Geophysical exploration of coal and gas resources associated with a buried Triassic basin in the N. C. coastal plains

A comprehensive field geophysical study was conducted in an area including Lenoir, Jones, and Craven counties in the coastal plains of North Carolina in order to determine the subsurface geological features and favorability of any hydrocarbon occurrence thereof. The study employed an integrated approach using gravity, aeromagnetic, and electrical sounding methods combined with three shallow test holes drilled by the State of North Carolina during the study. Results are negative: the Graingers Basin originally suggested from the aeromagnetic data is now believed to be of Paleozoic age rather than the initially assumed Triassic age. The basement structure, originally inferred from gravity data, is re-interpreted to match the top of phyllite in the light of drill hold data. Although electrical sounding data in the area suggest that the crystalline basement is much deeper than the phyllite basement, the intervening formations are most likely of metamorphosed Paleozoic sediments similar to the slate-belt type rocks, having little chance of containing any hydrocarbon materials. The study has revealed another possibly more promising basin structure between New Bern and Havelock. The data thus far show that the basin may be much deeper than the Graingers basin.