张强凹陷及邻区火山岩特征与构造属性  

PROPERTIES OF VOLCANIC ROCKS AND STRUCTURAL ATTRIBUTES IN ZHANGQIANG DEPRESSION AND ITS NEIGHBOURING AREA

作　　者：陈全茂[1] 张光亚[1] 梁晓东 陈昭年 周绍强[2] 王占忠[2] 

机构地区：[1]中国地质大学石油系 [2]辽河石油勘探局

出　　处：《石油与天然气地质》1997年第4期309-313,共5页Oil & Gas Geology

摘　　要：火山岩地球化学特征与构造背景关系十分密切。经分析，张强凹陷及邻区大洼昌图凹陷的火山岩具有以下特征：（１）火山岩都为中酸性，以碱性玄武岩系列为主；（２）张强凹陷火山岩属既有钾质也有钠质的碱性玄武岩，另外还有钙碱性和大陆型拉斑玄武岩，邻区大洼昌图凹陷火山岩全部为钠质碱性玄武岩；（３）张强凹陷和邻区大洼昌图凹陷火山岩的球粒陨石标准化稀土元素分配曲线向右倾斜，轻稀土富集；（４）微量元素ＺｒＣｅ，ＺｒＬａ图解上，张强凹陷与大洼昌图凹陷差别明显。这些特征表明，张强凹陷及邻区大洼昌图凹陷的火山岩均为大陆裂谷活动的产物，但张强凹陷发育时间稍早；张强凹陷与大洼昌图凹陷火山岩的岩浆来源不同，应分属不同的构造单元。The geochemical properties of volcanic rocks bear close relations with structural background.It has been proved by analysis result that volcanic rocks in Zhangqiang and its neighbouning Dawa Changtu Depressions have following characteristics:(1)the volcanic rocks are neutral acid,and most of them are alkaline basalt;(2)the volcanic rocks are sodium alkaline basalts in Dawa Changtu Depression,but sodium and potassium alkaline basalts as well as calc alkali and continental tholeiitic basalts in Zhangqiang Depression;(3)the standard rare earth element distribution curves of chondrite in the volcanic rocks tilted rightwards and light rare earth element are rich in the rocks.(4)Zr Ce and Zr La diagrams show distinct differences between the two depressions.It is suggested that the volcanic rocks in the two depressions are all resulted from continental rift,the magma sources are different and should belong to different tectonic units.

关 键 词：构造属性 玄武岩 火山岩 特征 油气勘探 

分 类 号：P588.14[天文地球—岩石学] P618.130.8[天文地球—地质学]