, H., & Frimodt Pedersen, L. (1999). Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 65-78. https://doi.org/10.34194/ggub.v181.5114 _______________ Two Archaean supracrustal sequences in the area north-east of Disko Bugt, c. 1950 and c. 800 m in thickness, are dominated by pelitic and semipelitic mica schists, interlayered with basic metavolcanic rocks. A polymict conglomerate occurs locally at the base of one of the sequences. One of the supracrustal sequences has undergone four phases of deformation; the other three phases. In both sequences an early phase, now represented by isoclinal folds, was followed by north-west-directed thrusting. A penetrative deformation represented by upright to steeply inclined folds is only recognised in one of the sequences. Steep, brittle N–S and NW–SE striking faults transect all rock units including late stage dolerites and lamprophyres. Investigation of major- and trace-element geochemistry based on discrimination diagrams for tectonic setting suggests that both metasediments and metavolcanic rocks were deposited in an environment similar to a modern back-arc setting.


1992 ◽  
Vol 6 ◽  
pp. 155-155
Author(s):  
Kotaro Kamada

Before opening of the Japan Sea, the Japanese islands were attached to the eastern margin of the Asian continent. The Southern Kitakami Belt is regarded as a micro-continent in an accretional complex of the islands, that accreted before the Early Cretaceous. But its tectonic setting and location between the belt and the Asian continent is still an unresolved argument.Permo-Triassic sequences in the Southern Kitakami Belt are composed of shallow to off-shore deposits. These deposits are composed of clastics, carbonates with volcaniclastics. But there was no volcanic activity in the belt in the Middle to Late Permian. From the viewpoint of the sedimentary character and history, the Middle Permian to Middle Triassic sequences differ from their previous and their following successions in the belt. And the sedimentary basin of Middle Permian to Middle Triassic was bounded by transform faults. Magmatic arc was replaced by passive margin as hinterland of the Southern Kitakami Belt during the Middle Permian to Middle Triassic. It means that the sedimentary basin moved from the margin of Yangtze Platform to Sino-Korean Platform at that time.


Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 341
Author(s):  
Yalong Li ◽  
Wei Yue ◽  
Xun Yu ◽  
Xiangtong Huang ◽  
Zongquan Yao ◽  
...  

The Bogeda Shan (Mountain) is in southern part of the Central Asian Orogenic Belt (CAOB) and well preserved Paleozoic stratigraphy, making it an ideal region to study the tectonic evolution of the CAOB. However, there is a long-standing debate on the tectonic setting and onset uplift of the Bogeda Shan. In this study, we report detrital zircon U-Pb geochronology and whole-rock geochemistry of the Permian sandstone samples, to decipher the provenance and tectonic evolution of the West Bogeda Shan. The Lower-Middle Permian sandstone is characterized by a dominant zircon peak age at 300–400 Ma, similar to the Carboniferous samples, suggesting their provenance inheritance and from North Tian Shan (NTS) and Yili-Central Tian Shan (YCTS). While the zircon record of the Upper Permian sandstone is characterized by two major age peaks at ca. 335 Ma and ca. 455 Ma, indicating the change of provenance after the Middle Permian and indicating the uplift of Bogeda Shan. The initial uplift of Bogeda Shan was also demonstrated by structural deformations and unconformity occurring at the end of Middle Permian. The bulk elemental geochemistry of sedimentary rocks in the West Bogeda Shan suggests the Lower-Middle Permian is mostly greywacke with mafic source dominance, and tectonic setting changed from the continental rift in the Early Permian to post rift in the Middle Permian. The Upper Permian mainly consists of litharenite and sublitharenite with mafic-intermediate provenances formed in continental island arcs. The combined evidences suggest the initial uplift of the Bogeda Shan occurred in the Late Permian, and three stages of mountain building include the continental rift, post-rift extensional depression, and continental arc from the Early, Middle, to Late Permian, respectively.


2020 ◽  
Vol 22 ◽  
Author(s):  
Claudia Banks

The Singhbhum craton is one of five Archean nuclei comprising Peninsular India. It is a composite Archean block that includes the Older Metamorphic Group, the Older Metamorphic Tonalite Gneisses, the Singhbhum Granite, and the Iron Ore Group as its major units. The ages of these components range from ~3.5 to ~3.1 Ga, although overlapping ages and similar rock types confound their genetic relationships. Plutonic felsic rocks from the southeastern Singhbhum craton (BK1: a foliated tonalite, KP1: a non-foliated granite, and SG14: a non-foliated granite) yield U-Pb (zircon) ages of 3321 ± 2 Ma (BK1), 3301 ± 1 Ma (KP1), and  3261 ± 1 Ma (SG14) that coincide with a pulse of Singhbhum Granite emplacement at 3.27 to 3.33 Ga. REE patterns and tectonic discrimination diagrams based on major and trace element ratios suggest a subduction zone setting for these rocks. We report major and trace element data for and compare them to previous works in order to characterize the Archean felsic plutonic history of the craton.


2021 ◽  
Vol 37 (8) ◽  
pp. 2562-2578
Author(s):  
MA XueYing ◽  
◽  
LIU Qing ◽  
YAN FangChao ◽  
HE Miao ◽  
...  

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