Polyphase tectonothermal events recorded in the Baoban complex from Hainan Island,South China:Constraint from zircon and monazite U-Pb geochronology
The Baoban complex,the oldest Precambrian crystalline basement in Hainan Island,recorded polyphase tectonothermal events,and provides a good window for studying the tectonic attribution of the Hainan Island.In this paper,zircon and monazite LA-ICP-MS U-Pb isotopic data of metasedimentary rocks,amphibolites and pegmatite dykes from the Baoban complex in the Chongzuling area of the southwestern part of Hainan Island are used to investigate the polyphase tectonothermal events in the Baoban complex and discuss their tectonic implications.The Mesoproterozoic metasedimentary rock,granitoids and amphibolite in the Baoban complex recorded three phases of tectonothermal events:Late Mesoproterozoic to Early Neoproterozoic event(1.3～0.9Ga),Early Paleozoic event(470～440Ma)and Triassic event(～230Ma).Late Mesoproterozoic to Early Neoproterozoic tectonothermal event was related to the formation of the Rodinia supercontinent.Early Paleozoic tectonothermal event can be linked to the accretionary orogenesis along the northern margin of East Gondwana.Triassic tectonothermal event is a remote response to the amalgamation of Indochina and South China blocks.Take into account of the above results and regional geology,it is inferred that the Hainan Island has similar Precambrian crystalline basement and polyphase tectonothermal histories with the Indochina block,indicating an obvious affinity between the two blocks.
Zircon and monazite U-Pb dataTectonothermal eventTectonic attributionBaoban complexHainan Island
万方数据
维普
