| 摘要: |
| 四川盆地下三叠统嘉陵江组是我国钾盐矿产勘查的重点区域和层位，对其的岩相古地理研究是钾盐研究的一项重要的基础地质工作。本文结合四川盆地古地理背景和古气候条件，通过野外剖面、岩心观察、薄片鉴定等方法，对研究区下三叠统嘉陵江组的沉积相进行了分析研究，共识别出潟湖、潟湖边缘坪和台内滩相三种沉积相类型，并进一步划分出多种微相。在此基础上，通过区域地层对比以及岩相古地理编图，重建了四川盆地下三叠统嘉陵江组岩相古地理演化。结合前人研究认为：四川盆地嘉陵江组整体上属于障壁碳酸盐岩台地沉积环境，自西向东从碳酸盐岩局限海相演化为蒸发台地相。盆地周边水下隆起的障壁作用和干旱炎热气候条件共同影响了嘉陵江组台地咸化的演化过程，海平面升降变化是控制沉积相发育和空间分布的重要因素。最后，基于本研究的资料，编制了嘉陵江组各成盐期的岩相古地理图。 |
| 关键词: 四川盆地 嘉陵江组 主要成盐期 岩相古地理 |
| DOI：10.19826/j.cnki.1009-3850.2020.08002 |
| 附件 |
| 投稿时间：2019-11-21修订日期：2020-08-29 |
| 基金项目:四川省地质勘查基金项目“四川省钾盐资源调查评价”（项目编号：201801）和四川省科技厅基金项目“四川盆地三叠系杂卤石型钾盐形成条件与成因”（项目编号：2020YJ0426）联合资助。 |
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| Sedimentary facies and palaeogeography of the Lower Triassic Jialingjiang Formation in Sichuan Basin during the salt-forming period |
| TAN Zhiyuan1, HOU Xuewen1,2, WEI Jisheng1, XIONG Hongge2 |
(1. Research Institute No. 280 CNNC, Guanghan 618300, China;
2. Chengdu University of Technology, Chengdu 610059, China) |
| Abstract: |
| The Lower Triassic Jialingjiang Formation in Sichuan Basin is the key stratum for potash exploration in China. It is an important basic geological work to study its sadimentary facies and paleogeography. Based on the paleogeographic background and paleoclimatic conditions of Sichuan Basin, the sedimentary facies of the lower Triassic Jialingjiang Formation in the study area are analyzed and studied by means of field section, core observation and thin section identification. Three types of sedimentary facies are identified, including lagoon, lagoon marginal flat and platform beach facies, and a few of microfacies are further divided. Through the study of regional stratigraphic correlation and mapping of sedimentary facies and paleogeography, the evolution of the Lower Triassic Jialingjiang Formation in Sichuan Basin is reconstructed. Combined with previous studies, it is considered that the Jialingjiang Formation in Sichuan Basin belonged to a barrier carbonate platform depositional environment, which evolved from limited marine facies of carbonate to evaporation platform facies from west to east. The barrier of the underwater uplift around the basin and the hot and dry climate conditions affected the evolution process of the platform salinization of the Jialingjiang Formation. The sea level fluctuation was an important factor controlling the development and spatial distribution of the sedimentary facies. Finally, based on the data of this study, the map of sedimentary facies and palegeogrophy of the Jialingjiang Formation in each salt forming period is newly compiled. |
| Key words: Sichuan Basin Jialingjang Formation main salt-forming period lithofacies palaeogeography |
