Mica, Mica in the Sand, Tell Us Something Really Grand!

My graduate school professor,
Dr. Steve Austin, was a serious
field geologist. But periodically,
his childlike delight in exploring
God’s creation shone through.
He taught us to let the rocks and the
earth “speak to us,” as Job 12:8 (NKJV)
said several millennia ago. While on
field trips, he would ask us to consider
how large boulders ended up on
mountain slopes of the Anza Borrego
Desert. He would say—and I’m not kidding—“Boulder, boulder on the ground,
tell us something really profound!”

I learned well from my professor
and have come to apply his rhyme not
only to boulders but also to small sand
grains.

Hidden Treasures in Grand Canyon

Photo courtesy DR. JOHN H. WHITMORE

For some time now, I have been
studying a famous layer of yellow rock
known as the Coconino Sandstone
found in the walls of Grand Canyon.
Other creationists and I have devoted
many years to this sandstone because
most other geologists interpret the
sandstone as sand dunes that formed
in an ancient desert some 275 million
years ago and later fossilized (hardened
into rock). How different from
the view that Noah’s watery flood
laid down these layers quickly around
4,300 years ago!

Conventional geologists know the
Coconino is a problem for those of us
who trust the accuracy of the Noah’s
flood account described in Genesis
6–9. They have used the Coconino to
try to make creationists look foolish—because you cannot have a desert in
the middle of a global flood.

The answer requires arduous field
work and looking closer in the laboratory—a lot closer—under the microscope.
For the answer is granular, literally
looking at sand grains.

Sandstone is made up of sand grains
cemented together. As my team started
to study the Coconino, our goal was
to observe the sandstone in as many
locations as we could. During the process,
we collected many rock samples
so we could examine the details under
the microscope. We also visited many
modern sand dunes in deserts so we
could examine their windblown processes
and sand grains carefully and
then compare the two.

What’s Missing in Windblown Desert Sand?

We noticed almost right away one
astonishing difference between the
Coconino sand and the sand grains
of modern sand dunes. We weren’t
surprised to find that by far the primary
mineral is quartz, because
quartz is chemically resistant and
hard (7 on a scale of 10). It is the same
mineral used to make window glass.
About 90% of the Coconino sand
grains are also composed of quartz.
However, Coconino has another common
mineral that is not so common in
desert sand.

In almost every one of the 400
microscope slides of Coconino that we
observed, we found the mineral muscovite.
What’s that? Well, it is a silver-colored
type of mica that is extremely soft
(2.5 on a scale of 10)—about the same
hardness as your fingernail. All types
of mica are flexible and can peel apart
into paper-thin sheets, thin enough so
that light can easily pass through. (We
carefully looked for micas in our desert
sand dune samples, but we found none
except for when the sand was in close
proximity to a mica source like granite.)

As we thought about our observations,
we realized that mica is so soft
that it probably was chewed up quickly
in desert settings as grains of quartz
violently collided during strong winds.
But how could we test this?

A Test

Alex, a Cedarville University geology
student who was on the team, came
up with an ingenious experiment. He
attached a model airplane motor and
propeller to a large pickle jar, with the
blade sticking into the jar. He placed a
small amount of muscovite-rich sand
into the jar. He then adjusted the speed
of the propeller so the sand moved
slowly around the bottom of the jar similar
to a small migrating sand dune.

He collected small amounts of
the sand at regular intervals to see
what was happening to the mica. We
expected that the experiment might
have to run a month or longer. But to
our surprise, the mica quickly disappeared
after four days.

A second experiment was devised
to test the durability of mica when
transported by water. Another Cedarville
geology student used the same
sand source and pickle jar that Alex
had used. This time water was added,
and the jar was rotated sideways on a
rock tumbler. Again, we expected we
might have to run the experiment for
a month. But visible mica flakes could
still be seen tumbling around in the
sand after a year of continuous motion.

We decided that we could end our
experiment at that time. By the way,
the research was published in the
journal Aeolian Research, which specializes
in research regarding sand
dunes and their processes.

Something Really Grand

The experiments confirmed that
fragile mica grains are chewed up
quickly in desert environments. However,
if the quartz-mica mix is submerged,
water cushions the collisions.

The results of our experiments
are consistent with other real-world
observations, which have been published
in journals like Sedimentology and Earth-Science Reviews. Researchers
have found that mica grains are quite
abundant on the beaches along the
coast of the African nation of Namibia.
The ocean has carried this sand northward
along the coast for hundreds of
miles, but the mica survived the entire
way despite the chaotic surf.

But guess what? Strong winds have
picked up some of the sand and carried
it inland to the massive dunes of
the Namibian Desert. Mica cannot be
found in these sand dunes, even short
distances away from the beach. The
researchers surmised that mica either
gets quickly broken down or wafted
away by the wind.

Now, back to the Coconino. If it were
a vast desert deposit, as purported by
secular geology, then why is there so
much mica? This soft, shiny, inconspicuous
mineral is trying to tell us
something really grand. Instead of
being an embarrassment to the creation
geologist, the Coconino Sandstone
is a powerful testimony to formation
of this rock under the waters
of Noah’s flood.

Mica, mica in the sand, tell us something
really grand!

Formation of the Coconino Sandstone—Water Not Wind

The massive sedimentary strata
known as the Coconino Sandstone
in the Grand Canyon is one of the
most common formations used
as evidence against the Genesis
flood. Secular geologists say it was
formed in a desert over millions
of years. The debate is whether its
fossilized sand dunes were formed
by wind or under water. Features
would be very different under these
two conditions.

Gentle Slopes. In modern windblown
deserts, dry sand avalanches
at a steep angle of about 34°. The
Coconino does not have steep
angles—the average is only about 20°.

Different Grain Sizes. Sand grains
in desert dunes are usually very
similar in size, or well sorted,
because the wind carries only select
sizes. However, Coconino sand
grains are many different sizes,
moderately to poorly sorted.

Jagged Sand Grains. In deserts, sand
grains forcefully collide with each
other, chipping off most of their
sharp, angular corners. Therefore,
many sand grains in deserts are
rounded. The Coconino, by contrast,
is composed of sand grains with
sharp, angular corners.

Winds in modern deserts blow sand grains into large piles
called sand dunes. As sand grains collide with each other, the
grains become rounded and get sorted by size. The piles of sand
eventually collapse (avalanche), forming steep deposits called
cross-beds. The angle is usually around 34°.

Under the ocean, strong water currents can leave piles of
sand grains in large dunes. However, because water can cushion
sand grain collisions better than air, the grains do not become
rounded and a variety of sand sizes get mixed together. Water
currents cause the piles of sand to collapse at lower angles than
those found in deserts, forming gentler cross-beds with angles
of about 20°.”

SourceThis article originally appeared on answersingenesis.org

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