Salt
dome, meteor impact, or neither?
In
several previous Pictures of the
Day, the catastrophic nature of
geological formations around the
world were compared to the
conventional analysis based on
gradual processes of erosion,
uplift, and faulting. In nearly
every case, the slow formation
hypothesis was found wanting.
In
particular, structures in the
American Southwest exhibit signs
that they could have been created in
an amazingly short time. The stone
escarpments have
vertical sidewalls,
flat tops, and valleys wide and deep
between them. Where there are peaks
they are often sharp, with many
spiky protuberances sticking up from
their summits. These spikes are
sometimes exotically shaped, looking
like stacks of fused boulders or a
thicket of pillars.
There
are often multiple,
alternating layers
of rock that have been sculpted in
regular,
repetitive patterns
covering thousands of square
kilometers. Erosion through wind and
water is a chaotic process because
the movement of air and water
molecules aren't predictable. It is
certainly the case that erosion has
and is taking place everywhere in
the world. However, erosion causes
blurring and softening of the
landscape, by no means does it cut
like a knife, or
excavate
like a posthole digger.
Upheaval Dome
is one such geographical formation
that is difficult to account for
with standard theories. It is more
than two kilometers wide from rim to
rim and is nearly half a kilometer
deep. It was once thought to be a
collapsed salt dome because there
are many salt domes in the
Canyonlands National Park region.
According to the theory, a vast
inland sea once covered the central
portion of the United States
approximately 300 million years ago.
As time passed, the sea evaporated,
leaving the dissolved salts behind
in a thick crust.
Over
millions of years sediments were
deposited that subsequently
compressed into thick layers of
rock—sandstone layers in the case of
Upheaval Dome. The weight of the
overburden gradually pushed the salt
deeper into the earth. Since salt is
not as dense as sandstone, the
pressure caused it to become
buoyant, whereupon it rose through
weaker layers until it pushed, or
"heaved" the overlying strata into a
dome. As the sandstone eroded, it
uncovered the salt and exposed it to
the same corroding effects that,
over more millions of years bored
into the easily dissolved mineral,
causing it to collapse from within.
However, there is no definitive
evidence that an accumulation of
salt exists beneath
Upheaval Dome.
Recently, another theory has
suggested that the Dome was formed
in a so-called "rebound" event when
a meteor crashed to Earth 60 million
years ago. The original impactor is
long gone because of weathering, but
the appearance of shattercones
discovered by the late Gene
Shoemaker (for whom the comet
Shoemaker-Levy 9 was named) in the
sandstone layers around the central
mound has convinced most geologists
that it is an astrobleme, or "star
wound."
Shattercones form when impact forces
are transmitted through the rocks,
creating conical shapes of varying
size that have v-shaped grooves cut
into them. It is theorized that
explosive shock waves punch out
shattercones in much the same way
that a pellet gun will leave a
conical hole in your bay window.
Shattercones of enormous size are
found in and around a similar
circular formation called Vredefort
Dome, 100 kilometers southwest of
Johannesburg, South Africa. In fact,
Vredefort and Upheaval Domes share
many similar characteristics. They
are both multi-ringed craters with
uplifted central peaks. They both
display evidence for immense flows
of melted rock that contain chunks
of unmelted rock within. Both
contain "shocked quartz" grains:
quartz crystals that are internally
fractured, again supposedly due to
shock wave transmission.
Electric Universe theorists have
suggested in the past that electric
arcs cut crater walls and transport
large volumes of material through
electrodynamic forces. Electric
currents flowing through the rock
strata cause the rock to pulverize,
much like a pyroclastic flow from a
volcano. Once the current stops, the
material consolidates into rock-hard
mounds with high, steep faces.
Electric arcs cause subsurface
blasts, as demonstrated by
tachylites
found in the rims of both domes. The
concentric rings are reminiscent of
similar multi-ringed formations
discovered in other regions around
our planet, as well as on other
planets and moons. Perhaps a big
rock from space is no more
conclusive a theory than a collapsed
salt dome.
Stephen Smith
Editor's note: All images courtesy
Michael Steinbacher. Visit Michael's
web page for more geological images,
as well as to see his complete
portfolio.
Contact Michael Steinbacher
to arrange personal tours of the
desert Southwest.