Revisiting the lithic industries of El Abra sites (Sabana de Bogotá, Colombia, Northern South America). Implications for its significance and chronology

Abstract

In this paper we present a revision of the lithic industries of El Abra sites (Sabana de Bogotá, Eastern Cordillera, Colombia), among the most ancient and significant sites of Colombia. Dated to 12,400 ± 160 years BP, El Abra is an important reference for the prehistory of the country.

Our review mostly deals with the: a) methodological approach adopted for the study of the lithic industry; b) interpretation of the lithic industry; c) chrono-stratigraphy.

In 2017, 2019 we presented the revision of the lithic assemblages of the oldest levels of El Abra sites (Muttillo et al., 2019, 2017); here we integrate and complete the revision with the analysis of the lithic assemblages of the upper levels. This is the first revision of the historical lithic collections, adopting a technological approach and crossing the data with the chrono-stratigraphic context.

Our results have highlighted several discrepancies and critical elements contained in previous studies, that mostly affect not only the interpretation of the lithic industries but also the chronology of the site, that turned out to be more recent than previously assumed, for at least three thousand years.

Introduction

Despite the exponential increase of multidisciplinary researches (archaeological, paleoanthropological, genetic and linguistic) of the last decades, the first human peopling of the Americas is still a matter of intense scientific controversy. Consensus has yet to be reached regarding many aspects which are controversial and poorly understood: the number and timing of dispersions from Siberia within the Americas; the timing of Native Americans divergence from their East Asian ancestors; the precise spatial-temporal pattern of the peopling process; the dispersion routes, subsistence strategies and adaptive responses to different climatic and environmental conditions; cultural and techno-economic behaviors (e.g., Anderson, 2010; Ardelan, 2014; Ardila and Politis, 1989; Beck and Jones, 2010; Braje et al., 2017; Bryan and Gruhn, 2003; De Saint Pierre, 2017; Dillehay, 2008, 1999; Dillehay et al., 1992; Faught, 2017, 2008; Goebel et al., 2008; Llamas et al., 2016; Marangoni et al., 2014; Moreno-Mayar et al., 2018; Pitblado, 2011; Posth et al., 2018; Raghavan et al., 2015; Reich et al., 2012; Steele and Politis, 2009).

Apart for the recently discovered 130,000-year-old Cerutti Mastodon site (southern California, USA) (Holen et al., 2017), not unanimously accepted (Ferraro et al., 2018) and other debated sites such as the sites of the Piauí region, in Brasil, dated to 25,000–20,000 years ago (e.g., Boëda et al., 2014a, Boëda et al., 2014b; Lahaye et al., 2015, 2013), current genetic and archaeological evidence suggests a dispersal from a Siberian population toward the Bering Land Bridge not earlier than about 30 ka, moving into eastern Beringia between 26 and 18 ka, spreading southward into the Americas after 17 ka and reaching southern South America by at least 14.5 ka (e.g., Braje et al., 2017; Dawe and Kornfeld, 2017; Dixon, 2013; Goebel et al., 2008; Madsen, 2015; Pedersen et al., 2016; Pitblado, 2011; Rabassa and Federico, 2013; Raff and Bolnick, 2014).

Although the place of initial entry into South America is not known, it must necessarily correspond to the north/north-western part of the current Colombian territory, which links Panama with the rest of the continent. Therefore, in this debate, Colombia, thanks to its strategic geographical position, constitutes a key area to understand the dispersal of early human population moving from Central to South America, through the Isthmus of Panama, which constitutes a sort of bottleneck that opens to an area with a large variety of environments (e.g., Aceituno et al., 2013; Cooke, 1998; Cooke et al., 2013; Delgado et al., 2015; Dickau et al., 2015; Dillehay et al., 1992; Politis, 1999; Ranere and López, 2007).

There are many critical issues in the reconstruction of the prehistory of Colombia, that do not allow us to achieve a full and detailed comprehension of chronology, routes of dispersion and the human economic strategies of the earliest inhabitants of the Colombian territory (for a synthesis, see Muttillo et al., 2017).

According to the available evidence, the early peopling of Colombia occurred during the final Late Pleistocene/Early Holocene; more precisely during the Guantiva-El Abra interval (ca. 12,500–10,000/9500 BP), the regional equivalent to the European Allerød-Younger Dryas sequence (van der Hammen and Hooghiemstra, 1995).

Sites dated earlier than 12,500 BP, such as Pubenza (ca. 16,400 BP, Magdalena valley) (Correal et al., 2005) and El Jordán (ca. 12,900 BP, Central Cordillera) (Salgado, 1998; Salgado and Varón Barbosa, 2019) are not unanimously accepted (Aceituno et al., 2013; Delgado et al., 2015) and will not be considered in this paper.

At the current state of the research, El Abra (Sabana de Bogotá, Eastern Cordillera, Colombia) is the oldest site of Colombia with a chronology of 12,400 ± 160 BP and a key-site for the prehistory of the country (Correal et al., 1969; Correal and van der Hammen, 1977; Hurt et al., 1977, 1972; van der Hammen, 1991).

The aim of this paper is to present and discuss the results of our revision of the El Abra historical lithic collections. Our review mostly deals with the: a) methodological approach adopted for the study of the lithic industry; b) interpretation of the lithic industry; c) chrono-stratigraphy.

Here we integrate and complete the revision of the lithic assemblages of the oldest levels of El Abra sites (Muttillo et al., 2017) with the analysis of those of the upper levels.

Our review revealed serious problems that affect not only the interpretation of the lithic assemblages but also the chronology of the site.