黑龙江依兰地区黑硬绿泥石片岩岩石学与P-T条件研究

Petrology and P-T conditions of stilpnomelane schist in the Yilan district, Heilongjian Province.

依兰地区黑龙江杂岩中黑硬绿泥石片岩矿物组合为黑硬绿泥+绿泥石+多硅白云母+钠长石+透闪石+钾长石±黑云母。岩石矿物学研究表明黑硬绿泥石片岩形成于250～400℃,6～9kbar的变质条件下。黄褐色黑硬绿泥石呈束状、放射状集合体。黑硬绿泥石片岩形成于佳木斯地块向西与松嫩地块俯冲拼贴过程中蓝片岩变质作用的后期,压力稍有降低而温度略有升高的变质变形环境,是蓝片岩向绿片岩转变的蓝闪绿片岩相变质条件下的产物。

Stilpnomelane schist contains mineral assemblage of stilpnomelane + chlorite + phengite + albite + tremolite + quartz + K-feldspar +/- biotite in Heilongjian complex, Yilan district. Mineralogical and petrological studies show that stilpnomelane schist formed under P-T conditions of 250 similar to 400 degrees C and 6 similar to 9kbar. Brown stilpnomelane occurs in the form of fascicular or radial aggregates. Stilpnomelane schist was formed in the process of Jiamusi block westward subduction with Songnen block during post-stage blueschist metamorphism, and was a product of geological deformation environment with pressure slightly decline and temperature slightly increase when blueschist facies transforms into greenschist facies.