LOCAL METAMORPHIC FLUID CONTROL ON SLIPS SYSTEMS AND RECRYSTALLIZATION ACROSS THE EJB AUREOLE, EASTERN CALIFORNIA
The data suggest that the primary variable controlling the type of CPO in the quartzites, and therefore slip systems, is the proximity to marble layers. Our interpretation is that aH2O in the quartzites adjacent to the marble layers was low due to production of CO2 during metamorphism of marbles and calc-silicates. The result is that the “effective temperatures” of deformation and recovery were reduced for “dry” rocks and resulted in slip. In contrast, higher aH2O in some quartzite layers, most likely from prograde metamorphic reactions in the surrounding and interbedded pelites, promoted [c] slip and complete recrystallization.
Stable isotope data supports our assumption of “dry” (or dryer) quartzites adjacent to marbles and “wet” quartzites interbedded with pelites. The most unrecrystallized samples have the highest δ18O(qtz) values and slip patterns while the most recrystallized samples have the lowest δ18O(qtz) values and [c] slip patterns. FI data suggests that the unrecrystallized quartzites maintained their pre-intrusive FI’s. Recrystallized samples have similar FI compositions, but underwent some reequilibration with a small amount of pore fluid.