LITHOTECTONIC ELEMENTS AND GEOLOGICAL EVENTS IN THE HENGSHAN-WUTAI-FUPING BELT: A SYNTHESIS AND IMPLICATIONS FOR THE EVOLUTION OF THE TRANS-NORTH CHINA OROGEN

Abstract

The HengshanFuping belt is located in the middle segment of the Trans-North China Orogen, a Palaeoproterozoic continental collisional belt along which the Eastern and Western blocks amalgamated to form the North China Craton. The belt consists of the medium- to high-grade Hengshan and Fuping gneiss complexes and the intervening low- to medium-grade Wutai granite2520 Ma, marked by the emplacement of the Wutai granitoids, which was followed by arc volcanism at 2530Wutai island arc (Japan-type) and the Fuping relict arc. At 2520Wutai island arc caused partial melting of the lower crust to form the Hengshan tonaliticgranodioritic (TTG) suites, whereas eastward-directed subduction of the marginal sea led to the reactivation of the Fuping relict arc, where the Fuping tonaliticgranodioritic suite was emplaced. In the period 2360Wutai2100 Ma granitoids in the Hengshan Complex, the c. 2100 Ma Wangjiahui and Dawaliang granites in the Wutai Complex, and the 2100Wutai island arc underwent an extensional event, possibly due to the subduction of an oceanic ridge, leading to the emplacement of pre-tectonic gabbroic dykes that were subsequently metamorphosed, together with their host rocks, to form medium- to high-pressure granulites. At 1880WutaiWutai1750 Ma.