Still greater age is claimed for certain other objects of the Abilene area. Below the Elm Creek Silts lie the Durst Silts, which were laid down, Leighton thinks, prior to the last glaciation.[38] In connection with these silts Sayles found what may be very crude artifacts.[39] They are the “eoliths” that, wherever found in the Old World, are accepted or attacked as problematical evidences of man’s first attempts at roughly chipped artifacts. If these are indeed the work of man, and if Leighton is right, the men who made them must have come to Texas during the Sangamon Interglacial period preceding the last, or Wisconsin, glaciation—a matter of perhaps 70,000 years ago. Some authorities attack Leighton’s dating and therefore Sayles’s eoliths. The reported discovery later of Abilene and other points in the Durst Silts suggested to Kirk Bryan that the silts would have to be moved up in time.[40] He might have argued that the artifacts should be moved back, which would have been in line with his championing of very early man elsewhere. Agreeing with Bryan and C. C. Albritton, Frank C. Hibben redated the Durst Silts by connecting them with a late glacier in the Rocky Mountains rather than with the Wisconsin ice field of the north.[41] Leighton, on the other hand, maintained—and he has had some good support—that the soil at various depths had been radically changed by chemical action which would take tens of thousands of years. This “soil profile” theory as a test of geological age is gaining in importance.[42] Sandia—Older Than Folsom