AMS RADIOCARBON DATING OF THE MESOLITHIC SITE MAROULAS ON KYTHNOS AND CALCULATION OF THE REGIONAL MARINE RESERVOIR EFFECT Yorgos Facorellis 1 , Brian N. Damiata 2 , Evi Vardala-Theodorou 3 , Maria Ntinou 4 and John Southon 5 1 Laboratory of Archaeology, Department of History, Archaeology and Social Anthropology, School of Human Sciences, University of Thessaly, 382 21 Volos, Greece; facorel@ha.uth.gr 2 Cotsen Institute of Archaeology, University of California, A210 Fowler, Los Angeles, CA 90095-1510, USA; damiata@ucla.edu 3 Hydrobiological Department, Goulandris Natural History Museum, 100 Othonos St., 14562 Kifissia, Greece; evard@GNHM.GR 4 University of Ioannina, P.O. Box 1186, 451 10 Ioannina, Greece; Maria.Ntinou@uv.es 5 Keck CCAMS Group, Earth Systems Sciences Department, University of California, Irvine, CA 92697-3100, USA; jsouthon@uci.edu INTRODUCTION The prehistoric settlement of Maroulas on Kythnos (37° 26´ 50´´ N Lat., 24° 25´ 53´´ E. Long, Fig. 1) is the second Mesolithic site excavated on an Aegean island – after the excavation of the Mesolithic strata of the Cave of Cyclops on the island of Youra near Alonnessos (Sampson 1996a, 1996b, 1998, 2001; Sampson and Koslowski, 1998, 1999) – and is the first open-air Helladic Mesolithic site ever lo- cated. During the excavation, very rare small pieces of ma- rine and terrestrial materials suitable for radiocarbon dating were revealed. The objectives of the present study included: (1) determine the time limits of the Mesolithic phase of this site, (2) date the contemporaneous marine mollusc shell- charcoal pairs in order to calculate the “marine reservoir ef- fect” (Stuiver et al. 1986; Stuiver and Braziunas 1993) for this region of the Cyclades and to compare values with co- eval ones from nearby Youra (Facorellis et al., 1998; Faco- rellis, 2003; Facorellis, 2009) and (3) calibrate previously published radiocarbon ages from Maroulas (Sampson et al., 2002) using the latest version of the international atmosphe- ric calibration curve (IntCal04; Reimer et al., 2004) and re- assess the results. This study represents the initial phase of a larger-scale project whose objective is to establish a marine reservoir correction curve for the entire Aegean Sea region. This curve will have wide application to the dating of archaeo- logical strata throughout the region and will be particularly useful where marine shells are the only datable material for a site. Although the project emphasizes archaeological ap- plications, the results will be of importance also to palaeo- climatic and palaeo-oceanographic studies. SUMMARY OF ACTIVITIES The major activities that were conducted for this study included the in situ collection of contemporaneous pairs of marine shell-charcoal samples during the final excavation campaign in September 2005, identification of the samples, and subsequent AMS radiocarbon dating. The archaeologi- cal site of Maroulas on Kythnos was targeted because of its proximity to the island of Youra and temporal coexistence with the site of the Cave of Cyclops, where there are already established dates for several pairs of samples which have yielded a value for the regional marine reservoir effect (Fa- corellis et al., 1998; Facorellis, 2003; Facorellis, 2009). It was hoped that by comparing results, temporal and spatial variations at both the local and regional scales, if present, would be discerned. In total, 16 pairs of marine shell-charcoal samples were collected from rectangles 10 and 11 of Trench 2, which cor- responds to a man-made paved floor at the eastern part of the site and from depths ranging from 0.05–0.35 m (Figs 2 and 3). All samples were catalogued, photographed and me- chanically cleaned. A complete description of the identifica- tion and archaeological context of marine shell and charcoal samples is given in the following paragraphs and is summa- rized in Tables 1 and 2, respectively. MOLLUSCAN SHELL IDENTIFICATION Marine Gastropoda belonging to 3 species of Patellidae Family, were sampled (see Table 1). In the absence of soft parts, the assessment of taxonomic affinities was based solely on detailed observation of the preserved shell. Frag- ments were identified to the Genus level and complete specimens to the species level. All the species are marine, still living, and commonly found in the Aegean Sea on hard substrate in the mediolittoral zone (Delamotte and Vardala- Theodorou, 2001; SoHelME, 2005).