Models of the internal architecture of gravel or mixed sand-and-pebble beach ridges are rarely proposed. Some studies have used GPR to investigate mixed sand-and-gravel beach-ridge systems (Neal et al., 2003, Engels and Roberts, 2005 and BjØrnsen et al., 200
cool , but these were not focused on providing architectural models of mixed
cadherin ridges. FitzGerald et al. (1992) proposed an organization with sigmoidal accretionary wedges, for a succession of alternating sand deposits and gravel-ridges (sand or gravel layers, not mixed) on Buzzards Bay (Massachusetts, USA). The architecture model proposed for the Miquelon-Langlade sand-and-gravel beach ridge system is quite different from models published for sandy beaches (Fig. 14), especially with respect to the well-pronounced sigmoidal-shaped reflectors and the multiple visions at different vertical resolution scales. However, detailed studies of other coarse, mixed-sediment beach-ridge systems will be required to determine the breadth of the model's applicability. Furthermore, most beach-ridge systems were developed during periods of RSL fall (Table 3). By contrast, the Miquelon-Langlade beach-ridge plain formed during a
period of RSL rise. Thus, an interesting extension of this work would be to compare coarse-clastic beach ridges formed as a result of forced regression (RSL fall) to those formed by normal regression.
