New identification and significance of Early Cretaceous mafic rocks in the interior South China Block.

ABSTRACT: Early Cretaceous mafic rocks are first reported in the northern Guangxi region from the western Qin-Hang belt in the interior South China Block. A systematic investigation of zircon U-Pb dating, whole-rock geochemistry, Sm-Nd isotopes and zircon Hf-O isotopes for these mafic rocks reveals their petrogenesis and the mantle composition as well as a new window to reconstruct lithospheric evolution in interior South China Block during Late Mesozoic. Zircon U-Pb dating yielded ages of 131 ± 2 Ma to 136 ± 2 Ma for diabase and gabbro from Baotan area, indicating the first data for Early Cretaceous mafic magmatism in the western Qing-Hang belt. These mafic rocks show calc-alkaline compositions, arc-like trace element distribution patterns, low zircon ε_Hf(t) of - 9.45 to - 6.17 and high

SUBMITTER: Su HM 

PROVIDER: S-EPMC8166846 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature