Thursday, August 30, 2012

Let's Learn How to Date a Rock

Hi everyone! My name is Stacy and I am a third-year doctorate student working in Kim's lab group. I am constantly captivated by the outdoors, and so am incredibly fortunate to have fallen into a career designed in earth's tropical rainforests and caves. I also am 1/2 scientist and 1/2 dancer, so I have always had a somewhat freakish love and appreciation for both the sciences and arts. Because of that favored relationship, I'd like to use this blog to explain specifically in "non-science" terms a little bit about how I use chemistry and geology to answer some incredibly difficult environmental mysteries. I find my scientific process to be both fascinating and nail-biting (as one mistake could potentially ruin the entire experiment) and I am excited to bring all you artists, engineers, and scientists along as I try to determine the age of some very old and super important climate "rock-capsules" from my favorite tropical caves. I am challenging myself to keep you captivated for the next several days as we all watch together and see if I am able pull off this very important data!

This month's experiment: To continue my current tropical climate history research, I am desperate to locate a few cave rock samples that formed about 125,000 years ago (wow, that's a long time ago!) In 2008 I traveled to our field research site, Borneo, and collected many rock samples that can be used as my potential options. Unfortunately it's impossible to know how old a rock is by just looking at its exterior, so this summer I've traveled to Dr. Jess Adkin's geochemical lab at California Institute of Technology (located in Pasadena, California) to do a chemical analysis and finally figure out exactly how old some of these cave rocks actually are.

This is a picture of one of the fallen stalagmites (those are the rocks that form on the cave floor) we collected in Gunung Mulu National Park in Borneo. My hypothetical guess is that the lowest third (the piece on the far right) formed itself over 100,000 years ago.

For the next several days I will be doing a huge analysis -- everything from cutting open the rock and drilling out some powder samples to a final analysis of these samples on a multi-collector inductively-coupled plasma mass spectrometer -- in order to find out if my guess of the age and growth-rate is anywhere near correct. And in order to share everything, I will be documenting every one of my scientific steps with experiment pictures and a helpful storyline. Let's see if we can all get some quality data together, and at the same time learn a little something about old rocks, caves, and climate! Yay! :)