This award supports Professor Mark Brandon and a graduate student of Yale University to collaborate with three German geologists, Professors Passchier, Den Brok and Ring, and their students at the University of Mainz. They will study the kinematics of the pressure-solution process by comparing its effects in natural and experimentally deformed materials. The naturally deformed rocks will include sandstones from northern Kamchatka and sandstone and siltstones from regions of the Swiss and French Alps near Mainz. Field work in these areas will be done by Drs. Brandon and Ring and their students. Dr. Brandon will direct the natural fabric measurements, which will be carried out on his specialized equipment at Yale. The experimental work will be carried out primarily by Drs. Paschier and Den Brok in their well-equipped laboratories in Mainz, Germany. They will manipulate very fine grained dense aggregates of `wet` halites, with selected grain size, temperature and differential stress, to provide valid comparisons. All the participating scientists and some students will interact in portions of the laboratory research during a series of exchange visits between the two institutions. Pressure solution appears to be the dominant ductile mechanism operating in the low temperature/high pressure setting that characterizes subduction zones. The specific objective of the project is to improve understanding of the kinematic development of fabrics that typify pressure-solution deformation in dense rocks. This information will improve the utility of such fabric data in efforts to understand regional tectonic problems.
