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No. 59: Sep-Oct 1988

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IS THERE TRUTH IN THE GRAINS?

Scientific creationists often come up with fascinating minor phenomena in geology, which, as far as most geologists are concerned, have already been satisfactorily explained and are now forgotten. Creationists exhume these tidbits because they can sometimes be interpreted as support for a "young earth" or some other cornerstone in creationist thinking. Of course, the true anomalist has a broader appetite, savoring any unexplained phenomena, regardless of which theories they support or undermine.

But that is enough palaver, creationist D.E. Cox has resurrected the quartz-sand-grain anomaly:

"Uniformitarian geologists, and many creationist geologists as well, interpret sandstones as sedimentary or aeolian accumulations of sand grains. Quartz arenites, for example, are supposed to be detrital accumulations of quartz grains derived from pre-existing formations. The source rocks may have either been igneous or sedimentary, but ultimately most quartz grains in sediments must have an igneous parent rock, probably granite, since this is the most abundant igneous rock on the continents. The quartz derived from granite is characterized by the presence of tiny mineral inclusions. Crystals of mica, rutile and tournaline are common. In sandstones formed from granite-derived quartz grains, mineral inclusions should be evident, but they are rarely present in sand-stones."

The accepted explanation of this apparent anomaly is that the inclusions in fresh, granite-derived quartz grains so weakened the grain structure that the flawed grains are quickly broken up during weathering, transportation, and deposition. By the time any sandstone is formed, only flawless bits of sand remain. Case closed.

No anomalist worth a grain of salt would let this delightful phenomenon escape without a bit more study.

  1. Do young sandstones with identifiable granitic sources show more inclusions than older sandstones?
  2. Do desert sands, beach sands, and other unconsolidated quartz grains show any flaws?
  3. Has anyone really examined fresh quartz grains weathered from granite to determine how the number of flaws in a grain varies with the grain size?

(Cox, Douglas E.; "Missing Mineral Inclusions in Quartz Sand Grains," Creationist Research Society Quarterly, 25:54, 1988.)

Comment. Most geologists will complain that we are going out of our way to make trouble. But consider the possibility that some unflawed quartz grains in sandstones may have actually been precipitated from gases and fluids and not be granitic at all. And what about those sandstone dikes and other sand-stone intrusive bodies? Where did their quartz grains originate? Not all sandstone is sedimentary.

From Science Frontiers #59, SEP-OCT 1988. � 1988-2000 William R. Corliss