合肥市滨湖新区早-中更新世岩相古地理特征及意义

FEATURES OF THE EARLY-MID PLEISTOCENE LITHOFACIES PALEOGEOGRAPHY IN THE NEW LAKESIDE DISTRICT OF HEFEI CITY

对合肥市滨湖新区大量第四纪钻孔作了岩性组合特征描述、粒度分析,对代表性钻孔ZK9A01进行了沉积体系域划分并绘制出滚子河组体系域图,据此探讨了该沉积区早—中更新世以来的沉积环境,并编制湖泊扩展期、凝缩期和萎缩期岩相古地理图。研究表明:滨湖新区早—中更新世为湖相沉积,经历了湖泊扩展—最大湖泛-湖泊萎缩的演化过程,湖泊中心位于滨湖新区东南方向,滨湖新区以东及西南地区为调查早—中更新世含水岩组有利区域。

This paper made lithological combination feature description and grain size analysis of a great number of borehole cores from the new lakeside district of Hefei City,performed depositional system domain division for representative borehole ZK9A01 and plotted the Gunzihe Formation system domain graph,on this basis,discussed the depositional environment evolution in the area since early-mid Pleistocene,and compiled lithofacies paleogeographic maps for the lake expansion,maximum lake flooding,condensing and shrinking periods.The study shows that the new lakeside area was of lake facies deposition in the early-mid Pleistocene period,experienced a process from lake expansion to maximum lake flooding and lake shrinking,the lake center was situated southeast of the new district and the favourable area for survey of early-mid Pleistocene aquifers was to the east and southwest of it.