Absolute and Relative Dating of Human Remains in a Bahamian Sinkhole (Great Cistern, Abaco) T ⁎ Richard M

Journal of Archaeological Science: Reports 32 (2020) 102441 Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep Absolute and relative dating of human remains in a Bahamian sinkhole (Great Cistern, Abaco) T ⁎ Richard M. Sullivana,b, , Peter J. van Hengstuma,b,Jeffrey P. Donnellyc, Tyler S. Winklera,b, Samuel E. Markd, Nancy A. Alburye a Department of Oceanography, Texas A&M University, College Station, TX 77843, USA b Department of Marine Sciences, Texas A&M University at Galveston, Galveston, TX 77554, USA c Coastal Systems Group, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, Massachusetts 02543, USA d Department of Liberal Studies, Texas A&M University at Galveston, Galveston, TX 7554, USA e National Museum of The Bahamas/Antiquities, Monuments and Museums Corporation (AMMC), PO Box EE-15082, Nassau, Bahamas ARTICLE INFO ABSTRACT Keywords: The Little Bahama Bank was likely the last island group colonized by the Lucayan natives in the tropical North Lucayan Atlantic, but preserved Lucayan remains are rare from this region. Furthermore, the Lucayan diet included both Bahamas marine and terrestrial contributions, which must be considered when calibrating conventional radiocarbon re- Sinkhole sults from human remains into Common Era (CE) calendar years. Here we present a new discovery of Lucayan Radiocarbon dating remains (proximal epiphysis of a right tibia) identified within a sinkhole on Great Abaco Island in the northern Abaco Bahamas, which was preserved in the extremely well-dated sedimentary infill (dated with 22 independent Burial radiocarbon ages). The age of the human tibia was estimated through both the associated stratigraphy (relative age), and direct radiocarbon dating of the bone (absolute age). The direct age of the bone was calibrated by using a two-endmember mixing model to estimate the average proportion of marine versus terrestrial contributions to this individuals’ diet using the δ 13C value of the bone collagen and applying a local ΔR value for regional aquatic settings. Absolute dating places the age of the remains from Great Cistern between 1255 and 1340 CE (2σ, probability: 0.89). Applying the same mixing model to the previously discovered remains from Sawmill Sink on Great Abaco Island indicates those remains are in fact 100 to 200 years younger than the previous estimate with internment likely occurring between 1110 and 1290 CE (2σ, probability: 0.95). 1. Introduction BCE by settlers emigrating from the Yucatan. This was followed in the 1st millennium BCE by the arrival of the Arawak-Taino in Puerto Rico At the onset of European colonization in the 15th Century Common and the Lesser Antilles from the north coast of South America. Carib Era (CE), the ethnic groups inhabiting the Caribbean were divided into expansion begins in 800 CE in Hispaniola and continues outward to- several distinct spatial and cultural entities (Fitzpatrick and Keegan, wards The Bahamas, giving subsequent rise to the indigenous Lucayan 2007; Keegan and Hofman, 2016; Lalueza-Fox et al., 2003; Ross et al., culture. The timing and sequence of Lucayan dispersal throughout The 2020; Rouse, 1992; Schroeder et al., 2018). The windward Islands of Bahamas remains uncertain. the Lesser Antilles were populated primarily by the Carib, the Leeward The earliest known Lucayan settlements in The Bahamas are The Islands and Greater Antilles by the Arawak-Taino, with the Lucayans Coralie Site on Grand Turk Island in Turks and Caicos (established occupying the eponymous Lucayan archipelago from Turks and Caicos circa. 705 ± 60 CE) (Keegan, 1997; Scudder, 2001) and the Three Dog in the southeast to Grand Bahama island in the northwest. Multiple Site on San Salvador in the central Bahamas (established between 800 migratory pathways have been proposed for human dispersal and 900 CE) (Berman and Gnivecki, 1991). However, the dearth of throughout the Caribbean (Berman and Gnivecki, 1995; Fitzpatrick and human remains from Great Abaco Island and Grand Bahama Island Keegan, 2007; Mendisco et al., 2015; Napolitano et al., 2019; Rouse, promotes uncertainty regarding the arrival of Lucayans in the northern 1986), but recent work by Ross et al. (2020) using craniofacial mor- archipelago. The lack of early Lucayan remains on the Little Bahama phology concluded that colonization began first in Cuba around 5000 Bank, along with recent work highlighting the lack of evidence for a ⁎ Corresponding author at: Department of Oceanography, Texas A&M University, College Station, TX 77843, USA. E-mail address: [email protected] (R.M. Sullivan). https://doi.org/10.1016/j.jasrep.2020.102441 Received 3 March 2020; Received in revised form 8 June 2020; Accepted 9 June 2020 2352-409X/ © 2020 Elsevier Ltd. All rights reserved. R.M. Sullivan, et al. Journal of Archaeological Science: Reports 32 (2020) 102441 Floridian-Bahamian migration route (Ross et al., 2020), and the tem- (Mylroie et al., 1995a, 1995b; Mullins and Lynts, 1977; Mylroie and poral and northward Lucayan site progression pattern along the ar- Carew, 1995). Sinkholes and blue holes are some of the most re- chipelago suggest that Great Abaco Island was one of the final islands to cognizable karst features throughout The Bahamas and are formed be colonized in the tropical North Atlantic Ocean. A wooden paddle through subsurface dissolution of the antecedent carbonate. This dis- indicative of Lucayan design found on the adjacent Moore’s Island in solution initially forms caves which subsequently experience ceiling 1912 (de Booy, 1915) provided a calibrated radiocarbon age of 1436 to collapse becoming a notable depression on the subaerial landscape. 1500 CE (IntCal13, 2σ, probability: 0.91; Ostapkowicz et al., 2012). After formation, the sediment and fossils that accumulate within sink- While artifacts such as this may provide evidence of a Lucayan presence holes and blue holes preserve excellent records of past landscape and at that time, our current knowledge for earlier pre-European occupation environmental change (van Hengstum et al., 2016, 2018; Steadman of the Little Bahama Bank follows from several lines of indirect evi- et al., 2007). When flooded by local groundwater, the often low dis- dence. solved oxygen and quiescent bottom water conditions promote excep- There are botanical indicators of landscape disturbance and poten- tional preservation of any deposited sediment, pollen, charcoal, or tial indirect evidence of human predation occurring around 1000 CE. faunal remains. Increasing charcoal concentrations between 1000 and 1050 CE in lake Great Cistern is a narrow (15 m diameter) terrestrial sinkhole lo- sediment records from Abaco suggest landscape disturbance by cated on the periphery of a shallow coastal embayment on the eastern Lucayans was initiated by this time (Slayton, 2010; Stork, 2006). shore of Great Abaco Island (26.57° N, 77.12° W; Fig. 1, S1). The depth Midden remains at Gilpin Point in southern Abaco contained green sea of Great Cistern varies from 9 m to 11 m along a southwestern gradient turtle (Chelonia mydas) remains, including a split shell. A split shell with a tidal range of approximately 50 cm. Measurements of the water indicates human presence since no terrestrial predators on Abaco were column structure reveal polyhaline and dysoxic conditions at the ben- − capable of this action (Steadman et al., 2014). Radiocarbon-dated green thos (dissolved oxygen: 0.1 mg l 1, salinity: 20 psu) and mesohaline − turtle remains from Gilpin Point yielded a calibrated age (using oxygenated surface waters (surface dissolved oxygen: 6 mg l 1, salinity: Marine13, Reimer et al., 2013) of 910 to 1075 CE (2σ, probability: 1.0; 10 psu). Steadman et al., 2014). The extinction on Abaco of the native Albury’s Tortoise (Chelonoidis alburyorum) and Cuban Crocodile (Crocodylus 3. Methods rhombifer) ~1000 years ago (Hastings et al., 2014) potentially indicates anthropogenic landscape alteration, since decreasing faunal diversity 3.1. Core collection, sedimentology and sediment age often follows human island colonization (Alcover et al., 1998; Crowley, 2010; Steadman et al., 2005; Stuart, 2015). However, crocodile and Continuous sediment cores were collected from Great Cistern in tortoise extirpation on Abaco may only correlate with human arrival, 2014 (9.5 cm diameter push cores, C2) and in 2015 using a Rossfelder and other non-anthropogenic mechanism (e.g., changing precipitation P3 submersible vibracoring machine (7.6 cm diameter vibracores, C7, patterns) cannot yet be discounted. The dearth of directly-dated Lu- C8; Fig. 2). It is likely that the entire unlithified sedimentary sequence cayan remains means that indirect evidence such as fire, extinction, and in Great Cistern was sampled because an impenetrable substrate pre- landscape change have thus far provided the best available constraints vented vibracoring below a depth of 485 cm. Core C7 (total length for the timing of Lucayan occupation of Abaco Island. 435 cm) sampled the complete Holocene sequence, though the upper To date, the only directly-dated Lucayan remains on Abaco are the 50 cm were not recovered. Core C8 sampled from the sediment water skeletal remains recovered from Sawmill Sink (Steadman et al., 2007). interface to a depth of 352 cm. C2 sampled to a depth of 250 cm below The conventional radiocarbon result on the human tibia from Sawmill the sediment water interface, though the upper 14 cm were not cap- Sink was originally calibrated to 900 to 920 CE or 950 to 1030 CE (2σ, tured due to over-penetration, yielding a recovered length of 236 cm. Steadman et al., 2007) using the IntCal calibration curve available at Cores were sectioned into 150 cm lengths for transport to the laboratory that time (Reimer, 2004). By applying this calibration curve, one is where they were subsequently split lengthwise, photographed, and X- assuming that the bone collagen tissue analyzed had incorporated radiographed (to image density variations). carbon entirely sourced from the atmospheric radiocarbon pool (non- Downcore textural variability was evaluated between cores with a marine).

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