桂林泥盆纪碳酸盐台地的发育

桂林地区中、晚泥盆世大量发育的碳酸盐岩构成了一个东西宽近４０ｋｍ、南北长近８０ｋｍ的浅海碳酸盐台地，其岩相变化复杂，生物群落丰富。本文论述了碳酸盐台地形成各阶段的岩相和生物相特征，阐明了影响碳酸盐台地形成的因素，认为从滨岸碎屑环境变为成熟碳酸盐台地中间阶段的沉积物──混积岩及滩（补丁礁）和滩间沉积物在碳酸盐台地形成过程中不可忽视。

DEVELOPMENT OF THE DEVONIAN CARBONATE PLATFORM IN GUILIN, GUANGXI

The Middle and Late Devonian strata in Guilin are characterized by well-developed carbonate rocks which display various micro factes and abundant biotic communities, and constitute a shallow-marine carbonate platform with nearly 40km width from east to west and nearlly 80km length from south to north. The southern, western and northern parts of this platform are coupled with the transitions into the deep-water platform depression deposits, and the eastern part of it is limited by the Yaoshan basement fault. The carbonate rocks consist mainly of bioclastic grainstones, wackestones, packstones and reefal limestones.The organisms which participated in organic upbuilding include mainly stromatoporoids,corals, chaetetids, blue and green algae, brachiopods, echinoderms, cephalopods, gastropods, bivalves. ostracods and bryozoans. Sedimentary structures such as flaster bedding, bird' s-eye structure, stromatolithic structure, geopetal structure, slide and sediment gravity flow are commonly disposed.The development of the Devonian buildups in Guilin exhibits the changes from littoral elastic environments to carbonate platform environments, and generally can be divided into three stages: the first stage, the deposition of the littoral elastic sediments before the deposition of the varcus zone of Givetian age; the second stage, the establishment of the carbonate platform dotted by some patch reefs and biostrome during the period of the development of the varcus zone to hermanni-cristatus zone of Givetian age, and the third stage characterized by the development of reef complexes during the period of the deposition of the disparilis zone to praesulcate zone.