Geology

Tools for Possibilities: issue no. 200

Tourist guide to geological power points

101 American Geo-Sites You’ve Gotta See

This will change your vacation plans. Visit your home planet! Geology is a force so huge we don’t see it. Yet evenly spread across the US (at least one in each state) are spots where our planetary behavior is made visible, erupting in either grand spectacle or in tiny gems on the ground. I was briefly a geology major in school, so call me geeky: but what bigger vacation can one imagine that inspecting 101 sites where you can see inside the Earth? A surprising number of US national, state, and county parks are dedicated to geologic power points. Other spots may be roadcuts or river beds. Use this guide to find them and interpret their incredible hidden significance. — KK

• Meteor Crater, Arizona

  Of the more than 180 impact sites recognized around the world, approximately 25 are in the United States. The recognized godfather of them all, meteor crater is a perfect example of a simple crater — one without a central uplift. It is the most thoroughly investigated and by far the best preserved of the many astroblemes that scar the face of planet Earth.

At Dinosaur State Park, intersecting sets of pockmarking footprints give evidence of a well-traveled freeway.

The main attractions at Kellyes Island are the first-order, big-boy grooves deeply scoured into the limestone bedrock at Glacial Grooves State Memorial.

Cross-section (not drawn to scale) of the Four Corners roadcut. The coal seems (black lines) formed in a swamp environment.

This Sandstone cast of a Gilboa Forest stump is believed to be the fossilized root remains of a primitive palmlike tree. The basal diameter is 3.5 feet.

• Gilboa Forest, New York
  42° 23’ 52” North, 74° 26’ 50” West
  Devonian Period Fossilization

  Only Sandstone casts of stumps and roots remain of this first forest to shade the American landscape.

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Where to find fossils

Fossil Collecting in the Mid-Atlantic States

The only thing wrong with this field guide is that it is restricted to the Mid-Atlantic States. It gives very specific driving directions (alas, no GPS coordinates) to easily accessible sites where one can collect small fossils. And each site and its ancient bounty is depicted in lovely sketches. I wish all guides books were like this. — KK

Field gear for the well-equipped fossil collector. Hand lenses (top), Elmer's Glue-All, various sizes of masonry chisels (or cold chisels), bandaids (and other first-aid supplies), a chisel-end and pick-end rock hammer, a rock bag, an assortment of maps, newspapers for wrapping specimens, paper bags, plastic bags, an old toothbrush, a notebook and pen, some cotton, small containers, gloves, safety goggles, and a little bit of luck.