My primary research interests include geochemistry, volcanology, and analytical techniques.
The majority of my doctoral research involved the understanding of interactions between meteoric water and volcanic tephra. This research is important for physical volcanology and paleoenvironment studies, as both these fields of research benefit from the understanding of water in volcanic glass. This research has four primary interests:
- What is the rate of secondary hydration of deposited tephra (mafic and silicic)?
- How can you distinguish relative amounts of magmatic and meteoric water in volcanic glass?
- How reliable is the use of hydrogen isotopes to determine paleoenvironments?
- Can oxygen isotopes also be used for these types of studies? Are they more reliable?
- Is secondarily hydrated tephra a reliable indicator of paleoelevation?
I have a recent publication on this topic that can be downloaded here.
[embeddoc url=”https://blogs.uoregon.edu/aseligman/files/2012/09/Seligman-et-al.-2016-1ij2noy.pdf” download=”all” viewer=”google”]
In 2014 I finished a project focused on the origin of three calderas located in central and eastern Oregon, which include the Crooked River (~30 Ma), Wildcat Mountain (~40 Ma), and Tower Mountain (~30 Ma) calderas. These calderas were recently mapped in 2009 by Jason McClaughry, from DOGAMI, but their tectonic origin was unknown. Furthermore, the rocks that form these calderas were originally mapped as part of the John Day and Clarno formations, which span across eastern Oregon and did not used to have a known source. This signifies a correlation, and likely source, for these paleontologically important formations. I used multiple geochemical tools in an attempt to learn about the tectonic and geochemical processes that lead to the eruptions forming these calderas. The article can be downloaded below.
[embeddoc url=”https://blogs.uoregon.edu/aseligman/files/2012/09/Seligman-et-al.-20142-2hn20wd.pdf” download=”all” viewer=”google”]
I am beginning a post doctoral research position with the Environmental Protection Agency at the end of August, where I will be focusing on water isotopes associated with contaminated waters.