NEW INSIGHT ABOUT THE DIAGENETIC HISTORY OF MID-PERMIAN SHANXI GROUP SANDSTONE IN THE NORTH CHINA BAISN - EVIDENCE FROM THE PORE SPACE EVOLUTION

2018 ◽  
Author(s):  
Zhiyuan Wu ◽  
◽  
Eric Law ◽  
Shangxian Yin ◽  
Lihong Ma ◽  
...  
Keyword(s):  
North China ◽  
Pore Space ◽  
The North ◽  
History Of ◽  
Diagenetic History

scholarly journals Diversified calcimicrobes in dendrolites of the Zhangxia Formation, Miaolingian Series (Middle Cambrian) of the North China craton

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ming-Xiang Mei ◽  
Muhammad Riaz ◽  
Zhen-Wu Zhang ◽  
Qing-Fen Meng ◽  
Yuan Hu
Keyword(s):  
North China ◽  
Cyanobacterial Mats ◽  
Third Order ◽  
Depositional Sequence ◽  
Middle Cambrian ◽  
Forming Mechanism ◽  
The North ◽  
Biological Affinity ◽  
History Of ◽  
Group 3

AbstractAs a type of non-laminated microbial carbonates, dendrolites are dominated by isolated dendritic clusters of calcimicrobes and are distinct from stromatolites and thrombolites. The dendrolites in the upper part of the Miaolingian Zhangxia Formation at Anjiazhuang section in Feicheng city of Shandong Province, China, provide an excellent example for further understanding of both growth pattern and forming mechanism of dendrolites. These dendrolites are featured by sedimentary fabrics and composition of calcified microbes as follows. (1) The strata of massive limestones, composed of dendrolites with thickness of more than one hundred meters, intergrade with thick-bedded to massive leiolites, formimg the upper part of a third-order depositional sequence that constitutes a forced regressive systems tract. (2) A centimeter-sized bush-like fabric (shrub) typically produced by calcified microbes is similar to the mesoclot in thrombolites but distinctive from clotted fabrics of thrombolites. This bush-like fabric is actually constituted by diversified calcified microbes like the modern shrub as a result of gliding mobility of filamentous cyanobacteria. Such forms traditionally include: the Epiphyton group (which actually has uncertain biological affinity), the Hedstroemia group which closely resembles modern rivulariacean cyanobacteria, and the possible calcified cyanobacteria of the Lithocodium–Bacinella group. (3) Significantly, dense micrite of leiolite is associated with sponge fossils and burrows, and is covered by microstromatolite. The Lithocodium–Bacinella group is a controversial group of interpreted calcified cyanobacteria in the Cambrian that has also been widely observed and described in the Mesozoic. Therefore, dendrolites with symbiosis of leiolites in the studied section provide an extraordinary example for further understanding of growing style of bush-like fabrics (shrubs) of the dendrolites dominated by cyanobacterial mats. Furthermore, the present research provides some useful thinking approaches for better understanding of the history of the Early Paleozoic skeletal reefs and the microbe–metazoan transitions of the Cambrian.

Deformation history of the Paleoproterozoic Liaohe assemblage in the eastern block of the North China Craton

2005 ◽  
Vol 24 (5) ◽  
pp. 659-674 ◽  
Author(s):  
Sanzhong Li ◽  
Guochun Zhao ◽  
Min Sun ◽  
Zongzhu Han ◽  
Yan Luo ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Deformation History ◽  
The North ◽  
History Of

scholarly journals Ultrastructure, dissolution and "pyritization" of Late Quaternary and Recent echinoderms

1987 ◽  
Vol 36 ◽  
pp. 275-287
Author(s):  
Margit Jensen ◽  
Elsebeth Thomsen
Keyword(s):  
Late Pleistocene ◽  
Sea Water ◽  
Late Quaternary ◽  
Pore Space ◽  
Water Interface ◽  
Sea Stars ◽  
Northern Norway ◽  
History Of ◽  
Organic Tissue ◽  
Diagenetic History

The diagenetic history of the skeletal elements of Late Pleistocene-Holocene Ophiura sarsi from the shelf off northern Norway (Andfjorden, Malangsdjupet) is elucidated by comparison with natural and induced degradation of the skeletal elements of Recent ophiuroids (brittle stars) and asteroids (sea stars) from Danish waters. Dissolution features ("core-and-rind") in the trabeculae of fossil and Recent echinoderm stereom are initiated during death and early decay of organic tissue in the animals. The trabeculae have a polycrystal­line lamellar ultrastructure and lose their older central part during later stages of dissolution, which are dependant on undersaturation of the sea-water with regard to CaC03• The presence of undersaturated sea-water is supported by palaeoecological studies (Thomsen & Vorren 1984, 1986) implying oxygen deficient periods in the Late Pleistocene and an increased biogenic production in the Holocene. Pyrite framboids are situated in the secondary voids within the trabeculae and in the pore space of the stereom of the Late Pleistocene elements. No pyrite is observed within the polycrystalline lamellar ultrastructure of the trabeculae. The Late Pleistocene "pyritization" took place during oxygen deficient periods at the sediment-water interface or within the reduced zone of the topmost sediment.

Interference fold patterns of the early Precambrian Rock Groups in the Songshan area, China

1982 ◽  
Vol 119 (5) ◽  
pp. 433-461 ◽  
Author(s):  
Shutian Suo ◽  
Ruqi Liu ◽  
Xingyuan Ma
Keyword(s):  
Large Scale ◽  
North China ◽  
Small Scale ◽  
Deformation History ◽  
North China Platform ◽  
Early Proterozoic ◽  
The North ◽  
Regional Deformation ◽  
History Of ◽  
Insight Into

SummaryThe Songshan area is located in the southern part of the North China platform, which is one of the most completely cratonized tectonic units of China. Its basement has experienced a complex evolutionary history and was eventually consolidated at the end of early Proterozoic time about 1.7 Ga ago.A systematic study has been made of the deformation history of the lower Proterozoic Songshan Group and the Archean Dengfeng Group. At least two widespread episodes of deformation can be recognised in the early Proterozoic Zhongyue tectonic cycle and three in the Archean Songyang cycle. Large scale and small scale interference patterns of the superimposed folding are investigated with the aim of recognizing possible regularities in their occurrence and of gaining an insight into the regional deformation history. Two important aspects of superimposition relationships are illustrated: the control of earlier structures upon later ones and the reform of the former by thelatter; their geometrical regularities are also dealt with respectively.

New paleomagnetic results of the earliest Permian dykes in South Mongolia and their implications for the paleogeography of the Eastern CAOB

2021 ◽  
Author(s):  
Donghai Zhang ◽  
Guochun Zhao ◽  
Baochun Huang ◽  
Qian Zhao ◽  
Hai Zhou ◽  
...  
Keyword(s):  
Secular Variation ◽  
North China ◽  
High Coercivity ◽  
The North ◽  
Magnetic Carriers ◽  
Central Asian ◽  
Paleomagnetic Study ◽  
History Of ◽  
Temperature Component ◽  
Funded Project

<p>Debates of the Permo-Carboniferous paleogeography of the eastern Central Asian Orogenic Belt (CAOB) mainly focus on the existence, extent, and thereby evolutionary history of the Paleo-Asian Ocean (PAO) in this period. South Mongolia locates at a key position that denotes the southernmost margin of the Mongolia block. Here, we present a paleomagnetic study on the earliest Permian dykes near the Khanbogd of South Gobi Province in Mongolia to better constrain the paleo-position of the Mongolia block. Zircon U-Pb dating results of the studied dykes indicate an emplacement age of 299 ± 3 Ma. Magnetites are the dominant magnetic carriers as revealed by the synthesized rock magnetic experiments. A likely primary high coercivity/temperature component was isolated from 66 of 125 samples and displays consistent reverse polarity, which coincides with the Kiaman Reverse Superchron that overlapping the emplacement age of our studied dykes. Accordingly, a ~299 Ma paleomagnetic pole is calculated at <em>λ</em>/<em>φ</em> = −4.1°N/146.3°E (<em>dp</em> = 3.8, <em>dm</em> = 5.8, n = 66). Potential influence from Paleo-Secular Variation (PSV) is excluded following the Deenen et al. (2011) procedure. Our new results present a ~30.9°N paleolatitude for the Mongolia block, which differs from the lower paleolatitude of the North China and Xilinhot blocks as well as the much higher paleolititude of Siberia. Surrounded by these blocks of different paleolatitude, the PAO and Mongol-Okhotsk Ocean both remained wide open at least by the earliest Permian.</p><p><strong>Acknowledgments<br></strong>This research was funded by the Natural Science Foundation of China (NSFC) (41902229, 41730213, 42072264, 41902229, 41972237), China Postdoctoral Science Foundation funded project and Hong Kong RGC GRF (17307918).</p><p><strong>References</strong></p><p>Deenen, M. H. L. , Langereis, C. G. , Van, H. D. J. J. , & Biggin, A. J. . (2011). Geomagnetic secular variation and the statistics of palaeomagnetic directions. Geophysical Journal International(2), 509-520.</p><p></p><p></p>

scholarly journals DROUGHT AND FAMINE IN NORTHWEST CHINA: A LATE VICTORIAN TRAGEDY?

2018 ◽  
Vol 2 (2) ◽  
pp. 373-391 ◽  
Author(s):  
Andrea Janku
Keyword(s):  
North China ◽  
Northwest China ◽  
Social Conditions ◽  
Qing Empire ◽  
Western Province ◽  
The North ◽  
Modern Chinese ◽  
History Of ◽  
Chinese Historiography ◽  
North Western

AbstractThe North China Famine of 1876–1879 has received some attention recently, but little of this work has focused on the north-western province of Shaanxi. This imbalance is reflected in the local histories that devote far more space to the documentation and commemoration of the Hui rebellion than to the famine. This paper argues that the drought of those years and the ensuing famine is historically much more significant than this biased documentation would suggest, and that the rebellion can only be fully understood by paying attention to the environmental and social conditions in which it unfolded. Further, the paper engages with Mike Davis’s argument that portrays the famine in China as part of a ‘late-Victorian holocaust.’ While persuasive, his focus on outside forces is problematic as it ignores the history of the Qing Empire as an expanding force in itself and inadvertently reinforces the victimization narrative that dominates modern Chinese historiography.

Phanerozoic accretionary history of Japan and the western Pacific margin

2018 ◽  
Vol 158 (1) ◽  
pp. 13-29 ◽  
Author(s):  
Koji Wakita ◽  
Takanori Nakagawa ◽  
Masahiro Sakata ◽  
Natsuki Tanaka ◽  
Nozomu Oyama
Keyword(s):  
North China ◽  
Japan Sea ◽  
Detrital Zircons ◽  
Oceanic Plate ◽  
The South ◽  
The North ◽  
Before And After ◽  
History Of ◽  
Japanese Islands ◽  
Plate Subduction

AbstractIt is generally accepted that oceanic plate subduction has occurred along the eastern margin of Asia since about 500 Ma ago. Therefore, the Japanese Islands have a >500 Ma history of oceanic plate subduction in their geological records. In this paper, the accretionary history of the Japanese Islands is divided into six main stages based on the mode and nature of tectonic events and the temporal gaps in the development of accretionary processes. In the first stage, oceanic plate subduction and accretion started along the margin of Gondwana. After detachment of the North and South China blocks in Devonian time, accretionary complexes developed along island arcs offshore of the South and North China blocks. After the formation of back arc basins such as the Japan Sea, accretionary processes occurred only along the limited convergent margin, e.g. Nankai Trough. Detrital zircons of sandstones revealed the accretionary history of Japan. An evaluation of a comprehensive dataset on detrital zircon populations shows that the observed temporal gaps in the development of the Japanese accretionary complexes were closely related to the intensity of igneous activity in their provenance regions. Age distributions of detrital zircons in the accretionary complexes of Japan change before and after the Middle Triassic period, when the collision of the South and North China blocks occurred.

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