Journal Article Mechanisms of Mantle Metasomatism: Geochemical Evidence from the Lherz Orogenic Peridotite Get access J. L. BODINIER, BODINIER 1Centre Géologique et Géophysique Montpellier, UPR 0361 CNRS, Université des Sciences Techniques du Languedoc, Place Eugène BataillonF34060 France Search for other works by this author on: Oxford Academic Google Scholar G. VASSEUR, VASSEUR VERNIERES, VERNIERES C. DUPUY, DUPUY FABRIES 2Laboratoire de Minéralogie, UA 286 Muséum National d' Histoire...

Mineral and whole-rock chemical data for peridotite xenoliths in basaltic lavas on Spitsbergen are examined to reassess mechanisms of melt–fluid interaction with peridotites their relative role versus melt composition mantle metasomatism. The enrichment patterns the primitive mantle-normalized diagrams range from Th–La–Ce ‘inflections’ weakly metasomatized samples (normally without amphibole) a continuous increase abundances Ho Ce typical amphibole-bearing xenoliths. Numerical modelling...

The Mayari-Baracoa belt occupies the easternmost part of east-west-trending Cuban ophiolitic belt. It comprises two large, chromite-rich massifs: Mayari-Cristal and Moa-Baracoa. Neither these massifs show a complete ophiolite sequence, but they consist an ideal section made up (1) harzburgites grading upward into interlayered dunites, (2) (with minor dunites) gabbros, (3) microgabbros, dolerites, diabase dikes, (4) pillowed basalt, cherts, radiolarites. Chromite deposits can be grouped three...

On the basis of their structural and compositional characteristics, mafic rocks in Ronda peridotite are classified into four groups: group A (garnet-bearing rocks) occurring spinel tectonite domain; B (spinel websterites) along recrystallization front; C (Ti-rich pyroxenites) granular plagioclase domains; D (Cr-rich as composite layers front, dykes tectonites, single other domains. The domain represent vestiges an old, veined subcontinental lithosphere. groups were formed during a later...

Abstract In the Pyrenees, lherzolites nowhere occur as continuous units. Rather, they always outcrop restricted bodies, never more than 3 km wide, scattered across Mesozoic sedimentary units along North Pyrenean Fault. We report results of a detailed analysis geological setting Lherz massif (central Pyrenees), type‐locality and one most studied occurrences mantle rocks worldwide. The body is only 1.5 long belongs to series ultramafic bodies size (a few metres some hundreds metres), occurring...

We propose a new plate model for the simulation of trace element transfer during magmatic and metasomatic processes taking place in Earth's upper mantle. As previously published models, porous flow is accounted by propagation fluid batches through macrovolumes mantle rocks. Being released from spatiotemporal constraints, allows much more freedom than one‐dimensional porous‐flow models fluid‐rock interactions. Hence this approach may account wide range processes, including melt extraction...

The Ronda orogenic peridotite (southern Spain) contains a variety of pyroxene-rich rocks ranging from high-pressure garnet granulites and pyroxenites to low-pressure plagioclase–spinel websterites. 'asthenospherized' part the abundant layered websterites ('group C' pyroxenites), without significant deformation, that occur as swarms layers showing gradual modal transitions towards their host peridotites. Previous studies have suggested these formed by replacement refractory spinel Here, we...

Despite a relatively 'uniform' fertile composition (Al2O3 = 2·19–4·47 wt %; Fo% 89·2 ± 0·3%; Cr#Spl 8·9 1·5%), the Montferrier peridotite xenoliths show wide range of S contents (22–590 ppm). Most sulphides are interstitial and peculiar pyrrhotite–pentlandite intergrowths low abundances Cu-rich phases. Sulphide-rich samples characterized by strong enrichment in light rare earth elements large ion lithophile without concomitant high field strength elements. Such trace-element fractionation is...

Complex multi-stage models involving silicate, hydrous and carbonate melts of distinct provenance have been invoked to explain the metasomatism observed in mantle rocks. In contrast, relatively simple requiring polybaric crystallization alkaline silicate proposed occurrence veined To address spatial temporal relationships between veins wall-rocks, a sequence drill cores was obtained from Lherz, France. outcrop vein (amphibole–garnet pyroxenite dyke) is spatially associated with hornblendite...

The Jijal and Chilas Complexes have been interpreted previously as the lower levels of layered Kohistan Island Arc, in Pakistan. We provide petro‐structural evidence for melt‐consuming reactions between mantle rocks infiltrated, volatile‐rich magmas both complexes. Precipitated minerals suggest that melt‐rock reaction occurred at higher pressure than Chilas. early appearance orthopyroxene spatial relationship ultramafic with quartz‐bearing norites indicate reactant melt was more silicic....