40Ar/39Ar Geochronology, Geochemistry and Petrogenesis of the Volcanic Rocks in the Jiangling Basin, China

Abstract

In this study, 40Ar/39Ar geochronology and major and trace element data were presented for Paleogene basaltic rocks from the Jiangling Basin, China. The volcanic rocks erupted at ca. 53.19–60.78 Ma and belonged to the sub alkaline series. These basaltic rocks are generally characterized by enrichment in large-ion lithophile elements (LILEs) and light rare earth elements (LREEs) ((La/Yb)cn = 6.14–11.72) and lack of Eu anomalies (Eu/Eu* = 0.98–1.09), similar to ocean island basalts. The geochemical signatures of these rocks are similar to hotspot-related Paleogene volcanic rocks in the North China Block and late Cenozoic volcanic rocks in Southeast China. The Cenozoic lithospheric mantle, as well as the Mesozoic basalts that are beneath the northern Yangtze Blocks, might be inherited from the Mesozoic lithospheric mantle. The basaltic rocks from the Jiangling Basin in the northern Yangtze Block were generated from the partial melting of EMII (enrichedmantleII)-like lithospheric mantle due to the intracontinental extension.