西秦岭礼县—武山杨河一带石炭纪地层的重新厘定

通过1:250000天水幅区域地质调查,在礼县鲁班石、郭家坪、青林寺、大南岔沟、固城一带的石炭系地层中相继新发现了丰富的珊瑚、腕足、蜓及非蜓有孔虫、牙形刺及古植物化石,为该地区石炭纪地层的划分和时代归属提供了重要证据。经过区域对比,发现原划地层单元的名称和时代归属都有值得商榷之处。根据新发现的化石及其组合特征,重新厘定了本区石炭纪地层的地层序列和岩石地层单元名称。

Revision of the Carboniferous Strata in the Lixian-Yanghe(Wushan)Area,West Qinling

There are still much divergence of views about the division of lithostratigraphic units and the determination of Carboniferous strata in the north of West Qinling orogenic belt. Through 1:250 000 regional geological survey, abundant fossils including coral, brachiopod, fusulinid, un-fusulinid foraminifera, conodont and plant fossils have been discovered in such areas as Lubanshi, Guojiapin, Qinglinsi, Dananchagou and Guchen of Lixian county. These fossils afford very important evidences for the dividing and determiation of the times of Carboniferous strata in this area. It is thought that the names and times of the former lithostratigraphic units are worth to be discussed after regional correlation. The stratigraphic sequence and the name of the lithostratigraphic units of Carboniferous strata in this area have been revised according to the newly-discovered fossils and their association.