Some Hard Rock Constraints on the Supply of Heat to Mid-Ocean Ridges

摘要: In this paper, we examine many aspects of how heat from melts and the mantle is transferred to oceanic lithosphere at mid-ocean ridges, focusing on constraints that can be derived rock specimen geological observations ridges in ophiolites. These range experimental specific latent crystallisation crustal materials, melt distributed throughout axial lithosphere, partitioned between gabbros, dykes, lava. We also discuss magma chamber processes episodicity input fast slow-spreading test four different ways estimating supply (seismic thickness; regional depth; sodium REE contents MORB). find these methods yield consistent results East Pacific Rise sites, but determination (and heat) crust not as straightforward requires a good integration local scale geological, geophysical, geochemical data. Many our conclusions concern tectonically lithologically complex ridges. under two end-members: magmatically-dominated, segment centre type, end-member, magma-poor, end end-member. magma-poor end-member mantle-derived peridotite must significant source heat, tectonic advection expected deeply-derived rocks are uplifted through emplaced into crust. estimate total per unit area young setting should much less than formed magmatically-dominated centres. This would not, however, available same way hydrothermal systems. show there substantial evidence for partial form gabbros production crystallisation) sub-crustal depth below