豫西甘山第四纪冰斗系统的发现及其与MIS的耦合关系分析

The Discovery of Quaternary Cirques System in Ganshan of Western Henan Province and Analysis of Coupling Relation with MIS

在调查东亚冷槽西壁冰川遗迹及其海拔梯度的过程中,发现了甘山冰斗系统与磨光面、擦痕、漂砾等冰川遗迹。进而对该冰斗系统进行成因分析的过程中,发现了冰斗系统的"冰斗环退"的形成方式。以此为基础,就甘山冰斗系统与MIS之间的耦合关系进行了对比分析。研究表明,甘山冰斗系统是以"冰斗环退"方式形成的,该冰斗环退系统完整展现了我国东部第四纪冰川作用的过程,对研究冰期的雪线高程、环境演化规律、冰川作用的进退等,都有着极其重要的意义。在"冰斗环退"的研究基础上,发现了对应的"冰斗环进"机制。冰斗环进代表了冰川作用由高向低推进过程,冰斗环退代表了冰川作用由低向高撤退过程。通过影像分析,初步将甘山冰斗系统划分四段,共解析出了50余套冰斗环,冰川作用的时代可追溯到2.56 Ma。根据冰斗的环进、环退特征,进而发现C28冰斗环所对应MIS56,也即1.60Ma,可能为我国第四纪冰川作用过程中的冰进向冰退演化的重要拐点。

The Ganshan cirques system and the glacial relics,such as polished surface,scratches and erratic boulders have been discovered in the process of investigating the glacial remains and its elevation gradient of west wall of cold trough in east Asia.In the process of cause analysis of the cirques system,the formation mode of the ＂ Loop-retreat＂ has been discovered.On this basis,coupling relation between Ganshan Ice bucket system and MIS has been compared and analyzed.It is showed that Ganshan cirques system is formed by a loop-retreat way.The system fully displays the process of the Quaternary glaciation in eastern China.It has great significance to study the snow line elevation,environmental evolution rules and the advance and retreat of glaciation in the region.Based on the study of cirques ＂ Loop-retreat＂,the corresponding cirques ＂ Loop-advance＂ mechanism has been discovered.The cirques ＂ Loop-advance＂ represents the advance process of glacier action from high to low,while the cirques ＂ Loop-retreat＂ represents the retreat process of glacial action from low to high.Through image analysis,Ganshan cirques system can be devided into four stages,and more than 50 sets of cirques system have been interpreted.The age of glacial action can be traced back to 2.56 Ma.According to the characteristics of the advance and retreat of the cirques,it is found that C28 cirques is corresponding to MIS56,that is 1.60 Ma.It may be the turning point from glacial advance to glacial retreat in the Quaternary glacial action in China.