Orthopyroxene retains the most argon, followed by hornblende, and finally, plagioclase.
The lava dome at Mount St Helens dates very much older than its true age because phenocryst minerals inherit argon from the magma.
Being a born again Christian, I believe in a young earth This;"The mountain also provided a clear reason to distrust radioisotope dating.
Geologist Steve Austin sampled new rock from atop the mountain that formed in 1986.
Uniformitarian geologists have long claimed that these features, which are common to earth's geology, were accomplished over great lengths of time. After hundreds of additional earthquakes, a steam explosion on March 27 blasted a crater through the volcano's ice capped summit.
Within a week the crater had grown to about 1,300 feet in diameter and two giant crack systems crossed the entire summit area.
Austin The conventional K-Ar dating method was applied to the 1986 dacite flow from the new lava dome at Mount St Helens, Washington.
Porphyritic dacite which solidified on the surface of the lava dome in 1986 gives a whole rock K-Ar ‘age’ of 0.35 ± 0.05 million years (Ma).
by Tas Walker It was not until I visited Mount St Helens volcano in Washington State, USA, that I fully appreciated the immensity of its 1980 explosion.
Over many years, I had learned a lot about the eruption, watching videos, listening to lectures, and reading reports.
Later, a catastrophic flood of snowmelt water and muddy debris tore a gash through those fresh deposits, revealing sharp and flat contacts between each earlier deposit.