You are browsing the archive for May 2015 - Mountain Beltway.
29 May 2015
Friday fold: Hayward neighbor
The Friday fold is some crumpled sedimentary rock near the Hayward Fault in California.
22 May 2015
Friday fold: Welsh carbonates
Kate Littler sent in this Friday fold, via Twitter: lovely parasitic folds in the Carb limestone, West Angle Bay south Wales. Awesome. Looks like a great place. Thanks, Kate! Happy Friday!
21 May 2015
Soft sediment deformation in sandstone and shale, Bolt Mountain
Two nice new examples of soft sediment deformation structures in Pennsylvanian-aged clastic sedimentary rocks from West Virginia.
20 May 2015
Liesegang banding in Pennsylvanian sandstones, Bolt Mountain, West Virginia
While out at the eastern section of NAGT’s annual meeting last weekend in West Virginia, I participated in a field trip to look at the stratigraphy of the Bolt Mountain section of Pottsville Group strata. One thing that was particularly eye-catching about the sandstones we saw was that many of them had been stained by rusty groundwater, producing the lovely stripey pattern known as Liesegang banding. Here are five examples: …
18 May 2015
Spheroidal weathering in sandstone
Here’s a nice example of spheroidal weathering in a sandstone, developed using orthogonal jointing and bedding: This is one of many sites I visited Saturday near Bolt, West Virginia, on a field trip with NAGT’s Eastern Section.
15 May 2015
Friday fold: Crumpled Carboniferous cyclothems
Twitter follower Bob J. submitted this week’s Friday fold: Carboniferous cyclothems at Scremerston, Northumberland. Thanks Bob!
8 May 2015
Friday fold: Foreknobs formation
Last one in the triumverate sent in by reader Eric Fulmer: Annotated: Happy Friday and (for many of you) happy end of the semester!!
1 May 2015
Friday fold: Tight syncline/anticline pair in Brallier Formation
The Friday fold shows clastic detritus (turbidites or “flysch” from the Acadian Orogeny) crumpled into tight folds due to the later Alleghanian Orogeny.