Recent Oneonta State Masters Program graduate Randall Willson was kind enough to send me a copy of his masters thesis and I decided (with his permission) to post it on here. The following excerpt is only the abstract to his 148 page thesis. Enjoy.
THE SEDIMENTOLOGY AND STRATIGRAPHY OF THE MANLIUS FORMATION (PŘÍDOLÍ?) AND ADJACENT UNITS: LOWER HELDERBERG GROUP, CENTRAL NEW YORK The correlation of disconformities within western portions of the Helderberg outcrop belt in New York State has clarified stratigraphic relationships within the Manlius Formation and between the Manlius and adjacent units. Throughout the region, the Minelot Falls Unconformity marks the contact between the Thacher Member of the Manlius and the underlying Rondout Formation. However, at Skaneateles Falls, the Elmwood C Member of the Manlius rests on the Rondout Formation owing to onlap along the edge of the basin. The Clockville discontinuity that marks the top of the Thacher Member and the base of the overlying Green Vedder Member (GVM), has been correlated westward, nearly to the limit of the outcrop belt. The GVM persists through this area, though it is significantly thinner than in eastern localities. Tracing of the Olney Member has revealed a previously undocumented occurrence of branching stromatoporoids (Clavidictyon) in upper portions of the member, stratigraphically much lower than previous reports. Rather than grading imperceptibly into the Dayville Member, the Olney is unconformably (Terrace Mountain Unconformity) overlain by the Dayville, a relationship that is clearly displayed in the town of Manlius. Therefore, strata previously assigned to the Olney east of Manlius, N.Y. are herein considered to be parts of the Dayville Member. A subaerial unconformity preceded Elmwood deposition and progressively beveled older units westward. The “Manlius tongue,” mapped by Rickard (1962), is not a simple progradation of Manlius strata into the surrounding Coeymans facies, but is a result of the misinterpretation of the uppermost Dayville strata as “undifferentiated Elmwood.” The top of the Elmwood/base of the Clark Reservation Member is also unconformable. Trypanites-bored hardgrounds throughout the Clark Reservation suggest significant stratigraphic condensation within this unit. The notion of a “Manlius tongue” is further compromised by recognition of a second subaerial unconformity that preceded deposition of the Jamesville Member. Traced eastward, this unconformity truncates the Clark Reservation, the Elmwood and then the uppermost portion of the Dayville Member before it is cut by the descending Howe Cave Unconformity near Cherry Valley. These stratigraphic relationships further emphasize the need to reassign the Dayville Member from the Coeymans Formation to the Manlius Formation as suggested by Ebert and Matteson (2003). The GVM (informal, upper thin-bedded Thacher) of the Manlius Fm. is present within most sections studied, and is characterized by hummocky cross-stratified wackestones and packstones interbedded with mudstones and calcareous shales. Beds of the GVM typically display flat basal contacts overlain by planar to cross-laminae and less commonly rippled caps, a sequence typical of tempestitic shelf deposits. Firmgrounds to hardgrounds developed on upper surfaces of many beds (mm to few cm) are strewn with ostracods, brachiopods, encrusting bryozoans and horizontal burrows of Planolites indicative of post-storm recolonization. Equant spar-filled fractures (mudcracks of Laporte (1969), and others) are common along hardground horizons in mudstone-wackestone beds and are interpreted as subaqueous in origin. Interbedded calcareous shales and mudstones exhibit ramifications of Medusaegraptus (a dacycladacean alga), vascular plant debris, soft tissues of annelids, microbial mats, and rare tentaculites. Thicknesses of the GVM at Oriskany Falls and Munnsville indicate maximum basinal subsidence in this area during deposition. At western outcrops, hummocks are much broader (> 1m) than their counterparts to the east. Shallower facies to the east are demonstrated by hummocks with much shorter wavelengths, sometimes displaying a nodular appearance associated with large ripple/dune forms. Correlations between outcrops displaying the GVM indicate an eastward shallowing from Oriskany Falls to Schoharie. To the west of Clockville, upper beds of the GVM are truncated by the overlying Olney Member of the Manlius Formation via the Terrace Mountain Unconformity. The presence of this sediment-starved, storm-dominated shelf setting in the presumed peritidal Manlius Formation raises new questions regarding the evolution of the Appalachian Basin during Helderbergian time.
Geologic Maps: Political Maps: Digital Maps: All Kinds of Maps.
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Also, we may have a new author soon. The suspense thickens.
Hmm. Maybe it's about time. Inhabitants of our planet are starting to take notice. In this short calendar year, we have seen quite a few devestating seismic events hitting populated area and regions proximal to high population centres. Along with the eruption of Eyjafjallajökull, the science of geology is becoming more and more a part of everyone's lives.
Take a look at your TV guide when you get a chance. Over the past few years, National Geographic, Discovery and Science Channel have produced many a show pertaining to geologic phenomena, but only now are we beginning to see repeated shows, marathons, and even geologists themselves narrating said programs.
Of particular commonality, I believe I have seen Iain Stewart's How The Earth Was Made series, and volcanologist Guy de Saint Cyr, host of On The Volcanoes of the World.For the record, I recommend both of these programs. On The Volcanoes..., however, is much more adventure-themed, rather than teaching-themed, but you may be able to see some things you never have before.
It is a bit troubling that tragedies such as Haiti, Chile, and most recently the Qinghai quake of China; are what it takes for seismic hazards to be noticed.
Since I have a meager full time job an hour away, I dont have time to go hunting for fossils like rockmaster Ruuy does (uber jealousy). I sometimes work 11 hours a day, often six days straight. On my days off, I coach a youth soccer club (crossing fingers for a 8-0-0 season). Anyways, I read a book awhile ago written by Jack Horner, Professor of Paleontology at Montana State University and from the sounds of it, God 2.0. The title of the book is "How to build a dinosaur." I suggest going out and buying this book. Its yummy.
Horner and his author-sidekick James Gorman, after explaining the idea behind the book, describe in detail the vast paleontological digs they took part in. The Hell Creek formation in Montana is a hotbed for dinosaur fossils (jealousy meter rising again). Later in the book, Horner begins to propose his hypothesis on hatching a modern day dinosaur using chicken DNA. Horner compiles the physical similarities between chickens and ancient dinosaurs and further supplements it with similar traits in their chemical and genetic makeups.
I'll leave the actual book review to Good Books and Wine, but Horner does infuse a good amount of humor into a potentially dry topic. He also dumbs down the writing so non-rockology readers can understand the concept. It was a good read.
With the coming of a new season, one which does not bury the Central New York strata in many feet of snow, is the gradual opening of an unofficial hunting season.
The snow disappears, some glaring ball of fire in the sky once again shows it's face. The ground dries out and pack boots are not required for simple tasks such as walking dogs or getting the mail.
Colorful birds show up or molt from earth toned ones, singing the hunter into the woods as he finally - after months of researching, planning, readying the weapons and of course - dreaming of the kill.
This time has approached in central New York. The season is open.
It's time to hunt some fossils.
ON Tuesday earlier on this week, fellow dead-animals-in-rock enthusiast Randall and myself decided to meet up in Mohawk, NY to start a journey through the Silurian and Devonian boundary rocks of New York's Mohawk Valley. Stops were planned in a total of three counties (Herkimer, Oneida and Madison) known for sedimentary rocks of the middle Paleozoic seas.
Starting near Mohawk, NY; our first stop were Dayville Member carbonates...which are pretty much in the middle of nowhere, near the town of Getman Corners. On top you can see some the much more planar-bedded Dayville. Member. We're still in the (upper) Devonian at this point. Here's a huge tabulate coral. Huge by my standards, anyways. This guy is the biggest I have found. The entire top layer you see in the first image is composed, almost entirely, of rocks similar to this. Float blocks at the bottom of the slope (which you may also view in the first image) are composed entirely of tabulates.
We then decided to do a short little drive in the nearby Spinnersville/Ilion area, in the vicinity of Lang's Quarry, famous for Eurypterids of the Fiddler's Green in great quantity and quality. As we neared Lang's however, there were up to six POSTED signs on each tree letting us know that we were not welcome. Maybe someday.
So we continued on to across the valley towards Litchfield. Near Jarusalem Hill there is a fine outcrop of Fiddler's Green in which Randall promised Eurypterid pieces. We got one better: Probably not complete enough to identify beyond it's genus, but still a great specimen in my opinion. I just managed to hit the rock in perfect spot, and this guy popped out. Randall also collecting an excellent carapace. This one was from a much bigger specimen, but as you can see, is quite incomplete. This came from a piece of float, so trying to find what could have been the carapace would be like, well, finding a Eurypterid carapace (not easy).
Then on to some of the Green Vedder Member (Devonian). Randall was here to collect some shales, and I was there to finally bite into my pulled pork sandwich I had packed five hours before. We did not stay long, as the aggregate company across the road had someone staked out watching us. We then visited the amazing Mosquito Point Outcrop in Munnsville(ish) which contained one of my favorite Devonian Formations, The Coeyman's Limestone. The darker rocks towards the top are Coeymans. The lighter, whitish rock, was composed almost entirely of these guys (On the right): Tabulata abound!
The Rugosa sp. to the left is from the Coeymans.
Typical Coeymans: Two nice fat gastropods. Gastropods, though incredibly interested to me, are not my specialty. I wish I could at least place them in a Genus, but alas, cannot at this time.
We ended at Stockbridge Falls, over the hill and across the valley from The Mosquito Point outcrop. The area was littered with Onondaga Limestone (Onondaga Formation), which in this area is likely to overlay either Coeymans or Kalkberg Limestone of the Helderberg Group of the Early Devonian.
A heads up i credited to Dave's Landslide Blog for posting this video earlier this morning (probably afternoon in Durham by now) but needless to say, this is a must see - not only for geologists and rock hounds alike, but for everyone. I mean everyone.
I will write up a post shortly on jokulhlaups - their causes, mechanisms and past events. Truly amazing phenomena. Stay tuned.
I wanted to brew up a quick post on the intermingling of two of my favorite past times.
Dinosaurs and Baseball Cards.
Recently, card companies have been exhuming the remains of baseball cards past. This includes resurrecting themes which vanished hastily when baseball cards first died in popularity. This was almost 100 years ago at this point, so I don't believe anyone who reads this will know what I'm talking about. Old designs are intentionally being reused, and with this theme, old idea. Back when card still came with tobacco, card would also come printed with pictures of boxers, flags of nations far away, historical figures, and of course, dinosaurs.
But I know many people love to collect dinosaur related things, and these "things" are my favorite.
Right now, I only have two dinosaur cards, and I will post them here.
The first, is Taurosaurus: As you can see, Upper Deck, the company which makes these, did a hell of a job. They are actually "mini" in size, roughly 1/2 to 1/3 the size of a normal card. You can count on getting one "Natural History" card in every fourth pack, so they're not very easy to come by for a modest collector.
From the back of the card: "The Taurosaurus, meaning "Wide Perforated Lizard," lived during the Late Cretaceous Period (About 70 Million Years Ago.) With a length of 25 feet and a weight of up to six tons, the Taurosaurus had two long horns over it's eyes."
Granted, you cannot fit much on the back of one of these cards, so understandably, the descriptions are brief.
Now for my favorite. This one is from 2008-2009 set, out for almost a year now. I looooves me some Stegos. They may have spent a little more time on this set, or maybe they're just better for having much more iconic dinosaurs, but here is the description for this one:
"An armored herbivore of the late Jurassic period, the Stegosaurus was distinguished by the dual rows of pointed, bony plates that ran along it's back as well as the long, dangerous spikes that rose from it's tail.
Roughyl 30 feet long, 15 feet tall and six tons in weight, the Stegosaurus' brain was only about the size of a walnut."
Way to dis the beast at the end, Upper Deck. Still, I'd rather be a Stegosaurus than anything that ever lived, except for maybe Eurypterus remipes, Amargasaurus cazaui or Canis familiaris.
If you're interested in finding some of these for yourself, hit up eBay and search for "UD Champs National History" or "2010 Allen Ginter Monsters of the Mesozoic" later this summer.
So I'll have to do some more snooping around with this stream. It seems to be getting bigger every year, and I am yet to figure out exactly where this particular stream is discharging into the river (if it is, even).
I threw this video together earlier today. This is another of a series of videos from "The Station", a first order drainage in which I conduct fluvial experiments. In this case I have released a plug from underneath a dam (fallen log across the stream) and record what happens with the stream afterward.
So this blog has had a steady diet of paleo lately, and, well, I'm okay with that. My initial thought in the formulation of this post was to pick a random image from the Western Regional Field Course this past summer and make a short little post on it, to keep the readers (all seven!) on their toes.
The above image is from Mesa Verde National Park in the southwestern corner of the magnificently geological state of Colorado. In reality, all states are amazing geologically, even Nebraska (you can't see the Ogalalla, but they still have a Fluvial gem in the Platte).
Mesa Verde may be most well known for the excellent preservation of Anasazi cliff dwellings, but the geology of this park is truly amazing. Perhaps Aucoin will get into the geology-archaeology intertwining in a future post here.
Back to the leaf fossils. The fossil leaves fall into the appropriately names Mesa Verde Group, a late Cretaceous, cliff-forming brown and gray layered sandstones. The importance of the leaf fossils were integral in determining the depositional environment of the Mesa Verde Group.
With the fossil leaves of the Mesa Verde Group, paleontologists or fossil seekers may find other wood debris and a huge variety of plant species, but rarely, if ever, marine fossils. The fossils are so well preserved in some places that the cuticles of the leaves can be peeled off of the rock when freshly split (Raynolds, 2007).
As of Raynolds, 2007, over 100+ seperate leaf species have been identified in late Cretaceous rocks in Colorado. Further investigation led to identifying many of these leaves as drip-tip bearing angiosperms. Drip tipped leaves are common on today's Earth in humid, high rainfall tropical rainforests. the drip-tips relieve the plant of leftover runoff moisture, which can lead to mold and disease in plants.
With the presence of these plant fossils, and the lack of marine specimens, coupled with the grain size and distal relationships (source and sink) of the sediments, the Mesa Verde Group has been labeled a lagoonal type deposit.
Raynolds, Robert G.; Johnson, Kirk M.; Ellis, Beth; Dechesne, Marieke; Miller, Ian M. 2007.Earth History Along Colorado's Front Range: Salvaging geologic data in the suburbs and sharing it with citizens. Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, Colorado 80205.
Johnson, K.R., and Ellis, B., 2002. A Tropical Rainforest in Colorado 1.4 Millions Years after the Cretaceous-Tertiary Boundary: Science, v. 296, p. 2379-2383.
Note: The above sources do not refer to leaves of the Mesa Verde Group. The units are similar at Mesa Verde to those of the Castle Rock Flora site, and this was the reason I used these papers. That, and, they were the only source I am aware of.