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International audience; This paper provides a field description and an analytical characterization of the fibrous minerals associated with ultrabasic and basic rocks from the Corsican Ophiolitic Complex, on the island of Corsica, in order to examine their asbestos potential. Thirty-five fibrous samples taken from serpentinites, magnesium-rich meta-gabbros and meta-basalts were studied, using combined EPMA, Ramanand FESEM methods. The results highlight that naturally occurring asbestos (NOA) are abundant in serpentinites and regularly occur in magnesium-rich meta-gabbros and meta-basalts in northern Corsica. The spatial distribution, abundance and mineralogical types of these NOA strongly depend on the petrographic nature of the hosting rocks and their structural pattern. NOA in serpentinites correspond to chrysotile vein networks in the internal parts of the thickest rocky masses and to tremolite veins and shear planes carrying tremolite fibers, both in the external parts of these masses and in highly sheared serpentinites within or close to tectonic contacts. NOA in highly deformed magnesium-rich meta-gabbros are associated with the opening and filling of albite-tremolite veins, associated with the syntectonic boudinage of the most competent meta-gabbros. In the meta-basalts, NOA are associated with late metamorphic, actinolite-bearing polymineralic veins cross-cutting the foliation planes. Fragments and pebbles of serpentinites, meta-gabbros and meta-basalts containing NOA are also present in colluvium, scree and alluvium resulting from erosion processes. Special attention should be paid to serpentinites and/or magnesium-rich meta-gabbros-bearing colluvium in which fibrous occurrences of tremolite regularly evolved into whitish clusters consisting of very long, easily separable, flexible and entangled fibers with a higher asbestos potential. The characterization of NOA in the COC serpentinites, meta-gabbros and meta-basalts leads us to consider them as hazardous materials. As these lithologies are very abundant within the whole structural edifice, they may be regularly impacted by development or construction work and thus require suitable monitoring.

Asbestos possesses properties that are ideally suitable for use as a friction material in automotive and a number of other applications. Animal and human studies carried out since the early 1900s have established that asbestos is carcinogenic and that exposure to especially asbestos dust causes a large number of diseases. Realizing the health hazards posed by asbestos, many countries started phasing out asbestos from all asbestos-containing products since the 1980s. Some of them imposed a total ban in the 1990s on the use of asbestos-containing friction products. This situation forced many manufacturers to look for alternatives to asbestos. But the efforts have only been partly successful. The search is, therefore, still on to find suitable substitutes for asbestos. Though steel wool, Kevlar, glass, and a number of other mineral fibers have been tried out on an experimental basis over the last two decades, glass and Kevlar fibers, in particular, have shown promise as potential substitutes for asbestos. These days, therefore, studies on polymer-based friction materials reinforced with glass, Kevlar, and ceramic fibers are being pursued with much fervor. However, conflicting views are prevailing even today as to the suitability of asbestos-free composites for automotive applications and freedom from the concomitant health risks posed by them. In the present work, therefore, phenolic resin matrix samples reinforced with different amounts of glass and Kevlar fibers were produced and characterized for their mechanical, physical, friction, and wear properties to assess their suitability for light passenger car applications. The study establishes that composites based on glass and Kevlar fibers show good mechanical, physical, friction, and wear characteristics, enhancing thereby their suitability for automotive applications. The property improvements achieved are correlated to the composition, microstructure, and the changes taking place on the surface of the friction composites.