From mantle peridotites to hybrid troctolites: Textural and chemical evolution during melt-rock interaction history (Mt. Maggiore, Corsica, France)

Reaction Between Mid‐Ocean Ridge Basalt and Lower Oceanic Crust: An Experimental Study

“…Hence, high‐Mg# clinopyroxene is most likely to form when a relatively evolved, clinopyroxene‐saturated melt reacts with primitive cumulates. This conclusion, which is not sensitive to crystallization pressure, is in keeping with the suggested formation of high‐Mg# clinopyroxene in natural oceanic (Lissenberg & Dick, ; Lissenberg & MacLeod, ) and ophiolitic (Basch et al, , ; Rampone et al, ; Sanfilippo, Tribuzio, et al, ) gabbros.…”

“…This includes Hess Deep in the East Pacific Rise (Coogan et al, ; Lissenberg et al, ); the Kane area (Coogan, Kempton, et al, ; Dick et al, ; Lissenberg & Dick, ), Atlantis Massif (Blackman et al, ), and 16.5°N (Sanfilippo et al, ) along the Mid‐Atlantic Ridge; Atlantis Bank along the Southwest Indian Ridge (Dick et al, ; Gao et al, ; Lissenberg & MacLeod, ); Uraniwa Hills from the Central Indian Ridge (Sanfilippo, Morishita, et al, ); and Godzilla Megamullion in the Parece Vela backarc basin (Sanfilippo et al, ). Further evidence is present in the plutonic sections of ophiolites (Basch et al, , ; Bédard, ; Bedard et al, ; Rampone et al, ; Sanfilippo, Tribuzio, et al, ). The samples revealed complex zoning patterns, reaction textures, and mineral compositions and modes that could not be explained by fractional crystallization: instead, the data suggest that melt‐mush reaction is a common process in the lower oceanic crust (Coogan, Saunders, et al, ; Dick et al, ; Gao et al, ; Leuthold et al, ; Lissenberg et al, ; Lissenberg & MacLeod, ; Meyer et al, ; Ridley et al, ).…”

Geological reactive systems from the mantle to the abyssal sub-seafloor: Preface

“…To better constrain the chemical and physical parameters driving these processes,Borghini et al (2018) investigate the origin of olivinerich troctolites and studied melt-olivine reaction using specifically designed experiments. They observe textural development comparable with disequilibrium features observed in natural olivinerich troctolites (e.g.,Basch et al (2018),Ferrando et al (2018)) and demonstrate the control of starting melt composition and melt-olivine ratio on modal composition and mineral chemistry of olivine-rich troctolites.High temperature hydrothermalism and cooling: Impact on architecture and composition of newly formed crustKoepke et al (2018), Grant and Harlov (2018),Currin et al (2018a, b) andZihlmann et al (2018) investigate the role of fluids and of hydrothermalism on differentiation processes during cooling of the gabbroic mafic lower crust and their impact on the architecture and composition of the newly formed crust Koepke et al (2018). present the first phase-equilibria study of the late stages of MORB differentiation and explore the role of water activity in these systems.…”

“…From mantle lithosphere to magmatic crust Basch et al (2018), Ferrando et al (2018) and Borghini et al (2018) investigate the nature of the transition from mantle to gabbroic lower crust with the aim to characterize and identify the magmatic processes controlling this transition. Basch et al 2018 Carbon occurs also as abiotic organic compounds as well as organic metabolic byproducts or remnants of microbial ecosystems in the shallow mantle lithosphere.…”

“…Maggiore Ophiolite (Corsica, France) Ferrando et al (2018). focus on the study of olivine-rich troctolites interlayered within a drilled gabbroic section of heterogeneous oceanic lithosphere (Integrated Ocean Drilling Program (IODP) Expeditions 304/305 Site U1309 Atlantis Massif 30°N, Mid-Atlantic Ridge) Basch et al (2018). andFerrando et al (2018) combine petrostructural and geochemical analyses and numerical modelling of major and trace element variations to determine the respective roles of fractional crystallization and reactive porous melt flow during the incipient stages of the formation of gabbroic oceanic crust.…”