Friday, May 15, 2009

Drills

Above images: Drills or Perforators

Flint drills or perforators are a common type of artifact that is found throughout all sections of Oklahoma. They are made from a silicious material such as flint or chert and vary considerably in size and form. There is much variation in size and they range from about 20 mm to 150 mm. Most examples, however, fall between 40 mm and 80 mm. They are all characterized by a slender, pencil-shaped section representing the point and shaft of the drill. The base or mounting portion is subject to considerable variation. Projectile points were sometimes reshaped to provide drill-shaped points and some items classed as drills were certainly used as projectile points. Hodge (1907:90) illustrated a human skull found in a mound in Illinois with a drill imbedded in the temporal area. Generally, however, these artifacts were used as drills or perforators for various kinds of material -- skins, leather, wood, shell, bone, and stone. Specimens that have been used for drilling or perforating stone, as in perforating a stone pendant or drilling a pipe stem, will display smoothed areas on the sides of the tip or drill shaft. Most of the specimens used for this purpose were mounted in a wooden shaft which served as a spindle for a bow drill or similar implement. In drilling stone such as slate, the drill point becomes damaged and worn from the drilling pressure and must be resharpened from time to time to serve efficiently; consequently, it becomes shorter and shorter with usage. Many drills or perforators were probably mounted in a short wooden handle and served as an awl or perforating tool for softer materials. Many specimens, of course, could be hand-held and would serve satisfactorily without the need for any mounting.

The typology of stone drills is not well developed and few terms are used in the same way by different writers. One rather common term in use is the "pin" drill which has no special shaped base section (Figure 5a). Another useful term is the T-shaped drill which has a T-shaped base to facilitate handling or mounting (Figure 5b). Another type, termed by Orr (1946) the ensiform drill, after its shape, is commonly considered to be a stone pipe drill (Figure 5g). Other variations in the stem or bases are illustrated in Figure 5. Perforations made with stone drills are usually conical in cross section and display concentric rings or striations along the bore produced by irregularities of the drill shaft (Figure 5d). Most perforations made in stone were made by drilling from both sides of the object, resulting in an hourglass shaped cross section. Frequently, the maker's judgment was off when drilling from both sides and the two cones from the drilling process are slightly offset making an irregular perforation.

Stone drills appear to be represented in about all of the archaeological assemblages found in Oklahoma. They are most plentiful in the eastern section of the state associated with the Archaic or Woodland periods. Although present in later time periods as well as in the Plains Villages, most of the latter drills tend to be smaller in size and of less sturdy construction.


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