Friday fold: a dome in plane view
The Friday fold is a structural dome in Wyoming, as seen out an airplane window.
structure
Friday folds: Selkirk Fan
The Friday fold is a selection of five fold photos from the Selkirk Fan in the Omineca Belt of British Columbia, submitted by structural geologist Marek Chichanski of De Anza College (California).
Ribs & hackles
Concentric ribs with hackles on a joint face, quartzite (metamorphosed fine-grained quartz sandstone stained with hematite) from Waterton Lakes National Park, southern Alberta.
Paw Paw Tunnel GigaPans
A weekend expedition to GigaPan the C&O Canal’s singular Paw Paw Tunnel results in an exposition on Devonian sedimentation, Alleghanian mountain-building, structural geology, and the incision of the Potomac River to produce entrenched meanders.
Friday fold: soft sed def in Kodiak
The Friday fold is a seaside outcrop of soft sediment deformation (not post-lithification tectonic deformation) on Kodiak Island, Alaska.
What those geologists were looking at
Yesterday, I showed you a scene of geologists (including me) clustered around some (presumably interesting) outcrop. I asked what you thought we might be looking at. Howard Allen, a denizen of this part of the globe, immediately identified the scene as that of the downstream end of the Athabasca Glacier. Several people guessed that we … Read more
Structures seen at Floe Lake
A showcase of geologic structures observed between downpours of rain at Floe Lake, Kootenay National Park, British Columbia. Cleavage, bedding, folds, faults, and strain are all presented for the discerning structural reader’s edification and titillation.
Friday fold: boxiness in Oman
Max Arndt contributed this week’s Friday fold: (click on the image to get to a larger sized version on Max’s Flickr page) That’s the Warah Formation exposed on the Batain Coast of northeastern Oman. This is the thrust front of a thin-skinned fold and thrust belt. I think it’s just lovely! Max has a ton … Read more
Veins perpendicular to foliation
To recap the week so far here on Mountain Beltway: On Monday we looked at some sweet vertical boudinage along the plane of tectonic cleavage (not to mention those folds in a (formerly) horizontal granite dike, now bearing vertical axial planes), and then on Tuesday we looked at a horizontal cut through that same outcrop, … Read more
Deformed pillow basalts from southern Ontario
Have you ever seen Archean pillow basalts? How about Archean pillow basalts that have grown much taller through vertical extrusion along a ductile shear zone? Come to the southern Superior Craton to see more!