Geologists
love rocks. That is pretty much a given for people making a career choice in
the geosciences. But geologists also are hard on rocks. We are trained, Neanderthal-style,
to bash rocks in the field with hammers and other hard objects, to pulverize
them in the preparation room, and to dissolve or vaporize them in the laboratory.
As an old song title goes, sometimes you have to hurt the ones you love in order
to gain a greater good. But a greater good also involves some considerate choices
in what we destroy for science. Intact outcrops — rock formations exposed
at the surface (for example in road cuts) — have lasting benefits for the
education of future generations of geoscientists or as classic localities that
can aid in teaching geology to the general public.
Removal of rock samples has defaced one
of the most easily accessible outcrops of the Yates Formation back-reef dolomite
(white) and sandstone (yellow) in Dark Canyon, N.M. Photo by Peter Scholle.
Hammers and chisels have been the traditional tools of our field-based trade.
Although they can do substantial damage in terms of removing material, they
leave behind fractured surfaces that mimic what was there before. Thus, they
generally preserve substantially unimpaired the visual benefits of an outcrop,
allowing geologists to sample with clear conscience virtually any locality for
which they have access and permission. The development, over the past decade
or two, of modern geologic weapons of mass destruction — powered rock drills
and saws, and even explosives — has changed that equation substantially.
Individual relatively small drill holes, craters left where rock saws have done
their work, and cavern-sized openings where larger power saws or explosives
have been employed do not leave natural-looking scars. Evidence of their use
will remain as unsightly markers literally for hundreds of thousands of years
or longer. Spray-painted markings of sample numbers or stratigraphic designations,
while less enduring, still form unsightly graffiti that will visually impact
subsequent visitors for many years to come, to the discredit of the entire geoscience
community.
Outcrops victimized by mechanized equipment abound in the famous Permian reef
complex in the Guadalupe Mountains of New Mexico and western Texas. Although
not an especially lofty or scenic mountain range, the Guadalupe Mountains nevertheless
expose one of the finest examples of an ancient reef and associated deposits
found anywhere in the world. Rising from insignificant hills near Carlsbad to
cliffs of 1,000 meters and more at the south end of the mountains, this area
allows someone to walk from an ancient basin floor upslope to the exposed ancient
reef that forms the skyline rim of the range. From there, a person can walk
or drive westward through a variety of ancient shelf deposits of limestone,
dolomite, sandstone and gypsum.
The range is home to two national parks (Guadalupe Mountains and Carlsbad Caverns)
that have helped to preserve these unique rocks. Although most of the vandalized
sites are outside the parks, they nevertheless are classic geological sites,
described in dozens of field trip guidebooks and visited annually by hundreds
to thousands of academic and industrial geologists as part of field courses.
One locality is just a few tens of feet from the entrance to Carlsbad Caverns
National Park, and involves an outcrop that had been cleaned and gently etched
with hydrochloric acid by many geologists over the years for better viewing
of its spectacular biological and sedimentary structures. The other sites are
from fossil reefs and related deposits that are wonderful resources for understanding
the fauna and environmental setting of the petroleum-producing rocks of this
region — a region that bears striking similarities to modern limestone-forming
areas such as the Bahamas.
These other sites have had many of their best fossils and sedimentary structures
removed with rock saws and are now gouged with unsightly pits that range in
size from tens of centimeters to meters in surface diameter and depth. Similar
damage can be found at other Guadalupe Mountains localities and at many other
superb outcrops throughout the United States (including ones along the Colorado
River in the Grand Canyon region that will continue to offend the sensibilities
of rafters in that area for millennia to come).
Although I know some of the geologists responsible for the destruction at these
sites, I do not know all of them. I have little doubt, however, that their work
was worthwhile, or at least potentially worthwhile. The point is not to stop
such sampling where it has a valid purpose. But at the risk of becoming known
as the Emily Post of geology, let me suggest that there should be some sense
of etiquette, and some consideration for the rest of the geoscience community
and the public, both now and in the future.
The same or similar samples could have been obtained, albeit with a bit more
effort, at some nearby, far less-visited and less-photogenic outcrop. I understand
that the sampling equipment, the water required to cool such machinery and the
obtained samples are heavy. But permanently defaced oft-visited outcrops are
also a “heavy” price to pay for convenience. Some of this destruction
was done by graduate students as part of thesis projects. Their graduate advisors
bear a substantial share of the responsibility; a discussion of suitable sampling
methodologies and localities should have been part of their advising process.
There are many rock outcrops in this country, but only a limited number that
are frequently used for teaching. We should all be working to protect those
classic outcrops, and we should be training students to do the same. Let’s
not become known as the utterly self-centered “me generation” of geologists,
and let’s get our act together before laser and nuclear field equipment
is developed.
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