Rock mapping a challenge for biology student

The students create stratigraphic columns at a field site south of the city of Tiana. (Photo by Josette Wooden Legs).

Geology and I are new acquaintances so when I found out that we were doing stratigraphic columns, I had some questions. What the heck is a stratigraphic column and how do I even start? I was nervous because our group is full of smart paleontology and geology majors who really know their stuff and here I was a recent biology convert looking up at a huge wall of sediment in puzzlement. All who passed by our roadside adventure seemed to be just as stumped at what we were doing as I was.

The stratigraphic column group is made up of Amanda, Christi and Jobi. (Photo by Frankie Jackson).

We began a short walk away from where we disembarked the bus along a roadcut, south of the city of Tiantai. Step one was to determine which of the layers was deposited last. Just previous, we were given a quick intro/review on how to use a Brunton compass and a Jacob’s staff. I still didn’t feel completely comfortable with those, but with the help of my two group members, I started describing all the features I could see. We didn’t find any new eggs (though the other group had a clutch in their section!) but we had a lot of other information to record. We jotted down sediment size, sorting, erosional features, strike and dip, clast size and all the other crucial components of a good stratigraphic column. The piece we were working on had about four layers, but then continued somehow to the other side of the road. Amidst interested onlookers, we trekked across the road and scrambled to the top of our next section. From here we could see the construction of apartments, chicken houses, our fellow researchers, and of course, the layers of sediment we would be getting to know very well. In comparison to the opposite side of the road, the layers were quite defined and although we had to constantly avoid falling down the hill, we started to get into a good rhythm. Jobe would describe each layer and then I would document these observations in my field book; Christi was in charge of the Brunton. These layers were very repetitive, alternating between varying conglomerate and mudstone, but interestingly, some of the mudstone layers pinched off. We had to move one more time to find the next layer, and finally things were changing up. It was still the same alternation between mudstone and conglomerate, but here there were drastic color changes, a large variation in clast size, and a glimpse at the final layer. After a long day of looking at layer upon layer, the fact that we were nearing the end helped push us to completion. After we finished we hopped on the bus and rode to our hotel where we began to assemble our information into a master copy.

The groups gather after a long day of field work to assembly information. (Photo by Josette Wooden Legs).

This was another point where I got lost and at first I was just there for moral support. After the column had been mapped out, I finally added my contribution; the descriptions of each layer. We drew in the patterns and were done! We had mapped out the layers of rock in which our eggs were found, which will help us to interpret the environment for central Zhejiang in the late Cretaceous, when dinosaurs walk these basins. I’m not going to say creating a stratigraphic column was easy or that I’m a professional, but I am definitely way more confident in the whole process. — Amanda

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2 Responses to Rock mapping a challenge for biology student

  1. Dear Krista,
    I have been reading your e mail. Are you in China now or are you just sending accounts to me “after the fact?”
    They are very interesting. Send more.
    From Sheila Christy, E mail: lilac-purple@hotmail.comm

  2. Krista,
    Are you actually in China on this date of June l2, 2011 at 8:49 am? Please let me know. Love, Sheila

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