苏浙皖地区黄龙组下部白云岩的隶属问题

一、前言苏、浙、皖地区石炭系分布广泛,发育较全,含化石较丰富,地层时代和划分的分歧也较少。长期以来,关于中、下石炭统的分界,一直沿用李四光（1930）、朱森等（1935）对宁镇山脉的研究成果,以黄龙组下部白云岩底部的假整合面（即淮南运动）,作为二者的分界线。但近十年来,这一分界线似乎又成为一个争论的问题。有些地质古生物工作者

ON THE PROBLEM OF THE TIME ASSIGNMENT OF THE DOLOMITE IN THE LOWER PART OF THE HUANGLONG FORMATION IN THE JIANGSU-ZHEJIANG-ANHUI REGION

In the Jiangsu-Zhejiang-Anhui region,the disconformities at the base of the dolomite of the Huanglong Formation had always been taken as the boundary between the middle and lower Carboniferous in the light of the study of the Nanjing-Zhenjiang Mountain Range by Prof. J. S. Lee et al.（1930,1935）. But in the past twenty years,some geologists have changed this assignment. Basing themselves only on corals such as Lithostrotion found in the dolomite in Nanjing and Chaoxian county and considering a transition bed between the dolomite and its overlying crystalline limestone as the "basal conglomerate",they separate it from the Huanglong Formation,call it the "Laohudong Dolomite"and assign it to the lower Carboniferous. Some people even consider that this dolomite is different from that in the Jiangsu-Zhejiang-Anhui border region in age and that the latter is stratigra- phically high