Discovery of a Neoproterozoic granite in the Northern Alxa region, NW China: its age, petrogenesis and tectonic significance

Abstract

Abstract A Neoproterozoic granite (Western Huhetaoergai granite) from the Northern Alxa region, southern Central Asia Orogenic Belt (CAOB) is first recognized by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb zircon dating (889±8 Ma). It is a highly fractionated potassium-rich calc-alkaline pluton with low ε Nd ( t ) (−2.6 to −1.1) and high ( 87 Sr/ 86 Sr) t (0.727305–0.735626), and is probably derived from a mantle source and assimilated crustal rocks with very high 87 Sr/ 86 Sr. Regional geology implies that it may reflect the existence of a microcontinent, and the formation of the Western Huhetaoergai granite is related to the assembly of Rodinia.