塔里木北缘及邻区海西期碱性岩岩石化学特征及其大地构造意义  

PETROCHEMISTRY AND TECTONIC SIGNIFICANCE OF HERCYNIAN ALKALINE ROCKS ALONG THE NORTHERN MARGIN OF THE TARIM PLATFORM AND ITS ADJACENT AREA

作　　者：刘楚雄[1] 许保良[1] 邹天人[2] 路凤香[3] 童英[1] 蔡剑辉[1] 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]中国地质科学院矿产资源研究所,北京100037 [3]中国地质大学,湖北武汉430074

出　　处：《新疆地质》2004年第1期43-49,共7页Xinjiang Geology

摘　　要：塔里木地台北缘及邻区发育一套以正长岩、石英正长岩、霓辉正长岩、霓霞正长岩、碱性花岗岩类为代表,包括碱性辉长岩、碱长花岗岩、霓辉花岗岩、角闪正长岩、碱性辉石闪长岩、煌斑岩等类岩石在内的碱性侵入岩体.它们具有近东西向的带状分布特征.主体形成于海西期,相当于泥盆—二叠纪.钾钠含量较高,具有碱性岩类的岩石化学特征,构成一条碱性侵入岩带.其时空分布与北山—阿拉善地区的碱性岩带基本一致.该碱性岩带反映出在泥盆—二叠纪期间,塔里木地台北缘及邻区处于造山期后的拉张构造环境.A set of alkaline-rich intrusive complexes occurs along the northern margin of Tarim platform and its adjacent area. Such types of rocks have been found in this area as syenite, quartz syenite, aegirine-augite syenite, nepheline syenite, alkaline granite, alkaline gabbro, alkaline-feldspar granite, aegirine-augite granite, hornblende syenite, alkaline-augite diorite and lamprophyre. Forming in Hercynian, about Devonian to Permian, these complexes distribute in east-west direction, being rich in Kalium and Natrium, having petrochemistry features of alkaline-rich rocks, making up a alkaline to alkaline-rich rock belt. This belt is comparable to Beishan-Alxa alkaline rock belt. We can deduce from this alkaline rock belt that the northern margin of Tarim platform and its adjacent area is in a extensive tectonic environment during Devonian and Permian.

关 键 词：岩石化学 碱性岩 塔里木 海西 

分 类 号：P588.15[天文地球—岩石学]