东秦岭佛坪穹隆变质作用与构造动力学分析  

ANALYSIS OF METAMORPHISM AND TECTONIC DYNAMICS OF DOMES IN FOPING COUNTY OF EAST QINLING

作　　者：翟刚毅 

机构地区：[1]陕西省地质矿产厅地质科技处,西安710054

出　　处：《矿物岩石》2000年第2期86-90,共5页Mineralogy and Petrology

摘　　要：以佛坪穹隆为核心 ,(麻粒岩相 ) -高角闪岩岩相 -低角闪岩相变质相带呈同心环带状依次向外展布 ;研究表明 ,其为加里东 -海西期由于地幔上隆导致基底减压深熔而形成局部隆起 ,并引起上部盖层分层剪切 -滑脱作用过程变质作用所发生 ;变质峰期温、压力分别可达 82 9℃和 0 .75 Gpa。但变质峰期滞后于变形峰期。在变质变形过程中基底的隆升幅度可达 7km～ 8km。反映主造山前隆The metamorphic zones of granulitic facie s-high amphibolite facies-low amphibolite facies are distributed at concetric rings from the center to outside around the Foping dome Researches have indicated tha t the result was formed by mantle doming during the Hercynain and Caledonian per iods, thus resulting in the decrease of pressure in basement and forming domes i n localities, which caused the metamorphism occurring in the process of cover-b edding shearing-decollement. During the intensive period of the metamorphism, t he temperature. and pressure could be up to 829℃ and 0.75 Gpa. The intensive pe riod of metamorphism occurred later than that or deformation. In the period of m etamorphism and deformation, the upwarped range of basement could be up to 700 m or 800 m ,which reflecting that the uplift and decollement structures before t he orogenic period are important in evolution the complicated orogenic zones.

关 键 词：佛坪穹隆 变质作用 隆-滑构造 构造动力学 

分 类 号：P588.3[天文地球—岩石学] P542.1[天文地球—地质学]