Sequence Stratigraphy and other topics (April 28 & 30)

During the last of this course we traditionally cover topics of our choice. If we have time, we will talk about the Channeled Scablands of eastern Washington and related topics, including the famous jökulhlaups. There is a good story here as well about a persistent and ingenious geologist named J Harlen Bretz.

We may finish the course with a look at the incredible Snowball Earth Hypothesis. It is supported by evidence we can examine with your new sed-strat skills, and the counter-arguments are also relatively easy to grasp.

We’ll discuss your final exam, including the content, format and timing.

New Oxford Conglomerate (Triassic) of York County, Pennsylvania. Collected by Dr. Shelley Judge. (Click to enlarge.)

Geology in the News –

When methane hydrates are in the news, it is rarely good. The warming of the Arctic with the epic thawing of permafrost, is already producing thermal feedback and massive expenses.

The extraordinary decline of air pollution in India during this COVID-19 crisis is just one example of how natural systems are recovering quickly as we humans dramatically diminish our activities.

Check out this photo of a glacial ice cave in Iceland. Fantastic.

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Tectonics and Sedimentation (April 21 & 23)

On Tuesday we will cover petroleum from a sedimentary perspective. Please review the links from last week.

“Tectonics and Sedimentation” is a broad topic with few direct web references; we’ll start with a review on Tuesday. You may want to revisit Plate Tectonic theory with this primer on plate tectonics. An excellent (and very useful) website is that of Ron Blakey at Northern Arizona University. It contains superb maps for each period and excellent discussions of issues in tectonic sedimentology. Here is an excellent website from James Madison University on the Wilson Cycle (love that name). This will be useful when we discuss sediments produced under particular tectonic conditions. James Madison University also has a good summary site on sedimentary rocks.

We will also cover general stratigraphy, which will be in part a review. There is no better resource for sequence stratigraphy than the excellent on-line guide written by my colleague Steve Holland at the University of Georgia Stratigraphy Laboratory. The extensive sequence stratigraphy webpages at the University of South Carolina are also very good for our work next week. They include animations and exercises. Who needs professors these days?

Remember that your Research Paper is due at 7:30 a.m. on Thursday (April 23) as a Microsoft Word document in your Dropbox folder

Swan Peak Quartzite (Ordovician) exposed near Tony Grove Lake, Cache County, Utah. (Click to enlarge.)

Geology in the News –

Here’s a new paper describing an astounding amount of microbial life in old seafloor basalts. There are as many or more bacterial cells in some of these rocks than there are in the human gut. I’m not impressed, though, by “what it tells us about life on Mars”.

“Geologists have studied exposed, 3.2-billion-year-old ocean crust in Australia and used that rock data to build a quantitative, inverse model of ancient seawater. The model indicates the early Earth could have been a ‘water world’ with submerged continents.” (I can’t bring myself to rewrite this elegant description!)

Ancient monkey Atlantic raft adventures! It is likely that the ancestors of modern South American monkeys came to the New World from Africa by floating across the Atlantic Ocean on mats of vegetation and earth.

 

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Coal and Petroleum (April 14 & 16)

We’ll finish phosphates on Tuesday (review last week’s links) and then on to King Coal and Big Oil. Let’s start with the Wikipedia page on coal, which is very good. A visit to the World Coal Association page will give you a sense of the magnitude of coal production. Here are some evocative pictures from the coal industry. The coal industry in the USA is in serious decline for obvious reasons.

Petroleum is remarkable stuff — so much energy packed into such a convenient fluid. You may want to visit the websites of the American Petroleum Institute and the U.S. Energy Information Agency to see just how dependent we are on the black gold. There are few topics in geology so politically volatile as petroleum. Of course petroleum is from life sources, but a debate continues among a very few.

Methane hydrates (also known as “methane clathrates”) are fascinating hydrocarbon deposits. The USGS reminds us that the methane contained in these ices is a greenhouse gas with considerable potential to warm the Earth’s atmosphere significantly and quickly. This certainly has happened in the past, possibly during the Paleocene-Eocene Thermal Maximum. There is now even an experimental methane hydrate production well in the permafrost of the Far North. Here’s a video of the Alvin mucking about with a methane hydrate deposit.

Cannel coal from the Upper Carboniferous of northeastern Ohio.

Geology in the News –

Here’s the best account I’ve found describing the marvelous image of a black hole revealed last week. An historical moment. If you’re not impressed it is because you don’t understand the gravity of the situation. [Sorry. An old joke too good to delete.]

No geologist is surprised by this: There are fossil remains of a Cretaceous rainforest underneath the ice of Antarctica.

I am very impressed with this compendium of animals in amber from the Triassic through Paleogene of the southern hemisphere. Many new taxa discovered recently.

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Siliceous Sediments, Ironstones, and Phosphates (April 7 & 9)

Chert is not a big topic on the Web. Wikipedia’s article on chert is scholarly but short. An amateur has put together a very detailed page on flint and chert (and what may or may not be the differences between the two). The most important ironstones are the banded iron formations (BIF) that form the bulk of Michigan’s iron industry. Wikipedia’s page on banded iron formations is accurate and well-sourced. Nothing very exciting, but note that BIF includes chert. Phosphorites are less common on the Web. At least we can bring in the “Phosphorite War” in Estonia! Oh, and Peak Phosphorus is another future calamity you can now worry about. Otherwise I must say this is a rather boring week for our webpages. Good time to work on your research paper.

Banded Iron Formation specimen from Upper Michigan. (Click to enlarge.)

Geology in the News –

Last week a 6.5 magnitude earthquake shook Idaho and surrounding states. I bet you didn’t see this in the news. Earth processes continue, of course, with or without us.

NASA’s new internet and social media special, NASA at Home, will show and engage you in the agency’s discoveries, research, and exploration from around the world and across the universe – all from the comfort of your own home.

Speaking of NASA, check out this highest-resolution-yet image from the surface of Mars. Lots of sedimentary deposits to check out someday!

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Evaporites and the Environments in Which They Form (March 31 & April 2)

For evaporites, there is nothing quite like a virtual field trip to a sabkha, courtesy of Dr. Wikipedia. The Wikipedia page on evaporites is another good gateway of information and links. I’ve worked with the evaporites in the Purbeck Formation (Jurassic-Cretaceous) of southern England. We can take another virtual field trip to the Great Salt Lake in Utah to see modern evaporites forming. (I was there three years ago and will show plenty of photos in class.) You can also take a short trip to Badwater in Death Valley — the lowest point in North America — where salts of various kinds are forming from evaporation. (The Wooster Geologists visited Death Valley during a Spring Break trip.) The Dead Sea (Israel and Jordan) is a fascinating place for geology, ecology, economics and politics, as you can see in this short video (emphasizing its environmental problems) and this visit by IS student Melissa Torma and me. Did you know that during the Miocene the Mediterranean Sea became a vast evaporative basin? Of course you didn’t — this is why you need me!

Dr. Ian West, who, as we Americans often say, is “very British,” has a comprehensive page of sedimentary geology web resources, including bibliographies. It may be useful for your research paper. If you want to see all the ways to get hurt on a geological field trip, check out his safety page.

Just for your entertainment, here is utter nonsense with a sedimentological basis: “The Artistic Technology of the Ancients: Osijela Hill in the Bosnian Pyramid Complex“. It is a bottomless pit of senseless speculation grounded on complete ignorance of sedimentary structures and stratigraphy.

Your second lecture exam is on Thursday, April 2, and it covers everything we have done through Tuesday, March 31. Here is a copy of the Spring 2019 second Sed Strat test. We’ll figure out a system for you to take this test off campus.

Teepee structure in a modern halite deposit; Dead Sea, Israel. Note a Wooster IS student for scale! (Click to enlarge.)

Geology in the News –

NASA’s new internet and social media special, NASA at Home, will show and engage you in the agency’s discoveries, research, and exploration from around the world and across the universe – all from the comfort of your own home.

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Continental Margins and Deep Marine Systems (March 24 & 26)

Our Spring Break coincided with a crisis point in global history. The COVID-19 pandemic has changed everything we’re doing. This course, like all Wooster courses and, for that matter, all college courses in the country, is going online only. We will work out the details as a class. Our first official “class meeting” is now on March 26. By then I will have contacted each of you with the new course guidelines and will have uploaded narrated PowerPoint lectures and other exercises to your Dropbox folders. I will keep these course pages updated in the usual manner to give our scattered class an online home. I will very much miss seeing you in person, but we’ll try to make up for the physical separation with virtual experiences.

We will spend some of your first week “back” from Spring Break finishing carbonates and their depositional environments (see previous links). We will then move into deeper marine systems and return for a short time to siliciclastic sediments (especially clays).

Let’s begin with the field experiences of our own Team Utah 2020 during the first week of the break. The trip was sadly truncated, but we got our job done. Please note all the sedimentary indicators of the Jurassic carbonate paleoenvironments we worked with.

Here is an absolutely beautiful (and large) color physiographic map of the oceans and continents, courtesy of your federal government. This would make a nice desktop image, suitably slimmed down. Here is another NOAA map showing the ocean floors only, again in vivid colors. Makes you proud to be a geologist. Move on to a sediment-thickness map (a work-in-progress from NOAA) and we can begin our week’s material. (Be ready to explain the thickness patterns.) The NASA SeaWIFS Project has stunning color satellite images of the oceans. (I like the design-your-own-globe part.) The world’s greatest source of information about deep-sea sediments is housed in the Lamont-Doherty Earth Observatory Division of Marine Geology and Geophysics. The Monterey Bay Aquarium Research Institute (MBARI) also does fantastic (and photogenic) deepsea work.

Here is a turbidity current video we would have used in class; here’s another of a geologist explaining turbidites. Here is a diagram of a Bouma Sequence.

Did you know that the director, producer and explorer James Cameron made an extraordinary dive to the deepest waters on Earth? Check out the Deepsea Challenge website.

Your second lecture exam is on Thursday, April 2, and it covers everything we have done through Tuesday, March 31. Here is a copy of the Spring 2019 second Sed Strat test. We’ll figure out a system for you to take this next test off campus.

Notes for this week — 11. Carbonate Dep Systems (pdf) 12. Slope, Rise, Basin (pdf)

Class material — (YouTube videos)

11a Carbonate environments
11b Carbonate environments
11c Carbonate environments
11d Carbonate environments
12a Slope, Rise, Basin (Deep Sea, etc.)
12b Slope, Rise, Basin (Deep Sea, etc.)

Oxford Clay (Jurassic) exposed near Weymouth, England. (Click to enlarge.)

Geology in the News –

Here’s an interesting article speculating on how the dinosaurs would have fared without the asteroid impact. It turns out to be a complex statistical problem to solve. Of course, we mean the non-avian dinosaurs!

Climate change is threatening half the world’s sandy beaches. This should not be news to you.

Check out the Late Cretaceous “wonderchicken“, a key new specimen that will tell s much about the early evolution of birds.

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Carbonate Systems (March 3 & 5)

Carbonate sediments are gifts of the sea, so let’s go there first. Maybe you’d like to stay in this nice little resort in Belize? NOAA has a wonderful website called “The Coral Kingdom” with many online photographs of reef animals and plants. The NOAA photo album is also very good. For that matter, visit the NOAA oceans page for links to extraordinary marine resources and images. The health of coral reefs is a great concern. Here’s a detailed USGS website which explores the hypothesis that airborne Saharan dust is devastating Atlantic and Caribbean coral systems. Let’s not forget all those wonderful ancient reefs as well. Everyone will want to visit “Jurassic Reef Park“. Apply your language skills to these reef pages in German.

Here’s a taste of our field research last spring in the Middle Jurassic carbonates of Utah. Will and Juda will be there soon!

Don’t forget your first lab test this week (Thursday). It is entirely devoted to siliciclastic rocks.

I hope you enjoy your long Spring Break!

Pisolites in the Conococheague Limestone (Upper Cambrian) of eastern Pennsylvania. (Click to enlarge.)

Geology in the News –

Climate change is both threatening archaeological (and geological) sites and revealing new artifacts and rocks. I suppose we can conclude that there are some silver linings as the ice relentlessly retreats.

This should be no surprise to you: Don’t build a house on a flood plain! Seems pretty obvious.

This is cool: A recently discovered critter is the first known animal not to require oxygen. It has no mitochondria. You’re not likely to see it, though, since it is a tiny parasite in some fish muscles. They are cnidarians, oddly enough, and they still have a variety of stinging cells (nematocysts).

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Carbonate Petrology (February 25 & 27)

It is with carbonate rocks that we see most distinctly that life is a geological process (trademarked, all rights reserved). The large majority of carbonate sediments are directly derived from living systems, and as such they are excellent indicators of past depositional environments. You will want to see these ultimate mineralogy pages for calcite, aragonite and dolomite. For simple introductions to carbonate sedimentology, visit the excellent carbonate pages from the Texas Bureau of Economic Geology. (They have nice online review questions!) As we approach more detailed carbonate topics, please visit the Wikipedia page on carbonate biomineralization, and this one on carbonate classification. There are some  good photomicrographs of carbonate rocks (and others) on this Oxford University webpage. And we must take a field trip to the Bahamas someday, but for now we have to do it virtually!

Here is your Second Essay Assignment (due 7:30 am, Thursday, February 27, in your Dropbox folder).

Coral sand from a beach on Aruba. (Click to enlarge.)

Geology in the News –

A new articulated skeleton of a Neanderthal was recently found in Iraq — the first such skeleton to be found in over a decade. The locality is in Iraqi Kurdistan, so you can imagine how difficult it is to work there.

Here’s an analysis of a cool reconstruction of the orthoceratoid nautiloid Endoceras. It’s not often we’re told the reasons behind this type of art/science.

Using carbon and oxygen stable isotope ratios in fossil eggshells, paleontologists show strong evidence that dinosaurs were endothermic.

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Coastal & Shallow Sea Systems (February 18 & 20)

The USGS Coastal and Marine Geology Program maintains an extensive set of webpages. One of the most interesting for coastal geology covers the coastal damage produced by Hurricane Katrina in 2005, including impressive lidar images of pre- and post-hurricane coastal changes in three dimensions. The more recent USGS National Assessment of Storm-Induced Coastal Change Hazards website is scary. El Niño is a climatic state which greatly affects coastal processes, especially on the west coast of North America. You may enjoy looking at surf webcams to escape this cold Ohio winter! Here’s a “documentary” on waves and surfing.

We now know much about tsunamis and their often tragic effects. The Tsunami Information Website from NOAA has tsunami graphics and simulations. The PBS webpage on tsunamis has graphic stories and a small animation. You will want to read about the 2011 earthquake and tsunami in Japan. To really terrorize yourself, watch the Top Five Tsunami Videos on YouTube. (Don’t be fooled by the fake title photo.) It appears to be a good idea to just stay away from large bodies of water.

When it comes to understanding the difference between spring and neap tides, you can’t beat this simple animation by James Irwin which I will use in class (if I can just figure out how to slow it down). There is a nice barrier island panorama and other images from the coast of North Carolina on this website from Steve White.

Here is your Second Essay Assignment (due 7:30 am, February 27, in your Dropbox folder).

Sediment plume from DeGeerladen, south shore of Isfjorden, Svalbard, Norway. (Click image for larger view.)

Geology in the News –

The insect apocalypse is upon us. We are in the midst of a terrible Mass Extinction equivalent to some of the worst we’ve seen in the fossil record. Insect losses signal ecosystem collapse. Yikes.

A new tyrannosaur has been found in Canada. Thanatotheristes degrootorum (“Reaper of Death”) is one of the earliest of its fearsome kind.

As for meandering rivers, here is a spectacular new series of LiDAR images of past Mississippi River channels.

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Deltaic and Estuarine Systems (February 11 & 13)

With deltas and estuaries we can apply all those principles of aquatic sedimentation we have learned, and add a few more. The Danube Delta looks like an interesting place to visit, even if it is under siege from pollution and over-fishing. The Niger Delta is a much more socially-troubled place because it is so rich in petroleum. The Ganges Delta is gorgeous from space. Has there ever been a more perfect delta than that of the Nile River? (An image from the European Space Agency.) This small site from the USGS on the San Francisco Bay and Delta region is interesting for both the deltaic and estuarine issues. We cannot, of course, forget America’s greatest delta, that of the Mighty Mississip. For an introduction to Mississippi River Delta geological issues, click into the Coastal Studies Institute pages from Louisiana State University. There is also a series of animations showing land losses along the Louisiana coast. Do you know why this erosion is occurring? The USGS has a large set of wonderful satellite images of the Pearl River Delta in southern China. How about this delta on Mars? It will be the site of a 2020 rover mission. Here is the excellent summary Wikipedia page on deltas.

Please note again the Earth Sciences Department Writing Page, the link to which is always on the right side of this page.

Finally, Test #1 will be on Thursday, February 13. As a sample of what to expect, here is a pdf of the 2019 first Sed Strat test. We will not have covered all the same topics, so some questions in that test are on material we may not do this year.

Cross-bedding and scour in the Logan Formation (Lower Carboniferous) of Jackson County, Ohio.

Geology in the News –

Great images of “ice dust” dunes on the surface of Mars. Mars has a fascinating geological history still being worked out.

More dunes in the news. Here’s a story claiming experimental dunes somehow “communicate” with each other. First, they seem more ripples than dunes, and second the mechanism of communication is unstated. I hope the original article is more illuminating. I wish it was cited. [Better explanation — and a citation — here.]

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