摘要
宿松杂岩的变质作用可分为３个阶段：早期、主期和晚期阶段。主期阶段的矿物组合在云母片岩中为石榴石＋多硅白云母＋石英＋磁铁矿±钠云母±绿帘石／黝帘石；在白云母钠长（二长）片岩和片麻岩中为石榴石＋多硅白云母＋钠长石＋石英＋绿帘石／黝帘石±冻蓝闪石；在石榴石钠长角闪岩中为石榴石＋冻蓝闪石＋钠长石＋黝帘石＋石英±钠云母±金红石／磁铁矿。根据多种地质温压计和变质反应可以推测主期变质条件为：Ｔ＝５２０℃～５８０℃，Ｐ＝１．２～１．４ＧＰａ，地热梯度为１２℃／ｋｍ，相当于高压过渡型。晚期阶段变质条件为：Ｔ＝４６０℃～４８０℃，Ｐ＝０．６～０．７ＧＰａ，为中压绿帘角闪岩相。宿松杂岩的变质条件介于其南部的蓝闪绿片岩相和北部的榴辉岩相之间，三者是扬子板块向华北板块之下俯冲到不同深度的产物。
Metamorphism of the Susong Complex can be divided into 3 stages: early, main and late stages. The mineral assemblages in the main stage are garnet+phengite+quartz+magnetite±paragonite±epidote/zoisite in the mica schist; garnet+phengite+albite+quartz + epidote/zoisite±barroisite in the muscovite albite(monzo ) schist and gneiss; and garnet+barroisite+albite+zoisite+quartz±paragonite±rutile/magnetite in the garnet albite amphibolite. According to several geothermobarometers and metamorphic reactions, it can be estimated that the P T conditions of the main stage are: T =520℃～580℃, P =1 2～1 4GPa, the geothermal gradient is 12℃/km, belonging to transitional type of high pressure. The P T conditions of the late stage are T =460℃～480℃, P =0 6～0 7GPa, belonging to epidote amphibolite facies of medium pressure type. The metamorphism of the Susong Complex is intermediate between that of the southern glaucophane greenschist facies belt and that of the northern eclogite facies belt, three of which represent the products of the different subduction depths of the Yangtze plate under the North China plate.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第3期356-368,共13页
Acta Petrologica Sinica
基金
国家自然科学基金
国家教委博士点基金
关键词
变质岩
变质作用
杂岩
大别山
岩相学
Metamorphic minerals
P T conditions
Metamorphism
Susong Complex
Southern Dabie Mountains
