Speaker:
Douglas Rumble
Geophysical Laboratory, Carnegie Institution of Washington, USA

Title:
Isotopic disequilibrium in methane, oxygen and nitrogen:
The necessity of resolving and measuring two co-existing doubly-substituted isotopologues

Measurements of doubly substituted isotopologues (clumped isotopes) was initially driven by a need of obtaining mineral formation temperatures exempted from potential biases caused by multiple assumptions in early 2000s. Over a decade, the advancement of instrumentation and theoretical development have opened up a new era for studies on stable isotope geo(bio)chemistry. To name a few, various materials (e.g. fossils, cements, and veins) have been analyzed to address climatic changes, diagenesis, fault slip, landslide, metamorphism, body temperatures of animals, etc. Through recently developed instruments (mass spectrometry and optic spectroscopy), it is now even possible to tap a wide range of molecules (e.g. CH4, O2, SO2, and organic molecules) for purposes beyond temperature estimate. As a cofounder of the newly installed high-resolution (M/△M>40,000), gas-sourced mass spectrometer, Dr. Rumble will cover from fundamental to applications of clumped isotopes in earth sciences and biology in this talk. Particular focus will be placed on recent development for clumped isotopes of CH4, O2, and N2, from which the formation of natural gases, microbial physiology and photosynthesis could be constrained. The perspective will be provided to facilitate further discussion on issues remaining untested yet.

Date and time:
15:30-17:30 of 11/15 (Wednesday)

Place:
Room 213, Geosciences, National Taiwan University

Convener and introduction:
Li-Hung Lin and Pei-Ling Wang