ESR Dating Ungulate Teeth and Molluscs from the Paleolithic Site Marathousa 1, Megalopolis Basin, Greece
Total Page:16
File Type:pdf, Size:1020Kb
quaternary Article ESR Dating Ungulate Teeth and Molluscs from the Paleolithic Site Marathousa 1, Megalopolis Basin, Greece Bonnie A. B. Blackwell 1,2,*, Neeraj Sakhrani 2, Impreet K. Singh 2, Kalyani K. Gopalkrishna 2, Vangelis Tourloukis 3 , Eleni Panagopoulou 4, Panagiotis Karkanas 5 , Joel I. B. Blickstein 2, Anne R. Skinner 1,2, Jonathan A. Florentin 1,2 and Katerina Harvati 3 1 Department of Chemistry, Williams College, Williamstown, MA 01267-2692, USA; [email protected] (A.R.S.); jonathan.a.fl[email protected] (J.A.F.) 2 RFK Science Research Institute, Glenwood Landing, NY 11547-0866, USA; [email protected] (N.S.); [email protected] (I.K.S.); [email protected] (K.K.G.); [email protected] (J.I.B.B.) 3 Paleoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls Universität, 72070 Tübingen, Germany; [email protected] (V.T.); [email protected] (K.H.) 4 Ephoreia of Palaeoanthropology-Speleology, Ardittou 34b, 11636 Athens, Greece; [email protected] 5 Malcolm H. Wiener Laboratory for Archaeological Science, American School of Classical Studies, Souidias 54, 10636 Athens, Greece; [email protected] * Correspondence: [email protected]; Tel.: +1-413-597-2285 Academic Editor: Valentí Rull Received: 10 August 2018; Accepted: 7 October 2018; Published: 15 October 2018 Abstract: At 37◦240 N 22◦80 E, the Megalopolis Basin lies in the central Peloponnese Peninsula, southwestern Greece. In the Megalopolis Basin at ~350 m amsl, the Paleolithic site, Marathousa 1, sits within a palustrine/lacustrine clastic package between Lignite Seams III and II, that both likely correlate with interglacial periods. At Marathousa 1, immediately below Lignite Seam III, lies a clayey-silty sand layer with a horizon rich in molluscs ranging from ~20–40 cm thick. About 0.8–1.3 m below the shell-rich horizon (SRH), lacustrine silty to muddy sands rich in organic matter yielded Paleolithic lithic artefacts associated with Middle Pleistocene fauna, some with cut marks and possible bone knapping, found within palustrine/lacustrine clastic deposits. Since ESR (electron spin resonance) can date teeth and molluscs aged >2 Ma, two bivalve samples, AM66 and AM65, five subsamples from a cervid molar, AT39, and one subsample from another cervid molar, AT68, were independently dated by ESR from Marathousa 1. To calculate the ages, time-averaged cosmic and time- and volumetrically-averaged sedimentary dose rates were calculated using past water depths and sedimentation rates as determined from paleontological and geological criteria. Found in the SRH in Layer UA2, AM66 and AM65 averaged 488 ± 37 ka, which correlates with MIS 13a. Because the bivalves sat stratigraphically above the artefacts and mammalian fossils, their ages constrain the ESR ages for the teeth deposited below. Lying on the unconformity at the base of Layer UA3c with UA4, and its correlative unconformity at the Layer UB4c/UB5 boundary, sat the dated teeth from large mammals. Because the bones in the Palaeoloxodon antiquus skeleton lay in quasi-anatomical association, the likelihood for fossil reworking on the Layer UB3c/UB4 surface is low. Isochron analysis suggests that using a U uptake model with p = 2 provides the most accurate ages for AT39. With p = 2, AT39 dates to 503 ± 13 ka, while AT68 dates to 512 ± 34 ka. Nonetheless, two to three more teeth and molluscs should be dated to confirm these ages, when more samples suitable for ESR dating are found. Both tooth ages correlate well with early MIS 13, an interglacial period with cooler mean global temperatures compared to MIS 11 or 9. Assuming that the archaeological site formed in one event, rather than as a palimpsest, the data suggest that hominins processed elephant and other Quaternary 2018, 1, 22; doi:10.3390/quat1030022 www.mdpi.com/journal/quaternary Quaternary 1 Quaternary2018 2018, , ,2 22, x FOR PEER REVIEW 22 of of 25 25 Megalopolis Basin at 503 ± 12 ka. Between the two horizons dated here, their sedimentation rate ± faunalaveraged carcasses 4.8 ± 1.8 along to 7.8 the ± shores 2.9 cm/k ofa . shallow lake or marsh in the Megalopolis Basin at 503 12 ka. Between the two horizons dated here, their sedimentation rate averaged 4.8 ± 1.8 to 7.8 ± 2.9 cm/ka. Keywords: Marathousa 1; Greece; ESR (electron spin resonance) dating enamel; ESR (electron spin Keywords:resonance)Marathousa dating molluscs; 1; Greece; Early ESR Paleolithic (electron archaeology; spin resonance) MIS dating(Marine enamel; Oxygen ESR Isotope (electron Stage) spin 13; resonance)mammalian dating paleontology molluscs; Early Paleolithic archaeology; MIS (Marine Oxygen Isotope Stage) 13; mammalian paleontology 1. Introduction 1. Introduction In the Pleistocene, Greece likely provided a relatively easy route for hominins migrating from In the Pleistocene, Greece likely provided a relatively easy route for hominins migrating from Africa into Europe. Yet, in Greece, the very rare Lower Paleolithic hominid finds have lacked Africa into Europe. Yet, in Greece, the very rare Lower Paleolithic hominid finds have lacked contextual contextual data or derived from a secondary depositional context [1,2]. Recently, however, data or derived from a secondary depositional context [1,2]. Recently, however, mammalian fossils, mammalian fossils, associated with hominin artefacts, have been found in situ in the Megalopolis associated with hominin artefacts, have been found in situ in the Megalopolis Basin [3–5]. The new ESR Basin [3–5]. The new ESR (electron spin resonance) dates reported here for teeth found in context at (electron spin resonance) dates reported here for teeth found in context at the open-air site, Marathousa the open-air site, Marathousa 1, in the Megalopolis Basin (Figure 1), provide the first absolute 1, in the Megalopolis Basin (Figure1), provide the first absolute (chronometric) dates for this site, in (chronometric) dates for this site, in which artefacts lie near mammalian fossils on the same surface. which artefacts lie near mammalian fossils on the same surface. Mollusc ESR dates are also reported Mollusc ESR dates are also reported for shells found stratigraphically above the horizon bearing the for shells found stratigraphically above the horizon bearing the archaeological materials, providing a archaeological materials, providing a capping age for the sedimentary package. capping age for the sedimentary package. Figure 1. The Marathousa 1 Site, Megalopolis Basin, Greece. The site sits in a lignite mine near the Figure 1. The Marathousa 1 Site, Megalopolis Basin, Greece. The site sits in a lignite mine near the village of Choremi within the Marathousa Member in the Choremi Formation in the Megalopolis village of Choremi within the Marathousa Member in the Choremi Formation in the Megalopolis Basin Basin in Greece (adapted after Panagopoulou et al. [3]). in Greece (adapted after Panagopoulou et al. [3]). Quaternary 2018, 1, 22 3 of 25 2. Marathousa 1, Megalopolis Basin, Greece Quaternary 2018, 2, x FOR PEER REVIEW 3 of 25 Located at 37◦240 N 22◦80 E at an elevation ~350 m amsl, the Megalopolis Basin lies in the 2. Marathousa 1, Megalopolis Basin, Greece central Peloponnese Peninsula, southwestern Greece (Figure1). During the Late Miocene-Pliocene, NE-SW tectonicLocated stretchingat 37° 24′ N formed 22° 8′ E aat hemi-graben an elevation ~ with350 m faults amsl bounding, the Megalopolis the eastern Basin edge,lies in creatingthe central Peloponnese Peninsula, southwestern Greece (Figure 1). During the Late Miocene-Pliocene, an intermontane depression. In the Pliocene-Pleistocene, a large lake filled the western side of the NE-SW tectonic stretching formed a hemi-graben with faults bounding the eastern edge, creating an basin several times, but periodically shallowed to a swamp. The six sedimentary formations in the intermontane depression. In the Pliocene-Pleistocene, a large lake filled the western side of the basin Megalopolisseveral times, Basin but reach periodically >250 m thick shallowed (Figure to1 ).a Organic-richswamp. The sedimentsix sedimentary accumulated formations mainly in the along the westernMegalopolis margin, Basin while reach detrital > 250 m alluvial,thick (Fig fluvial,ure 1). Organic palustrine-rich and sediment lacustrine accumulated facies were mainly deposited along to the east.the western In the late margin, Pleistocene, while detrital the currentalluvial, Alfeiosfluvial, palustrine River drainage and lacustrine system facies drained were the deposited lake, eroding to terracesthe intoeast. theIn the lacustrine late Pleistocene, sediment the [ 6current]. Alfeios River drainage system drained the lake, eroding Theterraces early-middle into the lacustrine Pleistocene sediment Choremi [6]. Formation is subdivided into the Marathousa Member, mainly displayingThe early-middle lacustrine Pleistocene or palustrine Choremi sediment Formation alternating is subdivided with into lignites, the Marathousa and the Member, Megalopolis Member,mainly with displaying only fluvial lacustrine sediment. or palustrine At Marathousa sediment alternating 1, the lacustrine with lignites, clay, silt,and andthe Megalopolis sand beds host Member, with only fluvial sediment. At Marathousa 1, the lacustrine clay, silt, and sand beds host freshwater bivalves, gastropods, and ostracodes (Figure2). The detrital beds likely formed during dry, freshwater bivalves, gastropods, and ostracodes (Figure 2). The detrital beds likely