海南岛西部八所组上部砂质沉积物的成因及其环境意义  

The Genesis and Environmental Significance of the Sandy Sediments of the Upper Basuo Formation in Western Hainan Island

作　　者：曾兰华[1] 李森[2] 李保生[3] 李会川[4] 郑影华[5] 

机构地区：[1]嘉应学院地理系,广东梅州514015 [2]佛山大学资源与环境科学研究所,广东佛山528000 [3]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室 [4]佛山市国土资源局顺德分局,广东佛山528333 [5]北京师范大学中国沙漠研究中心,北京100875

出　　处：《地质论评》2007年第6期783-790,I0007,共9页Geological Review

基　　金：国家自然科学基金资助项目(编号40671186;40271012;40471139);国家重点基础研究发展计划"973计划"(编号2004CB720206)的成果

摘　　要：海南岛西海岸地区砂质沉积物广泛发育。对昌化棋子湾剖面砂质沉积物的TL（热释光）测年表明，该地层沉积于32.1±3.30-10.30±1.30kaBP间，归属于上更新统八所组上部。通过对该地层沉积构造特征、粒度特征和石英颗粒扫描电镜分析，显示本区八所组上部自下而上为“风成砂—弱成壤—风成砂—冲积砂—风成砂”沉积“相序”，八所组上部总体上以厚层风成相为主，夹短周期气候波动引起的薄层河流相（Ⅱ层）和弱成壤风成相（Ⅳ层）沉积，与本区八所组陆相冲洪积成因地层为同期异相地层。由此说明，末次冰期时南海北部受冰期气候影响，海平面大幅度下降，大陆架广泛出露，局部沙漠化，并成为海岸风成沉积的物源区。Sandy sediments extensively developed in the west coast of Hainan Island. The TL dating data for the sandy sediments of Qiziwan section showed that the stratum which belongs to the upper Basuo Formation of Upper Pleistocene deposited between 32.1±3.30- 10.30±1. 30 ka BP. The stratum of Qiziwan section ranged from aeolian to weak soil-forming to aeolian to alluvial to aeolian from bottom to top, and this was proved by technical analysis including sedimentary structure characteristics, grain-size characteristics, scanning electron microscope etc. The arragement of sedimentary facies reflects that the stratum was mainly consisted of thick aeolian facies, mixd by some thin fluvial facies （layer Ⅱ ） and weak soil-forming aeolian facies （layer Ⅳ） which were caused by the short-term climate changes. This is heteropic deposit of Basuo Formation, which is considered as alluvial--pluvial deposition in this area. We infer that continental shelf of the South China sea broadly emerged by the climate change in the last Ice Age, accompany by the frequent sand-drift activities which caused sandy desertified process and provided an important sources of aeolian deposits in the west coast of Hainan Island.

关 键 词：海南岛西部 八所组上部 砂质沉积物 沉积环境 

分 类 号：P736.2[天文地球—海洋地质]