526 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1963 



Although an occasional isolated artifact of particular interest was 

 collected, the vast majority of material was taken from sites which, in 

 nearly all cases, appear to be localities of hmnan activity. In a few 

 instances, it is possible that the collected artifacts had been trans- 

 ported — probably no very great distance — ^by running water. The 

 sites can be grouped according to the morphological features upon 

 which they occur: On the plateau where artifacts are often fomid in 

 great abundance over considerable areas; on talus slopes where arti- 

 facts — presumably workshop and mining debris — are retained more 

 or less in place by the coarse, angular limestone cobbles; on benches 

 formed by the lower cliff- forming limestone; on the "flat" topped 

 si)urs; and on low-lying, terraced, alluvial remnants, gravel and 

 rubble spreads, and mounds of Cretaceous sediments. 



Sites on the upper plateau remnants (fig. 2-A). — A good quality 

 chert occurs at the top of some of these buttes and was very extensively 

 worked; the heaviest artifact concentrations are fomid on these 

 surfaces. In some cases, the artifacts are so abundant that they form 

 a solid pavement (pi. 1:2). At one such locality southwest of 

 Ghurfah, near the confluence of Wadi Jibb with the main wadi, a 

 crescent-shaped butte contains two areas of dense artifact concentra- 

 tion separated by some 200 metei-s of relatively sterile gromid. The 

 area covered by artifacts is rouglily 50,000 square meters. Within 

 this area, a 2-meter square was plotted at a randomly selected point 

 and 529 artifacts were collected from it. The majority of these 

 artifacts are small, relatively fresh, and characterized by a pink or 

 light reddish-brown patina. This is in sharp contrast to the larger 

 artifacts with dark brown-to-black glossy surfaces which are generally 

 found on the main plateau surface. A few of these larger, dark- 

 colored artifacts are, in fact, to be found on the upper plateau remnants 

 as well. This suggests that at a period much later than that of the 

 main human activity on the plateau, the isolated chert resources of 

 these old plateau remnants were exploited. 



Sites on the main plateau surface (fig. 2-B). — Because of the dif- 

 ficulty of gaining access to the plateau surface in certain areas, this 

 feature was investigated less intensively than those more easily reached 

 from the wadi floor. Access to the plateau is most readily gained 

 via certain tributary wadies which cut through the upper cliffs. 

 Such wadies are not abundant ; most of the small wadies cutting into 

 the plateau (see Caton Thompson and Gardner, 1939, plate 1) hang 

 well up on these cliffs (pi. 2:1). The fact that artifacts occur abun- 

 dantly around the upper portions of these access wadies suggests that 

 the same routes were available during Upper Pleistocene times (to 

 which the artifacts concerned must date) . At one locality near Tarim 

 where the plateau was reached by employing cliff-hanging tactics, arti- 

 facts were scattered over a wide area and found only occasionally. 



