Trihedrals in the Acheulian of Africa and Europe


This is an African trihedral quartzite pick hand-axe (16 cm long) exhibiting wind gloss and desert varnish, found in 1976 in the Grand Erg Oriental in Algeria by a Friend who has already passed away.

In Africa Acheulian stone tool assemblages are defined by the presence of the handaxe (or biface) and/or other large cutting tools (LCTs) such as cleavers, unifaces, or picks/trihedrals. In the absence of LCTs, an assemblage may still be identified as Acheulean by the presence of particular stone working techniques intended to produce large flake-blanks which are further knapped into LCTs. Among these techniques are the Victoria West, Kombewa, Talbalbal-Tachengit techniques.

Trihedrals in Africa seem to be more numerous during the older and early middle Pleistocene.  Many of these ensembles could be called either younger Oldowan or older Acheulian. The assemblages in Konso Gardula , Ethiopia were dated to 1.75 million years. The Nachukui Formation  is a geological deposit located on the western shore of Lake Turkana, northern Kenya, that includes archaeological sites dated to the earliest stone tool production in the world.  The KS4 ensemble, dated to 1.5 million years is characterized by the presence of pick-like tools with a trihedral or quadrangular section, unifacially or bifacially shaped crude hand-axes, and a few cores and flakes. At 1,5 million years ago, Trihedrals were also present in the Levant at Ubeidiya (Israel), situated on the edge of the western escarpment of the Jordan Rift Valley.


At Sidi Abderrahmane near Casablanca Thomas I quarry  unit L exhibits classical Trihedrals dated geochronologically  and by OSL to about 1  million years. Trihedrals were  still present during OIS 16 at the STIC Quarry (see a Trihedral from STIC from the classic Biberson Publication 1961 on the picture above). Here Handaxes were manufactured mainly on various quartzites available close to the site as pebbles of small to medium size and some blocks as well as a few flint nodules collected in a secondary position from beach deposits.

The site of Arkin 8, on the West margin of the Nile at the Sudanese-Egyptian border is undated. However, the character of the stone-tool industry, dominated by heavy duty tools, cordiform, ovate and lanceolate handaxes, as well as Trihedrals; tentatively aligns it with this early Middle Pleistocene group of sites. Similarly undated, early bifaces and trihedral pieces have recently been recorded for the Fazzan, Libya.

Sites of younger Middle Pleistocene age in Noth Africa and Egypt usually have no Trihedrals.  This hold true for the  younger localities at Sidi Abderrahman – Cap Chatelier, Grotte d’Ours, and Grotte des Littorines and sites in the Fayum depression (associated with the 40 m lake), the Wadi Midauwara in the Kharga depression, at Bir Tarfawi and Bir Sahara East. Geochronometric dating of the Acheulean deposits in the oases of the western desert suggest a minimum age of 350 k.a. while recent work on the geochronology of the fossil-spring tufas of the Kharga Oasis have provided U-series minimum ages of 300 k.a.

In Europe the presence / absence of Trihedrals seem to be not of much chronical value.  For example an  Acheulian with some Trihedrals is known all along the middle and lower Guadalquivir basin along the main river and several of its tributaries. The geostratigraphic sequence of the Guadalquivir depression is composed of 14 terraces, dated recently by U/Th and paleomagnetic determinations. Acheulian remains are especially concentrated on the middle terraces, dated not earlier than MIS 11. The most common raw material is quartzite and the local Acheulian is characterized by the presence of bifaces, often showing a trihedral concept, cleavers and tools made from medium and large flakes. A similar position of Trihedrals has been proposed for the Acheulian ensembles at the Manzanares at Madrid.

Trihedrals are part of the classic ensemble at La Micoque, layer N. The age of Layer N will possibly remain unknown. After the lower strata have been consistently  dated to a glacial circle at 250-300 k.a. BP, there is a possibility that they are much older than traditionally suggested ( Acheulian Trihedrals are part of the “Chalossien” of France, which has never been dated by modern techniques and are also frequent at some “Micoquian” ensembles of Germany (Bocksteinschmiede, Salzgitter Lebenstedt; ). These ensembles were part of the Keilmessergruppen, which are dated securely to the last glaciation.

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About Katzman

During my whole life I was fascinated by stone age artefacts. Not only the aesthetic qualities of these findings, but also the stories around them and the considerations arising from their discovery, are a part of my blog. Comments and contributions are allways welcome! About me: J.L. Katzman (Pseudonym). Born in Vienna. Left Austria in 1974 and did not regret. Studied Medicine and Prehistory at a German University. Member of a Medical Department at a German University. Copyright 2010-2017 by JLK. All Rights Reserved. You are welcome to use material in these posts so long as you cite the work.
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2 Responses to Trihedrals in the Acheulian of Africa and Europe

  1. gold price says:

    Additional sites in the region that show similar archaeological features and potentially early ages are Bori (on the river Kukdi) and Moregaon (on the river Karha) (both associated with volcanic ash beds) in the Bhima Basin of Maharashtra. The assemblage from Bori is dominated by trihedral handaxes and closely resembles Early Acheulian localities known from Africa and ‘Ubeidiya (Gaillard and Mishra, 2001). Although the initial dating at the site of Bori showed a controversial age of 1.4 myr (Korisettar et al., 1988), further work indicated that the artifacts here may be approximately 600 kyr old or younger (Mishra, 1994). However, the latest efforts by geologists have resulted in the correlation of the volcanic ash to the Youngest Toba Tephra (YTT), dated to be 75,000 years (Shane et al., 1995). However, Gaillard and Mishra (2001:82) state that the Acheulian assemblage at Bori is above the tephra and “represents the most convincing evidence that the correlation of the tephra with the Toba eruption, inspite of the chemical similarity, is erroneous”. The inconsistency and controversy of the Bori evidence indicates a need for further work at the locality and others like it. Acheulian bifaces from Moregaon (and adjoining areas) also possess an Early Acheulian character and also suggest a substantially early age (Kale et al., 1993; Mishra et al., 2002). Here, the artifacts occur on the surface of the regolith and are less closely associated with the tephra (than at Bori), which is at the top of a sequence of clays (Gaillard and Mishra, 2001).

  2. Jim Cleary says:

    Thanks for publishing the lovely colour photo. I have a very similar piece; it’s a little darker in colour, 10cm long, and has a more rounded end. I think it has wind-gloss and desert varnish, but I don’t know enough about those to be sure. I found it in the Great Sand Sea in the Western Desert of Egypt, about 475km West of Kharga.

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