Geochronology of Sandia Cave

Abstract

of Sandia Cave. Smithsonian Contributions to Anthropology, number 32, 32 pages, 7 figures, 2 tables, 1986.-Excavations in Sandia Cave, New Mexico, in the late 1930s provided the first recognized stratigraphic evidence for a pre-Folsom culture in North America. This, the Sandia complex, is represented by diagnostic projectile points found in a loose deposit underlying a limonite ocher deposit which, in turn, underlies a cave breccia containing Folsom artifacts and reportedly sealed by an overlying dripstone. Our investigations in the 1960s revealed that the Sandia deposit (unit X) is in fact, a rodent deposit created by bioturbation of the limonite ocher (unit C) and contains material derived from most of the other deposits. A second dripstone (unit D) is recognized as being much older (preoccupation) than the post-Folsom dripstone, instead of being a contemporary facies as originally reported. Its absence from the deposits near the mouth of the cave is believed to be due to removal during the mining of the yellow ocher by Paleo-Indians. Paleoclimatic interpretations of the stratigraphic units include (1) a warm moist period for the derivation of the ocher by leaching from a pedalferic paleosol formed during a previous cool moist period, (2) desiccation of the ocher during a dry climate, (3) formation of the lower dripstone during a cool moist period, (4) gypsum precipitation (unit E) due to either a dry period or opening of the cave or both, and (5) accumulation of dust and debris (units F and H) under dry conditions alternating with dripstones (units G and I) and breccia cementation under wet conditions. From 14,000 B.P. on, the cave interior was accessible to man and animals. Accumulation of dust and debris (unit F) occurred during a dry period during which a portion of the lower dripstone was removed, presumably by Paleo-Indians in order to extract ocher. During the sbusequent moist period the artifact-bearing debris became cemented by cave drip where not protected by the lower dripstone. Under recent climatic conditions another loose debris layer (unit J) has accumulated during the middle and late Holocene and has always been connected to the lower loose-debris deposit (unit X). We conclude that Sandia points are definitely less than 14,000 years old and suggest they may be specialized Clovis or Folsom artifacts used for mining ocher. However, we cannot preclude a pre-Clovis age or even post-Folsom. Undisturbed cave strata provide valuable paleoenvironmental data, but redeposition and bioturbation is the rule rather than the exception for most, if not all, cave deposits that were once unconsolidated debris. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: North American Indian design of mounted horsemen on animal skin.

U-series Dating of Authigenic Gypsum and Anhydrite: A new Sample-Dissolution Technique Using Cation-Exchange Resin

“…Sandia-El is a sample of unknown age, but stratigraphically overlays a carbonate speleothem which is at isotopie equilibrium and underlies another speleothem dated at ca. 30 ka BP (unpublished data from this laboratory; see Haynes and Agogino [12], for stratigraphy). This sample has a uranium content of about 0.4 ppm (Table 1), probably more typical of natural samples available for U-series dating.…”

Sandia cave reconsidered

“…Perhaps, they were not included in the sample made available to Preston. Haynes and Agogino (1986) found that Hibben's Folsom zone actually consists of three units-a lower breccia (Unit F), an intermediate dripstone (Unit G), and an upper breccia (Unit H). They further speculate that the Sandia material may have originally been in Unit F (Haynes and Agogino, 1986: 25) before being transported downward into their Unit X.…”

“…Publication of their report was delayed until 1986, by which time the final three sections of the original manuscript had been revised (Haynes and Agogino, 1986: vii). Based on examination of remnants of strata adhering to the cave walls in the area of Hibben's most extensive excavations (from the cave mouth to meter 24), augmented by test pits between the largely intact meters 27 to 40 and additional examinations throughout the rest of the cave (Haynes and Agogino, 1986: 4), a revised stratigraphy was produced (shown here as Figure 3).…”

Taphonomic Analysis of the Mammalian Fauna from Sandia Cave, New Mexico, and the “Sandia Man” Controversy

“…107° 106° 105° 104° 103° It is a natural cavity 148 m long and 2 to 4 m wide that runs through the Madera limestone of Pennsylvanian age (Haynes and Agogino 1986;Kelley 1975). The cave is situated on a vertical cliff about 100 m above Las Huertas Creek and cannot be easily accessed today without the aid of a ladder.…”