中国大陆大规模成矿作用油气田形成——来自岩石圈的约束  

Large-scale metallogenesis and petroleum field formation in continental China——constraints from the lithosphere

作　　者：邱瑞照[1] 李廷栋[2] 邓晋福[3] 周肃[3] 肖庆辉[4] 叶天竺[1] 耿树方[5] 陈秀法[1] 王翠芝[3] 刘勇[3] 

机构地区：[1]中国地质调查局发展研究中心,北京100037 [2]中国地质科学院 [3]中国地质大学,北京100083 [4]国土资源部信息中心,北京100812 [5]中国地质科学院地质研究所,北京100037

出　　处：《中国地质》2006年第4期852-865,共14页Geology in China

基　　金：国土资源部科技专项计划项目(200010103);国家自然科学基金项目(NSFC402344048;No.40572063);中国地质调查局地质大调查项目(1212010561502;1212010661315;1212010561501);中国地质大学"岩石圈构造;深部过程及探测技术"教育部重点实验室开放课题(2003009;2003010)项目联合资助。

摘　　要：由克拉通、造山带、裂谷、边缘海洋壳和岛弧等5大岩石圈类型构成的中国大陆,由于不同类型岩石圈对应的动力学机制及其效应不同,岩石圈不同类型之间的连接带必定是不连续带,与大陆成矿作用有密切的联系。中国大陆已知的绝大多数金属矿床分布于岩石圈不连续和再活化不连续处,表明岩石圈不连续为大型矿床(矿集区)形成提供有利的运-储空间。中国大陆西北、中国东部和西南地区构造-岩浆-成矿事件序列对比表明,一个地区岩石圈的壳-幔岩石学结构、大规模成矿作用,取决于最强的、最后一次的岩浆作用,大规模成矿作用的发生起始于造山岩石圈根失稳、去根和大规模软流圈上涌时期,C型埃达克岩的出现是其标志之一。分布于中国内陆的扬子、鄂尔多斯、塔里木和准噶尔盆地等地表热流值低的“冷盆”,深部属于克拉通型岩石圈背景,在构造上往往为造山带的前陆盆地,克拉通型岩石圈构造上的稳定性决定了这些克拉通盆地不断被周围造山带吞食、掩埋、改造的格局,虽然在这些盆地内如今都已发现油气田,但在盆地外那些现今被造山带前缘逆冲体覆盖的区域,也应该是油气田产出的有利区域,即盆地外造山带花岗岩下依然是寻找油气田的重要远景区。分布于中国东部的平原区和黄海、东海及南海等陆缘海区,属于地表热流值高的“热盆”,这些盆地下对应的是裂谷型或洋壳型岩石圈,它们是在新生代时期中国东部沿海地区进入了新的构造演化阶段——大陆裂谷作用下形成的,以伴随广泛的玄武岩喷发为标志,对流地幔物质和热输入使盆地热流值升高成为“热盆”、大陆裂谷型岩石圈,乃至洋壳岩石圈(如南海中央海盆);伴随裂陷作用及伸展构造普遍发育的幔源玄武岩浆大量喷发,以及大量沉积物的快速沉积、埋藏有利于油气田的形成,其中的组分,Continental China consists of five types of lithospheres, namely, cratonic, orogenic, rift, oceanic, marginal sea crust and island-arc. As different types of lithospheres have different dynamic mechanisms and effects, the junction zones between the different types of lithospheres are bound to be discontinuity zones and have close relationship with continental metallogenesis. The greater majority of known metallic mineral deposits in continental China are distributed along the lithospheric discontinuities or reactivated discontinuities, indicating that the lithospheric discontinuities provide favorable spaces for migration and accumulation of large ore deposits （deposit clusters）. A comparison of the sequences of the tectono-rnagmato-metaUogenic events in the northwestern, eastern and southwestern regions of continental China indicates that the lithospheric crust-mantle petrological structures and large-scale metallogenesis depend on the latest and strongest magrnatism, and that large-scale metallogenesis was initiated in the period of instability and de-rooting of the orogenic lithosphere and large-scale upwelling of the asthenospheric material. The occurrence of Ctype adakite may be regarded as one of their indications. The Yangtze, Ordos, Tarirn and Junggar basins distributed in China inland, which are called ＂cold basins＂ due to their low surface heat flow values, belong to the setting of the cratonic type lithosphere and tectonically are usually foreland basins of orogenic belts. The tectonic stability of the cratonic type lithosphere determined that these basins were swallowed, buried and modified continuously by their surrounding orogenic belts. Although many oil-gas fields have been found in these basins now, the areas outside these basins which are now covered by the front thrust sheets of orogenic belts should also be favorable areas for occurrence of oil-gas fields, i.e., those areas under granites of orogenic belts outside the basins are still important potential areas for off-gas field finding

关 键 词：岩石圈不连续 大规模成矿作用 油气田形成 岩石圈约束 中国大陆 

分 类 号：P618.13[天文地球—矿床学]