• 责任者：Xia Guoqing (Institute of Sedimentary Geology ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Yi Haisheng
• 刊名：Journal of Chengdu University of Technology
• 出版年：2010
• 卷期：37(2)
• 关键词：中侏罗世 ; Middle Jurassic ; 沉积旋回 ; sedimentary cycles ; 西藏 ; Tibet
• 页码：p.133-139
• 图表：5 illus., 2 tables, 21 refs.
• 分类号：1200
• issnNo：ISSN1671-9727
• isbnNo：CN51-1634/N

The Middle Jurassic Xiali Formation characterized by meter-scale cycles in the Yanshiping area of North Tibet is a suite of tidal-flat deposits. Based on the color, lithology and rock facies, the strata are divided into 85 meter-scale cycles, and all the cycles can be further divided into clastic rock and clastic rock-carbonate meter-scale cyclic sequences. Their common characters are that the grains become fine upward. This coincides with that the depositional environment becomes shallow upward, characterized by the positive graded bedding formed by the tides. The main cycles in Xiali Formation are in a very good correspondence with the Milankovitch cycles and the researched cyclic sequences are controlled by the Milankovitch cycles.