Number 14

International Association of Obsidian StudiesBulletin

Fall 1995

Bulinca Adlmu:: Oepanmem oi AnthtqlOloc,San Ja-: Stzte Uni...:niry. SaD J(Mt,

CAlifumia, 95191-011)

CONTENTS

· News and Information I· Article: lAOS World Wide Web Site

Update 3· Technotes 4· Abstracts and Annotations of Repons

and Publications 7· Meetings and Events 13· Call for Articles 14

NEWS AND INFORMATION

THE lAOS ANNUAL MEETING

The seventh annual meeting of the lAOSwas held at the Minneapolis Hilton andTowers in Minneapolis on Friday, May 5,1995, in conjunction with the 60th annualmeeting of the Society for AmericanArchaeology. Of 14 attenders present atthe lAOS meeting, 10 were alreadymembers and the four remainingindividuals expressed an interest in futuremembership. The lAOS member whocame from the greatest distance was Dr.Yaroslav Kuzmin from the Pacific Instituteof Geography in Vladivostok, Far EasternRussia.

I

The meeting was called to order by theincoming President (Michael Glascock).He reported on the accomplishments of thelAOS, during the term of outgoingPresident Kim Tremaine (i.e., April 1994through April 1995), which includedpublication of three lAOS Bulletins, anincrease in membership from 99 to lIS,and an modest increase in the lAOStreasury balance from $2501.89 in April1994 to $2905.63 in May 1995. Insummary, the current lAOS membershipconsists of 99 persons from the USA, twofrom Mexico, two from Russia, two fromNew Zealand, four from Australia, twofrom France, two from Greece, one fromIsrael, and one from Japan.

Results from the recent election forPresident-elect were reported with TomJackson being elected. Jackson's one-yearterm as the lAOS President will begin inApril 1996.

The proposed changes to the lAOS By­laws which Steve Shackley and othersworked on during the past year were read.It was announced that the complete By­laws, with changes noted, will be printedin the Fall 1995 lAOS Bulletin along witha ballot for member to vote their approvalor rejection the proposed changes (seeinsert with this bulletin). All ballots mustbe received by the Secretary-Treasurer onor before December 1, 1995 in order to becounted. The ballot will also include aplace to nominate candidates for the next

lAOS BULLETIN No. 14

election of lAOS officers to take placeearly in 1996. The positions are theSecretary-Treasurer for a two-year termbeginning in April 1996 and President­elect who later becomes lAOS Presidentfor one year beginning in April 1997.

Glascock expressed his goal that threenewsletters be published during the nextyear. Tentative plans are October 1995,January 19%, and April 1996. Thenewsletter editor (Blossom Harnusek) needshelp from the membership in terms of bothtimely and quality contributions submittedon diskette (using WordPerfect orMicrosoft Word) several weeks ahead ofthe printing date if we are to meet this goal(The next deadline for newslettersubmission is December 15, 1995).

Glascock mentioned the ongoing effort tocreate a descriptive data base (names,locations, archaeological significance,pertinent literature, etc.) on obsidiansources world wide. The eventual goal isto make the data base available to all lAOSmembers via diskette and/or Internet.Glascock is compiling information onsources in the western hemisphere; RogerBird is compiling information on sourcesin the South Pacific and eastern Asia.Thus far, Glascock has received extensiveinformation concerning approximately 200sources from both Fred Nelson and CraigSkinner. Help is needed in other regions.George Rapp (a visitor who expressed aninterest in joining the lAOS) offered tocompile information on sources in Turkeyneighboring areas in the Near East.Robert Tykot offered to compileinformation on sources in both theMediterranean and Europe. Potential

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contributors are encouraged to providetheir information to one of the abovenamed individuals.

The lAOS meeting concluded with a briefdescription of the Hitachi Model U-6000Microscopic Fourier-TransformSpectrophotometer by ChristopherStevenson who explained the potential ofthis instrument for non-destructivemeasurement of hydrated layers on thesurface of obsidian. The Hitachiinstrument includes an interference detectorinstead of a conventional grating moduleenabling rapid measurement of hydrationrims with a reproducibility of 0.02microns. An article published in HitachiScientific Instrument News, volume 35,1992, No. 3 explains the application ingreater detail.

The next lAOS meeting will take placeduring the SAA meeting in New Orleansfrom April 10-14, 1996.

GREETINGS FROM THE PRESIDENT

The President's gavel has been transferredfrom Kim Tremaine to me (MichaelGlascock), and I humbly follow in thefoot-steps of my able predecessors (Le.,Chris Stevenson, Craig Skinner, TomOriger, Steve Shackley, and KimTremaine). Each did an outstanding job inestablishing the lAOS and helping it togrow into a truly internationalorganization. On the other hand, ourcurrent membership of slightly more than100 is still predominantly US-based, and itis one of my goals to encourage more ofour international colleagues to join the

lAOS BULLETIN No. 14

lAOS. I regularly correspond/collaboratewith a number of people in other countries(many of whom are not yet lAOSmembers) and I'm sure that many othersof you are doing the same. I want toencourage you to mention the lAOS toyour foreign colleagues, and I am hopefulthat such recruitment efforts will bearfruit. If any members or non-membershave something that they think the lAOScould do for them that we are not doingalready, please feel free to write to me orone of the other officers. We will enjoyhearing from you.

In this lAOS Bulletin you will find alisting of the lAOS By-laws with proposedchanges. Steve Shackley and othersworked on this for a couple of years, andit is now time to vote your approval orrejection regarding these changes. A ballothas been enclosed which must be returnedto Viviana Bellifemine before December I,1995. You are also invited to mentionnames of possible candidates for the Spring1996 Election on the same ballot.

A final topic which I want to remindmembers concerns my efforts to create adescriptive database for obsidian sourcesworld-wide. The world-wide sourcesdatabase will offer members the ability tosearch listings of source names, sourcelocations, names of persons who haveaccess to source samples, archaeologicalsignificance of individual sources, andliterature pertinent to each source. Oncecompleted, the database will be madeavailable via diskette or Internet.

Thus far, I have accumulated informationfor -200 sources in the western hemisphere

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which one of my students is busilyentering into the database. There aremany sources for which we still lackinformation and 1 would appreciate anyassistance that members are able to offer tomake this effort successful. You canexpect to read more about this effort in thenext lAOS Bulletin.

lAOS WORLD WIDE WEB SITEUPDATE: Obsidian Studies on the

Information Highway

by Craig E. Skinner

Biosystems Analysis, Inc., Obsidian StudiesLaboratory Internet: skinncr@peak.orghttp://www.peak.orgrskinncr/ces4_0.html

As promised in the last issue of the lAOSBulletin, the lAOS World Wide Web siteis now up and running, albeit in veryrugged (sneak preview) form. The sitewent online in September at the URL(uniform resource locator):http://www.peak. org/iaos!obsidian. htm!.

At this point, I'm leaking the site'sexistence only to lAOS Bulletin readers andWeb surfers who happen to stumble ontothe link from my home page. Once thingsare more complete at the site, I willannounce its existence to the greaterarchaeological community and will addlinks from major archaeological Web sitessuch as the University of Missouri'sArchNet(http://spirit.lib. uconn.edu/ArchNet/Museums!Archeom. html).

lAOS BULLETIN No. 14

The lAOS Web site currently lives atpeak.org in the basement of the ComputerScience department on the campus ofOregon State University (Corvallis,Oregon). Peak has generously donated7MB of space on their Unix Web serverfor the lAOS to do with what we will.

The general structure of the site looks likethis:

1. Home Page:The main starting point forthe start.

2. AboUl the lAOS:A brief history anddescription, membershipinformation, how to join,who's who, and so on.

3. News, Projects, and Announcements:Annual Meetinginformation, availability ofthe lAOS ObsidianBibliography disk and book,hot new research projects,upcoming events, and so on.

4. lAOS Bulletin:Back issues of the lAOSBulletin converted to Webreadable (HTML) formal.

5. Obsidian-Related Resources:This is the core section andthe one that will take thelongest to complete, even inrudimentary form. Includedhere are (or will be)obsidian studies laboratorysummaries, bibliographic

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references, full-text articles,obsidian source lists anddescriptions, obsidian studiesdatabases, images,information files, andassorted other referencematerials.

6. Internet Resources:Links to any obsidian-relatedinformation that I'vemanaged to locate elsewhereon the Internet. Alsoincluded here are pointers toInternet sites with anemphasis in thearchaeological sciences anda number of other categoriesthat may be of interest toarchaeologists.

The resources organized and referenced atthe lAOS Web site are actually distributedon several different computers at severaldifferent physical locations. Because ofthe interconnectedness and wide reach ofthe Internet and the architecture of theWorld Wide Web, different Web pagesand resources can be placed at any locationon the Net.

Thanks to this distributed resourcecapability, the lAOS Bulletin will live atJeff Hamilton's Web site athttp://www.ohas.com. Jeff has begun thesomewhat thankless job of converting thepast printed bulletins to their electronicHTML (hypertext markup language)counterparts. Other resources, includingthe lAOS Obsidian Bibliography, links toother obsidian-related Web locations,descriptions of obsidian sources in Oregon

lAOS BULLETIN No. 14

and California, and a hypertext guideoutlining the megascopic characteristics ofobsidian can be found at the BioSystems'Obsidian Studies Laboratory Web site(http://www.peak.orgrskinncr/ces4_0.html). Online versions of obsidian­related journal articles from the journalCurrent Research in the Pleistocene arealso beginning to make their appearance atthe Center for the Study of the FirstAmericans new Web site (also now on theWeb in sneak preview form athttp://www.peak.org/csfa/csfa. html).

For those of you in the rapidly growinggroup of well-connected archaeologists andother researchers with full World WideWeb access, I invite you to take a lookaround the new site from time to time. Ifyou have any comments, suggestions,ideas, contributions, or notice anyproblems, be sure to let me know. Forthose of you who are not yet plugged intothe Web, I recommend that you give itsome serious thought. With the coming ofthe World Wide Web, the Internet hasfinally gotten almost easy to use. This is avaluable information resource whose timehas clearly come.

TECH NOTES

This section of the Newsletter is devoted tosharing new techniques, innovative ideas,source of equipment and supplies, anddiscussing new technologies. Obsidiananalysts are invited to submit informationrelated to these topics.

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OBSIDIAN SOURCINGAND HYDRATION STUDIES

AT MURR

byJ~ A. Ambrol aDd Michael O. GIu:a:k (MilDlri UftiYl:rJity Re.un::bR~). Craia E. StilUlCl' (BioS)'1teml, 11lC.). and Cbrislcvbcr M. S~UJll(A~ Scl"'ticct CooIUJtlntl)

Many factors, including temperature,humidity, water content, and elementalcomposition are responsible for affectingthe rate at which obsidian hydrates. TheArchaeometry Laboratory at the MissouriUniversity Research Reactor, working inconjunction with Chris Stevenson andCraig Skinner, is intent on studying andmeasuring these factors in order to create adatabase from which possible correlationsbetween the different factors can beinvestigated.

At MURR, we perform instrumentalneutron activation analysis (INAA) onobsidian source material in order to get anidea of elemental composition. Thesample undergoes two irradiations, oneshort (five seconds) and one long (70hours). The short irradiation is followedby one count and the long irradiation isfollowed by two counts. The sample sizeis usually 100-300 milligrams, however,samples as small as five milligrams arepossible in many instances. Using routineINAA, we can determine the concentrationfor each of about 27 elements. Eachsource has a distinctive distribution of theelements and this distribution may befound to correlate with other factors. Forexample, many sources low in iron arealso found to have a high intrinsic watercontent.

lAOS BULLETIN No. 14 Fall 1995

Fifl,ll't 2. Pkt of OH·" ~r~u deJUity. Wbc.n denlitY is known, Wlter c::on~ i,(l;NOO ulin. reiJ'UIioo a.o.aIyU

in order to strengthen this part of thecalibration curve.

In our research program, we intend tobuild upon the initial work of Ambroseand Stevenson who identified therelationship between obsidian density andwater content. Once the intrinsic watercontent is known, the hydration rateconstants may be accurately estimated forthe artifact in question. The intrinsicwater content of obsidian is determinedfrom an infrared scan of a 1 mm thicksection. An FTIR spectrometer is used toscan the waterbands located at 4500 cm"and 5200 cm" (Fig. I). A densitydetermination and induced hydration ratee,;periment will also be performed toe,;amine the relationships between each ofthe variables.

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The data will be further eMmined for theeffects, if any, of elemental compositionon these correlations. The calibrations asthey currently stand produce high qualityhydration rates that can be used forchronometric purposes. These new effortswill increase our ability to produce reliablechronological dates based upon theproperties of each artifact under study.

t-ipf'e I . .sc.n « thin IICCtion at oblidim shotr.rinl an CU' pe:U IJ aboJt 4500 an'i.By axnpu'ina the abtorb&Dct; co IWldatdl. pertt1ltI# at wuer ccoteal ~ caJaU.ued.

Recently completed research has foundstrong relationships between density andwater content (Fig. 2), and hydration rateand water content. Based upon a simpledensity measurement the water content,and thus the hydration rate, may beestimated. In this analysis, we intend toe,;amine additional 'water rich' samples

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6

Related research goals include the thoroughcharacterization of Oregon obsidian sourcesusing INAA. We are working to compilean extensive database of 27 elements foreach source. At this time, we haveanalyzed four sources: Glass Buttes,Chickabominy Reservoir, Horse Mountain,and Cougar Mountain. The results areinteresting because we have determinedthat Glass Buttes is composed of at leasttwo, and possibly four, distinct chemicalsignatures (Fig. 3).

lAOS BULLETIN No. 14 Fall 1995

We also plan to compare existing x-rayfluorescence (XRF) data, generated byCraig Skinner, with the INAA data fromMURR. This comparison should show uswhich sources are adequately characterizedby XRF and which may require INAA tocompletely determine their intra-sourcedifferences. When the full database iscomplete, different combinations ofelements will be investigated to determinepossible abbreviated-INAA methods. Bybeing able to measure only a few elements,artifact sourcing can be done more rapidlyand at lower expense.

results.

As a final note, we would like toemphasize that the work we are doing isapplicable to many areas of science. Theinformation that we are gathering may alsobe helpful to geochemists and geologists.The applications of elemental compositionthrough INAA are perhaps not endless, butthey can be used to explore magmatic andother tectonic processes as well as artifactdistribution.

ABSTRACTS AND ANNOTATIONSON REPORTS AND PUBLICATIONS

Ambrose, W.R.

Cs (ppm)

1994 Obsidian Hydration Dating of aPleistocene Age Site From the ManusIslands, Papua New Guinea. QuaternaryGeochronology 13: 137-142.

Abstract

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~ .., C"'......,.._,c:i ..'

FiiUft- 3. Pkc of cuium~ europium ~iDi tClUra: glWpt. HeM: dU! GlowBunu bas two 1OUrt:e arouPi. S~pleJ GB006 and GBOR05 are eitbu JdditiorWlroups or outlien.. The cllipte:l shown rep~lll !be ~ 'l confideac;c kYd.

We are also interested in sourcing obsidianfrom other states in the northwest as theypertain to our research goals. At this time,we are seeking samples from Oregon,Utah, Nevada, Idaho, and Wyoming. Ifyou or someone you know may beinterested in my dissertation project, pleasedon't hesitate to contact me (Jessica) orforward my name. We are alwaysinterested in obtaining more sourcematerial and any contributions would begreatly appreciated. If samples are sent,the sender will always be appraised of the

Obsidian hydration dating relies on theprecise measurement of the depth ofhydration developed over time in thesurface of obsidians, but the loss of surfaceby natural dissolution at somearchaeological sites can result in erroneousage determinations. By focusing thehydration measurement on internal cracksurfaces protected from external surfaceerosion, acceptable results have beenachieved from a Pleistocene age site inPapua New Guinea. Measurement of thehydration profile in thin sections of thesampled obsidian by computer imagingresults in an improved reading error forthe hydration depth. By using the system

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lAOS BULLETIN No. 14

on archaeological obsidians from thePamwak site, the relative age results aremore consistent with the radiocarbon agedeterminations than conventional obsidianhydration dating.

Barrett, Thomas

1995 Differential Specialization and GulfCoast Obsidian Production: The ViewFrom the Tuxtlas Mountain Region. Paperpresented at the 60th Annual Meeting ofthe Society for American Archaeologists,May 3-7, Minneapolis, Minnesota.

Abstract

The continuing controversy over theidentification of Mesoamerican centers asspecialized stone tool production loci isexamined from a "consumer" zone on theSouth Gulf Coast. Obsidian artifacts fromthe Tuxtlas region, Veracruz, Mexico, areexamined to shed light on the productionintensity and scale of a production­distribution system assumed to bedominated by Teotihuacan during theMiddle Classic period. Debitage analysesutilizing sourcing studies, technologicalattributes, and categories of use wear, arecontrasted within the Tuxtlas region toassess the differential regionalprocurement, production, and distributionof imponed obsidian. The implications ofthe Classic obsidian industry are discussed.

Barut, Sibel

1995 Raw Material Use in the Later StoneAge at Lukenya Hill, Kenya. Paperpresented at the 60th Annual Meeting ofthe Society for American Archaeologists,

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May 3-7, Minneapolis, Minnesota.

Abstract

This paper examines strategies for theprocurement and use of quartz, chert, andobsidian lithic raw materials at the earlyLSA sites of GvJm 10, 16, 19, 22, 46,and 62 from Lukenya Hill, Kenya.Implications for hunter-gatherer land andsite use during the period are examined.

Bove, Frederick J. and Hector Neff

1995 Obsidian Hydration Dating in PacificCoastal Southern Mesoamerica. Paperpresented at the 60th Annual Meeting ofthe Society for American Archaeologists,May 3-7, Minneapolis, Minnesota.

Abstract

The post-Formative chronology of theGuatemalan Pacific coast is beingreassessed in light of over 1000 obsidianhydration dates from the Cotzumalguapaand Manantial archaeological zones. Datesare calculated on the basis of artifactsource assignments determined by neutronactivation analysis and soil temperatureestimates based on measurements at fourdifferent elevations. The large number ofdates thus generated permits time to beviewed as continuous rather thansegmented. The traditional, segmentedchronology for the region implies a post­Formative occupation history marked byincredible population explosions andcollapses, whereas obsidian dates fromClassic period contexts indicate moregradual expansions and contractions.

lAOS BULLETIN No. 14

Fredrickson, David A.

1995 Obsidian Studies and SocialBoundaries in Sonoma County:Implications for the Development ofSociopolitical Complexity in CentralCalifornia. Paper presented at the 29thAnnual Meeting of the Society forCalifornia Archaeology, April 5-9, Eureka,California.

Abstract

Because patterns of obsidian use by sourcehave proved to correlate with knownethnographic boundaries, such patternshave been employed to assist in delineatingboundaries at time depths for which noethnographic data are available.Preliminary data, some of which arediscussed here, are congruent withtheoretical models that link the emergenceof firm territorial boundaries with thedevelopment of sociopolitical complexity.

Freter, AnnCorinne

1995 Reconstructing Complex SiteStratigraphy: The Harris Matrix andObsidian Hydration Dating. Paperpresented at the 60th Annual Meeting ofthe Society for American Archaeologists,May 3-7, Minneapolis, Minnesota.

Abstract

Reconstructing site chronology is acomplex process which involves theanalysis of multiple lines of data.Obsidian hydration dating, when employedas either a relative or chronometrictechnique, has great potential as a

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chronological tool particularly whencombined with other data sources. Thispaper employs the use of the Harris matrixto map complex stratigraphic deposits incombination with obsidian hydration,radiocarbon, and archaeomagnetic dates,from excavations at Copan, Honduras, todemonstrate how obsidian hydration canconstructively contribute to thereconstruction of complex site chronology.

Freund, Joanna

1995 A Prehistoric Perspective of theLaguna de Santa Rosa, Sonoma County,California: A Study in Obsidian HydrationAnalysis. Paper presented at the 29thAnnual Meeting of the Society forCalifornia Archaeology, April 5-9, Eureka,California.

Abstract

The Laguna de Santa Rosa is a wetlandarea that is believed to have occupied arelatively stable location within the CotatiValley for the past 7000 years or more.European migration and subsequentdevelopment rough draining andchannelization have, however, created amarkedly different environment thanexisted even a century ago. This paperuses historical and archaeological evidenceto provide a prehistoric perspective of boththe natural and cultural environment.Obsidian hydration analysis is used as atool for establishing temporal context.Among issues discussed are settlementpattern and changes in the shoreline overtime.

lAOS BULLETIN No. 14

Gilreath, A., and B. Blommer, T. Ozbun,J. Fagan, D. Wilson

1995 Distribution and Use of MedicineLake Highlands Obsidian. Paper presentedat 29th Annual Meeting of Society forCalifornia Archaeology, April 5-9, Eureka,California.

Abstract

Medicine Lake Highlands obsidian iscommon in prehistoric sites in northernCalifornia and southern Oregon. X-rayfluorescence and hydration data from avariety of sites are used to plot thegeographical and temporal distribution ofthis obsidian. Technological analyses of asample of lithic assemblages from withinthis region suggest changes in thedistribution of this glass are theconsequence of cultural developmentsreflected in the organization of technology.

Godfrey-Smith, 0.1., and J. Kronfeld, A.Strull, J.M. D'Auria

1993 Obsidian Provenancing and MagmaticFractionation in Central Oregon.Geoarchaeology: An International Journal8(5):385-394.

Abstract

In many instances, geologically distinctobsidian flows located within even arelatively small geographic area can beuniquely identified by their chemicalcomposition. This happens to be true forseveral obsidian sources from centralOregon. Internally each obsidian localityis chemically homogeneous, but the

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obsidian rocks from different collectionsites exhibit chemical differences. Basedon the geochemical variations and on K/Ardating of the end members of the chemicaldifferentiation trend, these differences arerelated to the fractionation of a single LateMiocene magma chamber, dated at 6.5Ma. By understanding the underlyingcauses of the chemical di fferences,constraints are disclosed that will governthe possible chemical variations of other,as yet unidentified but related obsidianflows. These can be useful for identifyingthe possible natural sources of obsidianartifacts which do not match knownobsidian sources, and for suggestingpossible geographic areas where these asyet undiscovered obsidian flows may befound.

Hughes, Richard E.

1995 Issues of Reliability, Validity, andScale in Obsidian Sourcing Research.Paper presented at the 60th AnnualMeeti ng of the Society for AmericanArchaeologists, May 3-7, Minneapolis,Minnesota.

Abstract

Obsidian provenance analysis dependsexplicitly on the reliability and replicabilityof measurement units, but early concernsfor these issues were largely implicit. Ithas become clear, however, thatmeasurement units appropriate for onescale of analysis (a local area) may fail toprovide valid measures when the scale andscope of research is expanded to a largerspatial universe (a region). This paperexplores some aspects of the relationship

lAOS BULLETIN No. 14

between reliability and validity at varyingspatial scales, and considers how geologicand geochemical factors impinge onconclusions archaeologists draw fromsourcing studies.

Norris, Susan M.

1995 New Methods in Obsidian HydrationDating: Results from Yautepec, Morelos,Mexico. Paper presented at the 60thAnnual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

Obsidian hydration dating has producedambiguous data. We addressed thisproblem by hydrating glass in its ambientenvironment (vs. Inducing hydration in thelab). We buried source obsidian,archaeological obsidian, and standardizedglass at the site of Yautepec for one year.The project goals were to 1) examine theeffect of micro-environmental variation onhydration rates; 2) develop a hydration ratefor obsidian in Yautepec consideringfactors besides temperature data; and 3)provide dates for archaeological obsidian.We measured the rims with a moreprecise, new technique called HydrogenProfiling, performed on a NuclearAccelerator. Results indicate that micro­environment may be a significant factor inthe rate of hydration.

Stevenson, C.M., and E. Knaus, J.J.Mazer, J.K. Bates

1993 Homogeneity of Water Content inObsidian from the Coso Volcanic Field:

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Implications for Obsidian Hydration Dating

Abstract

Users of the obsidian hydration datingmethod have routinely assumed thatartifacts which originate from the samegeological flow will be of the samechemical composition and thus hydrate atthe same rate under equivalent conditionsof temperature and relative humidity.Recent laboratory experiments into thehydration process has shown that theintrinsic H20 content of the glass is thedominant factor in establishing the rate ofhydration. H20 content determinations ona large suite of samples from numerousprehistoric quarries within the CosoVolcanic field, California, indicated thatH20 content values, and thus hydrationrates, varied significantly on a within flowbasis. It is recommended that H20determinations be made on individualartifacts prior to obsidian hydration dating.

Reanier, Richard E.

1995 Obsidian Hydration Dating: TheAlaskan Experience. Paper presented atthe 60th Annual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

After more than three decades ofexperimentation, obsidian hydration datingremains a promising, but by no means,routine dating method for arcticarchaeologists. The 1970s saw limitedsuccess in constructing radiocarbon­calibrated hydration rates. In the 198Os,

•

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[AOS BULLETIN No. [4

thennal cells were first used to measureEHT, and activation energies derived frominduced hydration were used to develophydration rates, but erratic results pointedto hydration rind measurement error andthe influence of forest fire as causes.Recent research suggests that within-sourceactivation energy variability, and the limitson rind measurement precision imposed byoptical microscopy may limit theusefulness of hydration dates in arcticenvironments.

Rhode, David

1995 Thennal Variation and ObsidianHydration Rates. Paper presented at the60th Annual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

Since the rate of obsidian hydrationdepends on temperature, and since thethennal environment experienced byartifacts varies considerably even oversmall spatial scales, it should be expectedthat hydration measurements from anartifact collection will also show significantvariability. Differences in thermal regimeswithin a small area may easily result indifferences in short tenn hydration rates onthe order of 100%. Whether these ratedifferences hold over longer periodsdepends on the stability of the small scalethermal regime. Simulation modeling andempirical measurements are used to assesslong-tenn hydration rate variability atYucca Mountain, southern Nevada.

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Ridings, Rosanna

1995 Modeling Subsurface Temperatureand its Effect on Obsidian Hydration at PotCreek Pueblo. Paper presented at the 60thAnnual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

A field study from Pot Creek Pueblo innorthern New Mexico indicates thatobsidian hydration dates may containsignificant errors when hydration rateconstants are extrapolated to depth-specificeffective hydration temperatures (EHTs).This problem is most likely to occur whenthe amplitude of the annual surfacetemperature wave exceeds 2-3°C. Basedon the large number of tree-ring dates forPot Creek Pueblo, artifact burial historieshave been modeled to account for a 3°Cchange in EHT with depth. Only 57% ofthe hydration age estimates are within theexpected range, suggesting that sources oferror in obsidian hydration dating are stillpoorly constrained.

Rondeau, Michael F.

1995 Technology as Context for ObsidianHydration Studies. Paper presented at the60th Annual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

Anomalous hydration band width readingshave plagued interpretative endeavors andcalled into question the general utility of

lAOS BULLETIN No. 14

obsidian hydration as a method ofestablishing relative chronologies. Recenttechno-hydration studies indicate thatcertain kinds of anomalies can beexplained. New interpretive benefits fromcombining technological and hydrationanalyses are recognized. It is argued thatsome unexplained results follow from afailure to establish context and, therefore,appropriate controls for sample selection.

Salgado, Sylvia and Wilson Valerio

1995 Lithic Industries of the Region ofGranada, Pacific Nicaragua (A.D. 3()()­1550). Paper presented at the 60th AnnualMeeting of the Society for AmericanArchaeologists, May 3-7, Minneapolis,Minnesota.

Abstract

This paper discusses the results of theanalysis of ground and chipped-stoneartifacts recovered in stratigraphicexcavations of the Ayala site, PacificNicaragua. Most of the artifacts weremade of local cherts and basalts, whileobsidian artifacts were made of importedmaterials from sources located inHonduras, Guatemala, and CentralMexico. The analyzed assemblagessuggest that some specialized activitieswere being carried out at the site, owing tothe prevalence of certain classes ofartifacts. Comparisons are established withcontemporaneous lithic industries of otherregions of Lower Central America,especially of Costa Rica and Panama.

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Stevenson, Chris, Peter 1. Sheppard,Douglas G. Sutton, and W. Ambrose

1995 Advances in the Hydration Dating ofNew Zealand Obsidian. Paper presented atthe 60th Annual Meeting of the Society forAmerican Archaeologists, May 3-7,Minneapolis, Minnesota.

Abstract

Newly developed methods and calibrationsfor determining the age of flaked obsidiansurfaces have been described and appliedto New Zealand archaeological obsidians.Hydration bands were measured under highmagnification (1000x) using a MOCHAcomputer imaging system to an accuracy of.2 microns. Hydration rates were thencalculated on the basis of obsidian watercontent as estimated from artifact densitywhile effective hydration temperatureswere established from publishedtemperatures derived from thermal cells.Hydration dates have been compared withradiocarbon dates from five archaeologicalsites in the North Island of New Zealand.The obsidian age determinations correlatedwell with the radiocarbon dates from thesame context except for those recoveredfrom sand dune sites. These resultsvalidate the ability of obsidian hydrationdating procedures to provide accuratecalendar year age estimates.

Tykot, Robert H. and Karen Hartshorn

1995 The Source of Corse Obsidian:Neolithic Exchange in the WesternMediterranean. Paper presented at the60th Annual Meeting of the Society forAmerican Archaeologists, May 3-7,

r

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Minneapolis, Minnesota.

Abstract

The provenance of several hundredobsidian artifacts from neolithic sites inCorsica has been determined bywavelength-dispersive spectrometry usingthe electron microprobe. The analysis of200 samples from nine stratigraphic levelsat Basi (Serra-di-Ferro) represents thelargest study ever of obsidian exploitationat anyone site in the westernMediterranean, and is singularly importantfor assessing chronological variation inobsidian exploitation. Our resultscontradict interpretations based on earlierstudies of small numbers of Corsicansamples, and indicate that obsidian fromfive Sardinian sources are represented.Changing procurement mechanisms mayaccount for differences between the Earlyand Late Neolithic periods.

Woodward, Michelle R.

1995 Provenience Studies of SurfaceObsidian Artifacts from the NorthernRidge of Lake Atitlan, Guatemala. Paperpresented at the 60th Annual Meeting ofthe Society for American Archaeologists,May 3-7, Minneapolis, Minnesota.

Abstract

Neutron Activation Analysis (NAA) hasdetermined the chemical characteristics forone hundred obsidian artifacts collectedfrom surface surveys along the northernshore of Lake Atitlan, Guatemala. Sixty­six samples collected and tested from threeobsidian sources (EI Chayal, Rio Pixcaya,

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Fall 1995

and (xtepeque) provide a comparativedatabase for the artifacts. Results indicatethe Rio Pixcaya as the source for themajority of the obsidian artifacts. Thedominance of Rio Pixcaya obsidiandiscounts the possibility of a local sourcewhile supporting a complex trade networksimilar to those of the Maya lowlands.

MEETINGS AND EVENTS

November 6-9. Geological Society ofAmerica, Annual Meeting. New Orleans,Lousiana. Vanessa George, GeologicalSociety of America, 3300 Penrose Place,Boulder, BO 8030[, USA; tel: 303-447­2020; fax: 303-447-1133.

November 15-19. AmericanAnthropological Association, AnnualMeeting. Washington DC., USA.American Anthropological Association4350 North Fairfax Drive, Suite 240,Arlington, VA 22203, USA; tel: 703-528­1902.

1996

May 20-24. International Symposium onArchaeometry. Urbana-Champaign,Illinois. Sarah Wisseman, ATAMProgram, University of Illinois, 116Observatory, 901 S. Mathews, Urbana, [L,61801, USA; tel:217-333-6629; fax: 217­244-D466; email: wisarc@uxl.sco.uicu.edu

lAOS BULLETIN No. 14

CALL FOR ARTICLES ANDINFORMATION

Submissions for articles, short reports,abstracts, or announcements for inclusionin the next newsletter should be receivedby December 15, 1995. We acceptelectronic media on IBM compatible 3.5"or 5.25" diskettes, in a variety of wordprocessing formats including Wordperfect(5.1), Wordstar, and Microsoft Word, orASCII text formats. A hard copy shouldaccompany diskettes. Send to BlossomHamusek, 2874 Camulos Way, Redding,California, 96002; (916) 221-7852.

Short Reports & Reviews: If you areinterested in briefly reporting on researchfindings (e.g. one column in length),contact Mike Rondeau at Caltrans,Environmental Project, 650 Howe Avenue,Suite 400, Sacramento, California 95825;(916) 263-3375; FAX (916)263-3384.

INTERNATIONAL SYMPOSIUMON ARCHAEOMETRY:

CALL FOR PAPERS

The 30th International Symposium onArchaeometry will be held on the campusof the University of Illinois at Urbana­Champaign, Illinois, USA, May 20-24,1996. Symposium organizers are solicitingabstracts of papers to be received byNovember 15, 1995.

Single sessions of oral presentations will beheld each day from May 20 through May24. Poster presentations are an importantpart of the Symposium and will be

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Fall 1995

allocated special time slots. The followingscientific sessions will be included:

1. Biomaterials (bones, residues, etc.);2. Dating (organic and inorganicmaterials);3. Field archaeology (prospection andgeoarchaeology);4. Technology/provenance of: a)metals,b)ceramics/glass, c) stone/pigments/plaster.

The Symposium schedule will include afull-day theme session, "BiologicalRemains and Organic Residues", featuringinvited contributions as well as submittedpapers.

A Preliminary Program with details onregistration, the scientific program, socialevents, hotels, travel and sightseeingoptions will be mailed in February 1996.Events being planned include: a receptionand exhibit at the Krannert Art Museum, areception and computer fair at theBeckman Institute for Advanced Scienceand Technology, a Symposium banquetand musical entertainment in the IllniUnion Ballroom, a pre-conference tour ofChicago museums and conservationlaboratories, and a post-conference tour ofCahokia, a center of prehistoricMississippian culture.

The organizers hope to provide limitedfinancial aid to qualifying applicants in thefollowing categories: 1. Archaeometrystudents from U.S. and abroad; 2. Non­U.S. researchers who can prove financialhardship and who plan to submitsignificant research papers. Thoseinterested in financial aid should requestapplication forms from the registration

r

IAOS BULLETIN No. 14

address below by December I, 1995.

If you would like to be added to themailing list for Archaeometry 96information, send you full name, address,fax and telephone numbers, and E-mailinformation to the registration address: C.Johnson, Conferences & Institutes, 302 E.John Street, Suite 202, Champaign,Illinois, 61820, USA; e-mail:johnsonc@uxl.cso.uicu.edu

lAOS OFFICERS, 1995-1996

President: Michael GlascockPresident-Elect: Tom JacksonSecretary-Treasurer: Viviana InesBellifemineNewsletter Editor: Blossom HamusekAdvisory Board: Clement Meighan, RogerGreen, Irving Freidman

Fall 1995

NEW MEMBERS LIST:

E. S. Elstcr, UCLA, California

Stcphcn A. Moen. Portland. Orcgon

Gcorgc Rapp Jr.. Univ. of Minncsota. MN

. - - . - - .. - - . - - - - - - - . - - - - - - - - - . - . - - . - ... - .. Cut-Qut - .. - ... - - .. - - - - - - - - - - - . - - - . - . - - - - - - - - - ••. -

Yes, rd like to rencw my membership. A check or money order for the annual membership fee is enclosed (see belOW').

Yes. I'd like to become a member of the LAOS DO"W. A cbeck or money order for the annual membership fee is eoclosed(see below). Please rush my first issue oftho lAos J3ULLETIN and a copy of the on'disk IBM PC'compatib~ lAOSObsidian Bibliography. Please ebeck disk format neede~ _ 5'" 360K _ 3'h 740K

Still not coDYinced. but want to know mace?Please send me a complimentary issue of the l3...t lAOS l3UU.ETIN.

Please send me a copy of the on'disk lAOS Obsidian Bibliography and a complimentary copy of the lAos 13UU.ETIN.My check or money order for 510.00 (refundable if I join the lAOS this calendar year) is enclosed.

NameTItIe-------------------------------------S_tAd<h= _Uty _Country _

AffiliationWntkPbooe-----------------------------------

Home Pbooe (optionaI) _IntemetIBITNEr _Other E-MaiIAddr=es -'-- _

My check is enclosed for the following amount (please check one):_ $20.00 Regular Member 550.00 Institutional Member S2OO.00 Lifetime Member

Please return thi.1 eut-out to: International As.soc::i:ltion for Obsidian Studies. Ms. VIViana Ines BelliIemine, Seaewy-Treasurer •Department or Anthropology. San Jose State University. San Jose. California 95192·0113