Obsidian Hydration Research Articles

Obsidian hydration dating from SIMS H + profiling based on saturated surface (SS) layer using new software

Further development on the water diffusion dating of archaeological obsidian tools, based on Fick's law of diffusion, is presented. It involves (a) a reassessment of surface saturation layer location and (b) a novel in-house made MATLAB software with reference to the age sensitivity of the SS layer, and the propagation of errors. So far, 11 dates have been produced for archaeological obsidian tools over the World and the SIMS-SS ages with present software versus archaeological and mean radiocarbon ages were in excellent concordance.

Obsidian hydration: A new paleothermometer

The natural hydration of obsidian was first proposed as a dating technique for young geological and archaeological specimens by Friedman and Smith (1960), who noted that the thickness of the hydrated layer on obsidian artifacts increases with time. This approach is, however, sensitive to temperature and humidity under earth-surface conditions. This has made obsidian hydration dating more difficult, but potentially provides a unique tool for paleoclimatic reconstructions. In this paper we present the first successful application of this approach, based on combining laboratory-based experimental calibrations with archaeological samples from the Chalco site in the Basin of Mexico, dated using stratigraphically correlated 14 C results and measuring hydration depths by secondary ion mass spectrometry. The resultant data suggest, first, that this approach is viable, even given the existing uncertainties, and that a cooling trend occurred in the Basin of Mexico over the past 1450 yr, a result corroborated by other paleoclimatic data.

Long distance trinket trade: Early Bronze Age obsidian from the Negev

The discovery of three small obsidian flakes at the Camel Site in the central Negev, Israel, constitutes the first discovery of obsidian in Early Bronze Age contexts in the Negev and Sinai. Obsidian hydration analysis and X-ray microprobe analysis confirm the association of the artifacts with the site and the period, and indicate origins in Eastern Anatolia, in significant contrast to the exclusively Central Anatolian source of Southern PPNB obsidian. The structure of the obsidian trade system in the Early Bronze Age seems to contrast significantly with its Neolithic predecessor, and may be related to a system of pastoral nomadic exchange.

High Precision Measurement of Obsidian Hydration Layers on Artifacts from the Hopewell Site Using Secondary Ion Mass Spectrometry

Obsidian hydration dating has served as one of the chronological indicators for the Hopewell Culture earthworks (ca. 200 B.C.—A.D. 500) in central Ohio. This work presents new obsidian hydration dates developed from high precision hydration layer depth profiling using secondary ion mass spectrometry (SIMS). These data suggest that long-distance exchange in obsidian occurred throughout the Hopewell period.

DATING THE RISE AND FALL OF XUNANTUNICH, BELIZE

This article presents the chronological framework used to reconstruct the political history of the ancient Lowland Maya site of Xunantunich in the upper Belize River valley. Extensive excavations from 1991 to 1997 by the Xunantunich Archaeological Project produced the ceramic, architectural, and epigraphic data needed to place the site within a temporal context. Refinement of the Barton Ramie ceramic chronology was the first step toward clarifying the Xunantunich chronology. Seriation of well-known Spanish Lookout types and modes from stratified deposits established a framework for understanding Late and Terminal Classic assemblages. Twenty-two radiocarbon samples place these ceramic complexes in absolute time. Obsidian hydration and masonry techniques were found to be less reliable chronological markers. The results indicate that Xunantunich emerged as a regional center during the Samal (A.D. 600–670) and Hats' Chaak (A.D. 670–780) phases of the Late Classic period. Arguably, this rapid growth and florescence was initiated under the auspices of nearby Naranjo. Although the polity achieved political autonomy in the following Tsak' phase (A.D. 780–890) of the Terminal Classic period, civic construction diminished and rural populations declined until the site collapsed sometime during the late ninth or early tenth century.

Reasserting the Utility of Obsidian Hydration Dating: A Temperature-Dependent Empirical Approach to Practical Temporal Resolution with Archaeological Obsidians

In a recent paper in this journal, Anovitz et al. (1999) identify potentially serious flaws in the measurement and modelling of obsidian hydration for dating archaeological obsidians. This critique follows other recent papers highlighting potential problems with the method (e.g., Ridings, 1996; Stevenson, Mazer & Scheetz, 1998). Contrary to this latest critique, the current paper offers evidence for the apparent efficacy of a quadratic model for obsidian hydration dating of archaeological obsidians, using empirical results from archaeological projects throughout the western United States. It is posited that this model is sufficient, in part, due to limits of commonly used methods of hydration analysis, which also provide a cost-effective means for large-scale sampling. Given apparent support for quadratic modelling and, hence, the diffusion theory underlying it, an empirical approach to obsidian hydration rate formulation that incorporates field temperature data is explored. Although evaluation of the resulting rate formula for Casa Diablo obsidian is somewhat equivocal, the results are relatively robust when compared to other posited rates. As such, the approach appears to hold promise within the limits of temporal resolution necessary for many regional research strategies, while also serving as a potential check of laboratory-based strategies.

Infra-red Photoacoustic and Secondary Ion Mass Spectrometry Measurements of Obsidian Hydration Rims

A procedure has been developed for measuring obsidian hydration rim thicknesses on archaeological artefacts using infra-red photoacoustic spectroscopy (IR-PAS). Calibration of the IR-PAS values with depth was completed using secondary ion mass spectrometry (SIMS) and optical microscopy to relate the quantity of diffused water to the measured thickness of the hydration layer. By monitoring the absorbance intensity at 1630cm−1wavenumbers, hydration rims between approximately 1μm and 12μm may be accurately measured and used for chronometric age estimates. SIMS depth profiling has the ability to measure layers less than 1μm thick, extending the age calibration to samples of less than 100 years in age.

The Failure of Obsidian Hydration Dating: Sources, Implications, and New Directions

Obsidian hydration dating (OHD) originally promised to be a rapid, inexpensive, simple and reliable method for dating obsidian artefacts. The perceived elegance of OHD resulted in rapid acceptance and widespread application despite questions concerning its theoretical rigor. With increased usage it has become evident that, while economical, simple and fast, OHD is unreliable. Here results of a secondary ion mass spectrometry (SIMS) study of obsidian and synthetic glass artefacts are presented that explain why OHD has not lived up to expectations. The results suggest that the standard OHD equations are inappropriate and that traditional optical measurements are inherently flawed. Although significant refinement will be needed, the results suggest that both chronological and palaeoclimatic data might be obtained from glass hydration rims through an improved analytical methodology and more rigorous treatment of the data.

Recent developments in obsidian hydration dating

This paper presents recent experimental results from the obsidian hydration dating research programme conducted at the Centre for Archaeological Research (CAR), Auckland University. Two elements of the essential hydration rate component are examined. First, the influence of potentially significant environmental variables other than ambient temperature is explored. Our results demonstrate that environmental variables other than temperature may have a significant influence on hydration rate, though for many archaeological situations their influence is insignificant. Second, an alternative approach to estimating the exponential mean temperatures necessary for dating is presented. It is based on modelling the soil surface energy balance. A comparison with other prediction methods shows it to be a preferable approach. Finally, the results of a blind dating applications are presented. These show that the dating method can produce results which are both sensible and useful.

Archaeological obsidian studies: method and theory

Current Issues and Future Directions in Archaeological Volcanic Glass Studies: An Introduction M.S. Shackley. A Systematic Approach to Obsidian Source Characterization M.D. Glascock, et al. Mediterranean Islands and Multiple Flows: The Sources and Exploitation of Sardinian Obsidian R.H. Tykot. Intrasource Chemical Variability and Secondary Depositional Processes: Lessons from the American Southwest M.S. Shackley. Characterization of Archaeological Volcanic Glass from Oceania: The Utility of Three Techniques M.I. Weisler, D.A. Clague. Application of PIXE-PIGME to Archaeological Analysis of Changing Patterns of Obsidian Use in West New Britain, Papua New Guinea G.R. Summerhayes, et al. Factors Affecting the Energy-Dispersive X-Ray Fluorescence (EDXRF) Analysis of Archaeological Obsidian M.K. Davis, et al. Laboratory Obsidian Hydration Rates: Theory, Method, and Application C.M. Stevenson, et al. Obsidian Hydration Dating at a Recent Age Obsidian Mining Site in Papua, New Guinea W.R. Ambrose. Perspective in the 1990s on Method and Theory in Archaeological Volcanic Glass Studies R.C. Green. Index.

Chronology of the Later Stone Age and Food Production in East Africa

Evidence from several archaeological sites in sub-Saharan Africa suggests that the transition to modern human technology, marked by the change from the Middle to the Later Stone Age (LSA), occurred first in East Africa. Enkapune Ya Muto rockshelter, in the central Rift Valley of Kenya, contains the oldest known archaeological horizons spanning this transition. Radiocarbon and obsidian hydration dates from this 5·6-m deep cultural sequence show that the Later Stone Age began substantially earlier than 46,000 years ago. Ostrich eggshell beads were made 40,000 years ago. Early dates for the LSA and beads may have implications for the origin and dispersal of modern human behaviour and modern humans out of Africa.This site also contains the only known occurrences dating to the Middle Holocene dry phase in highland Kenya and Tanzania, as well as occurrences that span the transition from hunting and gathering to food production, and from the Neolithic to the Iron Age. The adoption of domestic animals by indigenous Eburran hunter–gatherers in highland East Africa occurred gradually between 4900 and 3300 uncorrected radiocarbon yearsBPand the Neolithic/Later Iron Age transition occurred around 1300BP.

Late Ceramics in Samoa: A Test Using Hydration‐Rim Measurements

Previous articleNext article No AccessLate Ceramics in Samoa: A Test Using Hydration‐Rim Measurements1Jeffrey T. Clark, Peter Sheppard, and Martin JonesJeffrey T. ClarkDepartment of Sociology and Anthropology, North Dakota State University, P.O. Box 5075, Fargo, N.D. 58104, U.S.A.Department of Anthropology, University of Auckland, Private Bag 92019, Auckland, New Zealand. 22 iv 97 Search for more articles by this author , Peter SheppardDepartment of Sociology and Anthropology, North Dakota State University, P.O. Box 5075, Fargo, N.D. 58104, U.S.A.Department of Anthropology, University of Auckland, Private Bag 92019, Auckland, New Zealand. 22 iv 97 Search for more articles by this author , and Martin JonesDepartment of Sociology and Anthropology, North Dakota State University, P.O. Box 5075, Fargo, N.D. 58104, U.S.A.Department of Anthropology, University of Auckland, Private Bag 92019, Auckland, New Zealand. 22 iv 97 Search for more articles by this author Department of Sociology and Anthropology, North Dakota State University, P.O. Box 5075, Fargo, N.D. 58104, U.S.A.Department of Anthropology, University of Auckland, Private Bag 92019, Auckland, New Zealand. 22 iv 97PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 38, Number 5December 1997 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/204680 Views: 7Total views on this site Citations: 5Citations are reported from Crossref © 1997 by The Wenner‐Gren Foundation for Anthropological Research. All rights reservedPDF download Crossref reports the following articles citing this article:Yuichi Nakazawa The significance of obsidian hydration dating in assessing the integrity of Holocene midden, Hokkaido, northern Japan, Quaternary International 397 (Mar 2016): 474–483.https://doi.org/10.1016/j.quaint.2015.01.029Frederic B. Pearl, William A. Sauck Geophysical and Geoarchaeological Investigations at Aganoa Beach, American Samoa: An Early Archaeological Site in Western Polynesia, Geoarchaeology 29, no.66 (Sep 2014): 462–476.https://doi.org/10.1002/gea.21491Suzanne L. Eckert, William D. James Investigating the production and distribution of plain ware pottery in the Samoan archipelago with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), Journal of Archaeological Science 38, no.99 (Sep 2011): 2155–2170.https://doi.org/10.1016/j.jas.2011.03.009Peter J. Sheppard OBSIDIAN HYDRATION DATING, (Jan 2008): 1695–1698.https://doi.org/10.1016/B978-012373962-9.00220-XHelene Martinsson-Wallin Samoan Archaeology-A Review of research history, Archaeology in Oceania 42, no.11 (Oct 2014): 1–36.https://doi.org/10.1002/j.1834-4453.2007.tb00008.x

Soil Temperature and Obsidian Hydration Dating: A Clarification of Variables Affecting Accuracy

The results of a year-long soil temperature monitoring programme are presented. They increase understanding of the magnitude, spatial scale and predictability of variation in soil temperature regimes which affect obsidian hydration dating. It is demonstrated that current archaeological temperature estimation methods, either due to design or application, do not provide temperature control at a spatial resolution fine enough to control for microregional variation. This failure is resulting in significant and avoidable dating errors.

Changing sources: early Lapita period obsidian in the Bismarck Archipelago

AbstractThis paper argues that obsidian movement in the Bismarck Archipelago at the start of the Lapita period shows continuity with earlier patterns and that changes in sources used occur later than the introduction of ceramics. We base our argument on the analysis of obsidian from two ceramic sites in the Duke of York Islands. The sites contain very differently decorated pottery, but both radiocarbon and obsidian hydration dating show they are very close in time, dating to around 3000 years ago. Density and PIXE‐PIGME analysis show that nearly all the obsidian from the putatively older site (SEE), containing ‘classic’ Lapita, came from West New Britain, mostly the Kutau/Bao sources. The possibly slightly later site (SDP), with very thin walled pottery decorated only by rim notching, was initially supplied exclusively from the Umrei source in the Admiralties, with a subsequent reversion to West New Britain. The first two stages in this history appear to be repeated in the similarly dated sequence from EKQ on Mussau Is.Pre‐Lapita data from New Ireland, Nissan and the Papua New Guinea mainland show an extensive distribution of obsidian, exclusively using West New Britain sources, while in the same period Admiralty obsidian has not been found beyond the Admiralties. Thus the use of West New Britain sources in the probably oldest Lapita levels in the Duke of Yorks and Mussau suggests continuity in obsidian distribution with the preceding period. Some other evidence of continuity is noted.

Technology as Context for Obsidian Hydration Studies

Anomalous obsidian hydration band width readings have plagued interpretive endeavors and have been used to question the general utility of obsidian hydration as a method for establishing relative chronologies. It is argued that many anomalous band width readings follow from a failure to establish context and, therefore, appropriate controls for sample selection. The results of recent techno-hydration studies indicate that numerous anomalies can be explained. A range of interpretive benefits from combining technological and hydration analyses are recognized.

Mortars, Pestles, and Division of Labor in Prehistoric California: A View from Big Sur

The mortar and pestle, technologically linked to intensive acorn economies, appeared initially in low frequencies over a large portion of California ca. 4000-3500 B.C. Three sites on the Big Sur coast of central California illuminate the circumstances surrounding the advent of this new technology, which initially supplemented hand stones and milling slabs. Excavation results suggest that ca. 3500 B.C. production of hunting-related flaked-stone tools increased relative to ground stone, and hunted resources became more important, as part of a transition from a highly mobile, selective use of the coastal resources, heavily focused on gathering, to a less mobile, more intensified lifeway. Obsidian hydration profiles indicate that interregional exchange increased at the same time. Evaluation of alternative mussel collection techniques further indicates that shellfish-harvesting strategies became less efficient at this juncture, promoting the emergence of a processing specialization, concomitant with increased hunting intensity. These transitions apparently mark the appearance of lineal descent organization and the system of gender-specific task appropriation observed at European contact.

Advances in the Hydration Dating of New Zealand Obsidian

Newly developed methods and calibrations for determining the age of flaked obsidian surfaces have been described and applied to New Zealand archaeological obsidians. Hydration bands were measured under high magnification (1000 ×) using a MOCHA imaging system to an accuracy of 0 ·2 μm. Hydration rates were calculated on the basis of obsidian water content as estimated from artefact density while effective hydration temperatures were established from published temperatures derived from thermal cells. Hydration dates have been compared with radiocarbon dates from six archaeological sites in the North Island of New Zealand. The obsidian age determinations correlated well with the radiocarbon dates from the same context. These results validated the ability of obsidian hydration dating procedures to provide accurate calendar year age estimates.

Dating Results From Excavations in Quarry Tunnels Behind the Pyramid of the Sun at Teotihuacan

AbstractIn this article we summarize the results of an ongoing project designed to study the tunnels and caves of Teotihuacan, emphasizing those findings derived from the excavation of four extraction tunnels located immediately to the east of the Pyramid of the Sun. In particular, we present radiocarbon and obsidian-hydration dates from the Cueva de las Varillas, where 13 Mazapan-phase burials were found and which has substantial evidence for a post-Teotihuacan occupation. In addition, the Cueva del Pirul has produced evidence of another 14 human burials, which were predominantly children, as well as complete dog skeletons, in a context clearly related to underworld symbolism. After the fall of Teotihuacan, these underground cavities excavated into tezontle continued to provide space for the practitioners of Tlaloc and fertility cult activities. In Aztec times, they were living spaces, and given the lack of space on the surface, this was a function that they served well into the twentieth century.

Where in the World Does Obsidian Hydration Dating Work?

Results of a field study at Pot Creek Pueblo indicate that when effective hydration temperature varies significantly with depth, errors in obsidian hydration age estimates can occur if hydration rate constants are extrapolated to depth-specific effective hydration temperatures. This problem will be particularly severe in continental climates, but will have some effect anywhere the amplitude of the annual surface temperature wave exceeds 2-3°C.

Mogollon Village Revisited: Recent Chronometric Results and Interpretations

ABSTRACTIn 1933 Emil Haury conducted excavations at Mogollon Village that began to establish the Mogollon as a distinct region and to develop the current phase sequence. Haury's tree-ring cutting dates document occupation at the site for roughly 160 years (a.d. 736 to 898). Recent chronometric dates from Mogollon Village, including archaeomagnetic, radiocarbon, and obsidian hydration, identify occupations prior to a.d. 700 and document structures that span a period between a.d. 120 and 898. The site may have been used as early as 400 b.c. We are aware of no other pit structure site in the region that has some level of use for over 1000 years and is not capped by Pueblo period use. This extensive occupational range provides a foundation for future investigations into settlement and subsistence in the region.