This quartzite foliate biface dates to the Lupemban industry, ca. 12,000-40,000 BP.  The biface was collected by a missionary working in the Congo Basin, Central Africa.

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The quartzite foliate biface in this model was collected by the missionary Leon Emmert of the American Baptist Foreign Mission Society, who served in the Congo Basin from 1956-1989 in Kimpese, Nsona Mpangu, Moanza, Kinshasa, and Matadi.  Based on the biface’s size and shape, it likely dates to the Lupemban period.  Some archaeologists have proposed that Lupemban foliate bifaces functioned as woodworking tools, and this biface  may be a ‘core axe’.  Core axes were likely hafted onto handles and used as small hatchets or adzes.  This biface was made by hard-hammer percussion flaking from fine-grained quartzite (silcrete) sourced from the Kalahari Duricrust.  It is a ‘Stage 3’ biface because the flake scars extend to about the centreline, a flaking strategy known by ‘primary thinning’.  In primary flaking, the biface grows narrow at about the same rate as it becomes thin, resulting in a biface with a thick lenticular cross section.  Stage 4 ‘secondary thinning’ involves preparing platforms so that the flakes propagate beyond the centreline, thinning the biface and creating a flatter cross section.  Some Lupemban points are made on Stage 4 bifaces.

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The Sangoan industry overlies the Acheulean industry at Kalambo Falls, Tanzania, and dates to after ca. 250,000 BP.  It is characterised by thick bifacial ‘core axes’, choppers, and large scraping tools, although most of the assemblages are composed of small retouched flakes.  Use-wear studies have demonstrated that Sangoan core axes from Saï Island in northern Sudan, dating between 180,000-220,000 BP, were hafted onto handles.  This contrasts with the handaxes of the preceding Acheulean, which were hand-held tools.  Hafting was a significant technological breakthrough by the hominin toolmaker, either anatomically modern Homo sapiens or an archaic cousin species in the genus Homo.  The Lupemban industry is traditionally thought to have evolved from the Sangoan industry, but some Lupemban assemblages are very similar to and contemporaneous with Sangoan assemblages, prompting some archaeologists to lump this transitional period into a combined Sangoan-Lupemban.  The Lupemban is considered the first Middle Stone Age industry in Central Africa because the toolkit includes prepared Levallois-like cores and tools made on the flakes struck from them.  Lupemban assemblages also include a variety of elongated foliate (‘leaf-shaped’) bifaces, include core-axes that were probably hafted.  Most distinctive, however, is the emergence of long, well-made Lupemban points—well-made foliate bifaces that were probably used to arm spears.

The Lupemban may be equally as old as the Sangoan, perhaps appearing as early as ca. 266,000 BP at the site of Twin Rivers in Zambia, but the earliest age of the Lupemban in the Congo Basin is ca. 40,000 BP.  Microlithic technologies with backed microliths and barbed arrowheads appear in the subsequent Tshitolian industry, and are usually considered a manifestation of the Late Stone Age.  However, assemblages dominated by microliths are contemporaneous with biface-dominated Lupemban assemblages, and both date prior to ca. 20,000 BP in Central Africa.  Lupemban assemblages persist in the region until at least 12,000 BP in the Congo Basin.  Early interpretations were that the Lupemban toolkit was adapted to woodworking in closed forest environments, and microlith technologies were used for hunting in mosaic forest/savannah environments, but those environmental correlations have not been supported by more recent analyses.  Bifaces disappear almost entirely from later Tshitolian microlith assemblages prior to the advent of the Iron Age ca. 2000 BP.