This image, published earlier this week on NASA's Earth Observatory, reminded me that I haven't finished blogging up my time in the Adirondacks this summer yet:

Labels: mountains, new york, travel

Last night, Lily and I went down the street to the Carnegie Institution to catch a guest lecture by climatologist Wally Broecker of Columbia University. Broecker won the Balzan Prize last year, and this was 'the Balzan Lecture.'

Broecker was introduced by the Swiss and Italian ambassadors to the United States, as well as another man whose title was not made explicit, but who had the most pronounced eyebrows I have ever seen on a non-cartoon character.

Broecker's PowerPoint was written in all capital letters, and all Helvetica. It was a bold font for a man who has a reputation for boldness. He was blunt in his assessment of the climate crisis: "The problem is huge, and I wish I could live for fifty more years to see how it all plays out," he said. He pointed out that we are currently at "390" parts per million carbon dioxide in our atmosphere, up over a third from pre-industrial levels of ~280 ppm. "We're going up by two per year," he said, and that means that we will be at 450 ppm within 30 years. "If we want to stop at 450 ppm, we're going to have to go on a World War II footing."

He estimated that about 80% of humanity's energy comes from carbon, and stated "We must cut back to zero net emissions." However, he acknowledged that it is unlikely that we will be able to do this in the time we have (~30 years, see above), so he has come to the conclusion that the only way we're going to be able to avoid a doubling of CO2 is to capture carbon dioxide from the atmosphere and sequester it somewhere.

He showed both Keeling curves: Dave Keeling's CO2 data from Mauna Loa, and Dave's son Ralph Keeling's CO2 data and O2 data from La Jolla. (I've reported before on how compelling this oxygen data is: it's definitive information that shows the rise in atmospheric CO2 must be coming from the combustion of fossil fuels, a process which consumes oxygen by bonding it in an exothermic reaction to fossil fuel carbon.) Broecker then predicted that we are going to at least double CO2, triggering a rise in temperature of about 3.5 degrees C. He said, "This will not be a total catastrophe, but it's going to be a huge mess." He discussed ecological changes which will likely result - species shifting poleward or towards higher elevations, but able to migrate at different rates, which will be rough in terms of keeping ecosystems coherent and functional.

He said that water vapor is actually the biggest contributor to the greenhouse effect, and that it amplifies the warming caused by CO2. The partial pressure of water vapor over the oceans goes up by about 7% with each degree of warming: this means that a degree of warmth caused by CO2 would trigger a triple warming because of its effect on water vapor. He discussed uncertainties in our understanding of the climate system: the role of aerosols, the role of clouds. "We're perturbing climate," he said, "on a planet where we don't understand the whole thing."

He discussed his Columbia colleague Klaus Lackner, who has developed a plastic compound that can capture carbon from the air. Lackner has proposed a facility using filters of this compound, and estimates each facility, about the size of a shipping container, could remove 1 ton of CO2 per day, about the equivalent of 20 U.S. automobiles' emissions. Each facillity costs about as much as a car, so Broecker proposed paying for them by tacking a 5% surcharge onto automobile sales. They also cost money to maintain, and the calculation suggested that if we added a tax of 25 cents per gallon, we could generate enough income to maintain these carbon-capturing facilities.

The grants that Lackner got to develop this technology totaled about $6 million. Broecker pointed out that we pay (Yankee) baseball pitchers about $6 million per year, and that it's a shock and a shame that so very, very little is being invested in solving the problem of accumulating carbon emissions. He said, "That is peanuts compared to the amount of money that is being spent on any other serious problem on this planet."

Norway's 13-year record of success in storing captured carbon in deep sea sandstone reservoirs was his next topic, and he went on to suggest that we should try trial experiments where we inject CO2 directly into the deep sea's water, given that it has a ~1000-year circulation time. Below 3500 m depth, liquid CO2 is more dense than seawater, and would either sink or form clathrate slush. Broecker suggested it's quite possible it could be stable down there, and we need to figure out if in fact it is before it's time to actually start injecting it. Greenpeace opposes this idea, and Broecker said, "environmentalists are their own worse enemies." In Iceland, an experiment is being done where the small amount of CO2 that comes up in geothermal water is being re-injected into basalt. He pointed out that Iceland is investing MUCH more per capita in carbon capture and sequestration experiments, and lamented that the rest of the world was being so lackadaisical with its funding.

Finally, he discussed the 'geoengineering' solution of pumping SO2 into the stratosphere to filter out some incoming solar radiation (as happened naturally in the aftermath of Mount Pinatubo's 1984 eruption). Broecker and colleagues did a paper back then to calculate how much SO2 we would need in the stratosphere to counteract the warming effect of CO2 + H2O vapor, and found it to be about 30 million tons of SO2 per year. He calculated that you could deliver it with 747 aircraft, but you would need 250 of them, flying around the clock, year-round, to do it. The cost would be about $15 billion. Whether he advocated this approach was unclear to me, but that's where we ended up. The end.

Applause, more "hosting" from Mr. Eyebrow (who tried to inject a positive note into the grim discussion: "It will be okay. We're so smart; we will figure it out!"), and some audience questions. A walk home for Callan and Lily, followed by a gin and tonic.

Labels: awards, climate change, CO2, dc, global warming, meetings, new york

Yet five more of the maps I scanned from my recently-entered-the-public-domain copy of Vernon Quinn's book A Picture Map Geography of the United States. As before, clicking on the image will take you to a bigger version of the map. Enjoy!

Labels: art, books, connecticut, maps, maryland, new york, oregon, washington

First Geological Society of Washington meeting of the new academic year
September 23
http://www.gswweb.org/
Dupont Circle, Washington, DC

Virginia Region of the National Speleological Society caving convention (but without the caving)
September 25-27
http://www.varegion.org/var/events/FallVAR/FallVAR.shtml
Battle of Cedar Creek Campground (Route 11, between Strasburg and Middletown, Virginia)

New York State Geological Association meeting
September 25-27
http://www.newpaltz.edu/geology/nysga.html
New Paltz, NY

Virginia Geological Field Conference
October 2-4
http://web.wm.edu/geology/vgfc/2009.php
Big Meadows, Shenandoah Nat. Park, VA

Labels: caves, gsw, new york, shenandoah, structure, virginia

A quick sketch of a glacial boulder that I showed you two days ago...



Here's what caught my eye:



What else do you see here?

Labels: granite, metamorphism, new york, structure

Yesterday, I asked you, "What is the origin of these red polka-dots on this apparently white sample?"



And I gave you a hint that this cobble was photographed at the "half drumlin bluff" site I detailed the previous day! And the fact that the word "apparently" was in italics was also a hint.

Well, here's the deal -- this is a red cobble, with a white coating. I think Paul said it was the Oswego Formation, a fine-grained reddish sandstone. I think what's going on here is that all the limestone powder in the till is readily dissolving during rain storms, and the dissolved calcite gets carried along in solution, flowing over and around larger clasts like this cobble. Then, as it dries out, it begins to precipitate a coating of calcite all over everything (maybe with entrained clay and silt particles too?). Then along comes a little sprinkle of rain, and individual raindrops splash away this encrusting solution from little circular areas, revealing the red rock beneath. I saw this same phenomenon on several cobble and boulder lithologies, not just the red ones.

What do you think? Plausible?

Howard came pretty close in the comments (though this is the top side of the cobble, not the underside), and as the sole guesser, I reckon that entitles him to the prize. Howard, send me your mailing address if you want a bumper sticker.

Labels: contest, new york, sediment

A quick contest:



What is the origin of these red polka-dots on this apparently white sample?

Hint: this cobble was photographed at the "half drumlin bluff" site I detailed yesterday!

First one to answer correctly is entitled to a free "GEOLOGY ROCKS" bumper sticker!

Labels: contest, new york, sediment

Labels: glacial landforms, glaciation, new york, sediment, travel

Last week, I visited the Taconian Unconformity in the Catskills region of New York. I found out about the outcrop via the informative website the USGS put together in 2003 to explain southeastern New York's varied and interesting geology (Click here for a map).

Here's me at the angular unconformity, demonstrating the layering with my forearms:


Here's the same outcrop, sans goofball, avec annotations:


This is a classic angular unconformity. It even graced the cover of the (excellent) GSA publication Excursions in Geology and History: Field Trips in the Middle Atlantic States (Frank Pazzaglia, editor; cover photo by Marli Miller). Why should we care? Because like the "original" angular unconformity at Siccar Point in Scotland (described by James Hutton), this outcrop represents a lot of geologic time. First, during the Ordovician period, the Austin Glen formation had to be deposited as layers of clastic sediment in an ocean basin. Then, during the late Ordovician Taconian Orogeny, those layers had to be deformed: folded and buckled so they stood up on end, and then eroded down to their nubs. Then, on that newly-formed erosional surface, a fresh layer of sediment had to be laid down, in this case, the Rondout Formation was deposited as a layer of carbonate mud during the late Silurian period. Then, that too was deformed, during the Devonian period's Acadian Orogeny. Finally, the whole package had to be uplifted to the surface and exposed (in this case, when a highway roadcut was completed). That's a lot of time!

I'm delighted to have had the opportunity to visit it first-hand!

Labels: devonian, maps, mountains, new york, ordovician, silurian, structure, travel, unconformities

Just back to DC after a lovely week up in upstate New York, enjoying the scenery, hiking, and geology. Here's a little treat for you: a foam pattern on a stream, en route to Big Slide Mountain in the Adirondacks. What does it look like to you?


...I'll tell you what it looks like to me, tomorrow...

Labels: contest, new york

New Paltz, New York (a big climbing town).

Labels: humor, new york

I made it to Lake Placid. It's raining buckets here.

Labels: mountains, new york

Good morning! I'm in New Paltz, New York, right now, on my way up to the Adirondacks for several days of fun, to be followed by a visit to a geologist pal in Drumlin Land, and then a quick excursion to visit some other friends in Canada. Later this morning I'll visit the Taconic angular unconformity outside of Catskill, New York. I'll try and post photos and whatnot as I go, in the same manner as yesterday's ptygmatic fold post -- my first ever remote post from the new iPhone. But I forgot to bring the iPhone charger, so we'll see how I do... Anyhow, stay tuned.

Labels: canada, mountains, new york, tech, travel, unconformities

Very cool.

Labels: art, new york, tech

Started by Lockwood, perpetuated by Silver Fox... [UPDATE: Geology Happens, Geotripper, Hypocentre & Phreatic Ramblings have chimed in, too. The latter even posted about a huge paleofalls...] As per the geoblogospheric standard, the idea is to bold the ones you've been to.

#10 Lower Calf Creek Falls, Escalante National Monument, Utah
#9 Lower Falls of the Yellowstone River, Yellowstone National Park, Wyoming
#8 Upper Whitewater Falls, in southwestern North Carolina
#7 Snoqualmie Falls, between Snoqualmie and Fall City, Washington
#6 Havasu Falls, Supai Village, Havasupai Indian Reservation, Grand Canyon, Arizona
#5 Shoshone Falls, Twin Falls, Idaho
#4 Multnomah Falls, Columbia River Gorge, Oregon
#3 Bridalveil Falls, Yosemite National Park, California
#2 McWay Falls in Julia Pfeiffer Burns State Park, Big Sur, California
#1 Niagara Falls, Niagara, New York

Bonus Waterfall #1 [via Lockwood]: Salt Creek Falls, Oregon
Bonus Waterfall #2 [via Silver Fox]: Palouse Falls, eastern Washington
Bonus Waterfall #3 [from me]: Deer Creek Falls, Grand Canyon, Arizona (photo above)

For the record, I kind of don't get the appeal of waterfalls. I mean, they're cool and all, but they don't strike as particularly complex (and therefore, not particularly interesting)... I mean: gravity, right? ...It pulls water downhill... What's the big deal? (I had a conversation this summer along these lines at Waterfall #9 on this list, with a similarly-minded fluvial curmudgeon.)

...But people love them - When I poll my Physical Geology students at the end of the semester about what their favorite part of our Billy Goat Trail geology field trip, only a third or so invoke the migmatite, a third or so cite the physical challenge of climbing "The Traverse," and a third or so claim that viewing Great Falls was their favorite part. To each their own, I reckon: I'm glad they got something meaningful out of the trip... but I can't claim to understand it.

In my twisted worldview, Deer Creek Falls is interesting not merely because it's scenic (and a great place to go swimming), but because the waterfall issues from the Great Unconformity, and thus has geologic significance: It satisfies the intellect as well as aesthetic sensibilities.

Labels: arizona, california, grand canyon, new york, wyoming

There's a proposal to turn the Luck Stone diabase quarry south of Leesburg into a big reservoir for increasingly-populous Loudoun County, Virginia. It would then be followed by other tapped-out quarries in the area. Collectively storing 8 billion gallons, the reservoirs could serve the surrounding area for up to 120 days during a prolonged dry spell. The idea is to create the reservoirs by siphoning of about 40 million gallons a day from the Potomac River, starting in 2017.

These diabase intrusions are mafic igneous rocks that intruded into the crust during the opening of the Atlantic Ocean. As Pangea broke apart during the Triassic and Jurassic, a huge system of sags opened up in the crust. These low spots were the sites of (a) intense sedimentation, since water flows downhill, and (b) mafic igneous intrusions, since the thinned crust allowed decompression melting of the underlying mantle. (Partial melting of an ultramafic source usually yields a mafic distillate.)

The entire system of failed rift valleys extends along the same trend as the Appalachians, but further east, all the way up to the Bay of Fundy. Collectively, they are called the Newark Supergroup, after one of the larger rift basins in Newark, New Jersey. Dirty sandstones filling that basin were the source of all the 'brown stone' that made the brownstones of New York City. Locally, in our own Culpeper Basin, the main rock that is quarried is diabase, which has a coarser crystal size than basalt, but smaller crystals than a gabbro. It is distinguished by a lot of pyroxene.

Source for the reservoir proposal news: Today's Loudoun Extra, from the Washington Post

Labels: atlantic, culpeper basin, jurassic, minerals, mining, new jersey, new york, news, triassic, virginia, water resources

Ann Hornaday authored an interesting piece in this morning's Washington Post about Ota Benga, the Congolese Pygmy who was displayed for a time in a cage in the Bronx Zoo. It turns out that Ms. Hornaday's great-great-great-uncle, William Temple Hornday, was the one who put Ota Benga there.

Labels: africa, anthropology, new york, science and society

This image came to my attention the other day via Lutz's Geoberg blog. It's one of the high-res images provided by the newly-launched satellite, the GeoEye-1, which is supplying new images to Google*. The image shows a marginal lake associated with an alpine glacier in Kenai Fjords National Park, Alaska (just south of Seward):


The top of the above image is not north; it's southwest. Mentally rotate it, and you can see that the resolution is a lot better than the current level on Google Earth and Google Maps:


The thing that struck me about the new GeoEye image, aside from its beauty, is the distinct pattern of iceberg sizes in the lake: freshly calved off the glacier, the biggest icebergs are close to their source, while further away the icebergs are smaller. This pattern struck me as being analogous to sediment. Fresh from its source, sedimentary particles are at their largest size, and the further away they travel, the more weathering they experience. This weathering (in particular of the physical variety) tends to break them down into smaller pieces. Adjacent to an orogenic belt, for instance, you tend to find deposition of sedimentary particles shed off the uplifting mountains. As a general rule, these are of the largest sizes and the greatest volume closest to the source, and then particle size and stratum thickness both diminish with increasing distance from the orogen.

For a North American example, consider the Catskill Clastic Wedge, a tick pile of sediments shed off the late Devonian Acadian Orogeny along the east coast. Here's a cross-sectional view** (pre-Alleghany Orogeny deformation) of the wedge, running from the Bay of Fundy west to Michigan:


Same pattern! Coarse stuff, and more volume of stuff, close to the source. Finer stuff, and less volume of stuff, further from the source. Just like the iceberg, except the weathering of the icebergs is mainly thermal, while the weathering of the sediments is physical, accompanied by depositional sorting by the transporting currents of water.

__________________________________

* An original version of this post misidentified Google as the owners of the GeoEye-1, as opposed to the company called GeoEye, which sells images to Google. Thanks to Bruce Haley for the correction. (updated 8:14AM eastern time on Dec. 9, 2008)
** Image redrawn (by me) from an original in Prothero & Dott (2003).

Labels: alaska, analogies, art, canada, glacial landforms, glaciation, maine, michigan, mountains, new york, satellite imagery, sediment

Labels: appalachians, climate change, global warming, new york, rain, sediment, snow

Here's a quick recap of my cross-country journey, for those who are interested in such things.

I left Bozeman on Saturday morning, July 26, and drove east on the Interstate to Billings, then diverged southeast towards Little Bighorn. There, I verified a comment from a Lakota friend at MSU that with my new bushy mustache (see change in icon above), I look a wee big like George Armstrong Custer (Custer & his men were killed by Lakota and/or Cheyenne warriors). After a short picnic there, I kept driving across southeast Montana, and into northeast Wyoming. My goal for the night was Devils Tower, where I have positive memories from my "North by Northwesty" roadtrip two years ago. I got to Devils Tower in mid-afternoon, just in time for a wicked-looking thunderstorm to roll in. Pendulous looking mammatus clouds were hanging down, and the skies turned a darker grey than Lola. Rain and wind came through, and a big dead branch from one of the cottonwoods in the campground came crashing down, but not on anyone's car or tent. When the skies cleared up, I drove up to the visitor's center and took a walk around the tower. It's awesome: massive columns, some of them twenty feet across. The rock is a porphyritic phonolite, and it's quite pretty to look at: big feldspars (5mm) set in a fine-grained grey matrix. Lovely.

The next morning (Sunday), I headed for Red Bird, Wyoming (along Wyoming's eastern border), where Cruisin' the Fossil Freeway suggested there would be oodles of ammonites in concretions in the Pierre Shale, some a foot across. When I visited the Denver Museum of Nature and Science earlier this summer, Kirk Johnson reiterated to me that Red Bird was the place to go for ammonites. But once I got to where Red Bird should be (according to my road atlas), there were no highway signs indicating that the town existed. Worse, there were no outcrops, and no sign of public land. (And one thing that an amateur fossil collector does not want to do in Wyoming is trespass on a rancher's land.) So, no Red Bird ammonites for me. Oh well, no worries: I had collected ammonites from a tongue of the Pierre Shale (the Bearpaw Shale) earlier in the summer on BLM land near Glendive, Montana, and scored some good specimens there. I cruised south, stopping at the Sierra Trading Post outlet in Cheyenne, Wyoming, and dropping some cash on some new duds (STP is mainly a catalog business, famous ten years ago for their amazing deals, but the company seems to be shifting to more mainstream business nowadays, including multiple brick-and-mortar locations). Then another hour on the road brought me to Fort Collins, to the house of Larry Wiseman, where I stayed earlier in my trip. He and I got some pizza and 90-Shilling Ale (Odell's) and traded tales about our summers.


The next morning, we had coffee on Larry's front porch and watch the sun rise. I packed up and hit the road, heading for Kansas. In my rear-view mirror, the Rockies shrank and vanished from sight, a melancholy fade. Out into the plains... In mid-afternoon, I rolled into Oakley, Kansas, where I headed for the Fick Museum. The Fick Museum is interesting on multiple levels: it's got some stellar fossils from Kansas's Smoky Hill Chalk (member of the Niobrara Formation), like a Xiphactinus (massive fish) and a Tylosaurus skull (even more massive mosasaur). But it's also got some whacked-out art: the founder, Vi Fick, was into making art with local "art supplies," and so the walls show his portraits of eagles rendered entirely in rattlesnake tails (see image at right, from this online gallery), or his geometric arrangements of thousands of fossil shark teeth. There's even an oil painting Fick did of "God making the Cretaceous seas," which shows a bearded diety surrounded by flames (it kind of reminded me of Hindu art) making pleisiosaurs and pterosaurs. Not the usual way you see fossils displayed, or paleontology depicted!

At the Fick Museum, I met up with Ron Schott, doyen of the geoblogosphere, who graciously agreed to show me some cool Kansas geology. Ron and I headed south from Oakley towards Monument Rocks, an outcrop of the Smoky Hill Chalk. Ron was eager to gigapan the outcrop, and he set up the little device: essentially a robot that directs his camera to take high-resolution photos in a systematic grid. Pretty cool, really -- I guess I hadn't realized what a Gigapan really was before seeing it in action. I got to meet Ron's two little plastic elves that he uses for scale, and personally placed them on a ledge of chalk for the photograph. The grid of pictures eventually gets digitally stitched together by software, and available for sharing online.

From there, Ron and I headed back up to Oakley, stopping en route so I could collect a couple samples of the aquiferiferous Ogallala Formation, and then headed east, then south again, towards Castle Rock, another chalk outcrop. Here, we tested out my Prius' shocks on the dirt tracks, and checked out the largest cliff in Kansas (nearly getting blown off it by the intense wind), and then prospected for fossils below. I found some fish scales, and a shark tooth! Also inoceramid clam fragments, encrusted with oysters (apparently a common feature of the bottom of the Western Interior Seaway). No mosasaurs, though... Back to the road, and into Hays, Kansas, where Ron put me up in his guest room. We had dinner and a few beers at the Lb. Brewing Company, and thought about recording a PodClast, but then it slipped our minds. We discussed field trips, tenure, publications, and related topics. A good time! Thanks again to Ron for being such an excellent host.

The next two days (Tuesday and Wednesday) were essentially just driving. On Tuesday, I made it to Indianapolis, Indiana, and spent the night in a hotel there. On Wednesday, I turned north, and drove up into Michigan, and crossed into Ontario at Port Huron / Sarnia. Why go to Canada on my way from Montana to DC? Well, I'm teaching my Snowball Earth class this week at NOVA, and some of the rock samples I needed were stuck at Brock University in St. Catherines, Ontario. Usually they get shipped to educators who want to use them, but because of alleged border complications, I had to go get them myself; a five hundred mile detour! Fortunately, I have good friends who leave in Waterloo, Ontario, so I went and stayed with them. Mike and Natalie Leuty have been friends since 1996, and we had a good evening catching up. They have a sweet house in a suburb full of professorial types who teach at one of the several universities in town.

On Thursday morning, Mike and I had coffee on his front porch while his kids played in the yard, and then I packed up my kit and got rolling. I made it to Brock by 11am, and got the Snowball Suite. Because it's in a giant black case that looks suspiciously like a rifle case, I packed it under a pile of other gear in my car. At any rate, I crossed back into the United States without any static from customs officials, and rolled through Buffalo, New York (twice in one year!) I made my destination for the night Ithaca, New York, where I have a friend who's going to grad school at Cornell. I've never been to Ithaca, but I hear that it's "gorges" from many people. So I called my friend, Kathryn Werntz, and she was indeed around and accepting visitors, so I drove through the finger lakes region (five subparallel glacial troughs now filled with water), and found my way to her bungalow. Kathryn and I took a walk through Cornell's campus (two amazing gorges cutting through it), had some Indian food, and went to get dessert at Purity Ice Cream.

In the morning (Friday), I got up and we went to Gimme! Coffee for some caffeine. Thus fortified, I hit the road for my final day of driving. East to I-81, then south through Pennsylvania. At Harrisburg, I turned onto I-83, which took me to Baltimore, and from there it was a familiar zoom down the B-W Parkway into northeast DC. The dome of the Captiol was visible to my left, and then the comfortable sights of Florida Avenue and U Street. Up the hill, and a left on Harvard Street, and I was back in Adams-Morgan. Home! Finally!

Labels: appalachians, canada, chalk, colorado, field trips, glacial landforms, kansas, montana, national parks, new york, snowball earth, structure, travel, wyoming

On Wednesday, two students and I participated in an excellent field trip examining the sequence stratigraphy of the Niagara region. We saw uppermost Ordovician rocks (the Queenston Formation) and then a dozen Silurian formations, some of them only 3 meters thick, stacked atop on another in a stereotypical layer cake fashion.

The trip was led by Carl Brett, who did a great job. I wanted to showcase here a few of the photos I took that day. Here's Carl showing us Arthophycus trace fossils (interpreted to be the burrows of polycheate worms):

At Outwater Park, we found fossil stromatoporoid reefs. Stromatoporoids were primitive, layered sponges. These ones show glacial striations across their surface, a result of the outcrop being scraped by glaciers during the recent Ice Ages:

At another stop (on Lockport Junction Road) , there was a Leperditia ostracode-rich layer. Ostracodes are small arthopods, kind of like krill, but with bean-shaped shells.

At Pekin Hill, we looked at the Goat Island Formation, which showed ripped-up stromatoporoids deposited within it.

Here's a stromatoporoid that tumbled loose from the slope. I'm bringing this one back to Annandale to use as a teaching specimen. Note the upward-bulging dome of the stromatoporoid's internal layers.

One of our most amazing stops was hiking up into the Niagara Gorge. This is at the downstream end of the Niagara Escarpment, where the Falls once were. The adjacent town is Lewiston.

Here's Laura and Victoria in the Gorge, overlooking the Niagara River:

Now for some fossils from the Rochester Shale and other units exposed in the Gorge. Carl brought these out to show us what we might find. Here's a mouthwatering slab showing Dalmanites trilobites:

And a golf-ball sized cystoid (relative of crinoids, blastoids, and other echinoderms):

He had some Lingula dwelling traces, too. Lingula is a common inarticulate brachiopod that dwells / dwelled in vertical burrows beneath the seafloor mud:

Here's a shot of a crinoidal grainstone. This limestone is almost entirely made up of "sand" generated by broken up crinoid skeletons:

Some spectacular trace fossils (ichno-genus unknown) on a slab that was catching the rays of the sun just right:

And a close-up of the same slab:

And lastly, a nice slab showing tool marks:

It was really a great trip -- perfect weather, fascinating rocks, good company, and I felt nice and tired at the end of the day.

Labels: fossils, meetings, new york, nova, primary structures, sediment, silurian