Geology
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Sandstone and Basalt
Kind 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. The castle itself, a ruin now,…
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Oh, Schist!
I never get tired of quoting that guy in the Times who wrote succinctly that “Manhattan is gneiss, but full of schist.” The bare bones of the little island of Mannahatta are exposed on the upper, upper west side where a ridge of mica schist, the famed Manhattan schist, rises over the flatlands of Harlem.…
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Ice-dozer
The buck stopped here in what is now Brooklyn; indeed, the buck of glacial ice made Brooklyn and the rest of Long Island, depositing the rubble of rock and soil it had scraped forward until it stopped and retreated and left the jumble behind. Two pulses of glacial activity formed Long Island, leaving ridges that…
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Two Monhegan Cairns
Lobster Cove: sharply-edged fragments of igneous gabbro. Pebble Beach: sea-smoothed granite “pebbles”.
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Hello, Maine
Three views from Portland Head Lighthouse.Clarry Hill’s blueberry fields. The rocky coast of Monhegan.Looking towards White Head from Black Head, Monhegan.
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Cairns
No rocky place should be left unhonored. The Hudson shore at Croton Point. A weathered piece of old brick, from the kilns that fed the metropolis down-river, contrasts nicely with a downed tree, so like rock itself.
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Desert Varnish
The “varnish” here, looking a little like apparitional tree trunks, is made up of clay, iron and manganese oxides, and some organic material. And time. The darker it is, the more manganese, a mineral rare on the planet. In some accessible areas, this thin layer can be chipped off to reveal the lighter rock beneath.…
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DUE
At Cedar Breaks, a Ranger gave us a good mnemonic for the geological history of the Colorado Plateau: “Cedar Breaks is due for a change” with “due” initialing for deposition, uplift, and erosion. Ancient lake and sea beds heaved up and then slowly, differentially, whittled away…. Bryce Canyon in the fog. Not actually a canyon,…
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Tender Buttons
These smooth, hard clay nodules are from Croton Point Park, formerly the location of a brick factory. They were sticking out of a large pile of less-clayey material, as if the surrounding had been eroded away by… river, rain, wind, all of the previous? The largest is the diameter of a quarter.This is what the…
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Rock Slide
In May, a 10,000-ton piece of rock broke off the nearly vertical face of the Palisades in Alpine, NJ, and came crashing down. Yesterday evening, we cruised by in the Commodore’s boat. It obviously hasn’t taken long for some plant life to return. The Palisades were preserved into a park in 1900 after being deforested…
Backyard and Beyond 