| The
history of the Lone Star State - the history before
the Kawakawa and Comanche, before the Spanish and the
settlers from the East - is engraved in stone. Those
rocks tell a turbulent story of environmental and biological
change that makes the present-day "crisis"
of global warming appear trivial. Aaron Reed takes the
family on a road trip into the geological past, when
parts of Texas now 1,500 feet above sea level were,
literally, the bottom of the ocean. |
Driving 300 million years into the past takes
longer than you might think, even if the destination is
only 140 miles one way. It doesn't help if you get a late
start.
Tamara, Patrick and I loaded Pete-the-dog into
the trusty Subaru and headed north on U.S. Highway 183 about
10 a.m. one recent Saturday. Our destination: the Lake Brownwood
spillway, a famed Pennsylvanian-period fossil-collecting
site.
Fossil hunting, or "fossicking"
as the Aussies call it, is one of our favorite family activities.
For me, it's a holdover from childhood, when my father would
take me out to the spoil islands dotting Aransas Bay and
we'd find mastodon teeth, Glyptotherium
(giant armadillo) scutes and fossilized sand dollars dredged
up from 16 feet below the surface as the Gulf Intracoastal
Waterway was being constructed.
Those remnants of Pleistocene-era
megafauna are relatively recent; in fact, the last of the
giant ice age mammals disappeared only about 12,000 years
ago. Most of the fossils found in Central Texas are much,
much older - dating back 60 million to 125 million years
to the Cretaceous period -- and most are of marine animals:
oysters, clams, starfish, snails, spiny urchins and their
kin. That was also the age of the dinosaurs, but since much
of Texas was under a
great inland sea at the time, terrestrial forms are
hard to come by.
Fossickers are typically cagey about their
collecting locations. I'm not going to tell you, for instance,
where I find those perfectly preserved "devil's toenails"
(giant, extinct oysters) or where that cool shark's tooth
came from, or even from which county road river crossing
you can see the meandering tracks of the giant dinosaurs
called sauropods. Some sites, though, are so extensive that
decades of fossil hunting have not exhausted them, and so
well-known that I'm unlikely to receive death threats for
writing about them here.
Such is the Lake Brownwood spillway. A Lagerstätte
of extraordinary richness, the site has yielded amazingly
detailed specimens of sea urchins, starfish, crinoids
and bryozoans
for decades.
As we drive north, we take the new, U.S. Highway
183 tollway to bypass the sprawling Austin exurbs of Cedar
Park and Leander, stop for coffee in the tiny farming community
of Briggs, and continue on through Lampasas. We have been
passing likely-looking road cuts for miles now - places
where highway engineers have blasted through layers of ancient,
fossil-bearing limestone -- and even though Cretaceous limestone
is not what we're looking for, I'm itching to add a few
specimens to my collecting boxes. North of Lampasas - almost
to the town of Lometa, in fact - a tall ridge looms to the
west of the highway.
"That looks pretty promising," Tamara
says. "It looks like a big old reef."
I agree, and we pull over onto the broad, grassy
verge and pile out of the car. Patrick, my third-grader,
is the first to make a find: a perfect sea urchin lying
at the base of the slope.
As we work our way slowly across the embankment,
it becomes clear that this is no ordinary site; the ground
is literally, liberally littered with 100-million-year-old
oysters from a genus called Texigryphea.
Tamara picks up a curving, sutured plate - the outside of
an ammonite shell. I find a small handful of the tiny, bead-like
round urchins called Salenia
mexicana.
Finally, with boxes and plastic bags full of
fossils, we get back into the car and strike out again on
U.S. 183, headed for Brownwood. We pass through Goldthwaite,
famous for an early 20th-century jaguar and for the gold
dust reportedly mixed into the asphalt of its highways.
In Brownwood, U.S. 183 merges into U.S. 84 headed west.
We eat a quick lunch at Schlotzsky's Deli - the only obvious
eatery we can see from the highway - and then take a right
on Texas Highway 279, and another on Farm-to-Market Road
2125. FM 2125 proves a pleasant drive through low, red hills
and pecan groves before dead-ending at Spillway Road.
We take a right and stop at the Brown
County Water Improvement District No. 1 office, where
we check in and sign waivers that allow us to hike down
into the spillway. I had checked the lake levels online
before we left Austin; it's important to do so before setting
out because any water coming over the low dam puts the fossil
site off-limits. Following the lake patrol officer's directions,
we drive down the hill and park in the designated area.
A short walk across the low-water bridge and up a rutted
track that meanders across a hill, and the gorge is spread
out below us.
The thing that strikes me - after the surprise
of just how deep the valley is and how rugged the terrain
- is the colors. Alternating layers of limestone and shale
paint the valley in reds, creams and greens. We clamber
down into the first broad plateau of what must be a three-stage
waterfall when the lake is overflowing.
Huge, red boulders are covered with the tracks
and burrows of what must have been some pretty large critters
- perhaps crabs, perhaps something else - and Patrick immediately
finds a nice slab of limestone with crinoid stems and lacey
pieces of bryozoan colonies embedded in it. As we work our
way down, it becomes obvious that there has been considerable
digging and chipping into the shale layers below some thick
limestone overhangs. I concentrate my efforts there, and
am soon rewarded with some small, irregular plates topped
with the compressed remains of urchins.
It's midafternoon by now, time to move on to
the Wilson Clay Pits.
Wilson's, as it is commonly known, is another
Pennsylvanian
site - an old quarry - where nearly all the finds are on
the surface. The problem is finding the site. I had turned
to Ed Elliott, president and field trip director of the
Paleontological
Society of Austin, and was following his directions.
Taken over the phone, the directions sounded
like this: "Go left a few miles, come to a stop sign
- the crossroad is 585. Go straight across. As soon as you
get across the road it should be gravel. Very shortly, in
a few hundred yards, you'll see a road that curves off to
the right - go left. You will see a graveyard. Stay on that
road. It winds back and forth, back and forth. Come across
a creek and cross into Coleman County. Shortly after crossing
Mud Creek, come back up and you should be able to see a
good distance to either side. There's a crick in the road
and a house on the left. Right when you pass that house,
the quarry is on the right."
Following those directions, we find the site:
huge mounds of red and green material heaped behind a barbed-wire
fence. As we slowly drive past, reconnoitering, we spot
two horsemen atop one of the hills. They wave, raising beer
cans in salute, and I snap a quick photo.
"Do you think maybe you should tell them
what we're doing here?" Tamara asks as I get back into
the car. "Maybe they own the place."
Elliott had already explained that, though
the quarry is in private hands, the owner of the defunct
site welcomes fossil hunters and we should just crawl through
the barbed-wire fence.
"Oh, I doubt they have anything to do
with the place," I reply. "I'm sure they're just
out for a ride." After all, seeing horses in Texas
- especially in rural areas - is not all that unusual.
After collecting our gear and helping Pete-the-dog
negotiate the pricking wire, we make for the nearest hill.
It's liberally strewn with the stalks and spines of the
flower-like crinoids, relatives of sea urchins and starfish
that once anchored themselves to the ocean floor here. As
we call out to each other about our finds, we're interrupted
by the clatter of hooves as the two riders we've seen earlier
come skidding down a slope.
"How y'all doin'?" calls one.
We introduce ourselves and it turns out, yep,
P.J. and Wes (Wilson) are somehow related to the landowning
family. Turns out, too, that Elliott was correct - they
really don't mind folks coming on their land and hunting
for fossils.
I offer P.J. a cold bottle of water, and he
declines.
"Never while I'm riding," he says,
then he reaches into a saddlebag and throws me an icy can
of beer and pops the top on his own. We talk horses and
"pop rocks" - the local term for crinoid stems
- which contain pockets of unimaginably ancient water and
explode when thrown into a campfire. At P.J.'s invitation,
I take a spin on his gelding, a recently-wild mustang purchased
in a federal auction. Then, his cell phone rings. Cows are
out on another part of the ranch, and the two take off in
a flurry of fossil dust.
We wander through the surreal landscape of
clay pit tailings. I find a perfect, white crinoid calyx
- the cup from which the animal's frond-like arms emerged.
It is startling against the backdrop of deep-red clay.
As the sun sets, we head on down the blacktop,
connecting with Farm-to-Market Road 1716 before looping
back through Santa Anna and catching U.S. Highway 84 back
into Brownwood. We arrive back home before midnight with
a sleepy dog and a sleeping child, bits and pieces of the
ages packed away in plastic boxes and bags.
Aaron
Reed
June 6, 2008
