The Composition of the Lower Oceanic Crust in the Wadi Khafifah Section of the Southern Samail (Oman) Ophiolite

The composition of the intrusive gabbroic lower oceanic crust remains poorly characterized in comparison to extrusive portion crust, especially for intermediate-fast spreading mid-ocean ridges. This is a consequence limited exposures extant or ophiolites similar ridge crust. One best analogues southern Samail ophiolite that formed during period rapid seafloor above nascent subduction zone. Here, we focus on geochemical stratigraphy (whole rock and mineral major trace element compositions) 5,200 m-thick, crustal, Wadi Khafifah section Wadin Tayin massif (Oman) ophiolite. Gabbros from lowermost 3,700 m this (the “lower gabbros”) show no systematic changes with height Mantle Transition Zone. In contrast, gabbros uppermost 1,500 “upper display marked increases incompatible concentration increasing height. Liquids equilibrium have compositions overlap those measured upper sheeted dikes. Upper preserve cores primitive range gabbros; however, gabbro whole are significantly more enriched elements relative gabbros. Our data reveal composite accumulated minerals derived melts large fraction evolved fractionation We propose new “Full Sheeted Sills” model which magmas mantle emplaced throughout crystallized situ. After diking events, leave replenish gabbros, thereby contributing higher budget reconstructed bulk plutonic yield plausible primary mantle-derived magma depleted basalts mantle.