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100			_aCosta, Ana Maria _951737
245			_aThe role of climate, marine influence and sedimentation rates in late-Holocene estuarine evolution (SW Portugal)/
260			_bSage, _c2019.
300			_aVol 29, issue 4, 2019 : (622-632 p.).
520			_aEstuaries are sensitive to changes in global to regional sea level, to climate-driven variation in rainfall and to fluvial discharge. In this study, we use source and environmentally sensitive proxies together with radiocarbon dating to examine a 7-m-thick sedimentary record from the Sado estuary accumulated throughout the last 3.6 kyr. The lithofacies, geochemistry and diatom assemblages in the sediments accumulated between 3570 and 3240 cal. BP indicate a mixture between terrestrial and marine sources. The relative contribution of each source varied through time as sedimentation progressed in a low intertidal to high subtidal and low-energy accreting tidal flat. The sedimentation proceeded under a general pattern of drier and higher aridity conditions, punctuated by century-long changes of the rainfall regime that mirror an increase in storminess that affected SW Portugal and Europe. The sediment sequence contains evidence of two periods characterized by downstream displacement of the estuarine/freshwater transitional boundary, dated to 3570–3400 cal. BP and 3300–3240 cal. BP. These are intercalated by one episode where marine influence shifted upstream. All sedimentation episodes developed under high terrestrial sediment delivery to this transitional region, leading to exceptionally high sedimentation rates, independently of the relative expression of terrestrial/marine influences in sediment facies. Our data show that these disturbances are mainly climate-driven and related to variations in rainfall and only secondarily with regional sea-level oscillations. From 3240 cal. BP onwards, an abrupt change in sediment facies is noted, in which the silting estuarine bottom reaches mean sea level and continued accreting until present under prevailing freshwater conditions, the tidal flat changing to an alluvial plain. The environmental modification is accompanied by a pronounced change in sedimentation rate that decreased by two orders of magnitude, reflecting the loss of accommodation space rather than the influence of climate or regional sea-level drivers.
650			_aclimate variability, _950988
650			_aenvironmental proxies, _951738
650			_a fluvial discharge, _951476
650			_asea-level oscillation, _951739
650			_astorminess _951740
700			_aFreitas, Maria da Conceição _951741
700			_aLeira, Manel _951324
700			_aCostas, Susana _951742
700			_aCosta, Pedro JM _951743
700			_aAndrade, César _951334
700			_aBao, Roberto _951336
700			_aDuarte, João _951744
700			_aRodrigues, Aurora _951745
700			_aCachão, Mário _951746
700			_aAraújo, Ana Cristina _951747
700			_aDiniz, Mariana _951748
700			_aArias, Pablo _951749
773	0		_012756 _916504 _dLondon: Sage Publication Ltd, 2019. _tHolocene/ _x09596836
856			_uhttps://doi.org/10.1177/0959683618824768
942			_2ddc _cART
999			_c12813 _d12813