40Ar/39Ar Age Determinations Using ARGUS-VI
The OSU Argon Geochronology Lab carries out 40Ar/39Ar analyses for researchers, students and outside clients against a service fee as defined in the OSU Fee Book. If you are interested in getting your samples age dated, please Contact Us to discuss your project and geochronology goals and to receive instructions for completing the analytical service request. We will send you a sample form in the Microsoft Excel format, which is required as a first step in defining your geochronology project. Geological materials that we can date, pricing and typical turnaround times for the different level of services provided are indicated below.
Geologic Materials
Here is a list of phases that we can separate and analyze:
Amphibole, Anorthoclase, Biotite, Clinopyroxene, Glass, Groundmass, Hornblende, Illite, K-Feldspar, Mica, Muscovite, Nepheline, Orthopyroxene, Phlogopite, Plagioclase, Pyroxene, Sanidine, Sericite, Tourmaline
Phases that we do not analyze:
Alunite, Jarosite
40Ar/39Ar Age Determination via Bulk Incremental Heating
Incremental heating experiments are carried out with a raster scanning 30W Synrad CO2 laser and the argon gas samples extracted are cleaned on a customized Thermo Scientific NG Prep System and analyzed using a Thermo Scientific ARGUS VI Multi-collector Mass Spectrometer. Included in this service are up to 30 heating steps, up to 15 blanks, sample irradiation, flux monitor measurements, air short calibrations and other age standard measurements. A minimal data report along with a description of our mineral separation protocol, acid leaching cleaning procedures, and mass spectrometry analyses will be included when the data is delivered via email.
Single Crystal Incremental Heating
Incremental heating for in total 5 single crystals from one sample using the Thermo Scientific Model ARGUS VI multi-collector mass spectrometer. Costs include up to 12 incremental heating steps; 6 blanks per single crystal incremental heating experiment; irradiation; flux monitor measurements; air short calibrations; other standard measurements; minimal data report; full mineral separation protocol and acid leaching cleaning procedures.
Service | OSU FEE ID | Cost per Sample | Crystals per Sample | Turnaround Time |
|---|---|---|---|---|
Standard | $2,500 | 5 | 8-12 months |
Collaborative Rates
For researchers that would like to collaborate with the OSU Argon Lab on scientific publications, students that visit Oregon State University and prepare their own samples or have pre-prepared samples.
Other Services
Service | OSU Fee ID | Rate | Description |
|---|---|---|---|
Special Mineral Separation Fee | $75/hour | Special mineral separation and sample preparation that goes beyond the standard procedures established in the OSU Argon Geochronology Laboratory | |
Technical Report Writing Fee | $75/hour | Complete geochronological report. | |
Special Software Instructions and Development | $130/hour | Development of special/new features upon request. |
OSU TRIGA Irradiations
Samples are irradiated at the OSU Radiation Center in the TRIGA experimental reactor, typically at 1 MW power for periods appropriate for the age and composition of sample unknowns. The neutron flux is monitored with a variety of standard samples (Mmhb-1 hornblende, FCT-3 biotite, TCR sanidine). There is also a Cd-shielded irradiation location which is designed to block slow (thermal) neutrons in preference to fast neutrons. Irradiated materials are disposed through the OSU Radiation Safety Office. All workers in our laboratory are trained in the safe handling of radioactive materials.