Re-dating the Lower Pecos Canyonlands SMM (Skiles) mummy burial, dating a red-colored deerskin strap
Description: An early 1980s University of Texas (UT) radiocarbon (¹⁴C) decay-based assay of colon contents from mummy SMM recovered from southwest Texas (41VV656) placed the death at 1150 ± 70 ¹⁴C years ago. This mummy of a “relatively tall, gracile adult male” was discussed in some detail in a comprehensive paper on Late Archaic mortuary […]
Non-destructive plasma-chemical extraction of carbon from organic artefacts
Description: Plasma oxidation for ¹⁴ C sampling utilizes low-pressure (133 Pa), low-energy (<50 W), and low- temperature (<50°C) Ar- and O 2 -plasmas generating CO 2 for AMS dating. O 2 -plasmas on empty chambers remove organic contamination. When clean, a new specimen is inserted and Ar-plasmas dislodge adsorbed atmospheric CO2 from surfaces. Finally, O […]
Extinct 244Pu: Chronology of Early Solar System Formation
Description: Early and recent work on Pu-Xe dating of achondrites (eucrites) is discussed here; the latter has focused on establishing the time of closure for Xe, not on the estimation of the time interval between the cessation of nucleosynthesis and the crystallization of solid bodies in our solar system. By using various Angra dos Reis […]
AMS Radiocarbon Ages of an Oxalate Accretion and Rock Paintings at Toca do Serrote da Bastiana, Brazil
Description: At the Toca do Serrote da Bastiana rock shelter in Brazil, a red, iron ochre pictograph of an anthropomorphic figure had become coated with a ‘calcite’ accretion over time. Using X-ray diffraction and Fourier transform infrared spectroscopy, we determined that the accretion also contains whewellite, the monohydrate of calcium oxalate, in addition to calcium […]
Radiocarbon dating of rock paintings using plasma-chemical extraction
Description: The use of plasma-chemical extraction in radiocarbon dating of rock paintings is discussed. Radiocarbon dating of rock art allows an inventory of images to be studied along with other cultural remains of a given archaeological time period. Assigning painted images to a particular prehistoric culture allows archaeologists to gain information on artistic, cultural, and […]
Group Problem-Solving versus Lecture in College-Level Quantitative Analysis: The Good, the Bad, and the Ugly
Description: The purpose of this semester-long study was to investigate the effect of replacing traditional lectures with cooperative group problem-solving sessions in a junior-level quantitative analysis course. The control and treatment groups had the same instructor, met on the same day, had the same reading assignments, and had common exams. The instructor worked on sample […]
Stable Isotope and Radiocarbon Analyses of a Black Deposit Associated with Pictographs at Little Lost River Cave, Idaho
Description: A glossy, black deposit covers much of the ceiling and walls of Little Lost River Cave No. 1, Idaho. This site is of particular interest because of the red, orange, and yellow pictographs underlying the coating. Carbon and nitrogen stable isotope analysis has allowed us to better understand the nature and origin of the […]
Comment on “some evidence of a date of first humans to arrive in Brazil”
Description: J Archaeol Sci reported extremely interesting dates on a calcite layer covering a pictograph at the Toca da Bastiana rock shelter within the Serra da Capivara National Park, Piaui, Brazil. Thermoluminescence and electron paramagnetic resonance ages indicate that humans were present in Brazil prior to 35 ky ago. We report radiocarbon dates for rock […]
Nondestructive Radiocarbon Dating: Naturally Mummified Infant Bundle from SW Texas
Description: Plasma oxidation was used to obtain radiocarbon dates on six different materials from a naturally mummified baby bundle from the Lower Pecos River region of southwest Texas. This bundle was selected because it was thought to represent a single event and would illustrate the accuracy and precision of the plasma oxidation method. Five of […]
AMS Dates from Four Late Prehistoric Period Rock Art Sites in West Central Montana
Description: In 2002, eight pigment samples were collected from three rock art sites in the Big Belt Mountains of west-central Montana. Samples from Hellgate Gulch (24BW9), Avalanche Mouth (24BW19), and the Gates of the Mountains (24LC27) were dated using plasma-chemical extraction and accelerator mass spectrometry. The dates were statistically indistinguishable with ages of 1170 ± […]
