Here at Backyard and Beyond, we spare no wonder for our natural and unnatural world. In the Bergen St. F/G subway station in Brooklyn, these stalactites descend from both platforms. They’re classic soda straw formations, hollow through the center. They are also, obviously, not exactly like the ones you’d find in a cave. (Frankly, you should be staying out of caves these days, since cavers are suspected in transporting white nose syndrome). Here it’s the calcium oxide in concrete that interacts with leaking water to form calcium hydroxide. This reacts with carbon dioxide in the atmosphere to precipitate as calcium carbonate. Voila!
Drip, drip, drip.
Posts Tagged 'Geology'
Two Projects of Note
Published November 4, 2010 Art Culture Politics , Other 1 CommentTags: Geology
The marvelously named “Friends of The Pleistocene” and Smudge Studio are working on a geological guide to the city’s building materials as a way to show how geological time very much intersects with human time. The work is called Geologic City: A Field Guide to the GeoArchitecture of New York and I’m really looking forward to it (as I pass by the guys mixing a little crushed Triassic into the sand in preparation of painting the brownstone brown).
The NYC BiodiverCITY blog pulls together submissions from thoughout the city on our biodiversity, to make the point that the revision of Bloomberg’s PlanNYC needs to take this wealth of plant and animal life into account. I’ve already contributed. Have you?
Some housekeeping: I’ve recently added some NYC bird lists and other blogs and sites to my blogroll. Check them out.
Also, I encourage you to subscribe to this blog and link to it as well as Digging/Tweeting/Stumbling/MyFacespacebooking and otherwise sharing it if you enjoy it. Comments are always welcome.
Last Saturday, I went up to Columbia University’s Lamont-Doherty
Earth Observatory for their annual Open House. I’ve passed the sign on 9W several times over the years, and really only noticed the “observatory” part of the sign; I thought it was an astronomical observatory, built before city and suburb light pollution pretty much ruined East Coast star-gazing. D’oh! But as it develops, LDEO actually observes this planet. Take a look at their site for the variety of very interesting things they do with the earth sciences.
One of them is dendrochronology. I spoke with a woman in that unit about the recent discovery of the wooden remains of an 18th C. ship at the WTC site. She told me that the clay the ship was found in was an almost perfect medium for preservation: they found actual leafs and other organic scraps, including some hair in the anaerobic muck. The hairs later revealed a louse. And boy, was the 18th C. lousy.
I’ve heard about the K/T boundary, but I never saw it before this core sample.
LDEO is located just north of the NJ/NY border. Nearby is the State Line Lookout atop the Palisades. This image is from the Lookout, looking northeast, across the mighty Hudson, and hundreds of millions of years of geological time. Hofstra Geology Professor Charles Merguerian gave a talk up here as turkey vultures and black vultures and red-tailed hawks drifted by on the thermals, practically at eye-level. Merguerian rocked my world: he argues that the Harbor Hill Moraine, where I live, is 50,000 years old, while the standard story is that the glacier that created it retreated by 10,000 years ago. The 10,000 year date he attributes to a valley glacier that carved out the Hudson ford. Merguerian’s webpage promises to keep my busy.
Geological Ruminations II
Published August 5, 2010 Art Culture Politics , Fieldnotes 6 CommentsTags: Geology, Hudson, Iceland
A trip to Iceland concentrates the mind on the subject of volcanism. Split between the separating-at-two-centimeters-a-year North American and Eurasian plates, Iceland is astride a tremendously deep plume of magma known as a hot spot. It has some major volcanoes, including Grimsvotn, Katla, Hekla, Krafla, and Laki. In 1963, a whole new island, Surtsey, named after the fire giant Surtur, emerged bubbling hot out of the water off the southern coast. (Cf. John McPhee’s two-part article on Heimaey, Surtsey’s neighbor.) This year’s smoker, Eyjafjallajökull, paralyzed Europe during the spring, but that’s nothing in comparison to blasts from the past.
This is Hverfell, east of Myvatn, a tephra or ash cone. It is about 460m high and 1040m across.
This volcanism does wonders for geothermal power, which lights up most of the country; natural hot tubs (ahhhhhh); geyser-steamed bread (tasty), and volcano tourism; it bodes ill for the future, though, and the inevitable cataclysms, which will not just be local. It was the Laki eruptions, the Skafka Fires, of 1783-84, in fact, which suggested to Ben Franklin — minding the store/impressing the ladies in Paris as our ambassador — that volcanoes could influence the climate; his thought — that the dry blue funk shrouding the City of Light was due to a volcanic eruption on Iceland — was the first documented making of that connection. Alas, nobody was reading him during the infamous “year without a summer,” 1816, when, following the eruption of Indonesia’s Tambora, the East Coast of the U.S. shivered through July and August (“ice made in pails”), and Mary Shelley, holed up in a damp, dank bust-of-a-holiday on Lake Geneva, started writing Frankenstein. The less literary effects were drought, crop failure, starvation, immigration, political upheaval, and huge numbers of dead around the world (hmm, sounds just like Planet Climate Change).
Tambora 1815 was a 7 on the Volcanic Explosivity Index, described as “Colossal”; Krakatau 1883 a 6, “Huge”; in comparison Mount St. Helens 1980 was a 5, “Very Large.” Indonesia can also claim Toba, c. 74,000 years ago, which was an 8, “Humongous”; it’s thought to have ejected 1000 times the material St. Helens did.
Our own metropolis occasionally feels a little tickle of a tremor from deep earthquakes in the St. Lawrence and Hudson valleys. It will probably come as a surprise to most, but the region has historically been subject to several 5 on-the-Richter scale quakes; the strongest was in 1836, an estimated 5.5, still rather moderate, under Gravesend Bay. That’s several miles from where I write, so quite local.
However, our great reminder of the hot power of the earth is the purple majesty of the Palisades.
From the Hudson River, Fall 2009.
This cliff stretches from Jersey City to Haverstraw, about 35 miles, along the west coast of the Hudson. The column-like diabase was formed when a surge of magma intruded into weaker material, sandstone, underground. This sill eventually cooled and hardened. Over time, the material above the sill eroded away, exposing the sill’s flank to the hammer of time, air, water, and ice.
Similar basalt forms were the subject of heated debate starting in the late 18th century, when the Neptunists — who thought such rock formed out of solution, after the great universal flood of the Bible — battled the Plutonists, who said it was volcanic in origin. The earliest field geologists pretty much had to become Plutonists; just look at Vesuvius, spewing lava like froth from a rabid dog; you could practically watch it cool into basalt. One of these was William Hamilton, English ambassador to Naples (technically, the Kingdom of the Two Sicilies). Hamilton was all over Vesuvius and the Campi Phlegraei (which is where Pozzuoli is), leaving the Mrs. at home with fires of her own to attend to (cf. Susan Sontag’s The Volcano Lover).
A few months ago, I wrote a little about Pozzuoli’s importance in the history of geology. Spelunking into the literature of volcanoes, I learned that the town’s name in Roman times was Puteoli, and that it was long known as a source of volcanic ash, which, when mixed with lime, made an excellent hydraulic (water-resistant) cement, called pozzolana. Pozzolana was the foundation of Rome’s port at Ostia; it still holds up the Pantheon and Colosseum. This reminded me of tufa, a constant in my Italian childhood just north of Pozzuoli and Lago d’ Averno, the gateway to Hades. (What neighbors! Plus, you really had to watch out for the ornery three-headed junk yard dog down there). More generally called tuff, tufa is hardened ash; it was a popular building material. Soft enough to scrap with a fingernail, it was also rather lightweight: I vividly remember the tufa wall at Pinetamare Elementary School (Fifth grade; Miss Smith’s class; the school was then brand spanking new and right on the beach, which we were not allowed anywhere near), collapsing along one side of the playground during recess. A workman was toppled beneath the big color-TV-sized blocks, but he and his fellows pushed them off without much trouble or evident personal damage.
I wish I knew more about geology. It is not a subject suitable for book learnin’. Still, I’m interested. My samples of NYC regional rock include Manhattan schist, purplish diabase from the Palisades Sill, and Staten Island serpentine. But poor Brooklyn, being terminal moraine and outwash plain, is just a jumble of gravel and clays and glacial erratics too large to bring home. You can see some of these in the BBG’s Rock Garden: the rock that came the farthest was pushed about 250 miles from PA.
When I was a sprat, we lived north of Naples, Italy. Between us and the city was the town of Pozzuoli, mutilated by the tongues of many of the imperial myrmidions we lived among – Naples being the homeport of the US Sixth Fleet –as “Pots-wally.” I have only vague recollections of a circle in the middle of town, and some ruins, and the knowledge that Sophia Loren grew up there. Years later I was reading Janet Browne’s excellent two-volume biography of Charles Darwin, and I had a strange flashback. Here was Pozzuoli, here were the ruins. They turn out to play an important role in the history of geology, or “undergroundology” as an early proponent called it.
Pozzuoli was founded by Greeks. Its pride remains what was once Romantically called the Temple of Serapis, but is now known to be the remains of a covered marketplace. The heart of this is three standing columns of marble. When Charles Lyell (1797-1875) visited he was struck by the damage to the columns. They had been scared and gouged by something, and he recognized the work of marine mollusks, which had dug holes into the marble. But how could this be, since not only were the columns in the dry air now, they had obviously originally been built on dry ground, and the damage began several feet up the column.
The context for this is that most Western peoples believed in a tradition of a text few of them could actually read in the original, but which told them that the planet, like the lifeforms on it, was immutable, and, based on some dubious math, just several thousand years old. A “great chain of being” ruled, founded on creation and instructions, and, notably for politics, a hierarchy, from a creator entity. (In this notion, there could be no extinct animals, either; Jefferson believed there had to be living mammoths in the American West and told Lewis and Clark to find them.) Now, plenty of free-thinking and evidence-based types had been questioning this for a long time already, but they had not yet reached the groundswell.
But there on the Pozzuoli ground was evidence that the earth was trampoline-like, rising and falling; that sediments could bury the base of the columns, and sea water surround them nearly half way up, allowing “lowly” creatures to burrow into rock (marble was once limestone, itself created by skeletal remains of sea creatures, so calcium carbonate ashes to calcium carbonate ashes, indeed). “Noah’s Flood,” if you insist, was dated to 3290 BC, before the Greeks, so that was no excuse. Pozzuoli is inside a caldera; it’s had a volatile ride over the centuries (my own dearheart has dived off shore to view the ruins of the now-drowned portion.) If this could happen over two thousand years, imagine what might happen over hundreds of millions of them! This was only one piece of the evidence Lyell gathered together for his Principles of Geology, the first volume (1830) of which has a frontispiece an etching of the “present state of the Temple of Serapis at Puzzuoli” reproduced here.
Darwin was given a copy of this volume before he boarded the Beagle by his mentor, who urged him to read it but not to believe it. Was there a twinkle in the reverend’s eye when he said this? Darwin would afterwards describe himself as a “zealous disciple” of Lyell, and Alfred Russel Wallace also devoured the book, but Lyell himself at first held firm against the notion of what was then called the “transmutation of species.” Yet he helped set up the undergroundology of it, and at last came to accept it, too — for as the earth moved, so too did life.
