甘肃南祁连余石山地区变粒岩原岩恢复  

PROTOLITH RECONSTRUCTION OF LEPTYNITE IN YUSHISHAN AREA, SOUTH QILIAN, GANSU

作　　者：贾志磊[1,2] 窦小雨 王金荣[1] 张岱[4] 侯荣娜[1] JIA Zhi-lei DOU Xiao-yu WANG Jin-rong ZHANG Dai HOU Rong-na(Key Laboratory of Mineral Resources in Western China （ Gansu Province ）, School of Earth Sciences, Lanzhou University, Lanzhou 730000, China Gansu Management Center of Geological Exploration Fund, Lanzhou 730000, China Gansu Provincial Bureau of Geology and Mineral Exploration ＆ Development, Lanzhou 730000, China Gold Geological Institute of CAPF, Langfang 065000, China)

机构地区：[1]兰州大学地质科学与矿产资源学院甘肃省西部矿产资源重点实验室,甘肃兰州730000 [2]甘肃省地矿局,甘肃兰州730000 [3]甘肃省地质勘查基金管理中心,甘肃兰州730000 [4]武警黄金地质研究所,河北廊坊065000

出　　处：《甘肃地质》2016年第2期9-14,共6页Gansu Geology

摘　　要：余石山地区位于南祁连西南端,处在祁连—柴达木—阿尔金地块的交汇部位,构造复杂。长城纪熬油沟组中的变粒岩,由于变质程度较深,以及后期构造的影响,原岩的特征难以辨别。本文通过岩石地球化学方法,对该区变粒岩及其原岩进行了研究,结果显示其原岩为中酸性岩浆岩,结合高场强元素特征和高的碱含量,确定其原岩为正长岩类。Located in the southwest of the south Qilian and the junction zone of the Qilian-Qaidam-Ahyn blocks, Yushishan area underwent complicated tectonics. The leptynites are the major rocks of Aoyougou Group of Changchengian Period in Yushishan area. Howerver, the protolith of leptynite is difficult to distinguish as the result of synantexis. Using the way of petrogeochemistry, the article researched the leptynite and reconstructed its protolith. The results shows the protolith of leptynite belongs to medium-acid magmatic rock and is syenitoid with the characteristics of HFSE and high Na2O＋K2O contents.

关 键 词：原岩恢复 变粒岩 岩石地球化学 余石山 甘肃 

分 类 号：P588.37[天文地球—岩石学]