夏邦栋(1959)将黄龙组下部的白云岩单独划出,称为“老虎洞白云岩”。20多年来,地层界对这层白云岩的时代归属尚未取得一致意见,争论的焦点在于该层白云岩是早石炭世晚期,还是晚石炭世早期,以及宁镇至巢县一带分布的与苏皖南部一带分布的白云岩,两者是一层还是两层。近年来,我们对下扬子地区该套白云岩从沉积学、岩石地层学和生物地层学等方面进行综合研究,认为它是一个穿时的岩石地层单位,由北向南时代渐新。 Xia Bangdong (1959) separate the lower part of the Huanglong Formation dolomite, called “tiger cave dolomite.” For more than two decades, no agreement has been reached by the stratigraphic community on the age of this layer of dolomite. The focus of the debate is whether the dolomite of this layer was distributed in the late Early Carboniferous, early Carboniferous, or from Ningzhen to Chao County The distribution of dolomite in southern Anhui, the two are one or two. In recent years, we conducted a comprehensive study of sedimentary, lithostratigraphy and bio-stratigraphy of the dolomite in the Lower Yangtze region, considering that it is a stratigraphic unit of rock formation worn from north to south.