海口江东新区新近纪-第四纪标准地层与组合分区

在新近纪-第四纪地层发育沿海地区,开展地层对比划分以及沉积特征研究,对于恢复古沉积环境、指导城市地下空间规划和地质灾害评价等方面具有重要的研究意义。选取海南岛北部海口江东新区内264个200 m以浅地质钻孔,以新近纪-第四系沉积环境与地貌、岩石地层划分标准为指标,结合微体古生物、光释光测年等分析手段,系统分析海口江东新区新近纪-第四纪地层的分布范围、岩石组合和结构特征,建立起江东新区新近纪-第四纪标准地层。在平面上划分出滨海堆积平原Ⅰ区、三角洲平原Ⅱ区、河流阶地Ⅲ区、冲积平原Ⅳ区、火山岩台地Ⅴ区共5个一级地貌-地层区,结合纵向地层特征进一步划分了21种地层组合序列,拓展了区域第四纪地质应用研究,有利于提升海口江东新区内水工环调查精度和研究深度。

Neogene-Quaternary stratigraphic Standard and Combined zoning of Haikou Jiangdong New District

In coastal areas with the Neogene-Quaternary strata, the strata comparative division and sedimentary characteristics research are significant for restoring the paleo-sedimentary environment, guiding urban underground space planning and geological disaster evaluation. To analyze the distribution range, rock combination and structural characteristics and establish the Neogene-Quaternary standard strata, 264 shallow geological boreholes of 200 meters were selected in the Jiangdong New Area, Haikou. The research is based on the Quaternary sedimentary environment and landforms, Quaternary lithostratigraphic classification standards, combined with micro-paleontology and optical luminescence dating. The results show that 5 first-level landform-stratigraphic regions are divided into the coastal accumulation plain area I, delta plain area II, river terrace area III, alluvial plain area IV, and volcanic platform area V. In addition, 21 types of stratigraphic combination sequences are clarified with longitudinal stratigraphic characteristics in the high-level landform-stratigraphic combination area, which helps to expand the application of regional Quaternary geological research, it is also conducive to improving the accuracy and research depth of the hydraulic environment investigation in the Jiangdong New District of Haikou.