全球岩石圈结构的快速求算及其结构特征  

A rapid method to map the global lithosphere heterogeneities and its feature analysis

作　　者：姜永涛[1,2] 张永志[1] 王帅[1] 刘宁[1] 

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]南阳师范学院、环境科学与旅游学院,南阳473061

出　　处：《地球物理学进展》2014年第6期2504-2509,共6页Progress in Geophysics

基　　金：国家自然科学基金项目(41374028,41274083,41304013);国土资源大调查项目(1212010914015)联合资助

摘　　要：确定岩石圈结构对研究其起源和进化特征,解释不同岩石圈结构对其下部地幔对流和周边板块构造运动的浅层响应有着重要的作用.本文基于1D岩石圈均衡理论,推导了一种快速求算岩石圈结构的方法,利用最新发布的CRUST1.0地壳模型,计算了全球岩石圈结构.通过与岩石圈已有研究结果的对比分析,得出如下结论：（1）海洋地区的岩石圈厚度与洋壳地质年龄呈正关系,距离洋中脊越远,地质年龄越大,对应的岩石圈就越厚;（2）大陆岩石圈结构更具复杂性,稳定的克拉通具有较厚的岩石圈根,厚度约120-220km,且厚度分布与岩石圈地质年龄有近似的正关系.除北美科迪勒拉山造山带岩石圈厚度较薄外,其余造山带具有较厚的岩石圈根;（3）同一类型岩石圈的Moho与LAB深度有一定的回归关系;不同类型的岩石圈,其回归关系不同,这可能与岩石圈形成年代、长时期所处的构造环境和地幔熔融过程等因素有关.The determination of lithosphere thickness is not only useful for the study of its origination and evolution character,but also very helpful for the explanation of its shallow response to different underlying mantle convection and surrounding plate tectonic.We present a rapid method based on the assumption of lithosphere local isostasy and use CRUST1.0model to map the global lithosphere thickness.By comparing with the latest research results of global thermal lithosphere and regional seismic lithosphere thickness,it is conformed that our results has some practical significances.The distribution of global lithosphere thickness shows the following properties：（1） The thickness of oceanic lithosphere has positive relationship with the geological age of oceanic crust.Around mid-oceanic ridge,the youngest lithosphere on earth has a lithosphere thickness of about 40 kilometers.The farther the distance from mid-ocean ridge,the older of oceanic geological age,and the thicker of corresponding lithosphere thickness,when the oceanic geological age is of 120 million years,the corresponding lithosphere thickness reach 110 kilometers.The cooling plate model is a perfect model to explain the distributing characteristic of oceanic lithosphere.（2）The lithosphere heterogeneity is more complicate in the continental area.Generally,the stable craton has a thicker lithosphere root ranging from 120 to 220 kilometers,and the lithosphere thickness of craton has a nearly positive relationship with its geological age,like in Africa,the Archean craton has the thicker lithosphere root than that of Precambrian craton.But in Australian the situation is different,that is the Precambrian craton has the thicker lithosphere root than Archean craton.The relationship of lithosphere thickness between craton and its adjacent orogenic belts is not clear,in North America the lithosphere thickness of craton is thicker than its adjacent Cordillera Mts orogenic belts,but in South America the lithosphere thickness of craton is shallower than its ad

关 键 词：岩石圈结构 均衡理论 CRUST1.0 海洋岩石圈 克拉通 

分 类 号：P541[天文地球—构造地质学] P315[天文地球—地质学]