Ar 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. 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 Cu Be electron multiplier.
Ar age data that appeared in more than 195 peer-reviewed publications and in 31 Senior, MSc and Ph D theses.
The Ar technique can be applied to any rocks and minerals that contain K (e.g. method is also used to date a myriad of other geological events such as volcanism, tectonic plate movements, mountain building rates, sediment formation, weathering and erosion, hydrothermal fluid movements, and alteration and diagenesis of minerals. The main advantage of Ar-Ar dating is that it allows much smaller samples to be dated, and more age and composition (e.g.
Ca/K) information can be obtained from each sample.
Generally, we expect all users to carry out their own mineral separations.
Therefore, mafic rocks and minerals often contain less potassium than an equal amount of silicic rock or mineral.What simplifies things is that potassium is a reactive metal and argon is an inert gas: Potassium is always tightly locked up in minerals whereas argon is not part of any minerals. So assuming that no air gets into a mineral grain when it first forms, it has zero argon content.That is, a fresh mineral grain has its K-Ar "clock" set at zero.However, the Argon, a noble gas, constitutes approximately 0.1-5% of the Earth's present day atmosphere.Because it is present within the atmosphere, every rock and mineral will have some quantity of Argon.Lava flows that lie above and below rock beds with ancient human fossils are a good—and true—example.