郯庐断裂带淮河南到女山湖段晚第四纪以来的新活动

以郯庐断裂带淮河南到女山湖段晚第四纪以来是否具有新活动为主要研究目标,通过遥感影像资料解译及地表反复调查,选择构造地貌显著地段开挖探槽,识别和记录其变形形态,分析其活动习性,定向采集新活动变形物质,在保持原态基础上磨制定向薄片,并进行微观构造分析论证。研究表明,断裂沿线线状构造地貌清晰,横跨断裂带的3个探槽均揭示出晚第四纪以来活动痕迹,断裂最新错断了晚更新世-全新世地层;滑移方式多表现为粘滑,典型表现为断层陡坎、楔状堆积、断层和充填裂缝等,总体显示为脆性高速变形特征,属于史前地震遗迹。上述认识部分得到微观分析证实。文中还初步探讨了淮河南北郯庐断裂最新活动特征的异同点及其可能的原因。

New activity of the Tanlu fault zone from Huaihe to the Nüshanhu since the Late Quaternary

We took the new activities in the Tanlu fault zone in the southern Huaihe to the northern shore of the Nüshanhu segment since Quaternary as the main research target,and analyzed their characteristics on the basis of the interpretation of remote sensing image data,the repetitive surface investigation,trenching in significant tectonic landform sections and the deformation for identification. New active deformation materials were collected selectively which were ground into thin slices with their original states for micro structural analysis. All of above research shows,linear tectonic geomorphology is very clear along the fault. Three trenches across the fault zone all reveal new deformation relics since Late Quaternary. The latest strata dislocated by the fault is the late Quaternary and Holocene strata. The sliding mode is the stick slip with the typical performances of fault steep ridges,tension crack wedges,and fault and filling cracks. the deformation in general belongs to the prehistoric earthquake ruins with brittle rapid deformation. All these have been confirmed by microscopic analysis. The paper also discusses preliminarily the similarities and differences of the latest activities in the northern and southern Tancheng-Lujiang,Huaihe,and their possible reasons.