Episodic growth of Precambrian lower crust beneath the North China Craton: A synthesis

摘要: a b s t r c A comprehensive review of U-Pb geochronology and Hf isotopes zircons separated from granulite xenoliths entrained in Phanerozoic magmatic rocks inherited xenocrysts the associated lower crust various domains North China Craton (NCC) provides new insights into under- standing evolution this part Precambrian nucleus Asia. The oldest recorded show ages up to 3.6 Ga, slightly younger than (3.8 Ga) samples exposed Archean upper crust. However, isotope features indicate that might have been derived 4.0 4.1 Ga primordial as indicated by data an zircon Qinling Orogenic Belt at southern NCC. Our synthesis also suggests ca. 2.5 mark important period for NCC cratonization blocks NCC, least Eastern Block, with pos- sible link mantle plume activity. occasional presence 2.6-3.1 crustal continuous reworking Paleoarchean during Archean. 1.8-2.0 was first significant event after which affected whole Episodic growth or rejuvenation beneath is revealed data, resulting corresponding addition juvenile materials crust, mixing old magma. This compositional modification resembles transformation refractory lithospheric fertile one through peridotite - infiltrated melt reaction