Specialist in magmatism, granite and granite landscapes, plate tectonics, national parks, and public engagement with geology

“Scenery = Geology”
— Me

Recent images from my Flickr photo account

View fullsize Sunset thunderstorm in Santa Fe
View fullsize Sunset thunderstorm in Santa Fe
View fullsize Lenticular clouds over Cuernos del Paine
View fullsize Aoraki/Mount Cook with lenticular cap
View fullsize Lenticular display over Cuernos del Paine, Torres del Paine National Park, Chile
View fullsize Late afternoon crepuscular rays, Beagle Channel, Tierra del Fuego
View fullsize Sunrise on Interstate 64, southern Indiana
View fullsize Late afternoon thunderstorm over Roanoke Rapids Lake, North Carolina
View fullsize Late afternoon thunderstorm over Roanoke Rapids Lake, North Carolina
View fullsize Clouds pouring over the High Sierra near Big Pine, California
View fullsize Wind turbines of Shiloh Wind Power Plant leaving V shapes in low-lying clouds near Suisun Bay
View fullsize Cloud shadows in wildfire smoke at sunset over Bishop, California
View fullsize Virga over Saline Valley
View fullsize Sierra wave March 1998 looking south across Owens Lake
View fullsize Curlicue clouds over Mammoth Lakes
View fullsize Lenticular clouds near Cimarron, NM
View fullsize Sierra wave seen looking north from top of Mammoth Mountain
View fullsize Lenticular clouds at sunrise seen from near Mammoth Lakes
View fullsize Clouds on cliffs of Wingate sandstone upstream of Moab, Utah
View fullsize Crepuscular rays over Taboose Pass, Sierra Nevada, California
Mars or Earth?

Mars or Earth?

Is the scenery at national parks basically geology? (Yes)

Is the scenery at national parks basically geology? (Yes)

How do mountain ranges such as the Alps form?

How do mountain ranges such as the Alps form?

How has volcanism affected the course of civilization?

How has volcanism affected the course of civilization?

Is the scenery at national parks basically geology? (Yes)

Is the scenery at national parks basically geology? (Yes)

Is this countertop made of granite? (Ha!)

Is this countertop made of granite? (Ha!)

  • "Petrology and Plate Tectonics: An Earth Systems Approach" is published!!!

    This new textbook, coauthored with Matt Kohn, is available from Oxford University Press, Amazon, and elsewhere

    Oxford University Press site

  • Educating the Public

    Expert guide with Smithsonian and National Geographic tours; field trips, writing for non-geologists

    Join Allen on a tour

  • Photography

    Aerial, ground, drone, structure-from-motion, and gigapixel images

    View

  • Current Research

    How granites form; climate and volcanism; plate tectonics and magmatism; evolution of landscapes

    Learn More

  • Geology Underfoot

    New editions of Allen’s titles in the popular book series are available

    Buy

  • Talks

    Video recordings of talks for the public and academic audiences

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  • About

    Allen is Mary Lily Kenan Flagler Bingham Distinguished Professor Emeritus, University of North Carolina at Chapel Hill

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Field Notes

Featured
Aoraki-Mount Cook with lenticular cap.jpg
New photo albums posted
Yosemite overflight photos posted
Yosemite overflight photos posted

Photos from a low-altitude (legal) research flight over Yosemite Valley and Tuolumne Meadows.

Patagonia photos posted
Patagonia photos posted

Photos from a two-week trip to Tierra del Fuego and Torres del Paine.

Torres del Paine vs. Split Mountain — 3 — Comparison
Torres del Paine vs. Split Mountain — 3 — Comparison

Torres del Paine and Split Mountain share strong similarities, but the latter lies along the faulted eastern margin of the Sierra Nevada and was thus resistant to glaciation.

Teaching Notes

Featured
A spreadsheet to model magma crystallization
A spreadsheet to model magma crystallization

In this post I describe a simple spreadsheet designed to show how compositions change as various minerals are crystallized from a magma.

A spreadsheet to help teach the rudiments of seismic tomography
A spreadsheet to help teach the rudiments of seismic tomography

This post describes a spreadsheet that can be used to understand the rudiments of how seismic tomography works, and to help get across the idea of ambiguity in interpretation.

Announcing “Teaching Notes”
Announcing “Teaching Notes”

In which I present some of the tools I developed, and things I learned, during my teaching career.