External Ligurian Units, Genoa, Liguria, Italyi

Regional Level Types
External Ligurian Units	Formation
Genoa	Metropolitan City
Liguria	Administrative Region
Italy	Country

The External Ligurian ophiolitic sequences occur as large slide-blocks within sedimentary melange related to the inception of convergence-related sedimentation in Upper Cretaceous times. The ophiolites consist of exhumed subcontinental mantle, MOR-type basalts and rare gabbroic rocks together with continental crust bodies locally displaying primary relationships with the ophiolites. This association has been interpreted as embryonic oceanic lithosphere formed in an ocean-continent setting similar to present-day magma-poor passive margins. The ultramafic bodies have variable size, ranging from only some tenths of metres to a few kilometres. The peridotites are Ti-amphibole-bearing spinel lherzolites with a fertile geochemical signature and widespread spinel or garnet pyroxenite layers. The origin of the pyroxenite layers have been attributed to melting of recycled crustal material or of hybrid eclogite-bearing peridotites followed by melt/peridotite reactions.
The External Ligurian mantle bodies represent subcontinental lithosphere exhumed to the ocean floor in response to Mesozoic lithospheric thinning and opening of the Jurassic Ligurian-Tethys.

Other Regions, Features and Areas containing this locality

References