地质学报2012，Vol.86Issue(7)：1143-1149,7.
湘西北王村地区寒武系花桥组是“钙屑浊积岩”吗?
Is "Calciturbidites" the Cambrian Huaqiao Formation in the Wangcun Area,Northwestern Hunan
摘要
Abstract
Cambrian sequences in the southeast margin of Yangtze Platform are characterized by various types of "carbonate gravity flow deposits". Such cases have been viewed as the proxies of "platform margin slope fades". The "Huaqiao Formation" at Wangcun section, northwestern Hunan, which is the "GSSP" of the "Guzhangian Stage", has been considered to "calciturbidites" lithologically. The detailed lithological and sedimentary study illustrates that the Huaqiao Formation is not typical "calciturbidites", but normal carbonate-dominating sediments from the low-energy depositional environments at depth below the wave base. Section A of the "typical turbidite sequence", which were considered to develop in the Huaqiao Formation, is composed of numerous limestone lens and lumps formed in diagenesis compaction. " Undulate bedding" developed in section B of the "turbidite sequence" should be deformed horizontal bedding and hummocky cross bedding, coupled with discovery of two layers of oolitic limestone. These suggest a deep-water environment intermittently effected by oscillatory currents. In comparison with regional sedimentary records, this study suggests new understanding for the paleogeographic pattern in corresponding period and considers existence of a carbonate shelf (ramp) without typical platform-edge slope developed in northwestern Hunan.关键词
扬子陆块/寒武系/钙屑浊积岩/古地理Key words
Yangtze blocks Cambrian/ calciturbidites/ paleogeography引用本文复制引用
周恳恳,牟传龙,梁薇,葛祥英..湘西北王村地区寒武系花桥组是“钙屑浊积岩”吗?[J].地质学报,2012,86(7):1143-1149,7.基金项目
本文为国家科技重大专项(编号2011ZX05043-005)和中国地质调查局项目"中国岩相古地理编图"(编号1212010916060)资助的成果. （编号2011ZX05043-005）
