新疆南天山榆树沟层状杂岩体中的副麻粒岩——岩石学特征及其地球动力学意义  

The Para granulite in Bedded Complex from Yushugou, South Tianshan, Xingjang Autonomous Region: Its Petrological Characteristics and Geodynamic Significance

作　　者：王润三[1] 王焰[1] 刘养杰[1] 炎金才[1] 王居里[1] 

机构地区：[1]西北大学地质学系

出　　处：《西北大学学报（自然科学版）》1997年第5期411-416,共6页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学基金

摘　　要：在前人定为“层状堆积杂岩体的辉长岩单元”中发现了一套副变质中－基性麻粒岩。它与正变质的基性麻粒岩成互层产出，二者又与层状变质橄榄岩共同组成了一个并非原生火成堆积岩的层状杂岩体。介绍了这套副变质麻粒岩的出露“层”序、主要岩石类型、原岩建造。认为其原岩是一套主要来源于洋盆内基性火山碎屑的深水沉积岩，其中碎屑锆石Ｕ－Ｐｂ年龄为４２１Ｍａ。这套岩石曾于中石炭世俯冲至中天山－哈萨克斯坦板块之下，同时遭受到麻粒岩相区域变质改造（３１５Ｍａ）；其后，又以高温韧性剪切方式，快速逆冲至南天山早古生代非岩浆型被动陆缘带中。A series of Parametamorphosed intermediate and basic granulite has been discovered in the "gabbro unit of bedded accumulative complexes" which was defined by some geologists. It occurs interbeddedly with orthometamorphosed basic granulite and they, together with bedded methamorphosed peridotite, construct a bedded non igneous accumulative complex. Here is the introduction for the parametamorphite with its exposed "stratum sequence", main types of rocks and protohth tormation. It is considered that the protolith is mainly derived from profundal sedimentary rocks composed of basic volcanic debris in oceanic basin, zircons in which has a 421 Ma U Pb age, and that this rock series may be subducted beneath middle Tianshan Kazakastan plate and undergone simultaneously metamorphic modification of granulite facies at 315 Ma and, then, thrusted rapidly to nonmagmatically south Tianshan passive continental margin belt of early Paleozoic by the way of high temperature ductile shearing.

关 键 词：中-基性麻粒岩 层状杂岩体 副变质麻粒岩 

分 类 号：P588.346[天文地球—岩石学]