Maximum flood area during MIS 1 in the Almenara marshland (Western Mediterranean): Benthic foraminifera and sedimentary record

Abstract

The sedimentological and micropaleontological analysis of three mechanical cores in the marshland of Almenara (Valencian Community, Spain) has allowed the reconstruction of the Holocene evolution of this wetland. The cold and dry 8.2-ka event might be represented in Almenara by a massive carbonate precipitation bed, upon which mid- and late-Holocene sediments were subsequently deposited. The direct influence of sea-level changes has been recorded in the two cores (S-4 and S-5) located near the marsh barrier, at 400–450 m from the current coastline. The maximum flood area during MIS 1 (last 11,600 years) is represented in these cores by sediments indicative of different littoral subenvironments (shoreface, foreshore, backshore). These sediments contain typically littoral marine foraminiferal species such as Ammonia beccarii, Rosalina globularis, Asterigerinata mamilla, Adelosina longirostra, Cibicidoides lobatulus, Elphidium macellum, and Bolivina pseudoplicata. The base of these littoral sedimentary materials has been dated as 5480 and 5580 cal. yr BP. At this moment, the inner area (core S-7) was occupied by a restricted oligohaline marsh subject to water-table fluctuations and with scarce individuals of brackish water foraminifera, such as Ammonia tepida, Haynesina germanica, or Cribroelphidium excavatum, that in more recent times (since at least 1700 cal. yr BP) gradually evolved to a palustrine area.

New relative sea-level insights into the isostatic history of the Western Mediterranean

“…Large uncertainties are associated with the SLIPs and poor descriptions of the original data did not allow us to robustly assess the RSL history in this area, notably for the last 6000 years. A new dataset of dated estuarine facies (Carmona et al, 2016;Blázquez et al, 2017;Rodríguez-Pérez, 2018) has facilitated a significant advance in the definition of the mid-to late-Holocene RSL evolution of this coastal sector.…”

Aridity events during the last 4000 years in Western Mediterranean marshes (Almenara and Benicasim marshes, E Spain)

“…For most of the last 4000 years, coastal wetlands have no direct connection to the sea. In the case of the marshes of Almenara and Benicasim, the paleoecological studies (foraminifers and ostracods) show that they were oligohaline marshes only affected by small fluctuations in their water levels (Usera et al, 1996;Mediato, 2016;Blázquez et al, 2017Blázquez et al, , 2018Rodríguez-Pérez et al, 2018). These authors did not reach conclusive paleoecological data that allowed distinguishing relative changes in salinity of wetlands during the period.…”

“…They are typical features of the coastal plain landscapes of the Spanish Mediterranean coast: Mar Menor, Valencia lagoon, Oliva-Pego marsh, Almenara, Benicasim and Torreblanca-Cabanes marshes. Previous sedimentological, geomorphological and paleontological studies focused on their paleoenvironmental reconstruction during the Holocene (Dupré et al, 1988;Usera et al, 1996Usera et al, , 2002Mediato and Santisteban, 2006;Carmona and Ruiz, 2011;Marco-Barba et al, 2013, Carmona et al, 2016Mediato, 2016;Blázquez et al, 2017Blázquez et al, , 2018Rodríguez-Pérez et al, 2018;Ruiz-Pérez and Carmona, 2019;López-Belzunce et al, 2020). These studies concluded that the Holocene paleoenvironmental changes were related to the eustatic variations that took place since the Last Glacial Maximum and climate was a minor forcing of local interest.…”

Millennial‐scale shifts in microtidal ecosystems during the Holocene: dynamics and drivers of change from the Po Plain coastal record (NE Italy)

“…A geological perspective is key for addressing this issue and stratigraphic studies can provide a long‐term view, useful for conservation and restoration strategies. In this respect, the subsurface sedimentary successions of the Mediterranean coastal plains represent invaluable archives containing the full set of bio‐sedimentary data able to provide insights on past ecosystem dynamics and associated forcing (Leorri et al ., 2006; Sacchi et al ., 2014; Zecchin et al ., 2014; Di Rita et al ., 2015; Bellotti et al ., 2016; Cearreta et al ., 2016; Ejarque et al ., 2016; Milli et al ., 2016; Rodríguez‐Pérez et al ., 2018; Revelles et al ., 2019; Seeliger et al ., 2019; Vella et al ., 2019). The integration of different fossil groups (e.g.…”