The Cenozoic Hannuoba basaltic province, 200 km northwest of Beijing, China, is composed of intercalated tholeiitic, transitional and alkalic basalts. Although the alkalic basalts contain abundant upper mantle xenoliths, they range in MgO content from 5.7 to 10.6% MgO. Most of the major and trace element abundance variations in the alkalic basalts can be explained by segregation of a clinopyrox...

Abstract The Rio Grande Rise in the western South Atlantic Ocean has been interpreted as either an oceanic plateau related to Tristan-Gough mantle plume, or a fragment of detached continental crust. Here we present new major and trace element data for volcanic rocks from eastern adjacent Jean Charcot Seamount Chain. older parts are comprised tholeiitic basalt with moderately enriched compositio...

Understanding how the Earth’s first continental land masses were generated is important because the processes responsible directly affected the evolution of the planet’s primordial silicate interior, and also its atmosphere and hydrosphere. Archaean continental crust is dominated by rocks of the trondhjemite–tonalite–granodiorite (TTG) suite. These can be divided into (1) a midto late Archaean ...

Abstract The growth of continental crust through melt extraction from the mantle is a critical component chemical evolution Earth and development plate tectonics. However, mechanisms involved remain debated. Here, we conduct petrological geochemical analyses on large (up to 5000 km 2 ) granitoid body in Arabian-Nubian shield near El-Shadli, Egypt. We identify these rocks as largest known plagio...

Recent studies have focused on the question of the stratigraphic sequence and thus the stages of tessera formation, specifically, if tessera re formed by contractional deformation followed by extensional deformation or vice versa. A major question centers on the interpretation of specific lineaments within tesserae as graben (bounded by faults -•60 ø) or, alternatively, open tension fractures (...