Manhattan Schist

In the first part of yesterday’s post, Oh, Schist!, I mentioned that schist’s alignment of platy minerals created planes of weakness in the rock, but that in some cases, schist can be a very strong rock. Meet the Manhattan schist.

The Manhattan schist formed from mud deposited on the ocean floor and scraped in continental collisions during the formation of Pangaea over 450 - 300 million years ago. These collisions, part of the Taconic Orogeny, created a mountain chain taller than the Himalayas, and squeezed and baked the rocks under high pressure and temperature forming the Manhattan schist. In New York, you can build very high skyscrapers on the Manhattan schist.

Why is the Manhattan schist so strong? It has to do with the mineralogy and the internal structure. The unit is characterized by a lack of internal layering, the presence of tough black amphibole, and of wear-resistant garnet, kyanite, and sillimanite. The last two minerals are metamorphic grade index minerals, and indicate the Manhattan schist was exposed to very high pressure and temperature.

Enjoy this outcrop of the folded and scraped Manhattan schist in Central Park, Manhattan from: https://geologypics.com/manhattan-schist-and-skyscrapers-of-ny-city/ by @MarliMiller

#ManhattanSchist #TaconicOrogeny #rocks #geology #ScienceMastodon

Central Park, An Urban Oasis in New York City

‘What artist, so noble, has often been my thought, as he, with far-reaching conception of beauty and designing power, sketches the outline, writes the colours, and directs the shadows of a picture so great that Nature shall be employed upon it for generations, before the work he has arranged for her shall realize his intentions.”
~ Frederick Law Olmsted, Landscape Designer responsible for many beautiful parks throughout our nation, and co-designer of Central Park in New York City.

One of my favorite places in the world is Tuolumne Meadows in Yosemite National Park, but this post isn't about that beautiful place. No, the reason I bring it up is there is a beautiful stop along the way to Tuolumne in the glacially-exposed granite along Highway 120 called Olmstead Point, which looks back at Yosemite Valley and Half Dome from the high country of the Sierra Nevada Mountains. The person the scenic stop is named after, Frederick Law Olmsted, Landscape Architect, Author, and Conservationist (1822-1903), is key to this post, because Olmsted, who loved Yosemite and was active in preserving Mariposa Grove, understood well humanity's deep-seated connection with and need for the natural world as his quote above demonstrates - so much so that he helped design one of the world's best and loveliest parks to preserve a piece of nature, Central Park in New York City.

Yosemite and Central Park share other similarities. Like Yosemite, Central Park sits astride the roots of an ancient mountain chain, but in New York the mountains have worn down over millions of years by the forces of erosion. The rocks the children are perched on contemplating the lovely lake in Central Park in the photo above is the famous Manhattan schist, which started about 450 million years ago as soft mud on an ancient seafloor and now forms the durable bedrock that anchors New York's tallest skyscrapers. And like Yosemite's rocks, the rocks in Central Park have been glacially scoured and feature other unmistakable signs of glaciation. But unlike Yosemite that is secluded high in the Sierras, Central Park forms an oasis in the middle of New York City.

Olmsted started work on the park in 1858 after winning a competition with a design called the "Greensward Plan." The project took over a decade and cost ten million dollars. The swamps of the area were drained and tons of topsoil was brought in. Bridges, fountains and lakes were built with miles of tree-lined pathway that wrapped around the park giving access to its rolling lawns, and colorful shrubbery and flowers. Today Central Park is surrounded by tall buildings in the midst of the hustle and bustle of the dense urbanity of the City that Never Sleeps. With its thousands of trees and air filled with birdsong, Central Park forms an oasis of tranquility, nature and wonder preserved through the work and foresight of Frederick Law Olmsted.

Learn more about Central Park here: http://www.centralparknyc.org/ and see the whole park at once in this great aerial panorama: https://goo.gl/UFYMiF

Image from: http://intransit.blogs.nytimes.com/2013/06/13/your-tips-for-tackling-new-york-with-kids/ More beautiful images at: http://theinsatiabletraveler.com/2014/12/09/rediscovering-new-york-central-park-lake-photo-essay/

#CentralPark #FrederickLawOlmsted #ManhattanSchist #Nature #DesigningCentralPark