Late Paleozoic tectonism of the Bogda region in  Chinese North Tianshan: Insights from sedimentary provenance analysis
0
Citation
0
Reference
10
Related Paper
Abstract:
<p>The Chinese North Tianshan (CNTS) extends E-W along the southern part of the Central Asian Orogenic Belt and has undergone complicated accretion-collision processes in the Paleozoic. This study attempts to clarify the late Paleozoic tectonism in the region by investigating the provenance of the Late Paleozoic sedimentary successions from the Bogda Mountain in the eastern CNTS by U-Pb dating and Lu-Hf isotopic analyses of detrital zircons. Detrital zircon U-Pb ages (N=519) from seven samples range from 261 &#177; 4 Ma to 2827 &#177; 32 Ma, with the most prominent age peak at 313 Ma. There are Precambrian detrital zircon ages (~7%) ranged from 694 to 1024 Ma. The youngest age components in each sample yielded weighted mean ages ranging from 272 &#177; 9 Ma to 288 &#177; 5 Ma, representing the maximum depositional ages. These and literature data indicate that some previously-assumed &#8220;Carboniferous&#8221; strata in the Bogda area were deposited in the Early Permian, including the Qijiaojing, Julideneng, Shaleisaierke, Yangbulake, Shamaershayi, Liushugou, Qijiagou, and Aoertu formations. The low maturity of the sandstones, zircon morphology and provenance analyses indicate a proximal sedimentation probably sourced from the East &#173;Junggar Arc and the Harlik-Dananhu Arc in the CNTS. The minor Precambrian detrital zircons are interpreted as recycled materials from the older strata in the Harlik-Dananhu Arc. Zircon &#603;<sub>Hf</sub>(t) values have increased since ~408 Ma, probably reflecting a tectonic transition from regional compression to extension. This event might correspond to the opening of the Bogda intra-arc/back arc rift basin, possibly resulting from a slab rollback during the northward subduction of the North Tianshan Ocean. A decrease of zircon &#603;<sub>Hf</sub>(t) values at ~300 Ma was likely caused by the cessation of oceanic subduction and subsequent collision, which implies that the North Tianshan Ocean closed at the end of the Late Carboniferous. This research was financially supported by the Youth Program of Shaanxi Natural Science Foundation (2020JQ-589), the NSFC Projects (41730213, 42072264, 41902229, 41972237) and Hong Kong RGC GRF (17307918).</p>Keywords:
Detritus
Geochronology
In order to understand the distribution of Carboniferous-Permian in Ejina Banner and its vicinities,and provide evidence for oil and gas resources investigation and evaluation,through fine processing and interpretation of previous data and newly finished integrated geophysical survey sections,by using joint inversion of gravity,magnetic and electronic data under restriction of seismic and well data,this paper preliminarily presented the distribution and burial situation of Carboniferous-Permian residues in the region.Thus it is concluded that the Carboniferous-Permian strata show the characteristics of thicker residual and suitable depth.The method has solved the technical problem of Carboniferous-Permian distribution interpretation and provides evidence for Carboniferous-Permian research within the internal part of the basin.
Banner
Inner mongolia
Cite
Citations (0)
The term formation is the basic lithostratic unit which is divided based on the lithological characters. The Carboniferous Permian strata developed well in the Deriangma Xiala section and the Angjie section in Shenzha, Tibet. All the lithostratic units of the Carboniferous and Permian strata in this area were named after them. However, some of them were not defined based on the lithological characters but on the fossil assemblages in the sections, and do not accord with the principle of the multiple stratigraphical classification. And the lithostratic system of the Carboniferous Permian has been a controversial subject for a long time. The lithostratic systems of the Carboniferous Permian in the area are manily remarked by the author in the present paper, and the Carboniferous Permian boundary is discussed briefly.
Section (typography)
Cite
Citations (2)
In 1998,Cathaysia flora containing Neuropteris, Pecopteris, Cordaites, etc. were found for the first time from the Upper Carboniferous-Lower Permian Dasuangou Formation in the eastern margin of Dunhua rise. Based on the discovery and considering the conformity between the Dasuangou Formation and its underlying Shanxiuling Formation, the Late Carboniferous-Early Permian strata in the Kaishantun area were demonstrated to be marineterrestrial sedimentary facies. The existence of Cathaysia flora during the Late Carboniferous-Early Permian and Late Permian shows that the Cathaysia flora began to differentiate and develop in the present area during the Late Carboniferous-Early Permian, and that the present area is an indiscerptible part of the Cathaysia continent.
Flora
Margin (machine learning)
Cite
Citations (6)
The fossil plants studied in this paper were collected from the Carboniferous and Permian strata in the northern part of the Helan Mountains. The flora is composed of 104 species in 39 genera, which may be divided into five plant assemblages in ascending order as follows:(1)the early Late Carboniferous Bothrodendron circulare-Mesocalamites cistiformi assemblage;(2)the middle Late Carboniferous Lepidodendron subrhombicum-Conchophyllum richthofeni assemblage;(3)the late Late Carboniferous Lepidodendron szeianum-Neuropteris ovata assemblage;(4)the early Early Permian Lepidodendron posthumii-Callipteridium koraiense assemblage;(5)the late Early Permian Caulopteris wudaensis-Paratingia datongensis assemblage. Their typical formations are the Hongtuwa Formation, the Yanghukou Formation, the Lower Taiyuan Formation, the Middle and Upper Taiyuan Formation, and the Shanxi Formation respectively. The geological ages of the five plant assemblages may approximately correspond to the Namurian B-C, Westphalian, Stephanian, Asselian, Sakmarian and Aritinskian. The Carboniferous and Permian flora contains typical Cathaysian elements and it is a typical Cathaysia flora. The flora can be compared with contemporaneous floras in the Cathaysian province. In addition, the evolution of the flora is discussed in this paper.
Flora
Westphalian sovereignty
Assemblage (archaeology)
Cite
Citations (12)
T he recurrence of Carboniferous species in Permian strata is not new to palæontologists; for recurrent species from the Carboniferous fauna, and such as were supposed to be recurrent, have been noticed by several observers. Messrs. Lonsdale, Jones, Howse, King, and Davidson, as well as others, have identified Permian with Carboniferous species, or vice versâ , though it may be remarked that in some cases their determinations have been undoubtedly erroneous. The discovery of another species which had long been thought characteristic of the Permian period, in Carboniferous strata, is therefore not so novel a fact as might appear at first sight. At the same time, I deem it well to record its occurrence, which is not without importance. It is of interest merely as the discovery of another species which is common to the faunæ of the two later palæozoic eras; and it is of consequence as a fact which assists in illustrating some of the physical conditions which prevailed during the deposition of the Upper Coal-measures of the North of England. In the Permian formation, Lingula Credneri is confined to the lower strata. In England it is restricted to the “Marl-slate,” and the lower beds of the “Compact Limestone.” It is not common in these members, having been found only at Ferry Hill, Thrislington, and Thickley. As a Carboniferous shell it only occurred to me during the summer of last year (1858), at the Ryhope Winning, near Sunderland. I first observed it in a thin bed of dark shale, at
Coal measures
Cite
Citations (3)
This paper reviews the sedimentary systems, oil-gas bearing systems of the Carboniferous and Permian and typical oil and gas fields in northwestern China. It suggests that the Carboniferous and Permian are important sequences for petroleum exploration due to their bright potentials and prospects. Also, this paper gives some favorable areas for further exploration.
Cite
Citations (0)
This article is an individual and necessarily brief overview of the history of geochronology in Queensland with emphasis on the contributions of scientists and technicians who played major roles in the implementation of the geochronology facilities at the University of Queensland. Geochronology and isotope geochemistry research summarised here have contributed among others to our understanding of the chemical and isotopic evolution of the early Earth, mantle dynamics, the thermal history of sedimentary basins and time-scales of weathering and climate change.
Geochronology
Geologic record
Cite
Citations (0)
Similarity (geometry)
Cite
Citations (21)
Geochronology
Cite
Citations (0)
Numerous granitoids occur in northern Xinjiang and its adjacent areas,with Carboniferous-Permian granitoids being most typical.This paper summarizes the spatial and temporal distribution characteristics of these granitoids.Carboniferous-Permian granitoids show different features in different units,and the peak values of their formation epochs are also different.Formation epochs of the Carboniferous-Permian granitoids in Altay are mainly concentrated in early Permian (289～266 Ma),and late Carboniferous seemed to be a distinct magmatic calm period.Western Junggar Carboniferous-Permian granitoids formation periods can be subdivided into early Carboniferous (340～320 Ma) and late Carboniferous-early Permian (310～290 Ma),with the latter being more stronger.Aluminum A-type granites,concentratedly formed at about 300 Ma,are widely spread,constituting an important feature of western Junggar.Carboniferous-Permian granitoids in eastern Junggar occur along the fault zones and were formed mainly from late Carboniferous to early Permian (320～270 Ma),characterized by the continuous emplacement of quite a number of alkaline (A-type) granites in this region in this period.Carboniferous-Permian granitoids in western Tianshan can be divided into three stages:early Carboniferous (355～345 Ma),late early Carboniferous-late Carboniferous (335～305 Ma) and early Permian (300～255 Ma).The early Permian granitic magma activity is the strongest,and Carboniferous granitoids mainly intruded into northern Tianshan,and the early Permian alkaline (A-type) granitoids are not only distributed in a large zonal area of southern Tianshan but also spread in northern Tianshan.Eastern Tianshan-Beishan is an area with most developed Carboniferous-Permian granitoids,characterized by both large quantities and wide distribution.Zircon ages show two obvious peaks,being respectively at 335～310 Ma and 300～270 Ma.Granitoids in eastern Tianshan are mostly Carboniferous ones,whereas granitoids in Beishan are mostly Carboniferous ones.In general,Carboniferous-Permian granitoids of northern Xinjiang and its adjacent areas were mainly formed in the late Carboniferous-early Permian period,especially during the early Permian,showing synchronization in the whole region.This period is also characterized by most developed alkaline (A-type) granitoids,which is regarded as the reflection of the extensional setting,maybe revealing extension characteristics in different tectonics.This is a microcosm of lots of acid and mafic-ultramafic magmatism in the Central Asian Orogenic Belt and the implication of its extensional setting.
Cite
Citations (31)