On Time Machines and Buried Treasure

      We noticed that most of the vegetation along the shoreline was very similar to vegetation of today. There were many pine and fir trees, a few poplars and alders, some currant bushes, and a few plants we couldn’t identify. The only insect we saw looked like a large mosquito. We were pressed for time, though, and after about an hour of exploring returned to the present and packed the time machine away.

      My “machine” is by no means perfect. It allows me to travel only backwards in time,  works only in specific places, and gives only a small and sometimes confusing glimpse of past worlds. However, it is easy to use and convenient to carry. It is about the size and shape of a geologist’s rock hammer. In fact, as you may have guessed by now, it is a geologist’s rock hammer. We were exploring fossil beds formed thirteen million years ago.

 How Were the Beds Made?
       What we now call Snowshoe Mountain is part of an old volcano. It was surrounded by a large but shallow lake. When other volcanoes in the area erupted, a fine ash rained down on the lake. As this ash settled to the bottom of the shallow water, it covered leaves and insects that had blown into the lake. More layers of ash built up on the lake bottom with each volcanic eruption. Eventually, pressure from the weight of  the upper layers caused the lower layers to turn to rock trapping evidence of once-living things inside. 

 A River Runs Through It
       Later, as the Rio Grande River formed through the erosion of the San Juan Mountains, the river eventually cut through the area where the lake once existed, washing away much of the lake’s sediments. By cutting down through the old lake bed, though, the river left some of the rock layers exposed where fossils can be easily found. The hill at the airport curve is just one of several rock outcroppings in the Creede area that contain these fossils. This rock, a yellow-white, layered volcanic shale, can  be easily spotted from highway 149 in cliffs above the Rio Grande River in a number of places above and below Creede. The airport curve, though,  is the most popular place for  hunting fossils because of its easy access.

Collecting Creede Fossils
      Anyone willing to spend a little time searching will almost surely find some fossils. A hammer and a chisel or flat-blade screwdriver are helpful for separating rock layers. One area may contain no fossils at all while rocks just a few feet away may be filled with fossils. Pine and fir needles are by far the most common, broad leaves are sometimes found, and insect fossils are the rarest finds of all. No one has ever found fish fossils in the Creede fossil beds.

Collecting Is For Everyone
      Fossils give us important clues to the history of life on earth. Some kinds of fossils are very rare  while others are quite common. Fossil hunting is not limited to paleontologists, though. Some of the most interesting fossils have been found by amateurs. Perhaps the most complete T. rex fossil known was discovered and collected by a teenage girl with no formal training in paleontology.  Fossils never discovered are eventually destroyed through natural processes of weathering and erosion, so fossil collecting should not be limited to the few “experts.” However, if rare or unique fossils are discovered but never shared with the scientific community, important information about the earth’s past may be lost.

Fossil Collecting Guidelines
      The following guidelines are important to follow for legal or ethical reasons: 

• Always get permission before fossil hunting on private land.

• Check for specific laws relating to fossil collecting on state or federal lands.

• In general, most amateur fossil hunting should be (and is by law in many areas) limited to surface collecting; fossil “mining” or “quarry digs” should be left to professional organizations.

• Safety should be a primary concern, particularly when collecting with children along roadsides.

• Unique, rare, or exceptional fossils should be shared with the scientific community.

 Collecting Sites In Our Area
      In addition to the Creede fossil beds, several other sites are worth mentioning. Between mile markers 273 and 276 on La Veta Pass a variety of shells, crinoids, and horn-corals can be found in rock 300 million years old that was once an ancient sea bed. The rest area on I-25 south of Pueblo exposes limestone formed 100 million years ago that sometimes yields fossils of  ancient clams, oysters, and ammonites.

Other Sites Of Interest

      Although fossil collecting is strictly forbidden at these places, two other sites are well worth visiting.  Florissant Fossil Beds National Monument (35 miles west of Colorado Springs just off Highway 24) contains fossils of huge tree stumps, many insects, and even a few animals that were buried when volcanic ash filled a lake thirty-five million years ago (sound familiar?). A visitors’ center provides information and fossil displays while trails lead to views of petrified Sequoia tree stumps. Dinosaur National Monument, on the northern border of  Colorado and Utah, contains what may be the only enclosed dinosaur fossil quarry anywhere. Visitors get to view (and even touch) 150 million year old dinosaur bones embedded in a rock wall that was once part of an ancient riverbed.

Why Hunt Fossils?

  © 2006  Dirk Oden