[CPProt.net] Pilfering part of prehistory. Thieves hit Mojave's fossil sites

[MSN CPPnet (Ton Cremers)]

Pilfering part of prehistory

Thieves hit Mojave's fossil sites

August 5, 2005

By Chuck Mueller, Staff Writer

It probably took less than an hour for vandals to chisel out the fossilized
tracks of long-extinct camels that roamed the Mojave Desert 15 million or
more years ago.
Four heart-shaped tracks of two-toed camels were removed from an overhanging
mudstone ledge capped with a layer of rock-hard volcanic ash.

"This is a profound loss to science and all of us,' said Robert Hilburn,
president of Barstow's Mojave River Valley Museum, who discovered the
desecration of the rare fossils while leading a group of hikers up a sandy
wash recently in the desert north of Barstow.

The fossil site is in the Rainbow Basin Natural Area, which gets its name
from its colorful, sedimentary rock formations.

Fossilized remains of the oldest North American mastodon, tiny prong-horned
antelopes and camels have been unearthed at the site, along with fossils of
ancient rhinos, three-toed horses and a fearsome creature called a bear-dog,
Redlands paleontologist Robert Reynolds said. 

During the Miocene epoch, which occurred from 5 million to 21 million years
ago, prehistoric camels fed on native grasses that flourished along the
shore of an ancient inland sea. Unlike today, the region was subtropical,
with stands of palm trees amid arrays of shrubs.

"These animals were walking along the edge of the inland sea, creating
footprints in mud on the shore,' Hilburn said. "Sometime later, volcanic
eruptions blanketed the region in ash. Heat, pressure and time then turned
the mud into stone.'

The fossilized tracks of the camels were protected from wind, rain and
intense sun by a 6-inch-thick overhanging layer of volcanic ash, pressed
into stone.

Visitors on 4-wheel drive or all-terrain vehicles have looted or damaged
hundreds of prehistoric sites throughout the Mojave during the past
half-century. It's virtually impossible to protect these locations in an
18,000-square-mile region, despite their remoteness in canyons and caves or
high on sides of cliffs.

"There are thousands of known archaeological sites,' said Joan Oxendine, an
archaeologist with the U.S. Bureau of Land Management for the past 21 years.
"An inventory conducted in the early 1980s for the California Desert Plan
determined that 36 percent of these sites were already damaged.'

Bureau geologist Ken Schule said destruction of petroglyphs and fossils is
extensive.

"A lot of vandalism has occurred at Inscription Canyon near Barstow over an
undetermined period of time,' he said. "The problem is quite severe, but we
don't have enough rangers to patrol the area.'

An extreme example of site desecration occurred in the early 1970s, said
Reynolds, consulting paleontologist with LSA Associates of Riverside.

"Petroglyphs (Indian wall paintings) at Black Canyon northwest of Barstow
were dynamited by people who thought they were maps for hidden treasure or
lost gold mines beneath the site,' he said. "Of course, no treasure was
found there.'

In an effort to protect a petroglyph area in a canyon in the Rodman
Mountains near Newberry Springs, the Bureau of Land Management installed
pipe barriers in the 1970s to prevent visitors from entering the canyon.

"Vandals used pipe-cutters to cut the pipes and haul them off,' Hilburn
said.

Despite severe penalties, vandals and others determined to profit through
black-market sales of remnants from the past wreak havoc at archaeological
sites.

"It's extremely difficult to protect these places,' Oxendine explained.
"However, if someone is caught damaging a site they could face a fine of up
to $100,000 or a substantial prison term. And new federal legislation is
being introduced that could impose a 10-year prison sentence and severe
fine.'

Meanwhile, scientists and educators aren't standing by idly in their efforts
to save the Mojave's rich archaeological and geological treasures for
posterity.

In the case of fossil sites, paleontologists on professional excavations
cover untouched fossils with sand or soil for future digs without leaving
hints of where they lie.

Or they try to educate youngsters, as early as third grade, in the intrinsic
value of petroglyphs, fossils and other cultural resources.

"Through our junior naturalist program, we teach kids to be environmentally
responsible,' said Rose Foster-Beardshear, program coordinator at Barstow's
Desert Discovery Center. "It's vital to protect the wonders of our desert
because once they are lost, they are gone forever.'

There is another way to save the images from the past.

Reynolds, Hilburn and volunteers from the Mojave River Valley Museum
reproduce copies of the fossils through the use of silicon rubber molds.

Working in the intense heat of summer, they painstakingly place a
petroleum-based mold release compound over the native rocks to ensure that
fossilized tracks are not damaged.

After 48 hours, team members retrieve the ancient images, add a fabric
backing and then peel the mold from the rock.

At the Desert Discovery Center on Barstow Road, the rubber molds are cleaned
and readied for casting. Plaster, plastic or concrete is poured over the
molds to create a life-sized replica of the fossil tracks.

"By adding an appropriate pigment, the replicas are easier to see and last
longer than originals,' Reynolds explained.

And without these images, he said the scientific world has lost a marvelous
and fundamental record of the desert's prehistory.