My research focuses on understanding paleoclimatic and paleoenvironmental changes in deep time, often through the lens of stable isotope geochemistry, petrography, and sedimentology.

​1. Secular seawater pH changes in deep Earth time

Modern ocean pH is slightly basic, averaging around 8.1. It is controlled by atmospheric CO2 level, marine carbonate dissolution/precipitation rate, continental and continental weathering, etc. For tens of million years, the ocean has maintained a relatively stable acidity level. Deep in Earth's history, the ocean pH could be regulated by different processes. Boron isotopes in marine carbonate is a proxy for seawater pH but Precambrian ocean pH data is very sparse. Current project revolves around measuring the boron isotope composition of carbonates of mid-Proterozoic age and older to better constrain the secular pH changes.

2. Tracing chemical weathering intensity during the aftermath of mass extinctions

​Long-term climate stability is regulated through CO2-weathering feedback. This feedback is often out of balance during major climatic events, such as mass extinctions. Understanding how weathering intensity changes after these catastrophes could provide important constraint on the recovery of long-term climate stability. I'm working on using Mg isotopes from silicate fraction in marine carbonates to delineate the tempo and changes in chemical intensity after the Latest Permian Mass Extinction. ​​

3. Silicon isotope fractionation in hot spring systems

​Kinetic isotopic fractionation between aqueous solution and solid precipitates is a fundamental process that controls the isotopic variations in the rock record. As part of the effort, I studied the Si isotopic fractionation processes between spring waters and associated siliceous sinter in Cistern Spring, Yellowstone National Park. I hope to answer the following questions:

1. What is the Si isotope variability of siliceous sinters in Cistern?
2. What is the mechanism of Si isotopic fractionation?
3. What controls the magnitude of Si isotopic fractionation between water and solid?

4. Silicon isotope compositions of euhedral authigenic quartz crystals

Silica is a common diagenetic constituent in shallow marine carbonate that occurs in a variety of crystal forms and morphologies. However, the mechanism of silicification is not well constrained. The sources of silica and their relative contributions are also not well understood. We combined silicon isotopic measurements with detailed petrography to constrain paleoenvironmental conditions during silicification. Modeling results indicate that seawater during the Early Cretaceous could have a significantly higher silicon isotopic composition than modern seawater.