1:25万区调中第四系深覆盖区野外工作方法研究——以淮安市幅为例

Study of field investigation method for 1:250,000 scale regional geological survey in quaternary deep overburden area: a case study of Huaian City

以淮安市幅区域地质调查为背景,总结了第四系深覆盖区的野外地质调查方法。主要步骤为:(1)根据已有资料总结区域地质特征,通过踏勘、遥感解译和地貌分析布置野外路线;(2)应用点线法确定调查路线方向与精度;(3)根据居民点分布、地形变化和野生草本植物组合准确判断地质界线;(4)针对不同地层时代、微地貌、成因类型确定槽形钻揭露深度;(5)地质观察点布置在地层时代、微地貌类型、成因类型等界线上,用槽形钻揭露,垂直界线两侧各打1个槽形钻来确定地质界线点位置。

The field geological survey methods in quaternary deep area of coverage in Northern Jiangsu were summarized, according to geological survey of Huaian City map. The methods were ： field geological routes were determined on basis of existed regional geological data, basic geological maps of working region, field reconnaissance, remote sensing image interpretation and morphologic analysis. The direction and precision of field investigation routes were determined according to point line method. The geological boundary was con- firmed based on residential area, topographical changes and wild herbs combination. The drilling depth of groove bit was determined on account of different geological and stratigraphic ages, micro landform and genetic types. The geological observation points, disposed in the boundary line of stratigraphic ages, micro landform and genetic types, were exposed by groove bit. Through each drilled holes by groove bit in two sides of vertical boundary line, the geological boundary location could be delimited finally.