Potassium argon dating labs
The rock samples are crushed, in clean equipment, to a size that preserves whole grains of the mineral to be dated, then sieved to help concentrate these grains of the target mineral.The selected size fraction is cleaned in ultrasound and acid baths, then gently oven-dried.Young rocks have low levels of Ar, so as much as several kilograms may be needed.Rock samples are recorded, marked, sealed and kept free of contamination and excessive heat on the way to the lab.
Developed in the 1950s, it was important in developing the theory of plate tectonics and in calibrating the geologic time scale.
That is, a fresh mineral grain has its K-Ar "clock" set at zero.
Apr 13, 2015. This K/Ar apparatus was originally built in the early 1970's and has been updated with a microcomputer controlled MS-10 mass spectrometer. The laboratory has tackled various problems including the dating of ash from the Lucy Fossil site in Ethiopia to constrain Lucy's age, and the dating of clay mineral.… continue reading »
Brief History of the Potassium-‐Argon Dating Laboratory in the ANU. 1960 to 2000. The laboratory was initiated by Professor J C Jaeger, head of the Department of. Geophysics, Research School of Physical Sciences RSPhysS, in 1960, the first K/Ar laboratory in Australia. There are now four laboratories in Australia.… continue reading »
How K-Ar dating can be used to date very old volcanic rock and the things that might be buried in between. In the lab samples are heated from 300°C to the melting point to release the trapped Ar. How do we know how much of a given isotope is inside something, whether it be finding carbon 14 or potassium/argon?… continue reading »
K-Ar dating is based on measurement of the product of the radioactive decay of an isotope of potassium K, which is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites, into argon. The decay product 40 Ar starts to accumulate when the rock solidifies recrystallises. Time since.… continue reading »