Chondrite Town

The road to the chondritic uniform reservoir. Switzerland, June 2010.

Last June I spent ten days in Switzerland and Italy exploring the geology of The Alps as part of Woods Hole Oceanographic Institution's annual Geodynamics Program. As we were driving one day on the trip, several geochemists in the group became very excited about the above sign. Apparently, the mysterious chondritic uniform reservoir (CHUR) is located in Switzerland! We tried our best to persuade our instructors that we should visit this important Earth reservoir, but we were told that Chur is a charming little Swiss town, not a place where we could find chondrites. So, we continued our drive to the mountains, but not before I snapped a photo as we passed a sign for Chur.

***For those who are not familiar, chondrites are primitive, stony meteorites that have not undergone significant melting or differentiation. Thus, chondrites are considered the original "starting material" for planet Earth, which scientists believe formed through accretion of chondritic bodies. The Earth probably started out as roughly chondritic then underwent chemical differentiation. To put it simply, the heavy stuff sunk to the center of the Earth (the core) and the lighter stuff floated to the top of the Earth (the crust) and the medium stuff stayed in the middle (the mantle).  For long-lived chemical systems (for example, the samarium-neodymium isotope system), geochemists like to think about how these chemical systems may have evolved over the ~4.54 billion year history of the Earth. Often, geochemists like to compare the evolution of certain chemical systems to a baseline. One baseline that is sometimes used is CHUR-- the chondritic uniform reservoir. The chemical composition of CHUR is based on the average chemical composition of chondritic meteorites. Where do we obtain these chondrites, if planets differentiated? Well, not all bits and pieces of the original chondrite parent bodies were incorporated into planets, which then differentiated. Some chondrite bits and pieces survived and have been zooming around our solar system. Chondrites often fall to Earth as meteorites, where they are sometimes recognized. Since these meteorites are stony, they look like Earth rocks and are tricky to tell apart. There could be one in your backyard! Most chondrite meteorites are found in places where there are few rocks, such as in deserts and in Antarctica.***

Geology Word of the Week: D is for Delta

The Nile Delta as seen from Earth orbit. Photo courtesy of
NASA and taken from Wikipedia here.

def. Delta:
1. The fourth letter of the Greek alphabet (uppercase Δ, lowercase δ).
2. A popular US airline with questionable service (except for those delicious little snacks they serve with your drink), often-delayed flights, and a hilarious in-flight safety video. 
3. A triangle-shaped deposit of sediment that forms where a river or stream flows into an ocean, lake, or other large, standing body of water.

Sorry, Folks, but Callan was Attacked by a T-Rex

This morning I had the pleasure of meeting up with Callan Bentley of Mountain Beltway. After several months of interacting on the internet, it was great to meet up in real life! I hope to meet some more of my fellow geobloggers over the next year or so.

Unfortunately, shortly after we met up, Callan was attacked by a T-Rex in the University of Wyoming Geology Museum:

A T-Rex attacks Callan.

Fortunately, Callan managed to escape, and we were able to tour the rest of the museum and have a sandwich afterward. Safe travels to Montana, Callan!

Limestone, Wildflowers, and Big Sky: A Wyoming Trail Run

I arrived in Wyoming last Sunday, and I'll be here for two months working with one of my advisors. I haven't had too much time to explore yet, but today (Monday) I went on a beautiful trail run*. Wyoming really is beautiful. I enjoy all the quiet, wide-open spaces. Here are a few pictures from today's trail run:

Wyoming big sky 1.

Forget Rent... I'm Moving to the Smithsonian

Note: For the next couple of weeks, I am going to be fairly busy. This weekend I started (finally) finishing up the book in which I compile all the interviews I carried out with my dad about the Fukushima Nuclear Power Plant Disaster. I've been listening to all the interviews again, cleaning up the transcripts, and writing a couple of background chapters. The task is taking me longer than I expected because, frankly, it is somewhat depressing to listen to all of the Fukushima interviews again. I can only handle one or two before I need to take a break. I am persevering, though. I am also busy working on a couple of super secret (for now) guest blog pieces. I'm also doing my regular graduate school work for ~8-9 hours a day. As I work on these other projects, I am going to limit my regular blogging to the geology word of the week and the occasional picture of my summer digs in Laramie, Wyoming. So, to keep my blog readers entertained over the next few weeks, I am going to re-post some geology posts that I wrote on Skepchick before I started a geology blog. The first post is below. This post originally appeared on Skepchick in 2006 here. Enjoy!

Elephant in the Rotunda, Smithsonian Museum of Natural History. Picture taken from wikipedia here.

There is nothing better than having an empty museum all to yourself. If I ever become wealthy, I think that I’ll rent out the great museums of the world at odd hours so that I can quietly appreciate them. Or maybe I’ll just hone my burglary skills and sneak it at night. I’m not interested in stealing anything, just enjoying the richness of the exhibits without all the lines, tourists, and misbehaving toddlers. 

One of my favorite books from childhood is From the Mixed-up Files of Mrs. Basil E. Frankweiler, a book about a little girl and her brother who run away from home and live in the Metropolitan Museum of Art for a week or so. After all of the tourists go home for the day, the two children have the run of the museum, bathing in the public fountain, sleeping in an antique bed in one of the exhibits, and generally having a good time with all of the artwork and artifacts. After reading this book, I nearly packed a bag and ran away to the nearest big museum, which fortunately was several hours away. Running away from home is not easily accomplished by an eight-year-old stuck in rural New Hampshire with no public transportation.

Geology Word of the Week: C is for Coquina

Coquina rock. Image taken from wikipedia here.

def. Coquina ("co-keen-ah"):
A sedimentary rock consisting of loosely-consolidated fragments of shells and/or coral. The matrix or "cement" consolidating the fragments is generally calcium carbonate or phosphate. Coquina is a soft, white rock which is often used as a building stone. Coquina forms in near-shore environments, such as marine reefs. According to the Oxford English Dictionary, coquina is a loanword from Spanish meaning "shell-fish" or "cockle" (a type of bivalve mollusc). Also according to the Oxford English Dictionary, the word was first used in English (to refer to the building stone) in 1837 in the book The Territory of Florida by J.L. Williams.

My New Favorite T-Shirt

I just love this shirt.

Just before leaving the East coast, I picked up a new t-shirt. Isn't it great?