苏胶地体内榴辉岩的成因环境探讨

本文重点论述了苏胶地体内榴辉岩的四种产出形态，从岩石化学特点，微量元素的分馏及稀土元素富集或亏损等规律用六种以上的方法判别了不同产状榴辉岩的原岩性质；同时从区域变质环境、共生矿物、阳离子配位系数的相关性等方面，分析估算了榴辉岩相变质事件的Pt条件，以及后成碱性闪石榴辉岩产生的Pt条件，并同世界各地碱性闪石榴辉岩的成因作了广泛对比，概括了榴辉岩的成因环境等重大地质问题。

RESEARCH ON GENESIS OF ECLOGITES IN THE SU-JIAO TERRAIN

In this paper we focus discussion on four occurrences of eclogite which are massive or sack-like , enclave-like, lenticulated or banded and stratiform or banded and stratiform or stratoid ones in the Su-Jiao Terrain and try to distinguish protolith of eclogites from characteristics of petrochemistry, fractionation of trace elements and enriching or depleting rare outh elements; and analyze for P-T conditions of metamorphic events of difftrent eclogite facies and deuterogenic alkali-amphibole eclogites from environment of regional metamorphism relative with paragentic association and cation coordinate coefficient of minerais. The results indicated that forming of eclogites in the area underwent a complicated process which is Progressive and retrogressive metamorphic events, i. e ; regional progressive metamorphism of first stage represented from epidote amphibolite facies, amphibolite facies to eclogite facies, and formed eclogites of different mineral associntion and coesite eclogite at peak stage of metamorphism;regional retrogressive metamorphism that changed eclogite facies to alkali-amphibotite pseudo-coesite eclogite. The alkali-amphiboite pseudo-coesite eclogite is only representative of product of highpressure metamorphic events at last phase during locating of the terrain.