Honors students' field work, Part 1
I mentioned on Wednesday that I was outside all day with Honors students, doing some geological fieldwork. This semester, I have three students who've opted for fieldwork projects: Victoria, Spencer, and Jason. Each of the three has spent significant amounts of time helping the others two out with data collection in the field. This is nice and convenient, because all three of their projects are located in northwest Washington, DC. I thought it might interest the readers of this blog to hear what they're working on.
We'll start today with Victoria, who is working on kink bands in the intensely-foliated metagraywacke of the Rock Creek Shear zone. This anisotropic rock was intensely squeezed from east-to-west, causing the foliation to develop with a north-south orientation. This foliation was later deformed, by kink bands which cut across it. Victoria is measuring the orientation of the foliation and the kink bands to deduce which direction that "second generation" of stress came from.
Here's our team (Victoria, Spencer, me, Jason) getting ready to go measure kink band exposures in a creek in northwest DC called Broad Branch:
We'll start today with Victoria, who is working on kink bands in the intensely-foliated metagraywacke of the Rock Creek Shear zone. This anisotropic rock was intensely squeezed from east-to-west, causing the foliation to develop with a north-south orientation. This foliation was later deformed, by kink bands which cut across it. Victoria is measuring the orientation of the foliation and the kink bands to deduce which direction that "second generation" of stress came from.
Here's our team (Victoria, Spencer, me, Jason) getting ready to go measure kink band exposures in a creek in northwest DC called Broad Branch:
Here's a view in the creek bed of Spencer and Victoria looking for kink band outcrops. (Ignore the date stamp in the lower right: it is not accurate.)
Victoria takes the strike of the metagraywacke's foliation:
Here's a Z-fold in the foliation -- more of a kink "knot" than a kink band. The kinematic sense of motion in this photo is top-to-the-right (right-lateral):
Here, Jason and Spencer measure the orientation of a kink band:
A nice little outcrop of crenulation cleavage, showing porphyroblasts of chlorite (green/blue) and garnet (red/brown). The pencil is parallel to crenulation "wrinkles".
Next time, we'll take a look at the projects that Spencer and Jason are working on.
Labels: field trips, geology, nova, sediment, structure, teaching
2 Comments:
Great idea of a project that involves lots of field time with a minimum of equipment and some real measurable results. It sure looks like the 4 of you were pretty happy being able to play in a creek and so some geology. I am looking forward to hearing about the other two projects.
So Victoria has a "kinky" project?
(Sorry, I couldn't resist.)
I wish I'd been able to spend a little more time looking at DC rocks; these look like fascinating projects. (They also remind me of a project I worked on in Surface Processes where we went out and studied potholes and fracture orientation at the Falls of the James down in Richmond. We weren't smart enough to wear waders, though - that ended up being a wet trip!)
Go Callan's honors students!
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