Discovery and Tectonic Implications of Early Triassic O-Type Adakite in Middle of Great Xing'an Range
Li Shichao
Zhang Lingyu
Li Pengchuan
Shi Lu
Zheng Changqing
Abstract：In order to study the tectonic setting of the Early Triassic of the middle of the Greater Xing'an Range,the volcanic rocks of Lower Triassic Hadataolegai Formation was studied by field observation.Respectively,the main elements and trace el-ements were analyzed by XRF and ICP-MS.The results show that the volcanic rocks are a series of calcareous series rocks with high Sr,low Yb,Y and high Sr/Y ratios,showing geochemical features of O-type adakites are related to subduction of oceanic slab.we suggests Paleo-Asian Ocean collision along the line of Silumulon River-Changchun-Yanji which activated Hegenshan-Nenjiang-Heihe structural belt in Early Triassic.The collision pushed the young crust to subduct northward along Hegenshan-Nenjiang-Heihe line.The residual Paleozoic oceanic crust are advanced to the deeper mantle melting and then the Hadataolegai Formation adakites were formed.At the same time,the Laolongtou Formation that is lacustrine clastic sediments was deposited in the intermountain basin.
Keywords：Early TriassicO-type adakiteHadataolegai Formationmiddle of Greater Xing'an Rangegeodynamicspetrology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 2117-2128 )