The Relevance of Rb-Sr, Sm-Nd, and Pb-Pb Isotope Systematics to Elucidation of the Genesis and History of Recent Andesite Flows at Mt. Ngauruhoe, New Zealand, and the Implications for Radioisotopic Dating | The Institute for Creation Research
 
The Relevance of Rb-Sr, Sm-Nd, and Pb-Pb Isotope Systematics to Elucidation of the Genesis and History of Recent Andesite Flows at Mt. Ngauruhoe, New Zealand, and the Implications for Radioisotopic Dating

Download PDFDownload The Relevance of Rb-Sr, Sm-Nd, and Pb-Pb Isotope Systematics to Elucidation of the Genesis and History of Recent Andesite Flows at Mt. Ngauruhoe, New Zealand, and the Implications for Radioisotopic Dating PDF

Presented at the Fifth International Conference on Creationism, Pittsburgh, Pennsylvania, August 4–9, 2003 and published in: Proceedings of the Fifth International Conference on Creationism, R. L. Ivey Jr. (Ed.), pp. 285–303.

© Copyright 2003 by Creation Science Fellowship, Inc., Pittsburgh, Pennsylvania, USA. All Rights Reserved.

Abstract

Mt. Ngauruhoe in the Taupo Volcanic Zone of New Zealand erupted andesite lava flows in 1949 and 1954, and avalanche deposits in 1975. Rb-Sr, Sm-Nd, and Pb-Pb radioisotopic analyses of samples of these andesites, as anticipated, did not yield any “age” information, although the Pb isotopic data are strongly linear. When compared with recent andesite flows from the related adjacent Ruapehu volcano, the Sr-Nd-Pb radioisotopic systems plotted on correlation diagrams provide information about the depleted mantle source for the parental basalt magmas and the source of the crustal contamination that produced the andesite lavas from them. The variations in both the depleted mantle Nd “model ages” and the Pb isotopes also suggest radioisotopic heterogeneity in the mantle wedge 80 km below the volcano where partial melting has occurred, contaminated by mixing with trench sediments scraped off the interface with the subducting slab. Thus the radioisotopic ratios in these recent Ngauruhoe andesite flows were inherited, and reflect the origin and history of the mantle and crustal sources from which the magma was generated. By implication, the radioisotopic ratios in ancient lavas throughout the geologic record are likely fundamental to their geochemistry, characteristic of their origin and history rather than necessarily providing valid conventional “ages.”

Keywords

Andesite, 1949–1975 flows, Mt. Ngauruhoe, New Zealand, Rb-Sr, Sm-Nd, Pb-Pb, Radioisotopes, Petrogenesis, Depleted Mantle, Magma Genesis, Crustal Contamination, Subduction, Mixing, Inherited Radioisotopic Ratios, Invalid Conventional “Ages”

For Full Text

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

The Latest
CREATION PODCAST
What Can You Expect from the ICR Discovery Center?
ICR scientists and scholars share their perspectives on the soon-to-open ICR Discovery Center for Science & Earth History. The Grand Opening for...

NEWS
Australopithecus Ate Like an Ape
Tim Clarey, Ph.D., and Jeffrey P. Tomkins, Ph.D. Secular scientists are continually trying to humanize ape fossils in an attempt to bridge the wide...

NEWS
DNA Repair Research Reveals Astounding Complexity
You have been designed with many trillions of cells. Within the nucleus of each cell (except for red blood cells) is the “molecule of life”...

NEWS
Photosynthesis: Clearly Designed from the Beginning
Unique structures in rare bacteria suggest the amazing process of photosynthesis is much “older” than evolutionists assumed. Photosynthesis...

NEWS
Under the Stars at ICR
On the evening of Friday, August 2, 154 creation enthusiasts attended an astronomy-themed evening at the ICR Discovery Center for Science and Earth...