Environmental Geology field trip photos
And now, a few images from April's Environmental Geology class field trip. We made three stops: (1) a large coal-fired power plant in Maryland, (2) Westmoreland State Park in Virginia to look at coastal erosion, and (3) Prince William Forest Park in Virginia to look at pyrite emplacement and acid mine drainage.
Here's one of the bluffs on the Potomac River at Westmoreland:
Note the recent pile of breakdown in the middle of the bluff where all the water seepage is, and also the orange trail as soil from the uppermost bluff has marked another mass wasting event's passage down to the river.
These are Miocene-aged sedimentary layers known as the Calvert Formation, part of the Coastal Plain. In places, the gray clay has been altered along fracture surfaces, as shown by these orange stripes criss-crossing one another. My toes for scale:
The students spent some time searching for fossils: this is an area where lots of shark teeth are found. We didn't have much luck, but after a long cold winter, it was nice to be standing in the warm sunshine and water:
At Prince William Forest Park, we hiked down to the Cabin Branch Pyrite Mine to look at the massive denudation there due to acid mine drainage, and we also spent some time poking around for treasures, in this case chunks of pyrite:
We had better luck than at Westmoreland...
...But of course we were in a national park at Prince William, so we left the pyrite where we found it. (Westmoreland, in contrast, allows you to keep any fossils you find in loose sediment: that figures, eh?)
I'd like to say that the group of students I had in Environmental Geology this past semester was terrific, one of the best groups I've worked with in a long time. Maybe it was because the class was discussion-focused, or maybe it was the cookies we ate every Tuesday night, but it was a great experience for me, and I'm looking forward to teaching the course again. Thanks, everyone, for making it so much fun!
Here's one of the bluffs on the Potomac River at Westmoreland:
Note the recent pile of breakdown in the middle of the bluff where all the water seepage is, and also the orange trail as soil from the uppermost bluff has marked another mass wasting event's passage down to the river.
These are Miocene-aged sedimentary layers known as the Calvert Formation, part of the Coastal Plain. In places, the gray clay has been altered along fracture surfaces, as shown by these orange stripes criss-crossing one another. My toes for scale:
The students spent some time searching for fossils: this is an area where lots of shark teeth are found. We didn't have much luck, but after a long cold winter, it was nice to be standing in the warm sunshine and water:
At Prince William Forest Park, we hiked down to the Cabin Branch Pyrite Mine to look at the massive denudation there due to acid mine drainage, and we also spent some time poking around for treasures, in this case chunks of pyrite:
We had better luck than at Westmoreland...
...But of course we were in a national park at Prince William, so we left the pyrite where we found it. (Westmoreland, in contrast, allows you to keep any fossils you find in loose sediment: that figures, eh?)
I'd like to say that the group of students I had in Environmental Geology this past semester was terrific, one of the best groups I've worked with in a long time. Maybe it was because the class was discussion-focused, or maybe it was the cookies we ate every Tuesday night, but it was a great experience for me, and I'm looking forward to teaching the course again. Thanks, everyone, for making it so much fun!
Labels: coastal plain, environmental, field trips, maryland, miocene, nova, ore, piedmont, virginia
2 Comments:
In 2004 the Virginia Museum of Natural History collected a whale skull and skeleton from the stretch of cliffs in your first photo (too small to see at that scale).
One of the chapters in "Geology and Paleontology of Stratford Hall Plantation and Westmoreland State Park" (VMNH Guidebook 5) describes why erosion occurs along those cliffs in the way it does. There is an indurated, impermeable bed about 40 feet below the top of the cliff. This causes rainwater to accumulate in the upper beds, especially if the ground above the cliff has been clearcut of trees (trees take up a LOT of water). Eventually those beds become so water-saturated that they fail. If you cruise along those cliffs in a boat, you can see that everywhere the cliffs are clearcut at the top, they're eroded back.
That Westmoreland exposure was pretty much my conception of the DC-Md-n.Va area prior to reading your blog: mucky Cenezoic seds. Very cool.
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