Jeff is a petrologist who focuses on Tertiary volcanic rocks in Central Colorado. His recent work includes projects on the origin of the basalt flows in Salida, Colorado, examination of the links between mineral composition and chemical exchange during magma-mingling processes, and a geophysical project at Shiprock, New Mexico, using gravity and magnetics to image the subsurface structure of this volcanic diatreme. He developed this project to encourage collaborative research between CC and Navajo students.