A Preliminary Study Of Archaeo-geophysical Prospection Of Large Sites In Southern Humid Area

Based on the difference of physical properties of archaeological objects and the surrounding soil media,Archaeo-geophysical techniques use special instruments to collect the abnormal field,and then analyze the characteristics of anomalies to infer the location,size,depth and shape of the underground archaeological target.This method has the advantages of non-destruction,high work efficiency,economical and deep sounding,etc.,just to meet the needs of archaeological exploration of large sites well.However,geophysical methods are also faced with the problem of applicability and non-uniqueness.Different geophysical methods have different effects on the same archaeological remains,and in turn,the same geophysical method has different geophysical response characteristics in different archaeological sites,so it is necessary to analyze the specific sites to choose the suitable method.The geological conditions and surface conditions of large sites located in the south of China where is wet and rainy are different from those in the northern arid areas,at the same time,the large site requires higher investigation efficiency and effectiveness because of its larger area.Therefore,the Archaeo-geophysical techniques also faced with the problems of applicability,effectiveness,collection efficiency and other issues in southern humid area.This paper takes the typical large site-Guangxi Hepu group tombs ruins of Han dynasty and Hangzhou Wuyue seawall site in Southern humid areas as the exploration target.Combining with the geological environment and surface characteristics of this two sites,we try to adopt electrical resistivity tomography method to carry out investigation in Hepu Han dynasty group tombs site,and in Hangzhou Wuyue seawall site we select the capacitively coupled resistivity method and seismic scattering method.Thereby,we conducted the corresponding archaeological investigation and research in different site by three kinds of Archaeo-geophysical techniques.The results show that the electrical resistivity tomography method can adapt well in the prospection of Guangxi Hepu Han group tombs site.The results of the detection in several areas are basically consistent with the drilling results by the archaeological team,and can be used to identify some structure of the tomb,such as the tomb chamber and tomb passage.The efficient data acquisition of capacitively coupled resistivity method improves the efficiency of geophysical survey in large site greatly,and it is sensitive to large stones and other high resistance object,especially for the prospection of seawall.At the same time,the characteristics of without inserting electrode into the surface let the capacitively coupled resistivity method show its talents in urban hard surface conditions especially,and the superiority of the capacitively coupled resistivity method is demonstrated convincingly.Seismic scattering method with the use of free-plug detector showed good effect in the investigation of Hangzhou Wuyue seawall site.It is very sensitive to the stone with high wave velocity,and can distinguish the shape and structural features of the seawall generally,indicate that it is a sort of Archaeo-geophysical technique has a very broad application prospect.Hereto,the applicability and effectiveness of the geological environment and surface conditions bring to geophysical survey for the great site in the humid area are studied preliminarily.