秦岭东段泥盆系中似碧玉层纹钠长石岩的发现及其意义

DISCOVERY AND ITS SIGNIFICANCE OF JASPEROID-LIKE STRIPED ALBITITE IN THE DEVONIAN SYSTEM OF THE QINLING MOUNTAINS

在秦岭东段泥盆系中新发现一种似碧玉层纹钠长石岩,发育有与中泥盆统同样良好的韵律层。野外和室内研究表明,岩石具古热泉沉积成因的可靠信息。这类岩石的发现,对研究秦岭泥盆系铅锌成矿海盆中古地热异常及热泉活动引起的局部热水沉积环境具重要意义,也为了解秦岭造山带泥盆纪时期的成因演化积累了新的资料。

A kind of jasperoid-like striped albitite is discovered recently in a Devonian metallogenic basin in the eastern Qinling. The rock conformably lies on the argillaceous siltstone facies of the Qingshiya Group and its rhythms are in accordance with those in the surrounding rocks.Clearly it is a special kind of syngenetic sedimentary rocks in the basin. It is suggested from the study of the albitite that the marked geothermal abnormality and local short-peroid hot-spring activities should be characteristic of the Qinling middle Devonian metallogenic basin and that a highly salted and hot-water environment similar to 'Atlantic II' abyss of the Red Sea should occur in the Qinling orogenic zone during the Devonian peroid althrough there did not appear a typical oceanic crust.