辽宁阜新地区太古宙变质岩变质作用及其演化规律

辽宁阜新地区的"太古宙变质岩"是华北板块北缘太古代的最下部的地体，它由连续性很差的表壳岩、TTG岩石及其他深成侵入岩构成。基本岩石类型包括：角闪石岩、辉石岩、斜长角闪岩、麻粒岩、紫苏花岗岩、片麻岩及少量的磁铁石英岩。主要特征变质矿物由石榴子石（Gr）、斜方辉石（Opx）、单斜辉石（Cpx）、角闪石（Hb）、斜长石（Pl）和石英（Q）。岩相学研究确定了指示变质作用不同阶段的3个变质反应的存在，并且它们与推测的矿物相的转化关系吻合。结合地质温压的限定，笔者得出了该区太古宙末期的强烈的变质热事件的IBC型的PTt演化轨迹，即具有近等压冷却过程。并推测出此变质热事件形成于大量岩浆的板低垫托，同时伴有深部的地壳拉张作用的大地构造环境。

Metamorphism of Archean Metamorphic Rocks from Fuxin Area in Liaoning Province and Their Evolution

The "Archean metamorphic rock" from Fuxin area in Liaoning Province is the lowest part of Archearn terrene in the northern margin of North China plate, which is composed of discontinuous supracrustal rocks, TTG series and some other plutons. The basic rock type of this metamorphic rock includes:hornblendite, pyroxenite, amphibolite,granulite, charnockite, gneisses and little magnetite quartzite. Its main diagnostic metamorphic minerals are garnet, orthopyroxene, clinopyroxene, hornblende, plagioclase and quartz.Petrographic studies identified that three metamorphic reactions occurred in different stages of metamorphism, and they are in good agreement with the transformation of the mineral phase.Combined with the limits of geological temperature and pressure, the IBC-type PTt evolution path of intense metamorphic thermal event at the end of the Archean Eon has been concluded in this paper, which is the near isobaric cooling process.And then, it's inferred that the metamorphic thermal event was formed in a large number of low-pad supports of magma, which is accompanied by the tectonic setting of the deep crust.