Swan song
A few reflections on the AGU Blogosphere’s long, strong run, and a vision for Callan’s future online outreach.
featured
Friday fold: a Massanutten cross-section from a century ago
The Friday fold digs deep into the historical archives for a near-century old illustration of the geology of the Massanutten mountain system in Virginia’s Valley & Ridge geologic province.
Glacial geology of Discovery Park, Seattle
A field trip to examine the glacial geology of Discovery Park in Seattle, Washington, leads Callan to contemplate the nature of expertise — and especially his steep learning curve on an oceanographic cruise.
Near-empty seas, near-empty air
Callan is currently at sea aboard the research vessel Thomas G. Thompson, crossing the North Pacific Ocean from Seattle to Honolulu. In this post, he explores a fascinating aspect of life on the high seas: there is shockingly little life! Explore the scant copepods and albatrosses and reflect on life in the oligotrophic open ocean.
Friday fold: Neoproterozoic rhyolite (of the Konnarock Formation?)
The Friday fold returns!
Today we join the Virginia Geological Field Conference to look at primary volcanic flow banding in a Neoproterozoic rhyolite, and consider what it might have to tell us about the ancient Snowball Earth glaciations.
Friday fold/fauxld duet from Glacier National Park
When is an apparent anticline not an fold? Find out on this week’s edition of the Friday Fold…
Seeing spots thanks to Canadian wildfires
The eastern United States is being choked by thick wafts of Canadian wildfire smoke, and that has resulted in a rare opportunity to observe detailed features on the surface of the Sun.
The unconformity gets its portrait taken
Callan recounts a little lesson in taking a photograph of an outcrop that expresses itself more readily to the novice eye.
The coastal section at Esterillos Oeste, Costa Rica
Callan documents a geological stroll along the coast of Esterillos Oeste, in central southern Costa Rica, investigating the sequence of sediment in the Punta Judas Formation (Mid-Miocene) exposed there. Fossils, sedimentary structure, diagenetic features, structural deformation, and modern weathering all make prominent appearances.
Book report
Callan offers reviews of a suite of good reads – some old and some new, some geology and some general science, and some social justice/history.
How the Mountains Grew, by John Dvorak
Callan reviews a recently-published book that offers “a new geological history of North America.”
Book report
Callan reviews five books, both fiction and non-. In this batch, we get Neal Stephenson’s latest techno-thriller, about geoengineering and its discontents, Barack Obama’s first memoir, a novel by Charles Dickens, a collection of short stories by Andy Weir (author of The Martian), and Bill Bryson’s sole foray into popular science writing.
Kinked metavolcanics of the Castine Formation, eastern Maine
Callan shares a few outcrops from coastal Maine, part of the Avalonia terrane that accreted to ancestral North America during the Acadian Orogeny. They are volcaniclastic rocks, coarse and fine, and showing both overprinting kink bands and cross-cutting basaltic dikes.
Book report
Five books get the Callan mini-review treatment: two novels from Amor Towles, an account of life in prison under solitary confinement, a history of Virginia slavery during the War of 1812, and finally a family account of the discovery of the fossil Hesperornis, a toothed bird, and various associated tangents.
Well-preserved mudcracks in Belt argillite, Glacier National Park, Montana
Fresh from the field, Callan shares a quintet of beautifully preserved desiccation cracks in Mesoproterozoic Belt Supergroups sediments, exposed in Montana’s geological gem, Glacier National Park.
Friday fold: Kinked Lynchburg metasediments near a soapstone body
Happy Friday! Here are some kink-folded metasediments from Virginia’s Lynchburg Group to help usher in the weekend.
Accretionary wedge turbidites from the Lost Coast
The Lost Coast of northern California shows geological evidence of deep sea turbidity current sedimentation, tectonic accretion during Mesozoic subduction, and then isostatic uplift interacting with shoreline erosion. Check out a few photographs taken by Callan’s wife on a recent backpacking trip through the region.
Super Volcanoes, by Robin George Andrews
Callan reviews the debut book by volcanologist Robin George Andrews. It details the diverse eruptive histories of Kilauea, Yellowstone, Ol Doinyo Lengai, the oceanic ridge system, our Moon, the planets Mars and Venus, and the cryovolcanoes of the outer solar system moons.
Book report
Callan reviews nine books in a big batch – some geoscience, some anthropology, some fiction, some natural history. Something for everyone!