认识青藏高原的重要窗口──羌塘地区近年来研究进展评述(代序)

    An important window for understanding the Qinghai-Tibet Plateau—A review on research progress in recent years of Qiangtang area, Tibet, China

    • 摘要: 2003年以来,中国地质调查局在羌塘地区部署了30多个1∶25万图幅和少量1∶5万图幅的地质填图工作,各种类型的科学研究不断开展,获得了大量重要的地质调查和研究成果。在古生界广泛分布的羌塘中部取得了基底组成、时代和性质方面的重大进展;冈瓦纳和扬子大陆边缘古生代沉积建造、地层序列和古生物区系研究更加深入,地层格架的建立臻于完善;龙木错-双湖缝合带蛇绿岩的研究更是令人鼓舞,不但识别出了二叠纪蛇绿岩,早古生代完整蛇绿岩的发现和精确的定年研究还使古特提斯洋的演化历史至少上溯到奥陶纪;羌塘中部高压变质带已控制的长度达到500km,榴辉岩的发现和研究丰富了高压变质带的研究内容,根据高压变质矿物学和变质作用的研究已经可以建立羌塘中部板块碰撞过程模型;岩浆岩与岩浆作用研究取得的成果揭示,羌塘中部自奥陶纪以来发生了多期重大的岩浆事件;构造运动分期的研究对冈瓦纳板块与扬子板块界线的确定起到了关键作用。如果把青藏高原喻为打开地球奥秘的金钥匙,那么把羌塘喻为打开青藏高原地学奥秘的钥匙是恰当的。

       

      Abstract: Since 2003,China Geological Survey has assigned more than 30 1∶250000 and a few 1∶50000 mapping tasks in Qiangtang area,various types of scientific researchs have been developing actively,which has achieved a large number of important results of regional geological investigation and scientific research.Significant progress has been obtained regarding the constitution, age and nature of the basement in central Qiangtang where Paleozoic formations are widely distributed; further study has been accomplished in terms of the Palaeozoic sedimentary, stratigraphic sequence and palaeontological fauna of Gondwana and Yangtze continental margin, establishment of stratigraphic framework has been perfected; moreover, results of Longmu Co-Shuanghu ophiolite suture zone study are really encouraging, and through this research, we succeeded in identifing the Permian ophiolite, discovering a complete set of Early Paleozoic ophiolite and precise dating, also extending evolutionary history of the ancient Tethys to the Ordovician; the length of high-pressure metamorphic belt discovered in central Qiangtang has been up to 500km, the discovery and research of eclogites has added much content into this field, mineralogical study of high-pressure metamorphic and metamorphism research are available for establishing Qiangtang central plate collision model now; it has been indicated by magmatic rock and activity research that in central Qiangtang area multi-phase major magmatic events have occurred since the Ordovician; the study of tectonic movement stage has played a key role in the determination of Gondwana Plate and the Yangtze plate boundary. If the Tibetan Plateau can be called the golden key to open the mysteries of the earth, then Qiangtang is the key to open the geological mysteries of Qinghai-Tibet Plateau.

       

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