Multi‐stage metamorphism of eclogite in the South Altyn HP–UHP belt, Northwest China: deep subduction and exhumation process of continental crust

2021 ◽  
Author(s):  
Tuo Ma ◽  
Liang Liu ◽  
Yong Sheng Gai ◽  
Chao Wang ◽  
Xiaoying Liao ◽  
...  
Keyword(s):  
Continental Crust ◽  
Northwest China ◽  
The South ◽  
Multi Stage

scholarly journals The formation of Neoarchean continental crust in the south-east Superior Craton by two distinct geodynamic processes

2021 ◽  
Vol 356 ◽  
pp. 106104
Author(s):  
D.R. Mole ◽  
P.C. Thurston ◽  
J.H. Marsh ◽  
R.A. Stern ◽  
J.A. Ayer ◽  
...  
Keyword(s):  
Continental Crust ◽  
The South ◽  
Geodynamic Processes ◽  
Superior Craton

The Silurian graptolite zonation of China

1984 ◽  
Vol 21 (2) ◽  
pp. 241-257 ◽  
Author(s):  
Chen Xu
Keyword(s):  
South China ◽  
Northwest China ◽  
The South ◽  
Yunnan Region ◽  
Western Yunnan ◽  
China Region

China is divided into five Silurian stratigraphic regions on the basis of biostratigraphy and lithostratigraphy. These regions are: Zhungar–Xingan region, Northwest China region, Xizang (Tibet) – western Yunnan region, Yangtze region, and the South China region. Twenty-four graptolite zones are now recognized in the Silurian of China. The earliest Silurian graptolite zones include the persculptus, acuminatus, and vesiculosus zones, characterized by an akidograptid–dimorphograptid sub-fauna; these are followed by the cyphus, gregarius, convolutus, and sedgwickii zones, characterized by a rastritid subfauna. The late Early Silurian zones include the turriculatus Zone with a spirograptid subfauna and the crispus, griestoniensis, and spiralis–grandis zones bearing a streptograptid subfauna. The Middle Silurian is characterized by a cyrtograptid subfauna, which is divided into 10 zones known, in ascending order, as the lapworthi, sakmaricus, insectus, centrifugus, murchisoni, riccartonensis, rigidus?, flexilis, ramosus, and lundgreni zones. The Late Silurian is divided into only three graptolite zones, characterized by a pristiograptid subfauna. They are the nilssoni, tumescens, and transgrediens zones.

A study on tectonic and sedimentary development in the rifted northern continental margin of the South China Sea near Taiwan

2016 ◽  
Vol 4 (3) ◽  
pp. SP47-SP65 ◽  
Author(s):  
Wei-Zhi Liao ◽  
Andrew T. Lin ◽  
Char-Shine Liu ◽  
Jung-Nan Oung ◽  
Yunshuen Wang
Keyword(s):  
South China Sea ◽  
Continental Crust ◽  
South China ◽  
Seismic Data ◽  
The South China Sea ◽  
Seismic Facies ◽  
The South ◽  
Northern Margin ◽  
China Sea ◽  
Breakup Unconformity

A series of Cenozoic rifted basins developed in the northern margin of the South China Sea (SCS). Tainan Basin is one of these rifted basins near Taiwan, lying in the outer margin. We have used reflection seismic data in the deepwater areas and boreholes drilled in the shelf of the Tainan Basin to understand the tectonic and sedimentary development in the northern SCS margin near Taiwan. Four key stratal surfaces (i.e., the base of the Pleistocene Series, the base of the Pliocene Series, the 17 Ma maximum flooding surface [MFS], and a breakup unconformity of approximately 30 Ma in age) and seven seismic facies (i.e., continuous- and parallel-layer seismic facies, wavy seismic facies, chaotic seismic facies, U-shaped canyon-cut seismic facies, imbricated-layer seismic facies, high-amplitude reflector package seismic facies, and extrusive volcanism seismic facies) are recognized from seismic data with ages constrained by borehole stratigraphy drilled in the shelf. We have established a model for Cenozoic tectonic and sedimentary development in the rifted northern margin of the SCS near Taiwan. The occurrence of Paleogene fault-bounded grabens/half-grabens topped by a breakup unconformity and draped by postrift sediments indicates that these deepwater rifted basins developed on the continental crust, attesting that a thinned continental crust underlies the deepwater study area, rather than oceanic crust as reported in some literature. Postbreakup extrusive volcanic bodies, of early Miocene age, were buried by thick deepwater sediments. Fairly continuous stratal surfaces of 17 Ma MFS reveal that volcanic activities ceased to be active since middle Miocene. A series of channel cut-and-fills is observed in late Miocene, Pliocene, and Pleistocene strata beneath and to the south of the modern Formosa Canyon. Two distinct fields of deepwater sediment waves developed since middle Pleistocene are found lying to the west of modern deformation front/Manila Trench and to the north and south of the Formosa Canyon, respectively.

Evolution of fold-thrust belts and Cenozoic uplifting of the South Tianshan Mountain range in the Kuqa region, Northwest China

2017 ◽  
Vol 135 ◽  
pp. 327-337 ◽  
Author(s):  
Lei Wen ◽  
Yue-Jun Li ◽  
Guang-Ya Zhang ◽  
Zuo-Ji Tian ◽  
Geng-Xin Peng ◽  
...  
Keyword(s):  
Northwest China ◽  
Tianshan Mountain ◽  
Mountain Range ◽  
The South ◽  
Thrust Belts ◽  
South Tianshan

Chapter 20 Multi-stage collapse events in the South Soufrière Hills, Montserrat as recorded in marine sediment cores

2014 ◽  
Vol 39 (1) ◽  
pp. 383-397 ◽  
Author(s):  
M. Cassidy ◽  
J. Trofimovs ◽  
S. F. L. Watt ◽  
M. R. Palmer ◽  
R. N. Taylor ◽  
...  
Keyword(s):  
Marine Sediment ◽  
Sediment Cores ◽  
The South ◽  
Multi Stage ◽  
Soufriere Hills

scholarly journals Influencing Factors of Maize Production in South Africa: The Case of Mpumalanga, Free State and North West Provinces

2020 ◽  
pp. 25-34
Author(s):  
Andisiwe Diko ◽  
Wang Jun
Keyword(s):  
South Africa ◽  
South African ◽  
Agricultural Practices ◽  
Maize Yield ◽  
Free State ◽  
The South ◽  
Maize Production ◽  
North West ◽  
Independent Variables ◽  
Multi Stage

Aims: Maize is of great significance in the national food security of South Africa. Maize production levels in South Africa continue to decline, further deteriorating the situation of increased food insecurity, unemployment and increased poverty levels in the face of increasing population. This paper investigated fundamental variables influencing maize yield in the South African major maize producing regions. Study Design: A multi-stage stratified sampling method was employed to select maize producing farmers in the major maize producing provinces, namely Mpumalanga, Free State and North West provinces of South Africa. Furthermore, three districts were selected from which maize farmers were then selected. Methodology: Using linear multiple regression for a sample of 202 maize farmers, maize yield as a dependent variable was regressed against land size, fertilizer usage, labour, herbicides and seeds as independent variables. The paper employed the Cobb-Douglas production function to estimate parameters. The data obtained from the field were subjected to analysis using inferential statistics using SPSS v20. Results: The study showed that fertilizer, labour, and herbicides used in the production of maize in the study area were positively and statistically significant at a 5% confidence interval (P<0.05) with elasticity coefficients of 0.55, 0.47 and 0.198 respectively. The independent variables computed in the model had positive elasticity coefficients indicating a direct positive relationship between the input variables and maize output. The study also revealed that farmers in the study area were applying fewer amounts of fertilizer than the recommended rates per hectare. Conclusion: The study recommends that the South African government should supply inputs to maize farmers at subsidized rates to promote correct application rates and attain higher yields.  The promotion of good quality extension services to foster good agricultural practices in the production of maize is also recommended.

scholarly journals Water Vapor Changes Affect Cross-Seasonal Strong Drought Events in the Eastern Region of Northwest China

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu Zhang ◽  
Kang Liu ◽  
Yaohui Li ◽  
Wei Shen ◽  
Yulong Ren ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Climate ◽  
Northwest China ◽  
Water Vapor Transport ◽  
Eastern Region ◽  
The South ◽  
Vapor Flux ◽  
Weather Forecasts ◽  
The North ◽  
Depth Study

Drought in eastern Northwest China (ENC) is severely affected by water vapor conditions. An in-depth study of the primary sources of water vapor and its characteristics, at intraseasonal and interannual timescales, was conducted. This information is crucial for further study of the causes and mechanisms of extreme droughts and floods in the ENC. This study evaluated the spatial distribution and transport characteristics of water vapor over ENC during the 1981–2019 period based on the fifth generation of the European Center for Medium-Range Weather Forecasts atmospheric reanalyzes data of the global climate (ERA5). We studied the water vapor transport routes, water vapor convergence, water vapor budgets as well as the changes in water vapor fluxes and budgets over time in four areas surrounding ENC. The Mediterranean Sea, Black Sea, Caspian Sea, Indian Ocean, Bay of Bengal, and the South China Sea were the main sources of water vapor in ENC, supplemented by mid to high-latitude continental sources. The monthly change in water vapor flux in ENC exhibited the peak on July. The transport of water vapor in ENC was mainly toward the east and north. For most cross-seasonal drought events, the water vapor output is the main way in the south boundary and the west boundary. However, for the longest duration of cross-seasonal strong drought events, it is characterized by that the water vapor output is the main way in the south boundary, while the water vapor input in the north boundary is obviously weak. Water vapor paths in cross-seasonal strong drought events are analyzed, by which the Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT). The intensity of the subtropical high in the western Pacific is weak and the position is south, which corresponds to the occurrence of cross-seasonal strong drought in the ENC.

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