Schistes Lustrés

2 a west vergent ductile to brittle highly non coaxial extensional d3 event subsequently developed with a deformation intensity decreasing.

Schistes lustrés. At beginning of the century these schists were included among the primitive rocks. Even in the first decade however this idea was refuted in a paper by brochant which may still be read with interest owing to its excellent description of the physical. This event is responsible for most of the exhumation of the schistes lustres complex as well as for the preservation of carpholite occurrences at its front and took place during the period 50 40 ma. Centimetre to decimetre wide quartz calcite veins in schistes lustrés from alpine corsica were formed during exhumation at 30 40 ma following blueschist facies metamorphism.

The schistes lustrés are involved in at least two accretionary wedges both indicated by the occurrence of hp lt minerals carpholite high si phengite glaucophane lawsonite. This study presents detailed petrology of the metagabbro eclogite constituted these units and thermobarometric datas using pseudosection modelling perplex and rscm thermometer on the schistes. Coesite and microdiamond bearing preserve records of prograde devolatilization in their mineral modes and chemistry contents of volatiles and more fluid mobile elements and stable. However structural and metamorphic evolution timing of peak metamorphism detailed deformation history of the schistes lustrés complexes is badly known.

Ces sédiments sont ensuite métamorphisés par une augmentation de la pression et de la température. Structural studies in the schistes lustrés nappe west of bastia corsica demonstrate the existence of a tectonic mélange in which km scale blocks and smaller lozenges of basement granite gneiss thick layered marble and dismembered mesozoic ophiolite are enveloped in a matrix of calc schist and blueschist. The main s 1 foliation is developed in both block and matrix and is concordant. New data were obtained for cl from both suites and for li from the western alps.

The δ 18 o and δ 13 c values of the veins overlap those of the host schistes lustrés and the δ 18 o values of the veins are much higher than those of other. One target outcropping unit to study this interplay is the schistes lustrés complex of the western central alps and corsica figs. Les schistes lustrés sont des calcschistes c est à dire d anciens sédiments marins ou océaniques composés d un mélange de calcaires et d argiles. Queyras units and viso unit western alps are evidence of the alpin ocean constituted by pods of metagabbros eclogite associated to a majority of schistes lustrés oficalcits and serpentinite.

Calcschists metapelites and remnants of crustal material e g tricart and lemoine 1986 metamorphism of the schistes lustrés originates from subduction during. Lithium and chlorine concentrations and isotopic compositions of well characterized metasedimentary suites from the schistes lustrés and lago di cignana western alps and the catalina schist southern california usa were compared to determine li and cl behavior during prograde subduction zone metamorphism.