Abstract

Carboniferous strata cover large areas of the Burin Platform on the Atlantic continental margin south of Newfoundland, where they are approximately 1800 m thick and overlain unconformably by Mesozoic strata. Study of seismic lines tied to the Hermine E-94 well has identified three unconformity-bounded units that are broadly similar to units else-where in Atlantic Canada. Unit 1 rests unconformably on poorly imaged rocks of the Avalon Terrane, includes prominent evaporite diapirs and pillows, and is assigned to the Windsor Group (Visean). Unit 2 is assigned to the Mabou Group (upper Visean to Namurian) and may include part of the Pictou Group locally; reflectors downlap onto a basal unconformity, which probably represents a slight hiatus. Unit 3 is assigned to the Pictou Group (Westphalian B and younger), and Westphalian coal measures are apparently missing. A local unconformity is present at the base of Unit 3 adjacent to Windsor diapirs, passing laterally into a correlative conformity. Deformation at this level is associated primarily with evaporite movement and appears to be the main expression of regional mid-Carboniferous tectonism. The diapirs do not cut the Cretaceous succession. The basal Windsor unconformity forms a regional detachment at the evaporite level, which is inferred to have been active during the latest Paleozoic and/or early Mesozoic, probably in association with a transfer fault on the developing continental margin. Carboniferous strata overlie Meguma Terrane rocks south of the hinge zone to the Mesozoic Laurentian Subbasin.

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