Geochemistry of the quartz diorite - granite association, Roded area, southern Israel

The Roded quartz diorite of southern Israel formed by fractional crystallization of source magma probably derived from melting in a subduction zone slab. There is little evidence of either magma mixing or large-scale crustal contamination. Metamorphic xenoliths derive from either nearby country-rock or from sources at depth. Enclaves with igneous textures are mafic micro-granular enclaves with the geochemical characteristics of calc-alkaline I-type plutons. The granite, wholly contained within the quartz diorite, formed in irregularly spaced "pockets" near the end of quartz diorite crystallization from a late-stage residual liquid. The granite retains certain of the I-type characteristics of the quartz diorite. The aplitic nature of the granite bodies suggests initially high nucleation rates coupled with rapid cooling, the micro-shear veinlets having formed from high pressures in a late, volatile- and H₂O-rich phase.