【摘要】 <正> 陕西陇县位于西安西北约200公里处,属鄂尔多斯地台的西南缘,地层区划归陕、甘、宁盆缘分区平凉—永寿小区(图1).该区奥陶系发育,上、中、下三统俱全.中奥陶统在这里相当于胡乐期和(氵韩)江期的地层,全为笔石相沉积.在前人工作的基础上,傅力浦(1975)、陈均远等(1978)先后对本区中奥陶统笔石带作了进一步的划分.傅力浦根据陇县龙门洞剖面完整、笔石带齐全以及全为笔石相沉积诸特点,修订了原平凉组的含义,其范围相当于从Glyptograptus teretiusculus带—Dicranograptus clingani带的沉积.而陈均远等将这一部分地层重新命名为"龙门洞组".西北区区域地层表陕西省分册使用了"平凉群".笔者同意修订后的平凉组,理由将更多还原

【Abstract】 The definition of Pingliang Formation at Longxian,Shaanxi was expanded in meaning by Fu Lipu(1975).The finding of graptolite suggested that it ranges from the Glyptograptus teretiusculus zone to the Climacograptus spiniferus zone.In this paper,it is further subdivided into two members.That is the Lower Membet of the Pingliang Formation correspons to the range from the Glyptograptus teretiusculus graptolite zone to the Climacograptus peltifer graptolite Zone,in which mang conodonts,such as Pygodus anserinus,Periodon aculeatus,Roundya pyramidalis, Tetraprioniodus lindstroemi,Protopanderodus varicostatus,Panderodus(Dapsilodus)mutatus,Panderodus gracilis etc.are obiained.The fauna is similar to that of the Pratt Ferry Formation of Alabama,Eastern part of North,Amerian,the Ampyx Limeston of the Oslo region,Norwag and that of the Miaopo Formation of Yichang,South China.The Upper Member of this formation corresponds to the range from the Climacograptus longxianensis graptolite zone to the Climacograptus spiniferus graptolite zone and it comprises a few conodonts,such as Protopanderodus cf.insculptus,Panderodus(Dapsilodus)similaris,and P.gracilis.The feature of conodont elements indicates that they.may be correlated with the Baota Formation of Yichang,South China.更多还原