Skip to main content

Living with a Laccolith

North of Gunnison, CO. My little poodle and I hiked up the small "mountain" behind the camper. There was no real trail. We kept traversing the slope so it wouldn't be too steep. Eventually we found a game trail to follow. Then we'd lose it, or at least, it seemed so. This became a game, far more interesting than following a real hiking trail.

We found a large spherical mushroom, with a crack. It made me thick of that scene in "Jurassic Park" when they watch the dinosaur egg hatching.

The little "mountain" was not tall and we were soon at the top. It proved to be quite flat on top--maybe just a little tipped or domed. Geologists would call this a "laccolith," formed by igneous material intercalating sedimentary stratifications, followed by...you can see why reading geology books is about as much fun as conjugating verbs in Latin. What the geologists would say if someone taught them English is that hot lava under pressure squeezes between flattish layers of sandstone or shale, doming the top layer a little. Then the top layer of sandstone erodes away over the ages, leaving the volcanic rock as an erosion-resistant, flattish, domed caprock. But just imagine the pressure that was needed to split the layers of sandstone!

Our little mountain was a miniature poodle-sized version of the laccolith. There are quite a few of them in this section of Colorado. The top dog is the Grand Mesa, just east of Grand Junction, CO.

There was a nice stand of grass and aspen on top, and there should have been a herd of elk or deer too. 
Although there was no scenery to brag about, it was pleasant and soothing to walk lazily over the flattish glade. It was only as wide as a large lawn, in town, and felt quite personal; a comfortable, private little world hanging in the sky.

Comments