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2020-07-10 16:58:51   •   ID: 2187

Crossing the Strait of Gibraltar by early Humans?

Figure 1
Figure 1 shows a LCT-Cleaver made from from Quartzite and Figure 2 and 3 show two Acheulian Handaxes made from Quartzite and Basalt, found together in S-Spain / Iberian Peninsula in 1932, by F Sanchez, an Amateur collector of Stone Tools.

LCTs appears early in the East African Acheulian. At Konso (Ethipoia), the early Acheulean technology includes both large cutting tools (handaxes, cleavers, and knives) and heavy-duty tools (picks and core-axes) that are bifacially or unifacially worked appeared, radioisotopically dated, at 1,75 k.a.

Figure 4 shows a heavy Acheulian East African Clevaer from Olorgesailie- see: 1247

It has to be mentioned that the production of LTCs in Europe is a quasi unique feature of the Iberian Acheulian, compared to sites in N/W-Europe- where Cleavers are rare although not totally absent -see here: 2017 .

About Giant Cores and Large Cutting tools see here: 1003 and here 1173 .

Lets add a statement by G. Shanon, an expert in the definition and techno-typological evaluation of the LTC-penomenon:

"Acheulian industries in which the production of large flakes from giant cores was the primary technology for blank procurement are known from all parts of Africa, the Iberian Peninsula, the Levant (represented by only one site, GBY), the Caucasus, and as far as east India.

The other main indicator of these large- flake Acheulian industries is the presence of significant numbers of cleavers in their assemblages.

Figure 2
While it is impossible, in the current state of research, to define the chronological end of the large-flake Acheulian industries in Africa and India, it is evident that in the Levant none of the Acheulian sites that postdate GBY (at 790,000 years BP) can be classified as belonging to the large-flake Acheulian tradition.

The same chronological frame holds true for all Acheulian sites in Europe north of the Pyrenees. None of the sites in this region show evidence of the production of large flakes as their primary blank technology, nor are cleavers present in any significant numbers
(Sharon 2010).

Typically Iberian LCT ensembles, if absolute dates are available, belong to the Middle Pleistocene and are therefore much later, than the invention of this technique in Africa which already occured during the Early Pleistocene.

But the latest LCTs were still in use in Africa, and Arabia when they finally appeared in Iberia (for example at Casablanca and more important at Sidi Zin near Kef in north-western Tunisia- see 1578 . Unfortunately we have no absolute dates for the latter site.

LCTs are also a component of the South African Fauresmith Industry (400-200 k.a. BP) - see 2197 .

Of importance is the stratified Acheulean site at Saffaqah, situated in the Dawadmi region of the Nejd plateau, offering a very late Acheulian on the Arabian Peninsula with an abundance of LCTs dated to ca. 190 k.a. - currently the youngest documented Acheulean in Southwest Asia.

How should we interpret these facts?

  • as a convergence phenomenon in regions where large cobbles or blocks of suitable raw material were common?

  • as a longstanding tradition, beginning in Africa followed by a late technological transfer to Europe through one of the known Afro-European corridors?

Figure 3
One possible transcontinental connection between Eurasia and Africa is beside the Levantine corridor and the Bab al- Mandeb Strait, the The Strait of Gibraltar.

It is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Gibraltar and Peninsular Spain in Europe from Morocco in Africa.

Today the two continents are separated by 14.3 kilometers of ocean at the Strait's narrowest point.

The Strait's depth ranges between 300 and 900 meters which possibly interacted with the lower mean sea level during Pleistocene glacial conditions when the level of the sea is believed to have been lower by 110–180 meters.

Modeling a fall in sea level of about 150 meters indicates the emergence of several islands which would reduce the distance between Africa and Europe to 5+2 km.

During the early Pleistocene, Important falls in sea levels occurred at 2,4 and 1,6 mya. According to Robers (1992), the fall in sea level could have reached c 160m. Interestingly these two events coincided with faunal changes in Europe.

Figure 4
Other events occured during the Middle Pleistocene and during the last Glacial (especially during the LGM).

Here I discuss the hypothesis, that the production of LCTs was indeed not a convergence phenomenon but a longstanding tradition.

I my view there are some evidence that there was probably a technological transfer between N- Africa and Iberia via the Strait of Gibraltar during low sea levels.

This happened in analogy to the „island hopping“ of premodern humans to the island of Flores (Java), which was never connected with the Asian mainland. Notably, Human dispersal to Flores across a considerable marine barrier has been proven as early as 880 k.a. ago.

  • Geographically, Cleavers in possible corridors between the Near East / Arabia and Iberia are virtually absent

  • the specific and sophisticated chaine operatoire of cleavers virtually excludes a convergent evolution during different times and places

  • Beside LCT-Acheulian finds from middle Pleistocene terraces (+40−20 m) of the large Iberian rivers, dated between MIS 11 to MIS 7/6, at least one in-situ site with large accumulations of LCT is known from Spain and exhibits specific African signatures

This site is Porto Maior in the Galicia Province.

At this site lithic tool-bearing deposits date back to 293–205 k.a. Beside Handaxes, Flake Cleavers resembling their African counterparts both in large size, density of deposition and Typology almost exactly resemble their African Counterparts.

Most of the artifacts are in primary position and dated by several methods to 293–205 k.a. This dates are not only interesting regarding a possible African origin of he LCT ensemble, but also to the fact that an early Middle Paleolithic was also present in parts of Iberia at the same time-span.