Swan song
A few reflections on the AGU Blogosphere’s long, strong run, and a vision for Callan’s future online outreach.
Yard list 2023
Another year has elapsed at the usual rate, and now it draws to a close. Time for me to tally up the year’s sightings. My goals for the year were to be in the Top Ten eBird users in my county, and to attempt to take a good photo of each species. I ended up … Read more
The Greywacke, by Nick Davidson
Just finished a geologically focused book that the readers of this blog might be interested in. It is a history of work on delineating the early part of the Phanerozoic timescale in Wales and Scotland. The majority of the book is about Adam Sedgewick and Roderick Murchison and their close collaboration and increasing divergence and … Read more
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.
Friday fold: Floor paver in the Atlanta airport
On my way back to Virginia from Hawaii, I had a three hour layover in the Atlanta airport. There, I spotted this charismatic stone paver on on the terminal floor. It showed folds, and so I snapped a photo, but it also shows plenty more… An annotated copy: Happy Friday, all!
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.
Four new videos about east coast geology
Hi all! I’ve been putting my energy into video production more than blogging lately, but let me share some of that work with you:
Friday fold: Candler Formation
On a birding hike yesterday morning, I found this: This is a little slab of kinked phyllite of the Candler Formation. This metamorphic rock started as mud (and ash) deposited atop the Catoctin Formation, and it was later squeezed and heated during Appalachian mountain-building, encouraging the growth of micas at the expense of clay. A … Read more
Three new videos from Montana
I spent several enjoyable weeks in Montana last month, and shot some new video content there for my YouTube channel. Here are three videos that may be of interest to readers of this blog:
Bird update “July” 2023
Oops – July slipped by without a monthly bird update! Maybe that’s not the end of the world – I spent much of the month in Montana, and only tacked a few new species onto my county list – a Swallow-tailed kite, a Northern bobwhite, and a Great egret (photo above, 2nd column in the … Read more
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…
Friday fauxld: Sacagawea Cirque
Found this beautiful cobble while hiking Sacagawea Peak with my family yesterday, in Montana’s Bridger Range. It’s not actually folded as much as it appears to be; the laminations are slab like and nearly parallel to the surface in this photo, with the cobble surface sectioning them obliquely to produce this pattern.
Friday fold: Wissahickon block
Click to enlarge I’m writing this on the Amtrak train from New York back to Charlottesville, traveling (again) under orange-hazy skies due to Canadian wildfire smoke. I took my son to Manhattan for a concert, and we stopped off en route for an overnight in Philadelphia, visiting a former student of mine who’s now an … Read more
Bird update June 2023
Click to enlarge A brief update here, since it’s getting close to the end of the month. I’ve added a half dozen species to my county list since I last reported out to you all. I’m up to 151 for the county for the year. This means that I’m still ranked in the top ten, … Read more
Tension gashes in the Tonoloway Formation
I spent yesterday on Corridor H in eastern West Virginia’s Valley & Ridge province. The rocks here are a mid- to upper-Paleozoic set of strata that record the switch from post-Taconian passive margin sedimentation into Acadian clastic deposition, and then everything is deformed by Alleghanian folding and thrusting. I found myself taking photographs of the … Read more
Friday fold: Pleasant Grove Park
Happy Friday, friends. Here’s a rock sample that I recently polished up: It shows crenulations in “pinstriped” schist of the western Piedmont in Pleasant Grove Park in Fluvanna County, mapped as the Mine Run Complex. Lovely stuff, eh?
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.