Geology of the National Parks

GeoMations and GeoClips


This week, we feature one GeoMation and three GeoClips. The GeoMation focuses on "detective work"—the kind employed by geologists to trace and identify the geologic histories of the features and structures they study. The GeoClips take you out to Capitol Reef and Bryce with the CAUSE class, to see a little bit about how the detective work is done in the field. The real detective work involves more rainbows and rattlesnakes than you'll see here; for that, you might have to come see us about majoring in Geosciences.

We hope you enjoy this unit's multimedia presentations and that they help you make a little more sense out of Unit 9.



Oysters! - Capitol Reef National Park

Rocks reveal how and where they were formed. What is in a rock, how it is put together, whether the pieces are big or little, sorted or mixed, angular or rounded, and so much more provide clues. Fossils also provide clues. Here, Dr. Alley and the CAUSE class are out in the desert at Capitol Reef National Park, but they are also in a shallow seaway from long ago. See why.

Mud Cracks - Capitol Reef National Park

Rocks occasionally are turned upside-down, but nature tells us when that happens. Mud cracks can show us that; they are wide at the top, narrow, and then end at the bottom. Fill mud cracks with another layer of sand or mud, and the cracks are "fossilized," to tell us which way was up when the rocks were deposited. Here, visit Capitol Reef with Dr. Anandakrishnan to see mud cracks, with a brief look at some right-side-up ones from the Grand Canyon.

Conglomerate within a Conglomerate- Sevier Fault near Bryce Canyon National Park

Geologists read rocks, and the stories are fascinating--historical novels full of intrigue. In this next GeoClip, Dave Janesko and Dr. Alley perch high up in Red Canyon just west of Bryce, and read one of those stories of deep time.

A conglomerate is a sedimentary rock in which many of the clasts are bigger than sand. Dave and Dr. Alley are looking at a conglomerate that includes many different clast types, including one that is itself a finer-grained conglomerate. The clasts in that conglomerate-within-a-conglomerate include several types of sedimentary rocks, including sandstones that are themselves made from older pieces.

Want to see more?

Optional Enrichment Article (no, this won't be on the quiz!): What do beauty, saving money at Las Vegas, religion, oil exploration, emerging new diseases, and the planet’s recovery from global warming have in common? All in some way involve deep time, the immense age of the Earth. Eric Spielvogel filmed a discussion of these and other issues with Dr. Alley, for a special “time” issue of Research! Penn State. These Deep Time film clips will give you something to think about, and may even help with the course. Enjoy! Also, here are some optional animations you might also want to explore! (No, these won't be on the quiz either!)

Sedimentation Models
(An extensive collection of animations on this subject)

Sequence Stratigraphy
(An extensive collection of animations on this subject)