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.

Notes for this week — (coming soon)

Class material — (YouTube videos coming soon)

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

Geology in the News –

Coming soon!

Posted in Uncategorized | Comments Off on Evaporites and the Environments in Which They Form (March 31 & April 2)

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.

Posted in Uncategorized | Comments Off on Continental Margins and Deep Marine Systems (March 24 & 26)

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).

Posted in Uncategorized | Comments Off on Carbonate Systems (March 3 & 5)

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.

Posted in Uncategorized | Comments Off on Carbonate Petrology (February 25 & 27)

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.

Posted in Uncategorized | Comments Off on Coastal & Shallow Sea Systems (February 18 & 20)

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.]

Posted in Uncategorized | Comments Off on Deltaic and Estuarine Systems (February 11 & 13)

Terrestrial Sedimentary Systems (February 4 & 6)

This week we continue our discussion of the sedimentology of desert systems. (You’ll have to just endure my enthusiasm for deserts.) To fully sample my joy, I simply must link you to the Wooster Geologists blog entries for our field trips to the Mojave Desert. You may also want to see posts from our geological field trips in the Negev Desert of southern Israel. There are some other more spectacular desert geology websites. Start with the USGS page set on the geology and resources of deserts. The Great Sand Dunes National Monument also has superb geology sections, as does Death Valley National Park. Here is a nice site for Space Shuttle photographs of the Atacama Desert in Chile. The DesertUSA commercial site will introduce you to other desert pages and images.

Let’s take a moment to remember, as we will in class, a geological and military hero: Ralph Bagnold. He was a pioneering geologist, particularly in deserts. He was also a significant contributor to the Allied victory over the Italians and Germans in North Africa during World War II.

For fluvial systems, here is the Wikipedia page on alluvium (note links within to other specific pages). Here’s a video of a flash flood in southern Utah. (Don’t mess with flash floods!) Here’s another with a drone perspective. Note that people don’t drown as much in flash floods as they get pummeled to death by debris. Be safe out there. As for meandering rivers, here is a spectacular series of LiDAR images of past Mississippi River channels.

NASA has an extraordinary website called “The Visible Earth“. It is a diverse and large set of satellite and Space Shuttle images of the Earth’s surface, all searchable. Look for views of deserts from space.

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.

Sand from Kelso Sand Dunes, Mojave Desert, California. (Click to enlarge.)

Geology in the News –

We live in an anti-science age in which scientists and scientific ideas have lost considerable credibility with the public. Here is an interesting take on why we should not call this a “war on science”as so many do. Such aggressive language usually has a negative effect on audiences. What we should do to restore respect for the scientific method and discourse is unclear.

This BBC article on the Thwaites Glacier in Antarctica is fantastic, especially the images and graphics. This is where Dr. Alley did her recent field work. It is a very dramatic place of high consequences. Here’s an accompanying video.

Posted in Uncategorized | Comments Off on Terrestrial Sedimentary Systems (February 4 & 6)

Principles of Stratigraphy — Introduction (January 28 & 30)

It is difficult to construct an interesting page on stratigraphy. So many lecture outlines, so few useful pages. The Geology and Geological Time page of the University of California, Berkeley, is not bad as an introduction, especially for those of you with just one previous geology course. You can always practice your stratigraphic skills with this elaborate dating assignment you can download and then cut into little cards. (I wouldn’t bother, but maybe you have a roommate with little to do?) Visit Jurassic Tank, an experimental stratigraphy apparatus at the University of Minnesota. This detailed website on the geology of the south-central coast of England is also a very good example of stratigraphy in action (and where I had many students doing fieldwork years ago). For the lab, you can’t beat these brief descriptions and images of sedimentary structures from Wikipedia.

Here is your Essay #1 assignment.

Wadi sediments in Death Valley, California. (Click to enlarge)

Geology in the News –

Earth’s oldest rock was apparently found on the Moon by Apollo 14 astronauts. It is about 4.1 billion years old and was blasted off the Earth by a giant impact. You know there’s a good story here.

The famous 79 CE eruption of Mount Vesuvius apparently turned an unfortunate man’s brain to glass. I can’t tell exactly how this happened, but there is a skull with a supposedly vitrified brain. Obsidian, I suppose.

Posted in Uncategorized | Comments Off on Principles of Stratigraphy — Introduction (January 28 & 30)

Sediments and Sedimentary Processes II (January 21 & 23)

How can I make sedimentary dynamics, at least the statistical parts, interesting? The Web doesn’t help much. We could learn a bit about Sir George Gabriel Stokes (1819-1903) of Stokes’ Law. Most of the web material, though, consists of calculating pages for the Reynolds Number and the Froude Number, and the details of the Bernoulli Effect and Hjulstrom’s Diagram. Fortunately the US Government has livened things up a bit with a series of Quicktime movies of sedimentary bedforms in action, along with more than you want to know about bedform classes. This is a very nice presentation — you have many viewing choices. The USGS also provides downloadable code and software for simulating ripple and dune bedforms and crossbedding. We’ll have more pretty pictures and movies when we begin studying particular sedimentary environments.

This website will be helpful this week: The Math You Need.

Time to begin thinking about your research project for your paper. We’ll talk about your ideas in lab. Please download the list of 2020 Potential Research Paper Topics and the included form to turn in to me during your lab this week.

Here is a blog post I wrote on our glorious Ro-Tap sieving shaker system.

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


Geology in the News –

The Universe Is Disappearing, And There’s Nothing We Can Do To Stop It.” A dramatic headline that is certainly true. This is a good article in Forbes discussing modern ideas of cosmology. The future looks very cold and dark, but at least it is a long time from now!

Can this be true? One-quarter of Americans don’t know the Earth orbits the Sun. I hope most of these people are just trolling the poll.

Stardust older than the Solar System found in the ever-so-useful Murchison Meteorite. At least 7 billion years old.

Posted in Uncategorized | Comments Off on Sediments and Sedimentary Processes II (January 21 & 23)

Sediments and Sedimentary Processes I (January 14 & 16)

A thorough understanding of geologic time is fundamental in any geology course, and it is especially critical in Sedimentology & Stratigraphy. Because time scales change, I will hand out in class (as part of your first lab) our version of the Geological Time Scale. You will see that I recognize the Ediacaran Period before the Cambrian, and the Paleogene and Neogene instead of the old Tertiary. Remember that geologists make a crucial distinction between relative and absolute time, which is usually calculated radiometrically. Radiocarbon dating is a special case of radiometric dating. (Note that I’m a fan of Wikipedia. If an article there is inaccurate, we can fix it!)

Here’s a page that you may use often this semester: Internet Resources for Sedimentary Geologists (with only a few annoying dead links). It is a bit outdated, but you will still see the range of studies within sedimentary geology, from the interface with chemistry (low-temperature diagenesis) to the combination of sediments and biology (ichnology), along with plate tectonics, radiometric dating, sequence stratigraphy, and paleoenvironmental interpretations.

Our lectures and labs on the fabrics and textures of sediments and sedimentary rocks are not thrilling, although I’ll work hard on them! Here’s a clever graphic for the Udden-Wentworth grain-size scale. The Wikipedia page on grain sizes is very good. (And if it wasn’t, we’d make sure to fix it!)

Middle Triassic marginal marine sequence, southwestern Utah. (Click for larger view.)

Geology in the News —

This interactive tectonic globe is super cool. Try it!

Here is an excellent essay on Nazi geological and cosmological nonsense. “World Ice Theory also had the ideological advantage over other border sciences in that it was almost perfectly compatible with a Nazi cosmology.”

 

Posted in Default | Leave a comment