The epieugeosynclinal basins of Carboniferous, Permian, and Triassic age in the Canadian Maritime Provinces are cut prominently and bordered locally by northeasterly to easterly trending faults which were active recurrently during sedimentation. In southern New Brunswick, at least, these are predominantly strike-slip faults of both right-lateral and left-lateral sense. Structural forms and histories are analogous with post-Mesozoic tectonics of the strike-slip fault complex in California. The Harvey-Hopewell fault, which separates the Cumberland basin of northern Nova Scotia from the Caledonia arch of New Brunswick, slipped left-laterally in Early Pennsylvanian in response to N.-S. principal stress, offsetting a latest Mississippian marginal alluvial fan at least 10 mi and developing large decollement folds in the basin. The Lubec fault of Eastport, Maine, and its extensions and branches in New Brunswick, slipped right-laterally at the end of or within the Mississippian, probably some tens of miles, in response to E.-W. principal stress. Thrust faulting N. of the Caledonia arch can be attributed to NW.-SE. compression as the stress field was rotated in a counterclockwise direction, from the E.-W. orientation in Mississippian to the N.-S. orientation in Early Pennsylvanian time. Petroleum exploration should be planned with due consideration for offsets of structures and lithofacies, right-laterally in most of New Brunswick and, probably, in northern Prince Edward Island, and left-laterally or possibly both ways in the region on the SE.