Paleo Club Weblog

Well, my diligence in reporting has taken a serious hit as the summer progresses. Obviously.

Fortunately (at least for purposes of writing about it) Weeks 3 and 4 yielded nothing to report.

Weeks 5 and 6, however, have been much more interesting.

During Week 5, the week of 28 June, we (my undergrad research buddy Katie and I) did some instrument and lab
training, as well as some cave mapping.

The field instruments we used were just small meters for pH and CO2. The Hoffman Environmental
Research Institute Center for Cave and Karst Studies (CCKS) has an ongoing project at the university-owned Crumps
Cave, where a series of waterfalls present. At Waterfall 1, we take samples once a week and test their pH right there. Later, the samples are taken to a USDA lab and analyzed for their bicarbonate ion concentration and turbidity. On the surface, there is a meter that reads the CO2 concentration in the soil. The idea behind doing these things is to learn more about the behavior of water in the epikarst zone.

Later that week, Katie and I, along with speleologists Pat and Jason, went back to Crumps to do some mapping. The cave is very large and pretty straightforward (at least the part we’re concerned with for the moment). We set up a station every 10 feet approximately down the center of the tunnel. Using Disto laser measures, we shot the distance (from eye level) to the ceiling and floor, each of the walls horizontally, and at the points of contact between the walls and ceiling/floor. We also used a compass for orientation and a clinometer to measure the angle of each shot. Back in the lab, we put our information into cave-mapping software and are creating a 3D model of the cave. This is temporarily on hold as staff and grad students scatter for conferences and mapping in other caves.

This week (beginning 5 July), we have been out to the cave twice and worked with a new field fluorometer.

Our first cave day ended in no success. The meter would not cooperate, so we decided to just take a sample and gather information back in the lab. However, we ended up with the wrong key, so no samples either. (I thought it was funny; my grad student supervisor did not. Until later.)

Our next attempt was much more successful, although the gate system at Crumps is practically impossible even with the correct key. À la Boondock Saints, you really do always need rope!

Today, we calibrated the field fluorometer, affectionately known as the Schneggometer after its designer. Easier said than done, really. We calibrated it for dye tracers uranine and rhodamine, but were still having troubles with tinopal (an optical brightener) and turbidity after six hours, so we thought it best to save those for next week.

So on the table for next week is finishing calibrating the Schneggometer, learning how to use the spectrofluorophotometer, and a presentation to the other REU members and professors. It’s a lot of fun and I am definitely learning a lot!

I should be able to add some pictures to next week’s report, so be patient with me. I hope everyone is having a great summer!

This weekend, our research group went on a little private cave tour to parts of the cave that are no longer open to the public through some early 1900s trails and tubes.

We started in a food service elevator– one of the cave tours includes an underground dinner. Descending about 100 feet into a manmade shaft, we emerged in the Snowball Room, a cave so called because of the gypsum blossoms covering the ceiling and walls.  Dr. Groves (my research advisor) led us for a while down a tourist path. From there, it was the usual scuffling and sliding, punctuated by our wade through a subterranean creek and a couple crawls through unmarked tunnels. It was very exciting and a lot of fun, but caving is better done than retold (I highly recommend it!). Unfortunately, the vast majority of my pictures didn’t turn out, as caves have a tendency to be dark.

Even more unfortunately, I haven’t been able to actually start my project yet, as the university lost a LOT of field equipment (data loggers, etc) to the flooding a few weeks ago in the area. Hopefully at the end of this week, I’ll be starting some lab work, mixing up dye tracers and things of that nature.

I did learn that at least part of my work will be at a university-owned test cave near Bowling Green, which is useful because it allows researchers to study karst environments and the effects of land use without damaging the Mammoth Cave System (or filling out paperwork that would come with testing at the park).

In the meantime, I’m becoming well-studied in cave geology, and I’m looking forward to finding at least a little bit of trouble to get into!

Mammoth Cave National Park is located just off Interstate 65 approximately 90 miles north of Nashville.

The stage was set for the cave network about 350 million years ago. At that time, the area was ten degrees south of the equator and submerged beneath a warm, shallow sea, where sediments accumulated for 70 million years. The result is 1200-1400 feet of limestone overlain by sandstone and shale, which was deposited around 300 million years ago by a river flowing into the ocean from the north. Twenty million years later, as sea levels dropped and the continent began to rise. Deformations in the crust resulted in fissures in the limestone.

Fast-forward to the middle Pliocene. On the ‘Pennyroyal Plateau,’ a plain filled with sinkholes, water seeped through the limestone and eventually undercut the sandstone, forming an intricate underground river system. The water continues to dissolve the limestone, deepening the cave network. Today, of course, the caves we see nearer the surface are the oldest, while the new caves form deeper beneath the surface.

Continue reading Mammoth Cave Research, Week 1