I officially started my summer field work today! Unfortunately, here in West Chester, PA, it rained all day. That didn’t keep us from being productive, though. Lee Ann and Tim (from West Chester University) and Loretta (from Lock Haven University) and I began the day by visiting the quarries that we’ll be working in tomorrow. We spent the afternoon developing a plan for the rest of the week. It goes a little something like this:
Lee Ann set out all of her samples from these locations and let us play in the lab all afternoon. We immersed ourselves in diabase, so much so that we nearly forget to break for dinner!
You would think that a day of discussion would clear things up, but I’m more overwhelmed than ever! I realize that I have so much to learn about the emplacement and evolution of these rift-basin dikes and sills. I typically think of these large intrusions as composite structures, formed by multiple pulses of magma, but I wonder if I’ll be able to recognize evidence of this in the field? How did the complex plagioclase-pyroxene layers form, and why are they different in different parts of the sill? And what are the mafic channels that cut across the plagioclase-pyroxene layers? Fortunately, I have wonderful and experienced (not to mention patient) colleagues who are seeking answers to the same questions. Some insights, I hope, will be gained by whole-rock geochemistry (as long as my sampling strategy works). Whew! Are all new projects as exciting as this?