The two videos above are time-lapse movies of the transit of Venus observed from Mt. Haleakala on Maui, Hawaii. The right-hand video was taken in Hydrogen-alpha light using a solar telescope. The left-hand video has been color processed to bring out surface features on the sun, especially the sunspots. Solar flares are visible at roughly 3, 10 and 12 O’clock. Chandler Taylor, a former Union student of fine arts assisted in the preparation of these videos from raw video and still images. For more information go to: Venus transit
I am currently involved in three main projects. My major effort concerns the geochemistry of apatite phenocrysts from bentonites. The goal of the research is to investigate the use of trace element chemistry of the apatites as chemical fingerprints in correlating bentonites. One aspect of this project concerns the effect of alteration on apatite chemistry, since a major assumption in using phenocrysts is the preservation of chemical information in spite of the extensive alteration of the original volcanic ash (now > 99% clay). I was working with my daughter, then a geology student at Bryn Mawr College, who was doing her senior thesis comparing phenocryst chemistry from altered and unaltered parts of a thick Paleocene ash/bentonite (Sentinel Butte Formation) from North Dakota. Another elemnt of this work concerns the uniformity of apatites from older (Cretaceous and Devonian), thick, completely altered ash layers. One student completed a senior project analysing apatites rom a 1-1/2 meter thick bentonite from the GaspŽ Peninsula, and another student is currently working on a 2m bentonite from the Great Valley Sequenceof central California. I hope that these studies will help define the variability within a completely altered ash, and perhaps determine whether either of these two thick layers are comprised of more than one eruptive event. A third part of the project concerns the areal uniformity of apatite chemistry from a single well-defined bentonite. Apatites from a single layer at more than ten localities separated by hundreds of kilometers have been analysed and found to be very uniform. Additional layers are being studied in an attempt to demonstrate between layer differences, as well as areal uniformity. Yet another aspect of the work on phenocrysts from bentonites centers on the Great Vally Sequence of California. There are dozens of bentonites present in these rocks, spanning much of the time of evolution of the Sierran Arc. Preliminary studies indicate a significant temporal change in apatite chemistry which appears to be related to the development of a more "continental" arc. These studies are continuing, with a student from Colgate University working on a senior thesis project. Finally, a student has worked on apatites separated from Great Valley formation sandstones in order to assess the uniformity of detrital apatites for comparison with the volcanically derived apatites (presumably more uniform).
Chemistry of karst spring waters
A second area of my research concerns chemistry of karst spring waters. A former student carried out a baseline study of trace elements in spring water in an effort to establish background levels of possible metals useful in water tracing. This led to the observation that spring water chemistry seemed to be related to the lithology of the rock from which the spring emerges. Another student then analysed limestone samples for trace elements, indicating a relationship between chemistry of the limestone and the emergent water.
