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在秦岭构造带东段大别山北麓的河南信阳附近,作者发现了一个古消减带,其中消减杂岩由蛇绿岩:混杂岩及低温高压变质带的岩石组成。推断古板块会聚边缘的构造发育史可以划分为以下三个阶段: Ⅰ、晚元古代(约800—7000百万年前),东秦岭古洋壳向北朝华北古陆之下俯冲,产生了初始的桐柏岛弧及弧后的边缘海。 Ⅱ、元古代末(约700—600百万年前),俯冲带极性反向,边缘海洋壳向南朝桐柏岛弧之下消减,从而产生了信阳消减杂岩。 Ⅲ、早古生代初(约600—500百万年前),边缘海闭合,桐柏岛弧增生于华北古陆的南缘,东秦岭古洋壳沿岛弧之南的一个新贝尼奥夫带再次向北俯冲。
In the vicinity of Xinyang, Henan Province, in the northern foothills of the Dabie Mountains in the eastern part of the Qinling structural belt, the authors discovered a paleoclimate depleted zone in which the subducted complexes consist of ophiolites: melanges and rocks of low-temperature and high-pressure metamorphic belt. It is inferred that the tectonic history of the convergent fringes of the ancient plate can be divided into the following three stages: Ⅰ. In the Late Proterozoic (about 800-7000 million years ago), the Eastern Qinling paleoceanic subduction subducted northward under the North China ancient land and produced the initial The Tong Park Island arc and the edge of the sea after the arc. Ⅱ. At the end of Proterozoic (about 700-600 million years ago), the polarity of the subduction zone is reversed, and the marginal marine crust subsides to the south under the Tongbai Island arc, resulting in the Xinyang subduction complex. Ⅲ. Early Early Paleozoic (about 600-500 million years ago), the marginal sea was closed, the Tongbai Island arc was proliferated in the southern margin of North China ancient land, and a new Benioff With north dive again.