摘要
威海地区榴辉岩退变质过程表现为三个阶段：第一阶段，原生绿辉石分解形成钠质单斜辉石＋斜长石合晶体；第二阶段，原生石榴石及钢质单斜辉石＋斜长石合晶体，周边出现角闪石＋斜长石 状反应边；第三阶段，石榴石及钢质单斜辉石消失。其后榴辉岩相退变质的ｐ－ｔ演化轨迹是压力相对温度快速降低的顺时针形式，反映本区榴辉岩折返的地球动力学过程可能是在经历了快速上升的构造侵位同时，晚元古宙巨量花岗岩浆可将相辉岩块体携带到上部地壳。
The retrogressive metamorphism of eclogites took place in three stages in Weihai area. Inthe first stage, primary omphacite was broken down into sodic clinopyroxene and plagioclase. In thesecond stage, segmented reaction rim consisting of amphibole and plagioclase was formed along theboundaries of primary omphacite and the integrated crystal of sodic clinopyroxene and plagioclase. During the last stage, garnet and sodic clinopyroxene were disappeared. Then, the p-t path of eclogite retrogressive metamorphism is in a clockwise pattern with faster decreasing of pressure than temperaturereduction. It is suggested that the geodynamic process during eclogite uplifting was possibly quick tectonic process. However, it is also possible that huge amount of granitic magma carried eclogite segmentsup to the upper crust in Late Proterozoic.
出处
《长春科技大学学报》
CSCD
1999年第2期105-109,共5页
Journal of Changchun University of Science and Technology
关键词
榴辉岩
退变质
地球动力学
胶东
威海地区
eclogite retrogressive metamorphism
geodynamics
Weihai eastern ShangdongProvince
