You are browsing the archive for featured Archives - Mountain Beltway.
7 December 2022
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.
27 November 2022
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.
11 November 2022
How the Mountains Grew, by John Dvorak
Callan reviews a recently-published book that offers “a new geological history of North America.”
5 September 2022
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.
16 August 2022
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.
15 August 2022
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.
30 July 2022
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.
24 June 2022
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.
29 May 2022
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.
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.