扬子克拉通与秦岭造山带的构造关系及金刚石矿的找寻

TECTONIC RELATIONSHIP BETWEEN THE YANGTZE CRATON AND THE QINGLIN OROGEN AND EXPLORATION FOR DIAMOND

本文讨论了扬子克拉通与秦岭造山带之间的构造关系,认为其经历了非常复杂的历史过程,大致分为三个阶段:前震旦纪为双列岛弧式主动大陆边缘发展阶段,即发育了桐柏大别岛弧、郧县—随县弧间盆地、米仓山陆缘弧、神农架—大洪山弧后盆地;震旦纪至三叠纪为裂陷槽发育——断裂造山阶段;中新生代为热隆起—滑脱拆离—推覆构造阶段。此构造关系对比金刚石矿床的形成模式,认为扬子克拉通与秦岭造山带的过渡地带是寻找钾镁煌斑岩型金刚石矿床的有利地段。

This paper proposes a three-stage development of the tectonic relationship between the Yangtze Craton and the Qinglin Orogen. During the pre-Sinian stage,the tectonic environment was an active margin that included Tongbai-Dabie island arc, Yunxian-Suixian interar basin, Micangshan marginal arc and Shen-Nongjia-Dahongshan back arc basin. In the Sinian-Triassic stage, rift-sag- fault orogenic belts were developed. In the Mesozoic - Cenozoic stage, hot-uplift - gliding-detachment -thrust-nappe became dominent. Having compared the tectonic relationship with the diamond genetic model, it is considered that the transitional area between the Yangtze Craton and the Qinglin Orogen is a zone favorable for diamond ore deposits of lamproite type.