Magmas and magma chamber evolution, Troodos ophiolite, Cyprus

摘要: The Troodos ophiolite traditionally has been considered to have formed by constructive processes at an oceanic spreading center. New information on the phase layering and cryptic variation in gabbros ultramafic cumulates overlying tectonized harzburgites, however, does not support existence of a large, steady-state, frequently replenished, axial magma chamber. Compositional evidence suggests that was two distinct chemically unrelated magmatic systems. A stratigraphically lower websteritic gabbroic cumulate sequence exhibits only one major magma-chamber replenishment, suggesting nonspreading environment. An upper frequent replenishments, pointing relatively fast-spreading This alleged chamber off-axis, tectonic environment, probably underplating thin crust. Spreading-related activity confined dike complex.