【摘要】 蓝闪石+硬柱石是羌塘中北部红脊山地区首次发现的呈北西—南东走向展布的硬柱蓝闪片岩带中典型的低温高压变质矿物组合。蓝闪石呈浅蓝灰色,纤柱状;硬柱石无色,多呈团块状,较均匀地与蓝闪石混杂分布。电子探针分析表明,蓝闪石主要为铁蓝闪石和青铝闪石,硬柱石为较典型的硬柱石。硬柱蓝闪片岩呈(透镜状)构造岩块分布,与围岩呈断层接触,原岩主要为变质玄武岩及少量辉(长)绿岩、基性火山碎屑岩,围岩为变质砂岩、板岩和少量碳酸盐岩。红脊山硬柱蓝闪片岩带伴有构造混杂岩发育,二者共存构成红脊山地区北羌塘甜水河陆块与南羌塘查多岗日陆块之间的分界线。更多还原

【Abstract】 Glaucophane-lawsonite is a typical low-temperature/high-pressure mineral assemblage in a NW-SE-trending lawsonite-glaucophane schist zone first found in the Hongjishan area in north-central Qiangtang. Glaucophane is light bluish gray in color and fibro-prismatic in shape; lawsonite is colorless and mostly occurs as patches mixed evenly with glaucophane. Microprobe analysis suggests that glaucophane is mainly ferroglaucophane and crossite, while lawsonite is relatively typical one. Lawsonite-glaucophane schist occurs as (lenticular) tectonic blocks and shows a faulted contact with country rocks. The protoliths consist predominantly of metabasalt with small amounts of (gabbro) diabase and basic pyroclastic rocks. The country rocks consist of metasandstone and slate with minor carbonate rocks. The Hongjishan lawsonite-glaucophane schist zone is accompanied by tectonic mélanges, both of which constitute the boundary between the Tianshuihe block in northern Qiangtang and the Chagdo Kangri block in southern Qiangtang in the Hongjishan area.更多还原