Transgressive Sequences Throughout the Yijianfang Formation (Darriwilian, Middle Ordovician) at Well Gucheng 4, Tarim Block, NW China
详细信息
- 责任者：Wang Guan (Southwest University of Petroleum ; Chengdu 510500 ; China) ; Zhang Yunfeng
- 刊名：Acta Micropalaeontologica Sinica
- 出版年：2011
- 卷期：28(1)
- 关键词：中奥陶世 ; Middle Ordovician ; 海侵 ; transgression ; 层序地层学 ; sequence stratigraphy ; 塔里木板块 ; Tarim Plate
- 页码：p.137-144
- 图表：2 illus., 1 plate, 25 refs.
- 分类号：1200
- issnNo：ISSN1000-0674
- isbnNo：CN32-1189/Q
摘要
Well Gucheng 4 is located at the eastern margin of the Central High of the Tarim Block during the Middle Ordovician. The Darriwillian (Middle Ordovician) Yijianfang Formation limestones with thickness of 130 m from the borehole is conformably overlain by the Tumuxiuke Formation and underlain by the Yinshan Formation respectively. The ecological parameters such as the lithofacies, biotic as well as sedimentary structures are indicator of the water depth. The limestone sequences of the Yijianfang Formation consists of the reef mound community composed of Epiphyton-Renalcis-Calathium for the lower part and bank association of sandy clastic grainstones to bioclastic packstones and wackestones for the upper part. Therefore, it is reasonable to outline a transgressive succession from a subtidal fair-weather wave influence zone (10～30 m) to a storm wave base zone (30～60 m) in ascending order.