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Continued Interdisciplinary Research at the Water Canyon Paleoindian Site (LA 134764), Socorro County, New Mexico - Interim Report for the 2010 Field Season and Data Recovery Plan for the 2012 Season
Abstract
This report provides descriptions of the interdisciplinary
research efforts completed during the
2010 field session at the Water Canyon Paleoindian
Site (LA 134764) and a review of the previous
research undertaken at the site, discussions of the
2010 manual and mechanical excavation methods
in the field, and discussions and tabulations of the
samples recovered. The classes of samples recovered
and analyzed and presented in this report
include chronometrics (charcoal, bulk soil, bone,
OSL), bulk sediment for macrobotanical, pollen,
flaked stone artifacts, faunal remains, bovine
blood residue, and other auxiliary cultural materials.
The results of X-ray fluorescence analyses
of obsidian artifacts recovered in 2010 are not yet
available. Finally, there are interpretations of recent
findings in terms of both our understanding
of the site itself and of broader research questions.
ResearchGate has not been able to resolve any citations for this publication.
A late Pleistocene (Rancholabrean) fossil site containing partial to nearly complete articulated skeletons of large mammals preserved in fissure deposits was discovered in 2005 at the White Mesa mine near San Ysidro in Sandoval County, north-central New Mexico. The fissures are in gypsum of the Jurassic Todilto Formation. Structural analysis suggests the fissures opened to the surface during the Pleistocene in response to extension associated with the Rio Grande rift. Bones were found approximately 9-12 m (30-40 ft) below the modern land surface in three different fissures within approximately a 15-m (∼50-ft) radius. Four species of large mammals are preserved in the fissures, each known from at least one partial to nearly complete skeleton: stilt-legged horse (Equus cf. E. francisci), camel (Camelops hesternus), extinct bison (Bison antiquus), and mule deer (Odocoileus hemionus). The most fossiliferous fissure, containing one skeleton each of a camel and a bison, was 18 cm (7 in) wide and contained bones over a depth of approximately 40-50 cm (15-20 in) and a length of approximately 3.5-4 m (11-13 ft). The camel consists of a partial skeleton of a very old individual of Camelops hesternus with heavily worn teeth and evidence of osteoarthritis on the articular surfaces of several limb bones and toes. The bison is a nearly complete articulated skeleton of a juvenile Bison antiquus with deciduous premolars, unerupted third molars, and unfused epiphyses on all limb bones. A second nearby fissure contained an articulated front limb of an advanced juvenile or young adult Equus cf. E. francisci and an articulated hind limb of a second adult Camelops hesternus. A third fissure had a nearly complete skeleton of a young adult female Odocoileus hemionus. The White Mesa mine differs from most New Mexico Pleistocene cave faunas in the predominance of articulated skeletons and the rarity of small vertebrates, although a partial skeleton of the pocket gopher Thomomys talpoides was found in the same fissure that produced the deer skeleton. An AMS radiocarbon date on a Camelops metacarpal from the White Mesa mine yielded an age of 12,910 ± 60 14C yrs B.P. The predominance of grazing ungulates in the fissures, including horse, camel, and bison, suggests that the habitat in the vicinity during the late Pleistocene consisted of a grassland. The following is a hypothetical sequence of events that led to the preservation of partial to nearly complete skeletons of large Pleistocene mammals in very narrow fissures that were not wide enough to accommodate the living (or recently dead) animals. The fissures were open to the surface in the late Pleistocene and acted as natural traps into which the animals inadvertently fell. The fissures were wider near the surface and narrower at depth. The animals either died from falling into the fissures or were unable to climb out and starved to death. The articulated condition of the skeletons and the lack of bite marks on the bones suggest the fissures were inaccessible to predators or scavengers that would have damaged and disassociated the carcasses. The bodies of the ungulates began to decompose in the wider portion of the fissures nearer the surface. Finally, the mostly decomposed skeletons still held together by connective tissues fell and became lodged in the lower and narrower portion of the fissures where they were eventually discovered.
Early Holocene cultural material at Gerstle River, central Alaska, provides excellent contextual controls for examining variability in radiocarbon dating. Over 4,000 bone and teeth fragments are directly associated with over 7,000 lithic artifacts and 10 discrete charcoal-rich hearths
in a thin occupation layer (~10 cm vertical thickness) within well-stratified loess deposits. Radiocarbon dating of the hearth features indicates overlapping ages at 2σ, suggesting contemporaneity. This study uses the high level of resolution at Gerstle River to evaluate systematic radiocarbon
variation due to different materials (collagen and charcoal), different pretreatments of collagen (regular and ultrafiltered), and interlaboratory variation through paired bone and hearth charcoal dates, split samples, and cross-checks. Accurately dating bone collagen is important given the
closer association of dated samples with human activities (e.g., butchering) compared with charcoal fragments in certain contexts (e.g., driftwood, paleosols, or alluvial deposits). This study demonstrates the efficacy of bone collagen dating with ultrafiltration to counter potential site-specific
contamination. These results also indicate that even in high-resolution situations with little evidence for old-wood effect and contamination, considerable variability can exist among cross-check and even split samples from single pieces of charcoal from short-lived species.
Stratigraphic relations, lithofacies, and radiocarbon chronology of deposits that accumulated in and around the margins of late Pleistocene Lake Otero in south-central New Mexico provide evidence for the timing and relative magnitude of episodes of lake expansion that occurred in the basin during the last ice age. The lower few meters of stratified sediment in exposures along the margins of the wind-deflated floor of Tularosa Basin contain gypsiferous lithofacies, sedimentary structures, and fossils indicating deposition along the margins of a shallow saline lake. Radiocarbon dates indicate that these basal nearshore lake deposits accumulated from about 45,000-28,000 14C yrS B.P. A widespread erosional episode removed at least 2 m of lake-margin deposits between 28,000 and 25,000 14C yrs B.P. Lake-beds overlying the erosional unconformity contain a relative abundance of siliciclastic sediment and aquatic fossil organisms suggesting repeated episodes of increased precipitation, surface runoff, and freshening of the lake system. These inferred episodes of increased precipitation and enhanced fluvial activity in the basin began ca. 24,500 14C yrs B.P. and lasted for at least 9 millennia. High-stands of the lake during this period appear to have reached an elevation of ∼ 1,204 m. Details of the history of Lake Otero after 15,500 14C yrs B.P. remain sketchy due to wind deflation of the basin floor and wholesale removal of lacustrine deposits during the Holocene. The evidence from Lake Otero for the onset of maximum pluvial conditions during the late Pleistocene appears to be in good temporal agreement with lacustrine reconstructions from neighboring lake basins to the north and south. Additional study of the deposits associated with Lake Otero, including their abundant and diverse assemblages of aquatic fossil organisms, is clearly warranted.
Several genera and species are in the literature for morphologically similar algal cysts which should be assigned to Pseudoschizaea Thiergart and Frantz ex R. Potonié. Numerous specimens of these cysts were recovered from Pleistocene deposits in Alabama and provided an opportunity to re-examine their morphology and to comment to their nomenclature.
Immunological and microwear analysis was performed on 100 chipped-stone artifacts from four prehistoric sites located in the Virginia Piedmont. A total of 20 artifacts returned positive results for immunological analysis and 16 artifacts returned microwear results. The findings indicate the negative effects of postdepositional processes and the potential utility of the techniques for deciphering prehistoric activities, otherwise unavailable by conventional studies in piedmont contexts. The study further illustrates the value and problems associated with immunological and microwear analyses on chipped-stone assemblages.
Ethnographic accounts of animal pulverization using stone grinding implements have led archaeologists to believe that this same behavior took place in the past. This important subsistence activity can now be confirmed through the immunological analysis of archaeological materials. Small-mammal blood-protein residue has been identified immunologically for the first time on milling equipment from two archaeological sites in southern California. Immunoprotein trace analysis has the potential for a wide range of applications in the study of prehistory.
A hypothesized extraterrestrial impact in North America at ∼12,900 calendar years BP (12.9 ka) has been proposed as the cause of Younger Dryas climate changes, terminal Pleistocene mammalian extinctions, and a supposed “termination” of the Clovis archaeological culture. In regard to the latter, however, an examination of archaeological, geochronological, and stratigraphic evidence fails to provide evidence of a demographic collapse of post-Clovis human populations, especially where the Clovis and post-Clovis site records are reasonably well constrained chronologically. Although few Clovis sites contain evidence of an immediate post-Clovis occupation, interpreting that absence as population collapse is problematic because the great majority of Paleoindian sites also lack immediately succeeding occupations. Where multiple occupations do occur, stratigraphic hiatuses between them are readily explained by geomorphic processes. Furthermore, calibrated radiocarbon ages demonstrate continuous occupation across the time of the purported “Younger Dryas event.” And, finally, the relatively few sites purported to provide direct evidence of the 12.9-ka impact are not well constrained to that time. Whether or not the proposed extraterrestrial impact occurred is matter for empirical testing in the geological record. Insofar as concerns the archaeological record, an extraterrestrial impact is an unnecessary solution for an archaeological problem that does not exist.
The Berino paleosol is the first record of a directly dated Aridisol in the American Southwest where paleoclimatic conditions during the time of pedogenesis can be estimated. The noncalcic, argillic paleosol formed in eolian sand during the cool, wet climate of the mid- and late Wisconsin, marine isotope stages 3 and 2, in presently semiarid southeastern New Mexico. Optically stimulated luminescence dating of the Mescalero sand sheet and the Berino indicates that soil formation occurred during the period 50–18 ka. The paleosol is a red 2.5YR hue Bt horizon, 120 cm thick, with 25% clay, 0.36% Fe, and an absence of visible carbonate. It is buried by younger eolian sand, although at the edges of the sand sheet, it is unburied and a relict soil. Red argillic paleosols in other sand sheets in the region may correlate with the Berino. The Berino paleosol is formally named as a pedostratigraphic unit.