Author Archives: gymnosperm

A River Runner’s Guide to Grand Canyon Geology VI: The Schists

Posted on January 15, 2020

Geologists have great fun with puns on the term “schist”. Technically, it refers to metamorphic rock; rock that has been altered by high temperature and pressure. There are several grades of schist, our former favorite was “blue schist” as a … Continue reading →

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A River Runner’s Guide to Grand Canyon Geology V: Transects

Posted on October 3, 2019

River runners follow the water. The water is in our blood, and following it is what we do. We began this series by using the Colorado River as a transect, and following the drainages up to the South Rim as … Continue reading →

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A River Runner’s Guide to Grand Canyon Geology IV: Whither the Supergroup?

Posted on September 24, 2019

We left off the last post having seen the complete Supergroup sequence of over two miles of Neoproterozoic and Mesoproterozoic sediments. The river never encounters the Neoproterozoic part, roughly half. These lie above the river on the North Rim side … Continue reading →

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A River Runner’s Guide to Grand Canyon Geology III: The Supergroup

Posted on September 17, 2019

A typical visitor to the Grand Canyon looks down from the rim through about a mile of sediments to the river. Most of these are Paleozoic sediments extending back about 515 million years. They appear to be level, although in … Continue reading →

Posted in Geology, Grand Canyon | 1 Comment

A River Runner’s Guide to Grand Canyon Geology II: Muddy Creek and the Formation Problem

Posted on June 28, 2019

One might think that by now we would understand pretty well how the Grand Canyon formed. We don’t. Central to the problems of how and when the current Grand Canyon formed is the Muddy Creek Formation, a bunch of freshwater … Continue reading →

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A River Runner’s Guide To Grand Canyon Geology

Posted on June 25, 2019

River runners have a different perspective on Grand Canyon geology. Remarkably, the put in at Lee’s Ferry is above the entire Grand Canyon sequence, and all the strata seem to emerge in turn from the river. The Kaibab Limestone that … Continue reading →

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The Temperature and Altitude of Radiation to Space III

Posted on April 14, 2019

We left of the last post having found that brightness temperature was hopelessly asymmetric to radiance in the main CO2 deviation from the Planck temperature. This discovery dashed all hope of using brightness temperature to determine the temperatures of the … Continue reading →

Posted in MODTRAN | 1 Comment