We conduct broad geochemical research, but trace metal isotopes have been a strong focus to this point. We study modern isotope cycles. We oftentimes use this information to interpret isotopic trends in ancient marine sedimentary rocks. Similar to reading words in a book, we read the rock record to understand the history of Earth.
Trace Metal Isotopes
Some processes operating at Earth’s surface today impart isotope fractionation effects on trace metals. These effects are very small, so powerful mass spectrometers are required for their measurement. For example, multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS).
Modern Isotope Cycles
We cannot confidently interpret isotopic trends in the rock record unless we possess a strong understanding of how isotopes are cycled at Earth's surface today. Some of our most recent work is aimed at better understanding how trace metal isotopes are cycled today in ancient-Earth analogs, such as the Baltic Sea and O2-deficient lakes in northern Minnesota.
Ancient Marine Sedimentary Rocks
The history of Earth's surface is written in the ancient sedimentary record. Unfortunately, this record is imperfect and nowhere near complete. Think of a book that is missing many pages and that has been damaged in a fire (maybe even more than once). In order to get this story as close to correct as possible, an extremely strong emphasis must be placed on sample selection. Carefully extracted drill cores are a particularly attractive target.
Earth History
Over the past few decades, trace element isotopes have played an important role sharpening our understanding of the history of O2 on Earth. Yet, many exciting questions still remain unanswered, such as the timing of initial O2 accumulation, the role of O2 in facilitating the rise of animals, and the dynamics of very recent O2 fluctuations.
