关键词: 地球物理调查; 第四纪堆积; 周口店

Abstract: Under the organization of the UNESCO, with the participation of Chinese specialists from IVPP, a mission of geologico-geophysical investigations within the protected area of Peking Man Site aiming at localizing the Quaternary deposits that might hold fossils organized by EDF ( Electricité de France), the work was carried out between September 9 and October 3, 1996.
Methods adopted Geology Systematic surveys of the fracture plans and stratification joints ( strike and dip mea- surements) were realized at different points within the site, in order to carry out a Schmidt chart statis- tical analysis:density evaluations and rosettes.These meaeurements were done at the following locations:around the Upper Cave and Loc.3, more than 300 measurements had been taken.This work is aiming at the understanding of the basic geological structures of the site.
Geophysics The major methods adopted are as follows:microgravity measurements with a measuring pitch of 5 or 2.5m; horizontal electromagnetic measurements of EM 38 type with a measuring pitch of 2.5m; vertical electromagnetic measurements of EM 31 type with a locally measuring pitch go- ing from 2.5m to 5m; magnetic measurements on the less magnetically disturbed profiles with a measurement pitch of 2.5m; vertical and horizontal electromagnetic measurements of EM 34 type on 4 pro- files; electric soundings; electric panels.
Frame work and total points being measured. Investigations were conducted along all the roads and paths within the site numbered as L1, L2, L3, L3A, L3B, L4, L13, L16, and L18 as shown in figure 1; along the tracks cleaned out specially for this investigation, which were numbered as L5, L6, L7, L8, L9, L10, L11, L12, L14, L15, and L17, as shown in figure 1.
639 pointsfor gravity measurements on profiles; 143 pointsfor EMG at Loc.1; 834 points for EM 31; 985 points for EM 38 in horizontal position; 985 points for EM 38 in vertical position; 100 points for EM 34; 176 points for magnetic measurements; 6 electric panels; 4 electric soundings.
Results Geologico-geophysical anomaly Through the investigation, some anomalies in both geology and geophysics had been revealed.The major geological structures ( fracturing ) extend south-east north-west as shown in figure 2.The major geophysical anomalies occurred at the following locations: along the major road, near Loc.4, between Loc.4 and Upper Cave, west to the Upper Cave.The cav- ities 4 and 15 were developed from north-south faults and have the certainty of extending toward the further north.Promising Quaternary deposits Five zones of major anomalies had been summarized as shown in figure 3.
1) Zone 1 Starts from Loc.1 and continues until the access road to the Museum.
2) Zone 2 Starts from Loc.1, passing by the Upper Cave toward the south-west.
3) Zone 3 Located at the west slope of the Dragon hill.
4) Zone 4 This sector comprises Loc.4 and it' s extensions toward the north.
5) Zone 5 This sector comprises Loc.15 and it' s surroundings.
Because Zone 1 and Zone 5 were disturbed too much by man during the road construction and the quar- rying, so these two anomaly areas are not so reliable.Finally, the only promising areas of Quaternary deposits are Zones 2, 3, 4.

Key words: Investigation; Geologico-geolphysical; Potential Quaternary deposits; Peking Man Site; Zhoukoudian