FN Archimer Export Format PT J TI Importance of coarse sedimentation events in the resilience of microtidal back-barrier saltmarshes to sea-level rise BT AF Goslin, Jerome Bernatchez, P. Barnett, R.L. Ghaleb, B. Béland, C. Didier, D. Garneau, M. AS 1:1,2;2:2;3:2,3;4:4;5:2;6:2;7:4; FF 1:PDG-REM-GEOOCEAN-ODYSC;2:;3:;4:;5:;6:;7:; C1 Geo-ocean, IFREMER, 29880 Plouzané, France Chaire de recherche en géoscience côtière, Université du Québec à Rimouski, Québec-Océan et Centre d'études nordiques, Rimouski, Québec G5L 3A1, Canada Geography, College of Life and EnvironmeFntal Sciences, University of Exeter, Amory Building, Rennes Drive EX4 4RJ, UK Chaire de recherche sur la Dynamique des Ecosystèmes Tourbeux et Changements Climatiques, Université du Québec à Montréal, Centre GEOTOP, Montréal, Québec H3C 3P8, Canada C2 IFREMER, FRANCE UNIV QUEBEC (UQAR), CANADA UNIV EXETER, UK UNIV QUEBEC (UQAM-GEOTOP), CANADA SI BREST SE PDG-REM-GEOOCEAN-ODYSC UM GEO-OCEAN IN WOS Ifremer UMR copubli-europe copubli-int-hors-europe IF 2.9 TC 1 UR https://archimer.ifremer.fr/doc/00762/87388/92886.pdf LA English DT Article DE ;Sandy barrier;Saltmarshes;Sea-level;Accretion rates;Resilience;Washover;Storminess AB An improved understanding of the resilience capacity of salt-marsh environments, which are recognized as one of the most vulnerable yet valuable coastal morpho-sedimentary systems is important for enhancing resilience to future sea-level rise. The aim of this study is to provide a long-term (multi-centennial) context to the capacity of response of saltmarsh environments to relative sea-level rise by reconstructing the accretion histories of two microtidal back-barrier (one aggradational and one transgressive) saltmarshes in the Bay of Gaspé (Québec, Eastern Canada) over the last centuries. Particular emphasis is put on coarse minerogenic sedimentation and the role it played in the response of the two marshes to relative sea-level changes. To do so, lithostratigraphic, geochronological, and geochemical analyses are carried out on sedimentary cores taken in the back-barrier marsh areas. The accretion histories and the chronology of coarse deposition upon the marshes are reconstructed and yield the following two main results: (1) Coherent yet contrasting records of coarse sedimentation histories are obtained for the two sites, which relate to the distinct configurations and functioning of the fronting barrier systems. The coarse sedimentation time-series of both marshes carry pluri-decadal periodicities typical of atmospheric and intra-oceanic modes of variability, as well as periodicities of 18.0 to 18.5 years, which are interpreted as the expressions of the influence of the 18.6-year nodal tidal cycle. (2) We observe intra- and inter-site variations in the accretionary behavior of the two systems as well as in their respective histories of coarse minerogenic deposition. We show that coarse sedimentation at the surface of the two marshes has been crucial for maintaining accretion rates both in minerogenic and organogenic environments, and thus for allowing saltmarshes to build a resilience capacity in a regime of relative sea-level rise. PY 2022 PD MAY SO Marine Geology SN 0025-3227 PU Elsevier BV VL 447 UT 000793760700001 DI 10.1016/j.margeo.2022.106793 ID 87388 ER EF