Submitted by Sammy Smith (sammy@thesga.org)

The prehistoric tool called a hand axe is large, and has a sharpened edge all the way around it. The sharpening is on both sides, so it’s a biface. It is found in the Old World and not in the New World.

The Acheulean is a stone tool industry characterized by a particular style of tool-making. Acheulean-style tools are known from across Africa and much of West Asia, and date from approximately 1.65 million years ago to as recent as about 100,000 years ago. The earliest dates for Acheulean tools are from Kenya, in West Africa. The earliest dates for Acheulean artifacts and sites in Europe are much later than the African and Asian dates.

However, Gary R. Scott and Luis Gibert of the Berkeley Geochronology Center in California report paleomagnetic dates for two sites with Acheulean artifacts in southeast Spain are much earlier than previously known. A New York Times article by Henry Fountain dated 2 September 2009 reports that these researchers obtained dates of about 760,000 and 900,000 years old for the sites of Solano del Zamborino and Estrecho del Quípar, in Spain. Samples from the layers with the artifacts and those above and below the artifacts indicates that the artifacts date approximately to the time of the last geomagnetic reversal. That reversal has been dated to approximately 780,000 years ago.

Spain is, of course, on the Iberian Peninsula, which today is separated from northern Africa by the Strait of Gibraltar, a narrow body of water that is just under nine miles wide.

So, the question becomes: did the makers of Acheulean tools enter the Iberian Peninsula from the south—that is, from Africa directly—or from the east, following the northern Mediterranean coastline? Fountain writes:

“The question is, which route did they follow?” he said. Rather than coming through the Middle East and then westward, Dr. Gibert said he is convinced they came across at Gibraltar. “We think the Gibraltar straits were a permeable barrier,” he said. “It’s a provocative interpretation, but I think there is enough information to support it.”

What do you think?

NOTE: Scott and Gibert published their original report in Nature. The article is not free, but here’s the abstract:

Stone tools are durable reminders of the activities, skills and customs of early humans, and have distinctive morphologies that reflect the development of technological skills during the Pleistocene epoch. In Africa, large cutting tools (hand-axes and bifacial chopping tools) became part of Palaeolithic technology during the Early Pleistocene (1.5 Myr ago). However, in Europe this change had not been documented until the Middle Pleistocene (<0.5 Myr ago). Here we report dates for two western Mediterranean hand-axe sites that are nearly twice the age of the supposed earliest Acheulian in western Europe. Palaeomagnetic analysis of these two sites in southeastern Spain found reverse polarity magnetozones, showing that hand-axes were already in Europe as early as 0.9 Myr ago. This expanded antiquity for European hand-axe culture supports a wide geographic distribution of Palaeolithic bifacial technology outside of Africa during the Early Pleistocene.

Posted online on Wednesday, September 9th, 2009