一、引言遍布华中、西南大部分地区的宝塔灰岩(插图1),具有独特的裂纹构造,产有丰富的介壳化石。据笔者近年来的研究认为,其时代大致相当于 Caradoc 中、晚期至 Ashgill 早期,即晚奥陶世(盛莘夫,1974,1982)。关于宝塔灰岩裂纹构造的成因,过去许多地质学家认为是沉积物露出水面,受到曝晒而干涸发生收缩和裂开所形成的裂缝。笔者认为宝塔灰岩的裂纹构造可能是在稳定的浅海水体环境下,沉积物沉积之后,呈似泥浆状的凝胶 I. INTRODUCTION The Pagoda limestone (Fig. 1), located in most parts of Central China and Southwest China, has a unique crack structure and rich in shell-forming fossils. According to the author’s research in recent years, his era is roughly equivalent to the middle and late Caradoc to the early Ashgill, late Ordovician (Sheng Xinfu, 1974,1982). About the cause of pagoda limestone crack structure, in the past many geologists think that the sediment surface exposed by drying and drying occurs shrinkage and cracking cracks. I believe that the pagoda limestone crack structure may be in a stable shallow water environment, sediment deposition, was like a muddy gel