Advertisement

You are browsing the archive for structure Archives - Mountain Beltway.

15 September 2017

Friday fold: Dextral asymmetry in a shear zone, Italy

The Friday fold comes from highly foliated rocks in a shear zone near Tyrol, Italy. It was contributed by reader Samuele Papeschi.

Read More >>

2 Comments/Trackbacks >>


28 April 2017

Friday fold: Two more from the Lewisian gneiss of Scotland

Happy Friday! Here are two more folds in gneisses of the Lewisian, in the North West Highlands of Scotland, near Tarbet. Enjoy!

Read More >>

5 Comments/Trackbacks >>


7 April 2017

Friday fold: paper demo

The Friday fold is a sheet of paper. Yes, really!

Read More >>

No Comments/Trackbacks >>


27 March 2017

Cleaved, boudinaged, folded Edinburg Formation southwest of Lexington

Explore a dozen photos highlighting the structural geology of an outcrop of limestone and shale near Lexington, Virginia. Cleavage refraction, overturned beds, boudinage, folds, and even a small fossil – we’ve got something for everyone. Bring the whole family!

Read More >>

No Comments/Trackbacks >>


17 February 2017

Friday fold: Buckled at Baltinglass

Garnetiferous beds from the aureole of the Leinster Granite east of Baltinglass, County Wicklow, Ireland (Declan De Paor’s senior thesis mapping area, 1973). Manganese-rich metasediments. The prominent ‘elasticas’ or fan folds (folds with a negative inter-limb angle) are superimposed on isoclinal folds: so the brownish layer at top and bottom are the same, though that is not obvious from the image. This is a sample from the structural geology collection …

Read More >>

No Comments/Trackbacks >>


26 January 2017

Dore Holm

The scenic arch of Dore Holm (“Door Island”) in Shetland shows off the most efficient way of breaking a slab of rock. The island’s shape is a reflection of the parsimonious nature of natural deformation.

Read More >>

No Comments/Trackbacks >>


16 January 2017

Shear zones in Scottish gabbros

A quest to visit the “first shear zones” described in the scientific literature leads to an alternate location, and some GIGAmacro images of samples from the real, original spot.

Read More >>

1 Comment/Trackback >>


30 December 2016

Friday fold: one from the archive

As noted previously, my colleague Declan De Paor recently retired from Old Dominion University, and I was lucky enough to inherit some of his rock samples. I’ve been making super-high resolution images of the samples ever since. Here’s a particularly striking fold, weathered out differentially. Enjoy exploring it – and have a happy final Friday of 2016! Link 2.04 Gpx GIGAmacro by Callan Bentley (If the embedded GigaPan doesn’t work …

Read More >>

2 Comments/Trackbacks >>


12 December 2016

Fossils as strain markers: the boudinaged belemnites of the Swiss Alps

Don’t you hate it when plate tectonics ruins a perfectly good fossil? This is a sketch of a belemnite from the Swiss Alps: The thing has been broken into segments, with calcite filling the gaps between the segments. What a bummer! Now we’re going to have a much harder time reconstructing the life habits of the organism that left this fossil behind… It was a squid-like thing, with an internal …

Read More >>

1 Comment/Trackback >>


25 November 2016

Friday fold: intrafolial folds in Eriboll mylonite

At the birthplace of the term “mylonite,” we can find Friday folds hidden in the foliation.

Read More >>

2 Comments/Trackbacks >>