CAJ | 학술논문

牡丹江地区出露的黑龙江杂岩是由变质基性岩、泥质片岩、大理岩和变硅质岩系列组成的类似于蛇绿岩层序的构造混杂岩,代表了佳木斯地块西南缘碰撞增生的产物.钠长石和绿帘石变斑晶中共生的矿物组合(钠云母+蓝闪石+多硅白云母+绿帘石)的地质温压计估算结果表明,黑龙江杂岩的峰期变质的温压条件为T=320～4800℃,p=800--1600MPa,为典型的绿帘-蓝片岩相高压变质作用.黑龙江杂岩带中泥质片岩所含的多硅白云母单矿物给出的~(40)Ar/~(39)Ar坪年龄为164.9Ma±0.5Ma.根据白云母中K~Ar同位素体系的封闭温度(350～430℃)接近于得到的黑龙江杂岩的峰期变质温度,可以认为~(40)Ar/~(39)Ar坪年龄指示了这期高压变质事件的年龄,也证实了黑龙江杂岩带中普遍存在一期中侏罗世末期的变质-热事件.
모단강지구출로적흑룡강잡암시유변질기성암、니질편암、대리암화변규질암계렬조성적유사우사록암층서적구조혼잡암,대표료가목사지괴서남연팽당증생적산물.납장석화록렴석변반정중공생적광물조합(납운모+람섬석+다규백운모+록렴석)적지질온압계고산결과표명,흑룡강잡암적봉기변질적온압조건위T=320～4800℃,p=800--1600MPa,위전형적록렴-람편암상고압변질작용.흑룡강잡암대중니질편암소함적다규백운모단광물급출적~(40)Ar/~(39)Ar평년령위164.9Ma±0.5Ma.근거백운모중K~Ar동위소체계적봉폐온도(350～430℃)접근우득도적흑룡강잡암적봉기변질온도,가이인위~(40)Ar/~(39)Ar평년령지시료저기고압변질사건적년령,야증실료흑룡강잡암대중보편존재일기중주라세말기적변질-열사건.
The Heilongjiang complex exposed in the Mudanjiang area,southern.Jiamusi massif;is composed predominately Of metabasites,pelitic schists,marbles and meta-siliceous rocks that were tectonically interleaved melange similar to the series of ophiolite,represerning the rock assodafions of the accretionary complex in the southwestern Margin of Jiamusi massif The geothermobarometer estimatiom of the peak mineral assemblage (Pg+Gln+Phn+Ep)which are included in porphyroblastic albite and epidote show that the p-T condition of the peak metamorphic stage WaS T=320-480℃ and P=800-1600 MPa.indicaung typical epidote-blueschist faciesmetamorphism.In addition,~(40)Ar/~(39)Ar plateau age of 164.9±0.5Ma is dated from a pelitic schist in the Heilongjiang complex.Due to the analogous temperature in K-Ar system of phengite (350-430℃)to the peak metamorphism condition mentioned above,the ~(40)Ar/~(39)Ar phteau age may be taken as the timing of high-pressure metamorphism,which represents the widespread metamorphism event in the Heilongjiang complex at the end of the Middle Jurassic.