The Geology of Gentry's "Tiny Mystery"The Geology of Gentry's "Tiny Mystery"(Converted for HTML using
FrontPage 97 in March of 1997, colour images are for this
website)
(Originally published in the May 1988 Issue of the Journal
of Geological Education)
ABSTRACT
The unusual polonium halos described by Robert
Gentry have been a problem for some years now. Gentry claimed
that the polonium halos show that the Precambrian granite they
are hosted in were 'instantly created.'
Some research on the halos has been carried our by other
scientists, but most of it has been aimed at solving the problems
of the peculiar configuration of these halos. Fortunately, Gentry
provided two specific site locations in the Canadian Shield where
his samples came from. The geological setting of these sites
shows conclusively that Gentry’s notion of an 'instantly
created' earth composed of granite is false. Specifically the
samples came from crystallized rocks which can be shown to
crosscut several sedimentary and other plutonic rocks. Some of
the sedimentary rocks contain stromatolites. The geology of the
sites shows that the uranium, and most likely the polonium, were
deposited via postmagmatic hydrothermal fluids. Besides ignoring
the geology at his collection areas, Gentry also makes numerous
grossly erroneous generalizations about the origin of plutonic
rocks.
CONTENTS
Introduction
Gentry's
Basic Premise
Geology
of the Canadian Sites
Precambrian
Geology and Instantaneous Creation
Crystal
Sizes and Pegmatite Dikes
Sequence
of Rock Formation
Conclusion
References
Cited
Gentry Pays a Visit! [future]
Reply to Gentry's Reply [future]