Tholeiitic magma series
Tholeiit (also Tholeyit ) is named after the location Tholey Saarland and referred to a dark, dense volcanic rock with the Hauptgemengteilen pyroxene ( orthopyroxene clinopyroxene ) and calcium -rich plagioclase ( An> 50) in the matrix. As phenocrysts occur plagioclase (An 70-95 ) and pyroxene. More Gemengteile, quartz, olivine and ore minerals form. Is Based the Tholeiit in the group of basalts.
The type locality of this basalt variant is around Tholey at Schaumberg. The rock of the upcoming here Basalt Dykes, who gave her the name corresponds, due to its contents of rare earth geochemical not fully oceanic and continental tholeiitic basalts. Partly for this reason, according to the recommendation of the IUGS the name Tholeiit not been designated for this name, widespread group subalkalischer basalt rocks are used, but tholeiitischer basalt.
Tholeiitic basalts are the most common rocks in the crust. They form the bulk of the oceanic crust and the MORBs (mid ocean ridge basalt ), and also occur in the continental crust, such as also the Vogelsberg, Westerwald and in Lusatia.
Use find tholeiites like most basalt types often as paving stones in the road, or as ballast stones at railroad tracks.