UAF Geochronology Facility

Members of the Geochronology Lab use a laser or a furnace to melt grains of rock and release argon gas, which they can date using a mass spectrometer and the 40-argon/39-argon dating technique. They use this method to solve geological and geophysical mysteries in Alaska and elsewhere, including the eruptive history of Alaska’s volcanoes, the rate of uplift of Alaska’s mountains, and the tectonic history of Alaska and Russia. Lab users have dated fragments of stone-age tools in an attempt to find the sources of the tools and ancient trading patterns.

Research

Personnel

Jeff A. Benowitz

Paul W. Layer

Dr. Jeff A. Benowitz (Lab Manager)

jbenowitz [at] alaska [dot] edu (Email)

Google Scholar

http://www.gi.alaska.edu/profile/jeffrey-benowitz

Dr. Paul W. Layer (Lab Supervisor)

Paul paul [dot] layer [at] gi [dot] alaska [dot] edu (Email)

Google Scholar

Analytical Fees

Primary Services

Mineral separations (99% pure) are $200 U.S. a sample

Includes: muscovite, biotite, hornblende, plagioclase, potassium feldspar, glass and XRF of feldspar separate for K/Ca ratio.

Of note, sample separation cost is included in heating experiment costs and no discount for pure separated mineral aliquots (but appreciated).

Laser incremental 40Ar/39Ar heating experiments (~8 to ~10 steps) are $600 U.S. per sample

Includes: Single mineral phase heating experiments (multiple runs if needed), sample
preparation, irradiation costs, data reduction, digital report, and publication quality figures on request.

Laser total fusion 40Ar/39Ar experiments are $600 U.S. per sample for ~10 grains.

Includes: ~10 single grain fusions, sample preparation, irradiation costs, data reduction, digital report, and publication quality figures on request. In addition we will provide a statistically analysis of peak populations of the produced data.

Laser total fusion 40Ar/39Ar experiments are $2000 U.S. per sample for ~100 grains. We can also discuss a per grain cost.

Includes: ~100 single grain fusions, sample preparation, irradiation costs, data reduction, digital report, and publication quality figures on request. In addition we will provide a statistically analysis of peak populations of the produced data.

Temperature recorded furnace incremental 40Ar/39Ar heating experiments (~20 to ~30 steps) are $1500 U.S. per sample

Includes: Single mineral phase heating experiments (multiple runs), sample
preparation, irradiation costs, data reduction, digital report, and publication quality figures on request. We also include a single Laser incremental 40Ar/39Ar heating experiment (~8 to ~10 steps) on potassium feldspar samples to “predetermine if the sample is a good candidate for furnace isothermal-step heating experiments. We prefer
collaborations on potassium feldspar samples because of the amount of work involved. We will derive thermal history models (Time-temperature) from the analysis.

Thnx