Lake-Level Changes and Their Paleo-Climatic Implications at the MIS12 Lower Paleolithic (Middle Pleistocene) Site Marathousa 1, Greece

Abstract

Lithics and cut-marked mammal bones, excavated from the paleo-lake Marathousa 1 (MAR-1) sediments in the Megalopolis Basin, southern Greece, indicate traces of hominin activity occurring along a paleo-shoreline ca. 444,000 years (444 ka) ago. However, the local environment and climatic conditions promoting hominin activity in the area during the MIS12 glacial remain largely unknown. In order to reconstruct the paleo-environment including paleo-lake levels and governing paleo-climatic factors on a high temporal resolution, we analyzed a 6-meter-long sediment sequence from the archeological site MAR-1 and a Bayesian age model was computed for a better age constrain of the different sedimentary units. A multiproxy approach was applied using ostracods, sponge spicules, diatoms, grain sizes, total organic carbon, total inorganic carbon and conventional X-ray fluorescence analysis. The results from the site represent a protected region surrounded by high mountains under the constant influence of water, either as a shallow partly anoxic water body surrounded by reed belts (>463–457 ka, <434–427 ka), a riverine-lake deltaic system (∼457–448 ka), a floodplain (∼448–444 ka) or a seasonal freshwater pond (∼444–436 ka). The local changes of water levels resemble large trends and rhythms of regional records from the Mediterranean and appear to directly respond to sea surface temperature (SST) changes of the North Atlantic. In particular, when the SSTs are high, more moisture reaches the study area and vice versa. Additional water reaches MAR-1 through melting of the surrounding glaciers after brief warm phases during MIS12 in the Mediterranean realm, which leads to the formation of smaller fresh water ponds, where also the horizon of the excavated remains is placed. Such ponds, rich in ostracods and other microorganisms, provided mammals and humans valuable resources, such as potable water, a wide range of plant species and hunting opportunities. These deposits therefore bear a high archeological potential. The results from our study suggest that the Megalopolis Basin could have served as a refugium for hominins and other organisms due to its capacity to retain freshwater bodies during glacial and interglacial periods.

Life-history of Palaeoloxodon antiquus reveals Middle Pleistocene glacial refugium in the Megalopolis basin, Greece

“…However, such a pattern may also be produced by dampening related to hydrological processes (i.e., drinking from long-lived resident water bodies, such as lakes 60 ). A recent multi-proxy study on the water-level history of MAR-1 showed that, at the time of deposition of the MAR-1A-5 elephant skeleton, seasonal ponds had developed under a mostly dry and cold climate, conditions which persisted over ∼10 ka 8 . We therefore consider signal dampening due to such hydrological processes unlikely.…”

“…The vertebrates recorded at the site comprise terrestrial (e.g., Macaca, Bison, Cervus, Dama, Canis ) and semi-aquatic mammals (e.g., Castor, Hippopotamus, Lutra ) 10 , 15 and freshwater birds (e.g., Anas) 86 . It is indicative of a landscape with substantial woodland components as well as more open areas and the existence of a permanent freshwater body with mean summer temperatures reaching 10–15 °C (approximately 11 °C colder than present-day summer temperatures) in the Megalopolis basin 8 , 10 . These paleoenvironmental interpretations are consistent with a C 3 -dominated ecosystem consisting of C 3 woodland/open grassland under mesic conditions and low to moderate seasonality indicated by our isotopic analysis.…”

“…Our results show that, despite the severity of the MIS 12 glacial, the Megalopolis basin sustained a mesic habitat, sufficient plant cover and limited seasonal fluctuations in resource availability, pointing to its role as a glacial refugium for both fauna and hominins.The Balkan peninsula is considered to have played a major biogeographic role in Pleistocene Europe, broadly acting as a glacial refugium for both plant and animal species, as well as a source for the repopulation of higher latitude regions during interglacial periods (e.g., [1][2][3][4][5][6] ). In recent years, the Megalopolis basin, southern Greece, has emerged as a potential refugium-within-a-refugium area 7 (or micro-refugium 6 ), harbouring favourable environmental conditions, freshwater resources, rich faunal and floral communities, as well as human populations in the Middle Pleistocene [8][9][10][11][12][13][14][15] . Here, we investigate the life history of a straight-tusked elephant (Palaeoloxodon antiquus) from Marathousa 1 (hereafter MAR-1; Fig.…”

Crown outline analysis of the hominin upper third molar from the Megalopolis Basin, Peloponnese, Greece

“…800-300 ka (Tourloukis et al 2018b), with its upper age-limit being poorly constrained at around 300 or 200 ka (see also Jacobs et al 2018;Blackwell et al 2018). Recent multiproxy paleoenvironmental reconstruction (Bludau et al 2021) has highlighted the role of the Megalopolis Basin as a potential glacial refugium for Pleistocene humans due to its ability to retain freshwater bodies during glacial periods. The Megalopo-Words, Bones, Genes, Tools: DFG Center for Advanced Studies lis molar was part of a surface collection, in which many of the collected fossils were found still embedded in blocks of lacustrine sediments and derived from deposits of the Marathousa Member (Sickenberg 1976: 26).…”

The function of small tools in Europe during the Middle Pleistocene: The case of Marathousa 1 (Megalopolis, Greece)

“…The exceptionally preserved materials are composed of carpological remains, pollen, wood, phytoliths, diatoms, mollusks, ostracods and insects, indicating that hominin activities took place in a warming climate, in a wooded landscape with open areas near a lake (Field et al 2018). In particular, it appears that animal and plant resources and freshwater were available to hominins in close vicinity to the site (Bludau et al 2021). Cut marks and percussion marks on faunal remains attest to on-site butchering activities (Konidaris et al 2018), but no direct evidence for plant use has been identified so far.…”