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For anyone who has coasted into Walsenburg from the top of La
Veta Pass, the Spanish Peaks are a familiar sight A double-dose
of rugged beauty, the twin peaks dominate the surrounding
landscape. I hope, as long as I live in this area, that I never
take the unparalleled views for granted. Surely the Spanish
Peaks offer one of the most spectacular vistas anywhere.
I suppose each time I drive by the peaks, I should be inspired
to ask deep questions about the meaning of life and contemplate
my existence in the universe. As poetic as those snow-capped
ridges may be, though, I find my attention is always diverted to
a few odd formations at the base of the peaks. The only question
that comes to mind is, "What are those darned things?"
Mysterious walls
I'm referring to those long, thin, vertical rock walls that rise
up out of the ground. Like spokes on giant wheel, they radiate
outward in straight lines from the base of the Spanish Peaks.
Are they great walls erected by an ancient civilization? Do they
point to some secret alien refueling station inside the peaks?
(Hey, it's only 270 miles from Roswell!) Or are they natural?
And, if so, why are they so tall and thin? Why do they stick up
out of the ground? How did they form?
As it turns out, the walls are quite fascinating, but not much
of a mystery. They are natural, of course, and provide one of
the best known examples of interesting geological structures
known as "dikes." In fact, the Spanish Peaks dikes are often
featured in geology textbooks because they so prominently
illustrate the concept.
Looking back
To understand how the dikes of the Spanish Peaks were formed, we
must go back in time. Ninety million years ago, the eastern
two-thirds of what is now Colorado was covered with a shallow
sea. The western third, where land was slightly higher than the
sea, consisted of coal swamps and floodplains. Over time, the
seas receded as land rose during the birth of the Colorado
Rockies.
Twins are born
The Spanish Peaks formed when twin pools of magma (hot, liquid
rock) began pushing their way up towards the surface. The older,
overlying rock bent and slowly rose over each pool as the magma
pushed upward forming two large, dome-shaped humps. The magma
never quite forced its way through the overlying rock to spew
onto the ground forming a volcano. Still, the pressure on the
older rock was so intense, huge cracks formed beneath the
surface that radiated outward from the domes. (Much like a rock
chip in a windshield may send cracks out in all directions
without completely penetrating the windshield.) Molten rock
squeezed into the cracks and then began to cool and harden.
A
vanishing world
Over time, the slow but powerful force of erosion began carving
away on first the older, overlying rock and eventually the newly
exposed hardened magma. But the hardened magma was (and still
is) stronger than the softer surrounding rock. It has eroded at
a slower rate and now stands above the rock which once hid it.
More than just geologic oddities, the dikes are a reminder of
another world--one separated from us by the distance of time.
Worth the drive
A number of dikes can be easily seen in the distance from
Highway 160 on the way in to Walsenburg. But for a close-up look
at several of the dikes, and for a scenic and interesting drive
in general (a sharp eye will likely be rewarded with the sight
of wild turkeys), take Highway 12 out of La Veta to Trinidad. At
the town of Stonewall you will drive right through a thin,
vertical rock wall. This particular wall, though, is not a dike.
It is made of older sandstone tilted up on its side from the
awesome forces of mountain building millions of years ago. As
you near Trinidad, you will begin to notice seams of coal in the
exposed roadcuts, evidence of the swamps existing in the area
before the mountains formed. Some of the numerous old coal mines
in the area are still active.
A
lesson from the dikes
Whether or not you someday drive scenic Highway 12, the next
time you find yourself coasting down La Veta Pass towards
Walsenburg, take a good look at the dikes in the distance. While
their natural history is interesting, their significance lies in
what you don't see when you look towards the Spanish Peaks. The
dikes are visible only because a past world has been washed
away. As Gus McCray said in Lonesome Dove, "Yesterday's gone and
you can't get it back." If the sight of the dikes inspires you
to ask a question, I hope it is, "What will I do, while it is
still today?"
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