Reader Christian Gronau returns with another “guest Friday fold” submission. Christian writes, Greetings from a cold and wet west coast. A good time to root through old rock samples – and let the imagination run free … The little compilation below strikes me as visually compelling (both photographs are mine) – but how … Read more
A guest contribution for the Friday fold, from reader Christian Gronau: Christian reports that this is located on the North side of Hwy.11, 20 miles east of Saskatchewan River Crossing, Alberta. Eastern foothills of the Canadian Rocky Mountains. Faulting and folding in Early Cretaceous Luscar Group sediments. Typical repeating sequence of sandstone, siltstone and coal. … Read more
Reader Christian Gronau writes with this Friday fold contribution: Greetings from Cortes Island, BC – at the opposite end of the Strait vis-a-vis Lopez Island. Your Mountain Beltway blog is always of interest, and I have been following it for several years by now. Thank you for putting the effort into this worthwhile website. Quite … Read more
This Friday’s fold is found in a metasedimentary beach cobble I found last summer in southeastern Newfoundland: A lovely little “pocket fold,” it came home with me and is among the handful of “deskcrops” I keep in my home office. Happy Friday and happy November!
A moderate mesoscale monocline at Watern Cove, Newfoundland, shows off multicellular animal fossils of the Ediacaran Mistaken Point Formation.
At Bacon Cove in eastern Newfoundland, there is a nice example of an angular unconformity between Ediacaran and Cambrian sedimentary rocks.
Quick, awesome Friday fold here from the Canadian Rockies and Maggie Romuld: Maggie also posted another intriguing image of her hiking in the Canadian Rockies – and set geoTwitter abuzz with a discussion of whether she had captured load casts bulging out of the bottom side of a bed or stromatolites projecting upward from the … Read more
The Friday fold erupted out of a volcano, completing the second part of its two stage cooling history, then later got folded and metamorphosed. It was found atop a high cliff near the northern Newfoundland town of St. Anthony.
The ‘Friday fold’ shows gorgeous conjugate sets of kink bands transecting the plane of foliation in some phyllitic metasediments seen on the southern Burin Peninsula of Newfoundland.
Yesterday, I featured some folds from Broom Point, but there are also faults there. With the intriguing local limestone conglomerates providing easily-discernible marker beds, these apparently vertical faults are easy to spot. Here are three examples:
Here’s a look at some of the outcrops at Broom Point, within sight of the famous uplifted fjord called Western Brook Pond: The limestone beds here are Ordovician in age, and they dip to the east: In places through there are folds to be spotted in the beds:
Here is an outcrop of folded limestone along route 430 in Newfoundland, inside Gros Morne National Park, just west of the crossroads called Wiltondale: A detailed look at the left antiformal portion of the outcrop: A zoomed-in examination of the rightmost part, where a goopy looking synform resides: Just down the way, a second outcrop … Read more
Traveling in Newfoundland, Callan visits a seaside outcrop showing a Proterozoic submarine slump complex, overprinted by tectonic cleavage and weathered by the sea.
A reader asks: “What is foliation and what makes it so important to the structure of rock?”
Callan answers with a lot of images of beautifully foliated rocks.
Here’s a puzzler to warm up your chilly brain this Wednesday morning: Click to enlarge Figure out the story told by this set of imprints in the snow. The branch of science called ichnology studies the traces organisms leave behind. There’s a neat little story here. If you’ve got a guess, then you can check … Read more
It’s Friday, the end of the workweek, but also the beginning of the celebration of folded rocks. Examine a particularly sinuous example from the buckled Cambrian limestones of Canada’s Kootenay National Park.
The Friday fold is airborne over the Yukon Territory’s border with the Northwest Territories, high up in Canada’s Mackenzie Mountains. Helicopter for scale.
Erik Klemetti posted today at Eruptions about komatiite, which is apropos, considering I just finished imaging some samples of that ultramafic volcanic rock. Have a look at three samples from Barberton Greenstone Belt here, each from the 3.27 Ga Weltevreden Formation: Link GigaPan by Callan Bentley Link GigaPan by Callan Bentley Link GigaPan by Callan … Read more
More 3D models: digital facsimiles of real rock samples. Check them out and explore! Clinker from the Powder River Basin, Wyoming: Ripple marks from the Rose Hill Formation, West Virginia: Meta-komatiite from the Red Lake Greenstone Belt, northern Ontario, Canada:
One of the cool things about my plan for the GEODE grant from NSF is to put GigaPan imaging systems in the hands of people who will take them to cool places. I purchased five loaner GigaPan rigs, and they have gone out in the field with various people, but I think that the images … Read more