Northwest Research Obsidian Studies Laboratory
1414 NW Polk
Corvallis, OR 97330 USA
Voice/Fax: 541-754-7507
E-mail: cskinner@obsidianlab.com
E-mail: info@obsidianlab.com
Lab Website: www.obsidianlab.com
U. S. Source Catalog Website: www.sourcecatalog.com
ALL LINKS ON THIS PAGE WILL BE ACTIVE ONLY IF AN INTERNET CONNECTION IS ESTABLISHED
Introduction
The purpose of this file (README.HTML) is to provide a launch point for Northwest Research Obsidian Studies Laboratory analytical services. If you point your browser to the README.HTML file when you're online, the web links will be active and will take you directly to the always current information at our lab websites. The Northwest Research link above will take you to the lab website and current information about our lab services. The U. S. Obsidian Source Catalog link will take you to online information about obsidian sources in the United States.
The README file can be used either from the disk or from your hard drive. To install the README.HTM file from your hard drive, create a subdirectory or folder (e.g., NWR) and copy the README.HTML, NWR_HEADER.GIF, and DOMEART.GIF files to that location. In addition, the disk will contain a spreadsheet (multiple formats - see below), any graphics files related to your project (maps, scatterplots, and artifact images), and Adobe Acrobat documents that were produced as part of your project. Current price sheets and sample submission forms for XRF studies and legacy XRF/hydration studies can be found in the LAB FORMS subdirectory on the CD.
If you have any questions about our analytical services, please don't hesitate to contact us at any of the locations listed above.
Information About the Data Disk
A. SPREADSHEET FIELD DEFINITIONS
Along with a final report or Basic Report, you will usually receive a data disk (IBM PC) with a summary of all analytical results. The YEAR-NO spreadsheet files (e.g., 2008-43.xls) on the disk contain the results of the analyses in three formats - Excel, Quattro Pro, and a tab-delimited text file that's suitable for import.
Abbreviations
NM = Not measured; some hydration rim measurements and trace element values and uncertainties will almost always contain spreadsheet cells for which no data were acquired.
NA = Data not available.
PPM = Parts per million.
Field Name and Description
Sample Handling and Provenience Data
- BO_NUMBER: Northwest Research Obsidian Laboratory accession number
- SPEC_NUMBER: Northwest Research lab number for sample
- CAT_NUMBER: Catalog number of samples
- INSTRUCTIONS: Special instructions concerning the handling of individual specimens
- MATERIAL: Raw material type. OBS = Obsidian; FGV = Fine-Grained Volcanic Rock (basalt, andesite, rhyolite, etc.); TUF = Volcanic Tuff; NOT = Not Obsidian; TOO = Too Small for XRF Analysis
- SITE NAME: Name of site, trinomial if no site name exists, or other designation (e.g., temporary U.S. Forest Service site number)
- TRINOMIAL: Site trinomial (e.g., 35-JE-51B), if available
- XRF: XRF analysis of sample? Y(es)/N(o)
- OH: Obsidian hydration analysis of sample? Y(es)/N(o)
- OH_OK: If obsidian hydration slide was prepared, was a measurable rim observed? Y(es)/N(o)
- UNIT: Unit provenience of sample
- DEPTH: Depth provenience of sample
- CLASS3: Type of sample. GEO = Geologic Sample; BIF = Biface; DEB = Debitage; PPT = Projectile Point, etc.
Obsidian Hydration Analysis Data
- MEAN1: Mean hydration rim value, rim 1
- MEAN2: Mean hydration rim value, rim 2
- MEAN3: Mean hydration rim value, rim 3
- SD1: Standard deviation of hydration rim values, rim 1
- SD2: Standard deviation of hydration rim values, rim 2
- SD3: Standard deviation of hydration rim values, rim 3
- OH_COMMENTS: General comments about hydration rims; see Appendix B for an explanation of abbreviations
XRF Analysis Data
- CHEM_SOURCE: Chemical source of the sample, e.g., Obsidian Cliff
- TI_PPM: Titanium values (ppm)
- MN_PPM: Manganese values (ppm)
- FE_WT: Total iron values (Fe2O3) measured in weight percent oxide
- FE_MN: Iron-manganese peak ratio values
- FE_TI: Iron-titanium peak ratio values
- ZN_PPM: Zinc values (ppm)
- RB_PPM: Rubidium values (ppm)
- SR_PPM: Strontium values (ppm)
- Y_PPM: Yttrium values (ppm)
- ZR_PPM: Zirconium values (ppm)
- NB_PPM: Niobium values (ppm)
- BA_PPM: Barium values (ppm)
- PB_PPM: Lead values (ppm)
- TH_PPM: Thorium values (ppm)
- TI_ERR: Titanium analytical uncertainty; +/- 1 standard deviation
- MN_ERR: Manganese analytical uncertainty; +/- 1 standard deviation
- FE_ERR: Total Iron analytical uncertainty; +/- 1 standard deviation
- ZN_ERR: Zinc analytical uncertainty; +/- 1 standard deviation
- RB_ERR: Rubidium analytical uncertainty; +/- 1 standard deviation
- SR_ERR: Strontium analytical uncertainty; +/- 1 standard deviation
- Y_ERR: Yttrium analytical uncertainty; +/- 1 standard deviation
- ZR_ERR: Zirconium analytical uncertainty; +/- 1 standard deviation
- NB_ERR: Niobium analytical uncertainty; +/- 1 standard deviation
- BA_ERR: Barium analytical uncertainty; +/- 1 standard deviation
- PB_ERR: Lead analytical uncertainty; +/- 1 standard deviation
- TH_ERR: Thorium analytical uncertainty; +/- 1 standard deviation
B. ABBREVIATIONS USED IN THE "COMMENTS" COLUMN OF OBSIDIAN HYDRATION TABLES
- BEV - (Beveled). Artifact morphology or cut configuration resulted in a beveled thin section edge.
- BRE - (BREak). The thin section cut was made across a broken edge of the artifact. Resulting hydration measurements may reveal when the artifact was broken, relative to its time of manufacture.
- DES - (DEStroyed). The artifact or flake was destroyed in the process of thin section preparation. This sometimes occurs during the preparation of extremely small items, such as pressure flakes.
- DFV - (Diffusion Front Vague). The diffusion front, or the visual boundary between hydrated and unhydrated portions of the specimen, are poorly defined. This can result in less precise measurements than can be obtained from sharply demarcated diffusion fronts. The technician must often estimate the hydration boundary because a vague diffusion front often appears as a relatively thick, dark line or a gradation in color or brightness between hydrated and unhydrated layers.
- DIS - (DIScontinuous). A discontinuous or interrupted hydration rind was observed on the thin section.
- HV - (Highly Variable). The hydration rind exhibits variable thickness along continuous surfaces. This variability can occur with very well- defined bands as well as those with irregular or vague diffusion fronts.
- IRR - (IRRegular). The surfaces of the thin section (the outer surfaces of the artifact) are uneven and measurement is difficult.
- 1SO - (1 Surface Only). Hydration was observed on only one surface or side of the thin section.
- NOT - (NOT obsidian). Petrographic characteristics of the artifact or obsidian specimen indicate that the specimen is not obsidian.
- NVH - (No Visible Hydration). No hydration rind was observed on one or more surfaces of the specimen. This does not mean that hydration is absent, only that hydration was not observed. Hydration rinds smaller than one micron often are not birefringent and thus cannot be seen by optical microscopy. "NVH" may be reported for the manufacture surface of a tool while a hydration measurement is reported for another surface, e.g. a remnant ventral flake surface.
- OPA - (OPAque). The specimen is too opaque for measurement and cannot be further reduced in thickness.
- PAT - (PATinated). This description is usually noted when there is a problem in measuring the thickness of the hydration rind, and refers to the unmagnified surface characteristics of the artifact, possibly indicating the source of the measurement problem. Only extreme patination is normally noted.
- REC - (RECut). More than one thin section was prepared from an archaeological specimen. Multiple thin sections are made if preparation quality on the initial specimen is suspect or obviously poor. Additional
thin sections may also be prepared if it is perceived that more information concerning an artifact's manufacture or use can be obtained.
- UNR - (UNReadable). The optical quality of the hydration rind is so poor that accurate measurement is not possible. Poor thin section preparation is not a cause.
- WEA - (WEAthered). The artifact surface appears to be damaged by wind erosion or other mechanical action.
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