Research

Aug 2024, Olympic National Park, Washington, USA

Morphology and Chemistry of Veins

The orientation and internal structure of veins provide insights into paleo-stress fields and deformation kinematics, documenting the geological history of host rocks. Meanwhile, the geochemistry of vein minerals preserves records of pressure, temperature, and fluid characteristics, offering a window into past environmental conditions.

One of my published works (Chen et al., 2024a) exemplifies how veins in ancient subduction fault zones can be used to reconstruct the fluid history.

I am interested in extending vein studies to broader tectonic settings and exploring the potential integration of geochronology for temporal constraints.

A selection of review articles particularly useful in guiding my work:
Bons et al., 2012; Passchier & Trouw, 2005; Roberts & Holdsworth., 2022

Pressure Solution in Scaly Fabric

Pressure solution is a major deformation mechanism in subduction fault zones, as reflected by the depletion of fluid-mobile elements and the enrichment of fluid-immobile elements in the scaly fabric of subduction mélanges.

In one of my publications (Chen et al., 2024b), I integrated the geochemical mass-balance approach with image analysis to quantify strain attributed to pressure solution.

While scaly fabric is associated with tectonic processes in subduction mélanges, it can also form through other mechanisms. I am interested in examining scaly fabric in broader geological contexts, focusing on its microscopic characteristics to understand its formation mechanisms.

For a thorough review of scaly fabric, see Vannucchi (2019).

Frictional and Elastic Properties of Fault Materials

Laboratory experiments offer a powerful approach to investigating how transformations in fault materials influence fault rheology and, hence seismic behavior.

At the Rock and Sediment Mechanics Lab of PSU, I examined the effects of pressure solution on the frictional properties and healing behavior of subducting fault materials using biaxial and true-triaxial apparatuses (Chen et al., 2024c).

Currently, with the Fault Structure, Stress, and Tectonics Research Group at UW, I am quantifying how fabric development affects the dynamic elastic moduli of subduction fault materials through ultrasonic measurements of P- and S-wave velocities in a pseudo-triaxial apparatus.