陕西商南地区牛耳川组化石的发现及其意义

关于河南境内信阳群及陕西商南地区牛耳川组的时代归属问题，历来分歧较大，多数人认为属于前寒武纪，有的文献还将其定为中元古代。１９９２年，曾见河南西峡地区信阳群发现化石碎屑的报道；笔者近年在河南西峡八庙一陕西商南青山一带研究金红石矿床时，在陕西商南地区牛耳川组不同层位中首次发现了门类更丰富的化石，经过鉴定．并结合河南、陕西两省交界处的八庙、青山金红石矿床的对比及矿层的绝对年龄资料，认为牛耳川组与龟山组为同一套地层，均属中泥盆世。这一结论不仅对确定信阳群时代，而且对河南境内找矿方向的确定均具重要意义。

THE DISCOVER OF NIUERCHUAN GROUP'S FOSSILS ANDIT'SIGNIFICANCE SHANGNAN REGION

Abstract As for the gelolgical time of Xinyang Group in Henan province and of Niuerchuan Group in Shangnan region of Shaanxi province,there existS quite different opinioce. Most of researchers attributed it to Precambrian and some authoritative document even regarded it as middle-proterozoic.It was said to discover fossils clasties in Xinyang Group of Xixia district,Henan province in 1992.In recent years, through the detailed study of the rutile deposits along Bamiao area of Xixia district, Henan province to Qingshan area of Shangnan region, Shaanxi province,first,a great deal of fossils have been have been found in different formation of Niuerchuan Group in Shangnan region, Shaanxi province.According to fossils appraisal result,combined with the correlation meterial of rutile deposits in BamiaoQingshan and absolute date of formation, authors suggest that Niuerchuan Group is as same as Guishan Group formation should be attributtd to Middle-Dovonian.This suggestion is of great significance not only to the understanding time of Xinyang Group and other regional metamorphic time but also to research mine in Henanprovince.