Geophysical and geological study of surficial deposits near Frobisher, Saskatchewan

Abstract

Surface DC resistivity, total gravity field, and horizontal gravity gradient surveys were conducted in an area of approximately 200 square miles near to the city of Estevan in southeastern Saskatchewan, Canada. The results of these surveys, together with the first arrivals from oil-company seismic records, were interpreted in an attempt to locate and delineate the bedrock-drift contact and sand and gravel deposits. Of all the techniques, only the surface resistivity technique proved useful. It was used successfully, with certain reservations, to indicate sand and gravel deposits, but could not be used to determine either the thickness of, or the depth to, the deposits. The surface resistivity technique, in conjunction with a drilling program, was used to locate accurately the buried preglacial Missouri River channel in the survey area. Density, DC resistivity, texture and pebble composition studies were made on split-barrel and chip samples obtained during a drilling program. Laqoratory studies indicate that on the basis of the physical properties investigated tills found in the test area cannot be readily differentiated. An apparent dependency of apparent resistivity on current density was observed both in field and laboratory measurements. Measurements were made between approximately 3 x 10-7 and 6 x 10-2 amps per square meter. At current densities less than about 3 x 10-4 amps per square meter, the apparent resistivity increases with increasing current density. At current densities greater than 3 x 10-4 amps per square meter, the apparent resistivity decreases with increasing current densities. Note:This thesis contains maps that have been sized to fit the viewing area. Use the zoom in tool to view the maps in detail or to enlarge the text.