豫西狮子坪地区秦岭群中的斜长角闪岩-大理岩组

AMPHIBOLITE-MARBLE FORMATION OF THE QINLING GROUP IN SHIZIPING DISTRICT, LUSHI COUNTY, HENAN PROVINCE

在河南卢氏狮子坪地区的秦岭群中出露一套变质地层,其组成特点与各地已知的秦岭群明显不同,主要岩石类型为斜长角闪岩、透辉斜长变粒岩和含石墨大理岩。在构造迭置关系上这套变质地层位于秦岭群条带状长英质片麻岩层和云母片岩层之上,原始接触关系已不明朗,内部也难以逐层恢复层序,但内部三部分的迭置关系是明确的。作者提出这套变质地层应当作为一个独立的填图单位,进而建立岩组,并认为这可能是一套迭置于秦岭群之上的较新地层,但曾与秦岭群一道遭受了变质变形改造。

The amphibolite - marble formation occurs in the Qinling Group of Shiziping district. However, it is mainly composed of amphibolite, diopside - plagioclase fels and graphite - bearing marble and its rock assemblage features differ apparently from the well - known Qinling Group of other districts. As to the significance of structural superposition, the formation is located on the banded quarzofeldsparic gneiss and mica schist strata of the Qinling Group, but the primary contact relation between them is ambiguous. The stratigraphic sequence of the formation can not be restored from stratum to stratum, but the relation between the structural superpositions of the three parts can be determined clearly. The authors proposed that the formation was an independent rock -stratum or a mapping unit. They also believed that it was younger than the Qinling Group, but had been subjected to the same principal metamorphism and deformation with the Qinling Group.