Category Archives: Geological Evolution of the Western United States

Entropy and the Grand Canyon II

Posted on June 25, 2018 by gymnosperm

We left off in the last post having boated 78 miles, about five days on a typical trip, and having encountered the last of the suite of three books that comprise the geological story revealed in the Grand Canyon. We … Continue reading →

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The Pacific Triangle, Take III

Posted on December 28, 2017 by gymnosperm

Essentially, the Pacific Triangle IS the Pacific Plate. Unless you wish to consider it a sinkhole, a point subduction zone, all that we know as the Pacific Plate has grown out of this spot in the last 175 million years. Seafloor … Continue reading →

Posted in Continental Wander Path, Geological Evolution of the Western United States, Seafloor Isochrons | 1 Comment

Shiprock

Posted on April 26, 2016 by gymnosperm

This picture was taken in September 1979. There is a print of it in my office, faded a bit. When I wax geological, the sheer improbability of this mineralogically unusual salient weighs heavily. High in Magnesium, Potassium and Sodium; low … Continue reading →

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Rocks, The Origional Hard Data

Posted on March 3, 2014 by gymnosperm

You simply can’t deny rock. Kick it and it throbs your toe. They lie around us, largely ignored, Farmers curse them and pile them in walls, yet a few dedicated folks with pointed hammers have picked them to yield an … Continue reading →

Posted in Continental Wander Path, Geography, Geological Evolution of the Western United States, Geology, hard data, Paleogeography, Plate Tectonics, Seafloor Isochrons | Tagged , , , | Leave a comment

Sorting Rocks

Posted on December 1, 2013 by gymnosperm

Here at the gymnosperm/trunkmonkey research institute we have been spending a lot of time sorting rocks. It is utter drudgery and we would have quit a long time ago had the results not been so intriguing. Basically, we belatedly discovered … Continue reading →

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Follow the Granite

Posted on November 3, 2013 by gymnosperm

Granite is the currency in the construction of continents. Here we will time step through the existing surface expression of granites and related igneous and metamorphic rock in the Western US from the Archean to the present. Sediments are boring. … Continue reading →

Posted in Geography, Geological Evolution of the Western United States, Geology, History of Life, Paleogeography | Tagged , , , | 3 Comments

Yellowstone Hot Spot, Or Not

Posted on October 12, 2013 by gymnosperm

Besides the ocean spreading ridges there are several mysterious “hot spots” evident in seamount chains where volatile components of the mantle emerge at a point as a more or less continuous volcano. The most famous of these is the Hawaiian/Emperor … Continue reading →

Posted in Geography, Geological Evolution of the Western United States, Geology, Paleogeography, Plate Tectonics | Tagged , , | Leave a comment