Flint mining in prehistory recorded by in situ -produced cosmogenic ¹⁰ Be

Abstract

The development of mining to acquire the best raw materials for producing stone tools represents a breakthrough in human technological and intellectual development. We present a new approach to studying the history of flint mining, using in situproduced cosmogenic 10 Be concentrations. We show that the raw material used to manufacture flint artifacts Ϸ300,000 years old from Qesem Cave (Israel) was most likely surface-collected or obtained from shallow quarries, whereas artifacts of the same period from Tabun Cave (Israel) were made of flint originating from layers 2 or more meters deep, possibly mined or quarried by humans.T he first archaeological evidence of the use of stone tools dates to Ϸ2.5 million years ago (1). In prehistory, one of the most widely used raw materials was flint, a microcrystalline form of quartz. Because flint quality varies, the choice of raw materials for producing tools is important; flint mined from underground is generally more easily workable than surface-collected material, which is not always present in large quantities and usually weathered by atmospheric agents (2, 3). There are only a few reports of flint mining sites in the early Paleolithic, such as the Acheulian complex at Isampur (India) (Ϸ1.0 million years B.P.), ¶ ¶ the Lower-Middle Paleolithic in Mount Pua (Israel) (Ϸ200,000 B.P.) (5), and the Middle Paleolithic in Qena (Egypt) (Ϸ50,000 B.P.) (6). The approach presented in this article can be used to directly analyze flint artifacts from different stratigraphic layers in prehistoric caves, leading to information on the provenance of the raw material. We show that the analysis can determine whether the raw material originated from deep layers (1 m or more), possibly mined by humans. The application of this method will contribute to our understanding of the history of flint mining in different regions of the world and can be expanded to other raw materials. Be in Situ Production in Flint MineralsThe interaction of showers of high-energy primary and secondary cosmic ray particles with the atmosphere and shallow matter in the earth's crust produces a number of long-lived cosmogenic isotopes by nuclear reactions (7,8). The cosmogenic isotope in situ buildup in rocks has been extensively studied both theoretically and experimentally by accelerator mass spectrometry methods of analysis (ref. 9 and references therein). In situ cosmogenic production was shown to involve a complex balance between various geophysical processes and parameters: (i) altitude-and latitude-dependent cosmic-ray particle fluxes; (ii) proton and neutron absorption coefficients in the earth's crust (the mean attenuation length for spallation reactions in rocks is about ⌳ Ϸ 160 g͞cm 2 , and the average rock density is ϭ 3 g͞cm 3 ); (iii) the erosion rate of surface rocks; (iv) the burial history of rocks; and (v) the production rate by slow (stopping) and fast muons, penetrating particles produced as secondary particles in the shower caused by cosmic particles. The case of cosmogenic 10 Be (T 1/2 ϭ 1.5 milli...

Driving forces for the weathering and alteration of silica in the regolith: Implications for studies of prehistoric flint tools

“…Petro-archaeological studies of flints have difficulty in establishing a correlation between the artefact material and the potential sources of that material (Bressy, 2002;Briggs, 2001;Deflandre, 1935;Kars et al, 1990;Masson, 1981;Mauger, 1985;Sieveking et al, 1972;Valensi, 1957). Studies have been mostly on primary (in situ) and/or sub-primary sources, whereas gatherings of flints by prehistoric peoples were often probably made from secondary, redeposited materials such as glacial till and waterlaid gravels (Fernandes and Raynal, 2006;Hughes et al, 2010;Prothero, 1987, 1992;Stapert, 1976;Verri et al, 2004;Williams-Thorpe et al, 1999). Transformations of the flint cortex that can be identified from detailed petrographic studies are specific to some sedimentary environments (Fernandes, 2012;Fernandes et al, 2007).…”

Changing the Face of the Earth: Human Behavior at Sede Ilan, an Extensive Lower–Middle Paleolithic Quarry Site in Israel

“…The location of several Middle Pleistocene industrial areas and the study of cosmogenic isotopes in flints from the Tabun and Qesem caves indicated the existence of systematic, large scale, and long lasting human endeavors towards obtaining the stone they needed (e.g., Barkai et al 2002;Verri et al 2004Verri et al , 2005Barkai et al 2006).…”

“…Evidence for stone quarrying during the Early Pleistocene is still not widespread (e.g., Petraglia et al 1999;Paddayya et al 2000Paddayya et al , 2006, while Middle Pleistocene quarry sites are already part of the archeological landscape at many places (e.g., Barkai et al 2002, 2006, Sampson 2006. A new study of the cosmogenic isotope 10 Be in flint artifacts from Middle Pleistocene caves in Israel has confirmed the use of quarried stone as early as 400 kyr (Verri et al 2004(Verri et al , 2005 and recent field work has uncovered several Middle Pleistocene extensive quarry complexes in Northern Israel (Barkai et al 2002(Barkai et al , 2006.…”

Flint procurement strategies in the Late Lower Palaeolithic recorded by in situ produced cosmogenic 10Be in Tabun and Qesem Caves (Israel)

“…We recently developed a new approach for investigating procurement strategies of raw materials based on an in situ produced radioactive isotope of beryllium, 10 Be, in flint [21]. This approach takes advantage of the fact that 10 Be is produced inside rocks as a result of exposure to cosmic rays [12].…”