东秦岭中段宽坪群秦岭群地层厘定

Stratigraphic Redivision of Kuanping Group and Qinling Group in the Middle Segment of the Eastern Qinling Mountains

东秦岭中段商州地区下元古界宽坪群、秦岭群经１：５００００区调研究，宽坪群自下而上建立了竹林沟组、四岔口组、广东坪组、麻街组、谢湾组等五个有序地层组和层位不确切的五峰山岩组。秦岭群属无序岩群，可分为变基性火山岩夹黑云变粒岩组合，黑云变粒岩夹条带状斜长角闪岩组合与浅粒岩夹大理岩组合，推断三种岩石组合可能依次由老至新。

Abundant data and some new opinions have been postulated for the metamonphic rocksof the lower Proterozoic Kuanping Group and Qinling Group in Shangzhou of the EasternQinling Mountains,On the basis of the contact relation,the first deformation or partial melt-ing characteristics and the primary structures,the Kuanping Group can be divided,from thebottom to the top,into the sequential Zhulingou,Sichakou,Guangdongping,Majie andXiewan Formation,and unlocated Wufengshan Rock Formation,The Qinling Group is a non-sequential rock formation composed of three assemblages of metamorphic rocks:metabasicvolcanic rocks interelated with biotite leptynites,biotite leptynites interclated with stripeddagioclase maphibolites and the leptites interelated with marbles.It is supposed that the se-quence is got younger in proper order from the metabasic volcanic rocks to the leptites.