Analysis of Hafted Dart Points: Dating and CT Scans
Six hafted dart points from the shrine deposit at Ceremonial Cave and another from a nearby site in New Mexico have been analyzed for stylistic and temporal information. Stylistic change in projectile point form has long been used for cross-dating by archaeologists, especially in North America. In order to construct calendar age ranges for different projectile point styles, chronometric dating methods have been applied to remains inferred to have been associated and contemporaneous. Radiocarbon dating, in particular, has been important in determining age ranges of chipped-stone points, but virtually all such dates are on organic remains that have only indirect and inferential association with projectile points.
Rarely are there projectile points that have unambiguous and direct association with datable organic material, but we report here the dating of four points still hafted in dart foreshafts. This approach is a methodologically sophisticated enhancement of traditional chronology building efforts, avoiding the inferential nature of virtually all assessments of association between projectile point form and dated event. AMS radiocarbon dates were obtained on either the shafts or on the sinew wrapping or seizing that secured the point in the foreshaft. However, in these cases, the seizing covered the stem portion of the chipped stone points such that their shape cannot be seen. For the AMS dates to be useful in defining the calendrical age of the point styles, therefore, the stem shape had to be determined. For this, we had high resolution X-ray computed tomography scans done of each, thereby providing a clear image of each point, the second critical bit of data in this study. The combination of projectile point form and chronometric age provides a unique opportunity to fine tune the dating of specific projectile point styles in the American Southwest.
Additionally, wooden artifact specialist Ken Brown of TARL examined several of the specimens, and we include here his observations on the construction of the darts and materials used. To him, the darts appear almost diminutive in size, compared to specimens from regions such as the Lower Pecos area of Texas, and this is presumably a result of local geology. The foreshafts are scaled to the size of the points, which are small due to the poor quality of local stone. Several of the darts have been impact-damaged and were converted to knives by "amputating," or shortening them, then blunting the proximal end of the foreshaft. All but one of the darts are hafted onto a hardwood foreshaft. The other dart (Specimen 6) is unusual, having been hafted directly onto a mainshaft made of lightweight flower stalk. As such, the dart may have had limited utilitarian value; rather, it may have been a ritual item, intended only as an offering.
Six of the analyzed hafted points may have found in the apparent shrine deposit at the entry to Ceremonial Cave; a seventh point (Specimen 7) is from Chavez Cave in nearby Dona Ana, New Mexico. Three of the specimens from Ceremonial Cave were recovered in 1926 or 1927. The exact circumstances of recovery are not known, but they were apparently part of a large deposit of artifacts that had been placed together near the mouth of the cave over a long period of time (The other four specimens were recovered in 1928 during excavations by the Peabody Museum, Harvard University).
The so-called shrine deposit at the mouth of Ceremonial Cave evidently included spear shafts, numerous foreshafts (most without the hafted points, some simply pointed wood), rabbit or fending sticks, marine shell and stone ornaments, tablitas, snares, pipes, reed cigarettes, basketry, and yucca stalks and other sticks with attached fiber bolls containing tobacco. Based on the array of different styles, it seems clear that this deposit accumulated over a period of many centuries, beginning at least by the beginning of the Common Era and continuing until perhaps A.D. 1000. Until the dating effort reported here, no chronometric dating has been attempted on any of the objects from Ceremonial Cave.
The numerous spear shafts and foreshafts in the deposit of objects at the front of the cave constitute one of the largest collections of such objects from the Southwest. It is not known if they were deposited as a group or incrementally, although the dating effort reported here represents the initiation of a larger program of dating the remains from Ceremonial Cave. As these results become available, they will be reported on this exhibit on Texas Beyond History. |
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