This is a comprehensive summary of the geotechnical investigation of the historical Strickfaden Cemetery,California,Missouri(figure.1).The report demonstrates that the unmarked graves in the cemetery can be successfully located using Ground Penetrating Radar(GPR)and Time Domain Electromagnetic Metal Detector(TDEM)techniques,based on the interpretation of acquired data,there is a relatively high correlation between both tools in detecting the unmarked graves and determining the apparent depth to the top of the burial coffins or caskets.The report also aims to provide sufficient information for the cemetery owners to place markers(wooden crosses or headstones)on each identified grave.Geophysical methods such as Ground Penetrating Radar,resistivity,TDEM and Magnetic methods are effective tools to investigate the earth’s subsurface.In this project,we used the GPR and the TDEM tool to acquire data a long 32 South to North profiles to efficiently map the unmarked graves in Strickfaden cemetery.The GPR is probably the best known and most widely applied geophysical method used for cemetery investigations,and it’s considered to be succeeding for mapping historic cemeteries,but its success is very dependent on favorable site conditions.Therefore,TDEM method is used as a supportive tool to constrain the results and decrease the GPR limitations.Ground penetrating radar(GPR)is the electromagnetic equivalent of the reflection seismic technique for high resolution geological mapping.The transmitting antenna directs into the ground a pulse,which is reflected off subsurface boundary layers or single objects and picked up by a receiving antenna.The most convenient technique is recording one trace at each of a number of equally spaced positions along a survey with a fixed offset between transmitter and receiver.Since the GPR is a non-destructive tool,it would seem an obvious choice for cemetery investigations.The Time Domain Electromagnetic Metal Detector(TDEM)is a Geophysical technique used to detect the metals in the subsurface and electrical properties of earth material by inputting a current through the earth’ssubsurface and measuring the rate of decay of that current.The TDEM method is suitable to detect metals that are buried a few feet underground,so it’s adequate for our investigation since our target is not that shallow.
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