Kathu Townlands is a high density Earlier Stone Age locality in the Northern Cape Province, South Africa. Here we present the first detailed information on this locality based on analysis of a sample of lithic material from excavations by P. Beaumont and field observations made in the course of fieldwork in 2013. The results confirm the remarkably high artefact density at Kathu Townlands and do not provide evidence consistent with high energy transport as a mechanism of site formation, suggesting that Kathu Townlands was the site of intensive exploitation of highly siliceous outcroppings of banded iron formation. The results presented here provide a first step towards understanding this complex locality and point to the need for further research and the importance of preserving this locality in the face of intensive and rapid development.

Competing interests: The 2013 field work was carried out under the auspices of the Archaeology Department, McGregor Museum, for PZK Beleggings, under the direction of Jaco Minnie of Leon Frank and Partners. Although some of this project was funded commercially, this does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials.

Funding: PZK Beleggings, under the direction of Jaco Minnie of Leon Frank and Partners, funded field work. Support was also provided by Canadian Social Sciences and Humanities Research Council Grant 410-2010-722. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. McGregor Museum, Kimberley is the repository for all collections described here as well as our data (inventory number 6512). Analysis can be arranged by permission from the McGregor Museum.

Copyright: © 2014 Walker et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Introduction

Early to Middle Pleistocene localities that incorporate extremely high numbers of lithic artefacts present a challenge to our understanding of early hominin behaviour. In some cases, such as Ma’ayan Baruch, Israel [1], the deposits are dominated by very large numbers of bifaces while other localities show characteristics consistent with quarrying or primary production [2], [3], [4], [5]. There are also localities with a more ambiguous character such as the site of Canteen Kopje, South Africa [6], [7] which includes high densities of both production debris and finished artefacts. Both the quarry sites and sites dominated by finished artefacts provide evidence of stone tool transport but these sites also raise questions about group size and organization of activity among early hominin groups. Here we present the first detailed description of a site located in the town of Kathu, Northern Cape Province, South Africa that shows high intensity of lithic production during the Earlier Stone Age (ESA). Kathu Townlands is a site situated between the Kuruman Hills to the east and the Langberge mountains to the west on a low hill and is covered with a dense surface of lithics interspersed with exposures of bedrock, calcrete, and sand (Figure 1–2).

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larger image TIFF original image Download: Figure 1. Location of Kathu Townlands. A. Location map within South Africa. B. Location Map with relation to the regional topography and Wonderwerk Cave. C. Topographic context of sites of the Kathu Complex discussed in this article. Grey shading indicates developed areas and areas undergoing development. Note that the boundaries of Kathu Pan are approximate and do not indicate the limit of areas of archaeological potential. https://doi.org/10.1371/journal.pone.0103436.g001

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larger image TIFF original image Download: Figure 2. Views of Kathu Townlads. A. Digital Elevation Model (DEM) showing the topographic context of Kathu Townlands. Square shows the approximate area shown in Figure 2b. (DEM courtesy of Stephen Wessels, The Zimani Project). B. Aerial photo of Kathu Townlands. White shading indicates approximate limits of the declared locality. Asterisk indicates location of 2013 excavations. Image dated 5/27/2011 predates recent development south of Frikkie Meyer St. Image source Terraserver. C. View of Towlands site north of Frikkie Meyer St. D. Detail showing scatter of artefacts on the surface of the site north of Frikkie Meyer St. https://doi.org/10.1371/journal.pone.0103436.g002

Dense and broadly distributed archaeological deposits pose methodological and management challenges. The town of Kathu is rapidly expanding and this development is directly threatening Kathu Townlands (Figure 1c). The site was designated a Grade 1 National Heritage site in 2013 however the threat to deposits beyond the declared area remain acute.

Geological Setting The bedrock lithology is Precambrian, with exposures of banded iron formation (BIF), which belong to the Kuruman Formation within the late Archean to earliest Paleoproterozoic Transvaal Supergroup [8], [9]. There is a wide degree of variability within the BIF in the Kuruman Formation both in terms of the scale of banding and the percentage of chert (SiO 2 ) relative to iron-rich minerals. The outcroppings at Kathu Townlands (sometimes designated as jaspellite) are dominated by chert and show no fine-scale banding. As a result the structure of these rocks is ideal for stone tool manufacture and it is likely that the availability of high quality raw material is a major reason for repeated exploitation of the resource and the high density of stone tool and knapping debris at Kathu Townlands. Circular white to grey fossil traces are characteristic of the raw material found at Kathu Townlands. Outcroppings of raw material with similar fossil traces have not been identified in the surrounding region. The Kuruman Hills are today drained by a series of ephemeral streams that flow northwest (Figure 1). None of these streams pass through the research area, the closest drainage is the Vermulsleegte, to the north of the site. There is evidence for far more substantial drainage systems at some point in the geological past in the area around Kathu. At the Bestwood site the archaeological horizon is underlain by at least ten meters of river gravels and similar deposits are known from other localities in the region, although no such deposits are known at Kathu Townlands. Calcretes are a common feature in the area around Kathu and figure significantly in the deposits in the vicinity of Kathu Townlands. Calcretes develop in arid or semi-arid environments as the result of lateral and vertical movement of carbonates in solution but the diagenetic process causing the development of these deposits can vary depending on local conditions [10]. At the Mamatwan Mine near Hotazel, a calcrete horizon approximately 2 meters thick produced optically stimulated luminescence ages of 113,000 and 108,000 years ago [11]. Without detailed analysis it is not possible to determine the age of the calcrete deposits at Kathu Townlands. A sand sheet, derived from the Kalahari, is found across the surface at Kathu Townlands and comprises the matrix within which most of the artefacts are found. As with calcretes, there were likely multiple cycles of sand accumulation in the Kathu area. Research at Wonderwerk Cave has demonstrated that Kalahari sands were blowing into this region by 2 million years ago [12] and it is likely that the sands at the base of Kathu Pan 1 are of such an early age. At the Bestwood 1 site, sands overlie the archaeological horizon and are thus of a younger age. At the Mamatwan Mine the Kalahari sands produced optically stimulated luminescence ages ranging from 62–44,000 years ago.

Archaeological Setting Kathu Townlands is a component of a grouping of ESA localities designated as the Kathu Complex. This complex also includes the excavated sites of Kathu Pan1 (KP1) and Bestwood 1 (BW 1, Figure 1c). At Kathu Pan, evidence of early hominin occupation has been observed at multiple locations within the pan, but ESA deposits have only been excavated at KP 1 [13]. Stratum 4a at KP1 is dated by a combination of OSL and ESR/U-series to ca. 500 k BP [13]. The lithic assemblage from St. 4a is characterized by a prepared core technology that produced both blades and points, and has been attributed to the Fauresmith industry [14], [15]. The lithic assemblage of the underlying St. 4b at Kathu Pan 1 is characterized by well-made handaxes. At BW 1, located to the east of Kathu Townlands in a valley between two small hills, mining of sand has revealed a horizon at the interface of gravels and the overlying sands that contains abundant lithic artefacts [16]. These are characterized by bifaces, blades, and prepared cores and are dispersed over a very large area. Excavation at BW1 in 2012 exposed a surface of 36 m2 with over 1000 piece plotted artefacts recovered. All artefacts were observed lying flat on at the interface between the sands and gravels. The extremely fresh condition of the lithic artefacts at Bestwood 1 argues against this accumulation being a palimpsest deposited over a long period, or as the result of deflation. The possibility that the concentration of artefacts in a single horizon is the result of bioturbation also seems unlikely [17]. The excavated area is apparently representative of an extensive occupation covering several hectares. Kathu Townlands is located approximate 56 km. west of Wonderwerk Cave where a sequence of ESA occupation has produced early evidence of fire [18], [19]. At Wonderwerk the ESA occupation is characterized by low artefact density in marked contrast to Kathu Townlands.