Friday fold: “Chasing Ice”
Callan watches the new documentary “Chasing Ice” about James Balog’s Extreme Ice Survey project, and spots a lovely Z-fold during the largest glacial calving event ever recorded.
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Cross-bedding in Owens River sediments
Today, we take a look at an outcrop of young, basically unlithified sediments east of Bishop, California, on the way out Poleta Road, toward the White Mountain Research Station’s Owens Valley Lab, where you can get a nice view of the Coyote Warp Relay Ramp. These photos were taken just west of the bridge over … Read more
Friday fold: Hoerikwaggo Trail 5
We wrap up our week-long odyssey along South Africa’s Hoerikwaggo Trail with a look at something we look at every Friday: folds! In this case, we’ll be examining folds in the bedding layers of the Table Mountain Sandstone.
Hoerikwaggo Trail 4: fynbos vegetation
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the ‘fynbos’ plants seen along the trail.
Hoerikwaggo Trail 3: Joints, veins, and Liesegang banding
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the jointing, oxidizing and reducing fluid flow, and the emplacement of ore veins.
Hoerikwaggo Trail 2: the Table Mountain Sandstone
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the Table Mountain Sandstone.
Hoerikwaggo Trail 1: the hike
Callan begins a week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine scenery and logistics of the trail.
Inside the French Thrust
Callan zooms in on the meso-scale structure of the French Thrust fault, exposed in Sun River Canyon, Montana.
Stromatolites of the Green River Formation
The summer before last (2011), I spent some time in Wyoming on an energy resources field trip run by Sheridan College, and one stop we made was to look at “oil shale” (really kerogen-rich marlstone) of the Green River Formation, an Eocene lake deposit in southwestern Wyoming. The oil shale is exposed on the east … Read more
Friday fold: the Ross Sandstone
The Friday fold is an exposure of the Ross Sandstone in Ireland, bent into a syncline that dives below water.
Why Geology Matters, by Doug MacDougall
Callan reviews a new book by Doug Macdougall: “Why Geology Matters.”
Rock Cycle III: Igneous → Sedimentary
The Boulder Batholith outside of Butte, Montana, is actively weathering, and shedding off grus. In the third installment of the Transitions of the Rock Cycle series, we watch an igneous rock turn to sediment.
Rock Cycle II: Metamorphic → Igneous
Migmatite is a special rock that is partly metamorphic and partly igneous. Let’s take a look at it in Part 2 of Callan’s “Transitions of the Rock Cycle” series.
Rock Cycle I: Sedimentary → Metamorphic
An outcrop of the Ordovician-aged Martinsburg Formation is used to illustrate the development of slaty cleavage, and hence a major transition in the Rock Cycle.
Friday fold: Neoacadian Inner Piedmont trip, part IV: Migmatitic metagraywacke
The Friday fold comes from a stop on the “Neoacadian Inner Piedmont” field trip that Callan attended prior to the GSA meeting in Charlotte, North Carolina, last week.
Milestones
Callan reflects on major moments this week in his personal and professional lives.
Friday fold: Boomer Falls
The Friday fold is seen at one of the stops on Callan’s pre-GSA-Charlotte field trip: a small waterfall in North Carolina’s Inner Piedmont.
Neoacadian Inner Piedmont trip, part I: the Walker Top
Check out these lovely images (mouth-watering, even) of the protomylonitic and mylonitic Walker Top Granite of North Carolina’s Inner Piedmont. There’s also some views of the field trip participants and scenery.
Friday fold: dinner plate
The Friday fold appears on a flat slab along Maryland’s Billy Goat Trail.
Geology and wine in northern Virginia, part II: the Valley & Ridge
Callan attends the Geological Society of Washington’s fall field trip, examining the relationship between grape-growing and the underlying geology of two provinces in northern Virginia: the Blue Ridge and the Valley & Ridge. With GSW compatriots, Callan visited Hume Vineyards in the central Blue Ridge province and North Mountain Vineyard and Winery in the Shenandoah Valley. This is part II of the field trip report.