Excess Argon within Mineral Concentrates from the New Dacite Lava Dome at Mount St. Helens Volcano | The Institute for Creation Research
 
Excess Argon within Mineral Concentrates from the New Dacite Lava Dome at Mount St. Helens Volcano

Download PDFDownload Excess Argon within Mineral Concentrates from the New Dacite Lava Dome at Mount St. Helens Volcano PDF

Published in: Creation Ex Nihilo Technical Journal, Vol. 10, no. 3, pp. 335–343, 1996.

© 1996 by Answers in Genesis ACN 010 120 304. All Rights Reserved.

Abstract

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). Mineral concentrates from the dacite which formed in 1986 give K-Ar “ages” from 0.34±0.06 Ma (feldspar-glass concentrate) to 2.8±0.6 Ma (pyroxene concentrate). These “ages” are, of course, preposterous. The fundamental dating assumption (“no radiogenic argon was present when the rock formed”) is questioned by these data. Instead, data from this Mount St. Helens dacite argue that significant “excess argon” was present when the lava solidified in 1986. Phenocrysts of orthopyroxene, hornblende, and plagioclase are interpreted to have occluded argon within their mineral structures deep in the magma chamber and to have retained this argon after emplacement and solidification of the dacite. The amount of argon occluded is probably a function of the argon pressure when mineral crystallization occurred at depth and/or the tightness of the mineral structure. 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. The study of this Mount St. Helens dacite causes the more fundamental question to be asked—how accurate are K-Ar “ages” from the many other phenocryst-containing lava flows world-wide?

Keywords

Mount St. Helens, New Lava Dome, 1986 Flow, Dacite, Major and Trace Element Analyses, Mineral Assemblage, Phenocrysts, Mineral Concentrates, K-Ar Analyses, K-Ar Dating, Excess Argon, Excessively Old Age series

For Full Text

Please see the Download PDF link above for the entire article.

The Latest
NEWS
Did the Earth Tilt During the Flood?
Evolutionary scientists from the Chinese Academy of Sciences in Beijing and several universities in the United States, Italy, and Japan have recently claimed...

NEWS
ICR's New In-Depth Science Book: Chimps and Humans
Evolutionists frequently claim that human and chimp DNA are over 98% similar. They need this percentage to support their hypothesis that humans and...

NEWS
Fossil Chromatin Looks Young
What are the odds that a buried animal would still have intact DNA after 125 million years? Researchers publishing in the journal Communications Biology...

NEWS
Inside October 2021 Acts & Facts
How is the Lord’s handiwork on display at John Pennekamp Coral Reef State Park? Does the universe look old? What can we learn about science and...

NEWS
Two-Volume Series: Restoring the Truth about Origins
The subject of origins continues to attract interest from the public and the scientific establishment. Understanding our origins informs us of who we are...

ACTS & FACTS
Creation Kids: Floods Form Fossils Fast
Christy Hardy and Susan Windsor* You’re never too young to be a creation scientist! Kids, discover fun facts about God’s creation with...

ACTS & FACTS
A Battle for Hearts
Since the ICR Discovery Center for Science & Earth History opened in fall of 2019, tens of thousands of people have walked through our doors. They...

APOLOGETICS
Eating Bugs Isn't Always So Simple
The Lord Jesus Christ deserves glory for why He made Earth’s diverse creatures, and He also deserves glory for the complicated details of how...

ACTS & FACTS
Does the Universe Look Old?
Since distant galaxies are billions of light-years away, some understandably assume that distant starlight must have taken billions of years to reach...

ACTS & FACTS
Hawaii Behind the Scenes
ICR Research Scientist Dr. Brian Thomas and ICR Video Producer Clint Loveness, with help from friends and family, recently shot footage in Maui, Hawaii,...