Posts Tagged 'Geology'

Gorges

“Ithaca is Gorges” is awfully good branding. I thought the gorges that sliced away through shales and sandstones at the northern and southern edges of Cornell were gorgeous.Fall Creek in the rain during the morning. Most of this one is seen from above, on the Cayuga Trail. Only disconcerting thing: all the anti-suicide netting on the bridges.
Cascadilla Gorge in the late afternoon, after the sun had come out. We descended to town from the hill citadel of the university, right alongside the tumbling water.

Flinty

The National Museum of Copenhagen is filled with flint tools from the pre-metal millennia. This stuff makes for very sharp edges. The stone of Europe’s Stone Age, flint stones were also used to start fires and spark guns into the 19th century. The Baltic beaches were littered with nodules of this dark chert. It’s a finely-grained quartz, not, as I first thought, obsidian (which is volcanic glass). This fist-sized and rather knuckle-like piece was my Swedish souvenir, found on a beach in Malmo. Here’s the verso and recto of a piece I split on the Northumberland coast a few years ago when my dearheart said the original piece was too large to carry back on the plane.The white coating here is typical. According to this site, “The thick white crust, the cortex, is not made of chalk, but of fine-grained opaline silica.”

Chesapecten

These are fossilized shells of extinct scallops found on the Piankatank River in Virginia. They’re in the genus Chesapecten, all of whose members no longer live upon this earth. Such mineralized remains are dated from the early Miocene period to the early Pleistocene.

Here’s more detail about the rich fossil world of the Chesapeake.

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Trump yearns for an FBI to go after journalists. Secretary of Corruption (formerly Commerce) Wilbur Ross praises the lack of protests in the dictatorship of Saudi Arabia. A reporter was arrested when he tried to question Secretary of Death (formerly Health) Tom Price. Meanwhile, the Trump regime has been rather shameless about Turkish gestapo tactics in the heart of Washington D.C., because pretty clearly they want to be able to emulate them. After all, they cite the murderous kleptocracy of Putin’s Russia as a model.

Those who are against our best traditions are not patriots. They are, in fact, traitors. Never, ever, let supporters of Trump get away with claims of patriotism again.

Oregonia

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There’s your beautiful world, NW edition. Here’s Masha Gessen, an old hand at autocracy, on surviving Trumpism, very necessary reading now.

Traces of the Ice Age

striationsDon’t you just love these? These grooves are found along the path in the forest of the NYBG, and time and generations of feet have worn them down slightly. They’re glacial striations, gouged out by the rubble on the bottom the ice as it scraped across the hard surface rock.

These can be found in Central Park, too. But not here in the home borough, which is all glacial deposit–made up, come to think of it, with some of that Bronx rock.

Pothole

IMG_6951Seemingly drilled into the schist of Inwood Hill by some kind of large-bore drill, this is actually a glacial pothole, scoured out by the mighty power of swirling water and abrasive stones during the heady days of the Wisconsin glaciation. The diameter is a little over a foot and a half.

The heights of Inwood, very like a whale from the vantage point of the Hudson, are the northern prong of the Fort Washington Ridge. Geologically, this rock is known as the Manhattan Formation, made of mica and hornblende schist. (“Manhattan’s gneiss, but full of schist” goes the immortal line.) This is the good, hard stuff, the serious, no-nonsense rock, but everything has its weaknesses, and time grinds it all up, as in the mills of the gods.

Sandstone and Basalt

IMG_3353Kind of hot for blogging, wot? Let’s take a dip in the North Sea: this is Greymare Rock, also known as Saddle Rock and the Whale’s Belly, just south of Dunstanburgh Castle. It’s made up of buckled layers of sandstone, the same sandstone used to build the nearby castle. IMG_3345 The castle itself, a ruin now, was built on an exposed ridge of basaltic Whinn Sill, a natural wall to the sea. Brilliant budgeting, that. IMG_3351The pale discoloration in the far distance on the cliff is guano from birds. The cliff hosts a nesting colony of Kittiwakes.


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