Downhole geophysics as an aid to the interpretation of an evaporite sequence: examples from Nova Scotia

CIM Bulletin, Vol. 82, No. 925, 1989

B.C. Carter, Nova Scotia Department of Mines and Energy, Mineral Resources Division

The Nova Scotia Department of Mines and Energy located a drillhole at Riverside Corner, Hants County, Nova Scotia, to examine the stratigraphy, structure and potash potential of the Kennetcook River gravity low. This evaporite-related gravity anomaly is one of the largest virtually unexplored gravity anomalies in Nova Scotia. The drillhole intersected a structurally complex sequence of lower Windsor Group ('B' Subzone) evaporites. Downhole geophysical wireline logs were used, in conjunction with detailed lithological descriptions, to interpret the structure and stratigraphy of the sequence. Similar application of total gamma ray, density, caliper and neutron-neutron log responses allows stratigraphic correlation of Windsor Group carbonate marker units separated by up to 35 km in Cape Breton. This work confirms the value ofdownhole geophysical logs as a tool in the exploration of evaporite deposits regardless of the presence or absence of high quality core.

Keywords: Geophysics, Evaporite deposits, Exploration, Gravity anomalies