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 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

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.

scholarly journals AGE, PETROGENESIS AND TECTONIC IMPLICATIONS OF THE LATE PERMIAN PERALUMINOUS AND METALUMINOUS MAGMATIC ROCKS IN THE MIDDLE GOBI VOLCANOPLUTONIC BELT, MONGOLIA

2021 ◽  
Author(s):  
Ariuntsetseg Ganbat ◽  
Tatsuki Tsujimori ◽  
Laicheng Miao ◽  
Inna Safonova ◽  
Daniel Pastor-Galán ◽  
...  
Keyword(s):  
Active Continental Margin ◽  
Biotite Granite ◽  
Ridge Subduction ◽  
The North ◽  
Magmatic Rocks ◽  
Central Asian ◽  
Isotopic Analyses ◽  
History Of ◽  
Arc Setting ◽  
T Values

The Mongol–Okhotsk Belt, the youngest segment of the Central Asian Orogenic Belt, formed by the evolution and closure of the Mongol–Okhotsk Ocean. The oceanic closure formed two volcanoplutonic belts: Selenge Belt in the north and Middle Gobi Belt in the south (in present day coordinates). However, the origin and tectonic evolution of the Mongol–Okhotsk Belt in general, the origin and formation age of the Middle Gobi Belt in particular, remain enigmatic. To better understand the history of the magmatic activity in the Middle Gobi Belt, we conducted geochemical, U–Pb geochronological, zircon Hf, whole-rock Nd isotopic analyses of volcanic and plutonic rocks of the Mandalgovi suite, the major component of the Middle Gobi Belt. Our results show that the Mandalgovi suite consists of (i) 265 ± 2 Ma biotite-granite; (ii) 250 ± 3 Ma hornblende-granitoids; (iii) their volcanic equivalents of both: and (iv) gabbro-diorites. The geochemical compositions indicate that their precursor magmas were derived from crustal source. The protoliths of the biotite and hornblende-granitoids were metagraywacke and metabasalt, respectively. They are characterized by positive whole-rock εNd(t) and zircon εHf(t) values, indicating the molten protoliths were juvenile crust. The biotite-granites formed by remelting of fore-arc sediments by ridge subduction and later hornblende-granites were emplaced at an intra-oceanic arc by the subduction of the Mongol–Okhotsk Ocean. We conclude that the magmatic rocks of the Middle Gobi formed in an active continental margin and/or intra-oceanic arc setting.

scholarly journals The Issue Of The Central Asian Northern Pilgrimage Route In The Russian-Bukhara Diplomatic Relations In The XVIII Century (On The Example Of The Activities Of Ambassador Ernazar Maqsud Oglu)

2020 ◽  
Vol 02 (11) ◽  
pp. 99-104
Author(s):  
Tanieva Guldona Mamanovna ◽  
Keyword(s):  
Middle Ages ◽  
Russian Empire ◽  
Extensive Study ◽  
Economic Relations ◽  
Xviii Century ◽  
The North ◽  
Central Direction ◽  
Central Asian ◽  
History Of ◽  
The Russian Empire

In the Middle Ages, Central Asian pilgrims traveled to Mecca in three directions: the North direction ‒ through the Russian Empire, the central direction‒ through the territory of Persia, and the south direction ‒ along roads through India and the Arabian Sea. Therefore, the question of the directions of the Hajj was reflected in the diplomatic correspondence of the Central Asian khanates with Persia, India, the Russian and Ottoman empires тоо. Depending on the political, economic and ideological interests of these states, sometimes pilgrims were given permits to be sent to Mecca through their territories, and sometimes not. The degree of intensity of pilgrimage movements, in most cases, depended on the activities of interstate ambassadors. On the issue of eliminating various prohibitions and obstacles in the movements of pilgrimage roads, the Central Asian ambassadors were active and historical documents reveal these data to us. In this period the Central Asian ambassadors, who were sent to the reception of the governors those neighbor states on other issues, in most cases negotiated precisely on the direction of the Hajj of the Central Asian pilgrims also. One of such far-sighted ambassadors was a rich merchant from Bukhara, who lived in the XVIII c. Ernazar Maksud ogli officially sent several times by the Central Asian rulers to the Russian Empire. In this article analyzes the question of how the problems of the Hajj road were solved at the international diplomatic level by the example of the activities this ambassador. The history of negotiations between Ernazar and the Russian emperors on matters of the northern direction of the Hajj road and their results illuminated on base documents on this issue, which stored in the fund of the Archive of Foreign Policy of the Russian Empire (AFPRE). The scientific conclusions of this article serve for an extensive study of the issues of diplomatic and economic relations between the Central Asian khanates and the Russian Empire in the XVIII century, revealing the history of the embassy relations of the khanates and the history of the pilgrimage of the Hajj of the Central Asian people and the features of the directions of roads from Central Asia to Mecca.

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.

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