Depositional age, provenance, and tectonic implications of Neoproterozoic sedimentary rocks in the Xiangshan area, South China

• Published in: Geological journal (Chichester, England) Vol. 56; no. 3; pp. 1584 - 1603
• Main Authors: Wang, Kai‐Xing, Sun, Li‐Qiang, Sun, Tao, Huang, Hui
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.03.2021; Wiley Subscription Services, Inc
• Subjects: Detritus; Geochemistry; Isotopes; Precambrian; Sedimentary rocks; Tectonics; whole‐rock geochemistry; Yangtze and Cathaysia blocks; Zircon; zircon U–Pb–Hf isotope
• ISSN: 0072-1050; 1099-1034
• DOI: 10.1002/gj.4000

Detrital zircon U–Pb–Hf isotopes and whole‐rock geochemical compositions of exposed Neoproterozoic sedimentary rocks in the Xiangshan area are determined to discuss provenances and the boundary between the Yangtze and Cathaysia blocks. Zircon dating results reveal that the exposed Precambrian sedimentary rocks in the Xiangshan area were deposited in the Late Neoproterozoic era. The age spectra and whole‐rock geochemistry show that the detrital materials of the Shenshan Formation originated from the Yangtze Block and that the detritus of the Kuli and Shangshi formations came mainly from the Yangtze Block and partly from the Cathaysia Block. The source for the Neoproterozoic sedimentary rocks in the Xiangshan area may been intermediate rocks, mainly from a mixture of felsic and mafic rocks in the Yangtze Block. In combination with previous studies, we suggest that the Xiangshan area belonged to the Cathaysia Block before the amalgamation between the Cathaysia and Yangtze blocks and that the real boundary between the two blocks is located in the northern part of the Xiangshan area. 100 TiO2/Al2O3 versus 100 Fe2O3/Al2O3 (a), 100 TiO2/Al2O3 versus 100 TiO2/Fe2O3 (b); La/Sc versus Co/Th (c), and Cr/Th versus Th/Sc (d) diagrams of the basement rocks in the Xiangshan area. Those diagrams show the chemical compositions of protoliths for the Proterozoic sedimentary rocks in the Xiangshan area displaying intermediate‐acid affinity which were composed of 90–70% felsic rocks and 10–30% mafic rocks.