Alpine Eclogitic Blueschist Gigapan

This eclogitic blueschist was collected from Chamois, Italy in the Zermatt-Saas ophiolite. At this locality, smooshed pillow basalts are clearly seen at the top of the ophiolite section although in most areas the primary magmatic textures have been obliterated by high pressure metamorphism. This sample contains glaucophane, jadite/omphacite, lawsonite (pseudomorphs), and other secondary minerals. The […]

Return to the Western Alps

This month I was lucky enough to again participate in the “Anatomy of an Orogeny” field course in the  Alps with the University of St Andrews. Last year I had four posts outlining our transect from Milan, Italy to Berne, Switerzland (clockwise from upper left: Sesia-Lanzo, Ivrea Verbano, Flysch and Molasse, Helvetic Nappes). This year we had great […]

Central Alps – Flysch and Molasse

Flysch and Molasse are terms that describe different sets of sedimentary facies associated with orogenic belts. Molasse is defined as terrestrial and shallow marine deposits formed nearest the rising mountain front. It consists of various interbedded rock types including conglomerates, sandstones, and shales. The molasse on the other hand is made up of deep marine […]

Central Alps – Helvetic Nappes

First off we should define what is a nappe. A nappes is a package of rock that has been folded and deformed to the point that it is completely allocthonous, that is disconnected from its origin (generally over 5km from the original position). They are characterized by rootless, recumbent, and isoclinal folds. The word nappe is […]