9314819 Harlow The goals of the proposed research are (1) to examine experimentally the limits and parameters of K uptake in clinopyroxenes from 5 to 15 GPa and 1200-1700oC, (2) to verify by x-ray diffraction, TEM, ATEM that K enters the clinopyroxene structure and to characterize the structural characteristics of this substitution, (3) to conduct additional experiments with difference variance to produce coexisting clinopyroxene and other phases in order to examine K-amphiboles and K-rich minerals, and (4) to begin to examine Ba uptake in calcic phases, as a divalent analogue of K The proposed study has relevance for determining potential reservoirs of K in the mantle, which is central to understanding the source of K in mantle- derived rocks, mantle metasomatism, K recycling by subduction, and the heat budget of the Earth.
