西藏日土县拉竹龙—双陷大坂的泥盆系和石炭系

本文主要论述西藏日土县以北拉竹龙-双陷大坂地区,新发现比较完整的中、晚泥盆世和早石炭世地层。根据化石和岩性特征,把该区中、上泥盆统划分为中泥盆统的三岔口组、万泉河组,上泥盆统的邦达组、拉竹龙组;下石炭统划分为月牙湖组、双陷大坂组。上述各组除拉竹龙组外,均为新建组名。三岔口组、万泉河组、邦达错组和拉竹龙组的层位,分别与应堂阶、东岗岭阶、余田桥阶和锡矿山阶相当,而月牙湖组和双陷大坂组的层位,则分别与岩关阶和大塘阶相当。

DEVONIAN AND CARBONIFEROUS IN THE LAZHULONG-SHUANGXIANDABAN AREA OF RITU COUNTY, NORTH XIZAND (TIBET)

This paper deals with the preliminary subdivision of newly discovered Middle and Upper Devonian and Lower Car-bonifcrous at Lazhulong-Shuangxiandaban area of Ritu county of North Xizang. Based upon the examination of fossilsand lithological characters, the authors subdivide the Middle to Upper Devonian of the region into 4 stratigraphic units,namely Sanchakou and Wanquanhe formation of Middle Devonian, Bangdacuo and Lazhulong formation of Upper Devo-nian, Meanwhile, the Lower Carboniferous of the region can be subdivided into 2 stratigraphic units, or Yueyahu andShuangxiandaban formation. These formations are newly established except Lazhulong formation. The 4 stratigraphic u-nits of Devonian as mentioned correspond to Yingtang, Donggangling,Shetianqiao and Xikuangshan stages respectively.The 2 stratigraphic units of Lower Carboniferous correspond to Yanguan and Datang stages of China.