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.

This entry was posted in Uncategorized. Bookmark the permalink.