Late Glacial Marine Transgression and Ecosystem Response in the Landlocked Elefsis Bay (Northern Saronikos Gulf, Greece)

Abstract

Coastal landscapes are sensitive to changes due to the interplay between surface and submarine geological processes, climate variability, and relative sea level fluctuations. The sedimentary archives of such marginal areas record in detail the complex evolution of the paleoenvironment and the diachronic biota response. The Elefsis Bay is nowadays a landlocked shallow marine basin with restricted communication to the open Saronikos Gulf. A multi-proxy investigation of a high-resolution sediment core recovered from the deepest part of the basin offered a unique opportunity to record the paleoenvironmental and aquatic ecosystem response to climate and glacioeustatic sea level changes since the Late Glacial marine transgression. The retrieved sedimentary deposits, subjected to thorough palynological (pollen, non-pollen palynomorphs, dinoflagellates), micropaleontological (benthic foraminifera, calcareous nannoplankton, ostracods), and mollusc analyses, indicates isolation of the Elefsis Bay from the Saronikos Gulf and the occurrence of a shallow freshwater paleolake since at least 13,500 cal BP, while after 11,3500 cal BP the transition towards lagoon conditions is evidenced. The marine transgression in the Elefsis Bay is dated at 7500 cal BP, marking the establishment of the modern marine realm.

Late-Holocene paleoenvironmental and land-use changes in Western Greece based on a sediment record from Klisova lagoon

“…Asteroideae, Cichorieae, Rumex ) and microscopic charcoal, suggest a dynamic depositional environment with increased terrestrial run-off (fluvial input) and is in good agreement with increased values of Rb/Sr ratio (Figure 8). Increased terrestrial run-off is inferred from Glomus , Pseudoschizaea , as well as terrestrial biomarker concentration peaks occurring between 5000 and 4000 cal BP in the Elefsis Bay (Attiki region; Kouli et al, 2021). During this period, a maximum concentration of arboreal pollen related to increased ecosystem productivity and maximum forest cover suggesting optimum growth conditions is reported from several lake sites across the southern Balkans, such as Lake Prespa (Panagiotopoulos et al, 2013) and Dojran (Masi et al, 2018).…”

Mid-late Holocene vegetation history of the Argive Plain (Peloponnese, Greece) as inferred from a pollen record from ancient Lake Lerna

“…4300 BP. The high degree of forest cover might be related to increased moisture as also testified in the Mavri Trypa record from 4700 to 4400 BP [95] as well as in the Aegean Sea for the period 5400-4300 BP [96,97] and in the southern Mediterranean for 5000-4600 BP [98]. This wet phase interrupted the general aridity trend reported for the whole Balkans, based on a compilation of several palaeoclimate records from the Balkan peninsula and the Aegean Sea [99].…”

“…4600 to 3900 BP, with a lasting dry phase that started at ca. 4120 BP and correlated with the onset of an arid phase in the Elefsis Bay (Saronic Gulf; [96]) (Fig 7; details about methods of the isotopic analysis can be found in [34]). Dry phases are also identified in the stable oxygen isotope records from Mavri Trypa Cave (from ca.…”

“…Fig 9.Comparison between pollen sequences from the Peloponnese and southern Greece. Pollen percentage diagram of selected taxa from ancient Lake Lerna (present study), Vravron wetland[2,130,188], Elefsis Bay[96, 107], Kotihi lagoon[2,121]. For API group see §3.2.…”

Paleoenvironmental Evolution and Sea Level Change in Saronikos Gulf (Aegean Sea, Greece): Evidence from the Piraeus Coastal Plain and Elefsis Bay Sedimentary Records

“…A high-resolution marine record derived from a sediment core (named S2P) recovered from the deepest part of Elefsis Bay (see the coring location in Figure 1) provides good evidence for the paleoenvironmental conditions identified in the area. In particular, the establishment of full marine conditions in the Elefsis Bay, with a sufficient water column depth, i.e., at least 20 m, to sustain the pelagic coccolithophore community [112] documented by the dominance of Emiliania huxleyi in the S2P record, can be dated at 7500 cal BP according to the age model presented in the study of Kouli et al [83] (Figure 7). Elefsis Bay is connected to the inner Saronikos Gulf via two narrow straits, a western and an eastern one, both having sills occurring at water depths of~8 and~12-13 m, respectively.…”