Whole-Rock K-Ar Model and Isochron, and Rb-Sr, Sm-Nd, and Pb-Pb Isochron, "Dating" of the Somerset Dam Layered Mafic Intrusion, Australia | The Institute for Creation Research

 
Whole-Rock K-Ar Model and Isochron, and Rb-Sr, Sm-Nd, and Pb-Pb Isochron, "Dating" of the Somerset Dam Layered Mafic Intrusion, Australia

Download PDFDownload Whole-Rock K-Ar Model and Isochron, and Rb-Sr, Sm-Nd, and Pb-Pb Isochron, "Dating" of the Somerset Dam Layered Mafic Intrusion, Australia PDF

Presented at the Fifth International Conference on Creationism, Pittsburgh, Pennsylvania, August 4–9, 2003. Published in: Proceedings of the Fifth International Conference on Creationism, R. L. Ivey (Eds.), pp. 305–324, 2003.

© 2003 Creation Science Fellowship, Inc., Pittsburgh, PA, USA. Published with permission. All rights reserved.

Abstract

The Somerset Dam layered mafic intrusion in southeast Queensland, Australia, has been conventionally dated as Late Triassic by the apparently successful application of radioisotopic dating techniques. Mineralogical, geochemical, and isotopic evidence indicates that all of this gabbro intrusion’s cyclic units were derived coevally from the same parental basaltic magma, with an initial homogeneous
isotopic mixture ideal for yielding concordant isochron ages. However, newly obtained K-Ar, Rb-Sr, Sm-Nd, and Pb-Pb radioisotopic data from 15 whole-rock samples (representing all gabbro macrolayers in four of the intrusion’s cyclic units) yield discordant isochron “ages,” although the excellent-fitting 15-point K-Ar isochron suggests the resultant 174±8 Ma “age” (Middle Jurassic) should be regarded as the revised conventional age of the layered intrusion. Nevertheless, it is concluded that these discordances between the radioisotope systems are likely due to changes in their decay rates in the past, with the longer half-life β-emitter 87Rb being accelerated more and thus yielding an older “age.” Furthermore, the Sr, Nd, and Pb isotopes indicate the parental basaltic magma was derived from a depleted mantle source, while the large spread of Nd TDM “ages” suggests accelerated radioisotopic decay rates during the partial melting and magma ascent. It is concluded that the Somerset Dam layered mafic intrusion has inherited the radioisotopic signature of its mantle source, and so the conventional radioisotopic dating techniques do not provide its true age.

Keywords

Gabbro, Layered Intrusion, Australia, Potassium-Argon, Rubidium-Strontium, Samarium-Neodymium, Lead-Lead, Radioisotopic Dating, Whole-Rock Model “Ages,” Whole-Rock Isochron “Ages,” Discordances, Decay “Constants,” Accelerated Decay, Mantle Source Inheritance

For Full Text

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

The Latest
CREATION.LIVE PODCAST
Searching for Truth Across the Globe | Creation.Live Podcast:...
How can we bring the Gospel of Jesus Christ and the truth of creation to others outside our small spheres of influence?   Host...

NEWS
Marine Mammals: Designed for Deep Diving
While you’re reading this, hold your breath. What is now happening is your blood is delivering the last of oxygenated blood cells to your tissues...

CREATION PODCAST
Humanity's Demise at the Hands of Genetic Entropy | The Creation...
Welcome to the fourth episode in a series called “The Failures of Old Earth Creationism.” Many Christians attempt to fit old earth...

NEWS
''Inside-Out'' Fossil is Amazingly Preserved
It is widely known that vast numbers of fossils—vertebrate and invertebrate—have been discovered incredibly well-preserved.1,2...

NEWS
The Resurrection and the Origin of Life
At Easter time we focus on the cardinal Christian doctrine of the Resurrection. Without the Resurrection, Christianity is a sham. The truth that Jesus...

NEWS
Is an Ancient Extinct Tree-Dweller Our Relative?
Human evolution has always been hazy with seemingly as many attempted explanations for how we evolved from animals as there are paleoanthropologists. Evolutionists...

NEWS
The Return of the Dire Wolf?
There’s been much recent excitement about the birth of three dire wolf (Aenocyon dirus) puppies by a Dallas-based biotech company: Colossal Bioscience....

CREATION PODCAST
Cracks in the Layers: Lake Suigetsu and the Old Earth Illusion...
Welcome to the third episode in a series called “The Failures of Old Earth Creationism.” Many Christians attempt to fit old earth...

NEWS
Fish Fossil Vomit
A rather unsavory news story recently appeared regarding fossilized vomit. Although it’s hardly dinner table conversation, it nonetheless supports...

NEWS
Dino Footprints Down Under
Dinosaur trackways1 are once again making the news. Australia is the setting of a remarkable series of dinosaur tracks attributed to ornithischian...