foreland basins are a product of tectonic deformational loading, or crustal thickening along the orogen, a consequence of overthrusting and folding. the acadian foreland basin is categorized as a retroarc foreland basin, which occurs on the overriding continental lithosphere, adjacent to a foreland fold-thrust belt behind a continental margin arc. the initial result of loading is a bulge move out and uplift of the foreland, which generates a localized unconformity. the distributions of unconformities display an asymmetric pattern in relation to the promontories. subsidence follows bulge movement and uplift, and is produced on the cratonic side of the orogen due to regional isostatic adjustment to the load by the lithosphere. once thrust propagation declines, substantial relief and drainage nets have had time to develop, and the as a resulting coarser clastic sediment is eroded and transported to the foreland basin.