大别山印支运动的同位素年代学证据

本文根据Sm-Nd同位素年代学成果论证了大别山印支运动的表现。主要依据:(1)阿尔卑斯型橄榄岩的侵入(244±11Ma);(2)辉石岩类超基性岩浆岩的侵入(231±61Ma);(3)高压低温变质岩(如C型榴辉岩)的生成(221±20-224±5Ma)。它们都发生在印支早期,并从而证明了华北陆块、大别山微型陆块、扬子陆块三者是在早三叠世拼接在一起的。在此之前,华北陆块和扬子陆块之间存在一古特提斯洋。

ISOTOPIC CHRONOLOGICAL EVIDENCE FOR INDOSINIAN OROGENY IN DABIE MOUNTAIN

A group of Sm-Nd isotopic chronological results show that the Indosinian orogeny is in broad existence in Dabie Moutain.The manifestations of the Indosinianorogeny in it are mainly, (1) emplacement of Alpine peridotites (244±1Ma), (2) intrusions of pyroxenites (231±61Ma) and (3) occurrence of C-type eclogites (221±20-224±5Ma). They document that both the Dabie microeontinent and Yantze block were accreted to the North China block in early Triassic time. Prior to the Triassic, there was a Tethys ocean between the North Chain block and the Yangtze block.