In our OSU Argon Geochronology Lab we employ the 40Ar/39Ar geochronology method to determine how hotspots evolve and interact with lithosphere, in quantifying rates at which large igneous provinces are constructed, in deciphering the early history of the Earth and Moon, in tracking transport pathways of terrigenous sediments from rivers to deep-sea sediments, and more.
Geochronology
Sample Being Heated
by CO2 Laser
The versatility of the 40Ar/39Ar method allows geochronologists to generate important time constraints for many globally relevant questions in Earth system science through the precise measurement of the ages of common K-bearing rocks and minerals. Because of the opportune 1.25 x 109 half-life of the 40K-40Ar decay series and a high abundance of potassium in most terrestrial and extra-terrestrial materials, this method has been successfully used in dating lunar samples and meteorites, the full range of igneous and metamorphic rocks outcropping on Earth, bulk rock, mineral and groundmass samples, single crystals, and in situminerals using laser-probe systems.
Today, geochronology by the 40Ar/39Ar method is fundamental in determining how hotspots evolve and interact with the lithosphere, in quantifying rates at which large igneous provinces are constructed, in calibrating geological and geomagnetic polarity time scales, in deciphering the early history of the Earth and the Moon, in working out the evolution of hominids, in tracking transport pathways of terrigenous sediments from rivers to deep-sea sediments, in recording magma chamber evolutions, in characterizing young volcanic systems, and so on.
Technical advances in 40Ar/39Ar dating over the last two decades have been substantial. Sensitivity in mass spectrometry measurements increased significantly, whereas the construction of low-volume extraction lines has permitted age determinations from much smaller samples. Aggressive application of incremental heating protocols, in combination with thorough acid-cleaning procedures for severely “altered” rocks, have allowed for more accurate age determinations from submarine samples. And, most recently, the introduction of multi-collector noble gas mass spectrometry has allowed for faster and more precise 40Ar/39Ar measurements, on even smaller samples.
OSU Argon Geochronology Laboratory
Loaded Sample Tray Before Analyses
Our laboratory is equipped with two noble gas mass spectrometers for carrying out 40Ar/39Ar age determinations. We have an Mass Analyser Products MAP 215-50 single-collector mass spectrometer and also a brand-new Thermo Scientific ARGUS VI multi-collector (installed March 2012) with five fixed Faraday detectors and one ion-counting CuBe electron multiplier. Here we routinely carry out incremental heating experiments and single crystal total fusions using CO2 lasers or a resistance furnace. More details you can find on our Instrumentspage.
On this web site we are also providing an overview of the variety of Projects we are currently working on, as well as an overview of the larger projects we carried about with our students and post-docs over the last 30 years. Our most recent findings you can find on the Publications page where we have highlighted some of our most interesting papers. There you will find also an exhaustive list with all our publications and student theses.
If you are interested in getting your samples age dated using the incremental heating or single crystal 40Ar/39Ar age dating method, then please follow the instructions on the Services page.