Frequently Asked Questions
What areas are covered by the NWROSL source database?
- Obsidian sources in Oregon, California, Washington, Idaho, Nevada, Wyoming, New Mexico, Arizona, Utah, Colorado, Montana, South Dakota, British Columbia, and the Western Mediterranean are well covered; incomplete but improving coverage for Alaska, and other scattered areas in the Mediterranean, Mexico, Middle East, and Pacific islands. Fine-grained volcanic (FGV) source identification is available although is now limited primarily to artifacts from the Lake Tahoe area of east-central California.
Is your analysis destructive?
- No! Our lab use an EDXRF spectrometer which does not cause any damage to artifacts.
What elements are used for the identification of geologic sources of analyzed artifacts?
- We use Rubidium, Strontium, Yttrium, Zirconium, Niobium, and Barium. Occasionally Titanium, Manganese and Iron are also used.
Can we analyze geologic samples?
- We maintain a very active research program and are constantly adding new sources to our reference database. We will analyze limited quantities of geologic obsidian source material at no charge for sources that we do not currently have in our reference collection. If you would like to take us up on this offer, please contact us for details. We are also interested in geoarchaeological studies of geologic sources of obsidian and will provide analytical support for graduate students with an interest in this topic.
Do you have a GIS dataset of source location available for download?
- We are actively working to make a GIS dataset available for download that will include both point data for sources that are distinct in their locations as well as polygon data for sources that have a wide geographic area. We are aiming to make this available by winter 2019. Contact us if you would like us to let you know when it becomes available.
How should I submit a sample?
- Follow these instructions Submission Form when submitting a sample. Please make sure that they are well packed to avoid damage during shipping.
How do you handle payments?
- Invoices will be sent upon completion of your project. We accept cash, check, M.O., P.O., Paypal, Visa, or Mastercard. We are also registered with the US System for Award Management (SAM) and can accept federal contracts.
What are your prices?
- Click here for our current pricing.
What services do we provide?
- We provide EDXRF trace-element analysis of obsidian and fine-grained volcanic artifacts and identification of the geologic source of analyzed artifacts.
How large of a sample do I need?
- A good guideline is a minimum diameter of approximately 10mm and a minimum thickness of 1.5mm. Sometimes smaller samples can still be analyzed, contact us for specifics. Samples should be clean and free of painted numbers on one surface if possible.
Is there a source list available?
- Yes – all obsidian sources included in the Northwest Research reference database are listed on the lab website. Descriptions of many of the sources can also be found at the U. S. Obsidian Source Catalog.
What do I get when I submit a sample?
- You will receive a digital copy of the report in PDF format upon completion of the analysis. A hard copy will be included with your artifacts. A spreadsheet of submitted samples, trace element concentrations, and source assignments will be made available upon request.