#ophiolite

[alexanderbayon]

image from here – thank you, victormalonso

[noosphe-re]

Ophiolite

[propalitetz]

first meeting

[est-nord]

img: http://www.geolicimes.fr/wp-content/uploads/2020/03/IMGP8606-2000x1200.jpg

source

[earthstory]

Vermont Serpentinite Serpentinite is a common rock on Earth, and probably throughout the solar system. It is a type of metamorphic rock, produced when one of the most common minerals in the planet – olivine – gets exposed to water near the surface of the Earth, which of course happens all the time. A bit of water and a bit of pressure and the mineral structure changes, turning it into a soft, easily deformed rock.

Many serpentinites have a fibrous appearance like this one from Vermont. There can be two factors driving this appearance; first, these rocks are so soft that they can deform easily in response to the stresses of mountain building. In that case, these lines are slickenlines, reflecting one part of the rock grinding against another. Alternatively, some (But not all) serpentine minerals can grow in a habit where they form long needles; minerals that grow in this habit are lumped together as asbestos minerals. Serpentine-bearing rocks therefore can naturally host asbestos, and mines in the area where this rock came from in Vermont produced asbestos for more than half a century. Serpentinite rocks and serpentine minerals are most often found where little bits of Earth’s mantle get thrust up onto the continent, creating a feature we call an ophiolite. These are commonly produced when continents collide or when continents run into island arcs, as a bit of the mantle gets trapped in the collision zone. The serpentinites in Vermont are the remnant of the Taconic Orogeny, a mountain building event 440 million years ago where a volcanic island arc was thrust upon what is today New England, folding and faulting much of the area in the process. -JBB Image credit: James St. John https://flic.kr/p/2iE3pj4Reference https://bit.ly/2BhQPrk Previous TES series on Asbestos and health problems: https://www.facebook.com/TheEarthStory/photos/a.352867368107647.80532.352857924775258/778584158869297

[geogonzo]

Carbon folds road outcrop E851 Lezha to Kukes (maybe 20km from Lezha) Albania. Ionian tectonic zones nearby the contact Vlore-Elbasan lineament with the Mirdita ophiolites bearing zone, an SW-NE trending thrust belts over thrusting  East to west. The carbonate formation mostly is limestone of different kinds and dolomites in the Ionian zone( external Albanides) is of Upper Triassic-Eocene and belongs to pelagic faces. Image clippings region is 2*3m real.

[homemade-cage]

olivine swirl

Nikon D3200, click for better quality

[galswintha]

Serpentinite built Grochowiec hill in Brzeźnica Massif. Sudetic Foreland. Brzeźnica Massif  is one of the few ophiolite complexes in the area together with iconic Ślęża Massif and Szklarskie hills. Last two photographs were made at the place where XIXth century fort was built, from which to this day only some earthworks remain, together with artificial cave made in serpentinite rocks.