Sedimentary facies of Carboniferous–Permian mid‐oceanic carbonates in the Changning–Menglian Belt, West Yunnan, Southwest China: Origin and depositional process

作者：Tsutomu Nakazawa, Katsumi Ueno, Xiangdong Wang · 发表于：Island Arc · 年份：2009 · DOI：10.1111/j.1440-1738.2008.00650.x · 被引用次数：18 · 研究领域：Paleontology and Stratigraphy of Fossils、Geological and Geophysical Studies、Geological formations and processes

Abstract Huge carbonate rock bodies ranging in age from the Visean (Middle Mississippian/Early Carboniferous) to the Changhsingian (Lopingian/Late Permian) overlie a basaltic basement in the Changning–Menglian Belt, West Yunnan, Southwest China. These carbonates lack intercalations of terrigenous siliciclastic material throughout. These lines of evidence indicate that they formed upon an isolated and continuously subsiding mid‐oceanic island (or plateau), probably of hotspot origin. The carbonates are grouped into a shallow‐water carbonate platform facies regime observed in the Yutangzhai section and a relatively deep‐water carbonate slope facies regime typically represented in the Longdong section. These two facies regimes developed contemporaneously as parts of a carbonate depositional system on and around a mid‐oceanic volcanic edifice. The carbonate platform is subdivided into four facies, including platform‐margin, shoal, lagoon, and peritidal facies. Along the measured Yutangzhai section of the platform facies regime, the vertical facies succession from the platform‐margin facies into inner‐platform facies such as the shoal and lagoon facies is recognized. This facies succession is explained as resulting from the progradation of the carbonate platform. Worm tubes occur as a main reef builder in platform‐margin facies of the Mississippian. Their occurrence as major constituents in a high‐wave‐energy reef is peculiar to Carboniferous reef distributions of the world. The o...