Petrogenetic Evolution of Early Paleozoic Trachytic Rocks in the South Qinling Belt, Centra China: Insights from Mineralogy, Geochemistry, and Thermodynamic Modeling

2021 ◽  
Author(s):  
Hang Yang ◽  
Shao-Cong Lai ◽  
Jiang-Feng Qin ◽  
Fang-Yi Zhang ◽  
Ren-Zhi Zhu ◽  
...  
Keyword(s):  
Thermodynamic Modeling ◽  
Early Paleozoic ◽  
The South ◽  
South Qinling

Magma source and evolution process of Early Paleozoic basalts in the South Qinling Belt

2020 ◽  
Vol 36 (7) ◽  
pp. 2149-2162
Author(s):  
ZHANG FangYi ◽  
◽  
LAI ShaoCong ◽  
QIN JiangFeng ◽  
ZHU RenZhi ◽  
...  
Keyword(s):  
Evolution Process ◽  
Magma Source ◽  
Early Paleozoic ◽  
The South ◽  
South Qinling

Vein-plus-wall rock melting model for the origin of Early Paleozoic alkali diabases in South Qinling Belt, Central China

2020 ◽  
Author(s):  
Fangyi Zhang ◽  
Shaocong Lai
Keyword(s):  
Partial Melting ◽  
Wall Rock ◽  
Mantle Metasomatism ◽  
Central China ◽  
Primitive Mantle ◽  
Stability Field ◽  
Alkaline Magmatism ◽  
Early Paleozoic ◽  
The South ◽  
South Qinling

<p>Early Paleozoic mafic dykes are widespread in South Qinling Belt, central China. In this study, we present new major element, trace element, zircon U–Pb age and Sr–Nd–Hf isotopic results of Early Paleozoic diabases dykes in the South Qinling Belt to explore nature of the mantle source. The South Qinling Belt diabases have low SiO<sub>2</sub> (42.1–49.5 wt%) high TiO<sub>2</sub> (2.89–5.17 wt%), variable MgO (4.0–9.4 wt%) contents. In primitive mantle normalized multielement diagrams, all samples are strongly enriched in the majority of incompatible trace elements but systematic depletion in Rb, K, Pb, Zr and Hf. The negative K and Rb anomaly together with high TiO<sub>2</sub> and high Na<sub>2</sub>O/K<sub>2</sub>O character suggest magma was derived from a source rich in amphibole. Partial melting modelling indicate 20–36% partial melting of amphibole-clinopyroxene-phlogopite veins with subsequent dissolution of ~30% orthopyroxene from the wall-rock peridotite within spinel stability field can produce the observed compositions of diabases. Additionally, South Qinling Belt diabases are characterized by moderately depleted Nd (ε<sub>Nd(t)</sub>= +2.2 to 3.3) and Hf (ε<sub>Hf(t)</sub>= +6.2 to 7.2) isotopic compositions without pronounced isotope decoupling, indicating mantle metasomatism occurred shortly prior to Early Paleozoic magmatism. It is proposed that low-degree silicate melts released from asthenosphere infiltrated and solidified within lithospheric mantle, forming non-peridotitic lithologies rich in amphibole clinopyroxene and phlogopite. Subsequent lithosphere extension caused the melting of the most easily fusible material in the lithosphere, which gave rise to the Early Paleozoic alkaline magmatism in South Qinling.</p>

Vein-plus-wall rock melting model for the origin of Early Paleozoic alkali diabases in the South Qinling Belt, Central China

Lithos ◽  
2020 ◽  
Vol 370-371 ◽  
pp. 105619
Author(s):  
Fang-Yi Zhang ◽  
Shao-Cong Lai ◽  
Jiang-Feng Qin ◽  
Ren-Zhi Zhu ◽  
Shao-Wei Zhao ◽  
...  
Keyword(s):  
Wall Rock ◽  
Central China ◽  
Early Paleozoic ◽  
The South ◽  
South Qinling

Petrogenesis and tectonic significance of the middle Neoproterozoic highly fractionated A-type granite in the South Qinling block

2021 ◽  
pp. 1-20
Author(s):  
Xiao-Fei Qiu ◽  
Qiong Xu ◽  
Tuo Jiang ◽  
Shan-Song Lu ◽  
Long Zhao
Keyword(s):  
Tectonic Setting ◽  
Eastern China ◽  
Continental Rift ◽  
The South ◽  
Yangtze Craton ◽  
Dabie Orogen ◽  
Northern Margin ◽  
South Qinling ◽  
Type Granite ◽  
High Alkali

Abstract The South Qinling block, a segment of the Yangtze craton involved in the Qinling–Dabie orogen, is critical for understanding the tectonic evolution of eastern China. However, the tectonic setting of the South Qinling block and the northern margin of the Yangtze block during middle Neoproterozoic time has long been the subject of debate, with two distinctly different models (continental rift or volcanic arc) proposed. Here, a comprehensive study of zircon U–Pb geochronology and geochemistry has been carried out on the Chengwan granitic pluton from the Suizao terrane in the South Qinling block. The granites are monzogranite and syenogranite in lithology, and are mainly composed of potash feldspar, quartz, plagioclase and biotite. This suite has long been regarded as a Palaeozoic magmatic pluton, but zircon U–Pb ages of 809 ± 9 Ma and 816 ± 4 Ma are obtained in this study. The granites are metaluminous to strongly peraluminous with high alkali contents, and exhibit highly fractionated features, including high SiO2, low Zr/Hf ratios, rare earth element tetrad effects and enrichment of K and Rb. They show Hf–Nd isotopic decoupling, which may be genetically related to their petrogenetic process. Based on the geochemical features and the positive εHf(t) values of the zircons, it is indicated that the granites may have been derived from partial melting of juvenile tonalitic rocks by biotite breakdown under fluid-absent conditions. The Chengwan granite geochemically belongs to the A2-subtype granites, suggesting that it might have formed in a post-orogenic tectonic setting. The highly fractionated A-type granite in this study may represent extensional collapse shortly after the collisional events in the South Qinling block, and thus indicate a tectonic regime switch, from compression to extension, as early as middle Neoproterozoic time. Integrating our new data with documented magmatic, metamorphic and sedimentary events during middle Neoproterozoic time in the region may support a continental rift model, and argues against arc models.

Syn‐tectonic emplacement during sinistral transpression : The Late Triassic Gaoqiao pluton in the South Qinling Belt , central China

2020 ◽  
Author(s):  
Wei Tao ◽  
Yang Li ◽  
Yingtao Chen ◽  
Rukui Lu ◽  
Yazhou Ran ◽  
...  
Keyword(s):  
Central China ◽  
Late Triassic ◽  
The South ◽  
South Qinling

Early Paleozoic intracontinental felsic magmatism in the South China Block: Petrogenesis and geodynamics

Lithos ◽  
2015 ◽  
Vol 234-235 ◽  
pp. 79-92 ◽  
Author(s):  
Wenjing Xu ◽  
Xisheng Xu
Keyword(s):  
South China ◽  
South China Block ◽  
Early Paleozoic ◽  
The South

Discovery of late Paleozoic fossils in tectonic blocks of the Dabao Formation in the South Qinling Orogenic Belt and their significance

2011 ◽  
Vol 54 (7) ◽  
pp. 975-981 ◽  
Author(s):  
Tao Wang ◽  
ZongQi Wang ◽  
Zhen Yan ◽  
QuanRen Yan ◽  
YingLi Zhang ◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Late Paleozoic ◽  
The South ◽  
Qinling Orogenic Belt ◽  
South Qinling
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