The 213 nm ultra-violet laser is capable of high-resolution (up to 10 µm beam size) ablation of any mineral, allowing detailed analysis of individual mineral grains.
The infra-red laser (continuous wavelength 60W 1064 nm Nd-YAG) is capable of spot analysis (100-300 µm spot size), single grain total fusion, and incremental laser step-heating of K-rich minerals and whole rocks.
But we know that the amount as a function of time-- so if we say N is the amount of a radioactive sample we have at some time-- we know that's equal to the initial amount we have.
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.
Therefore, mafic rocks and minerals often contain less potassium than an equal amount of silicic rock or mineral.
Potassium can be mobilized into or out of a rock or mineral through alteration processes.