Billy, J.; Robin, N.; Hein, C.; FitzGerald, D., and Certain, R., 2018. Dominance of inherited geologic framework on the development of coastal barrier system. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 406–410. Coconut Creek (Florida), ISSN 0749-0208.
Many coastal systems are influenced by geologic framework (e.g., bedrock or inherited sedimentary systems), either in their initial development, morphology, or continuously throughout their evolution. This study adds to our understanding of the role of bedrock inheritance by describing the evolution of the Miquelon-Langlade Barrier (NW Atlantic; France). This barrier has a complex coastal planform (Y-shape, 12-km-long, 100–2500-m-wide) with several embedded sedimentary landforms. Ground-penetrating radar and HR seismic data collected along the subaerial and subaqueous portions of the barrier reveal: (i) the bedrock architecture (largely buried by Holocene deposits) and (ii) the presence of specific inherited sedimentary units. Indeed, both the location and early development of the barrier are largely controlled by bedrock morphology; the barrier is perched on a buried bedrock high in its center, and pinned to subaerial bedrock exposures at its northern and southern ends. Moreover, unconsolidated sedimentary shoals, formed and modified by waves and tides during earlier stages of rapid sea-level rise, provided important morphological constrains that influenced barrier development and the resulting complex morphology of the barrier and associated beach-ridge plain. This study demonstrates the utility of using coupled terrestrial and marine geophysical data to map geologic framework units, thereby determining the role of inherited geology in the evolution of coastal systems.