Heavy minerals and provenance of sands; modeling of lithological end members from river sands of northern Austria and from sandstones of the Austroalpine Gosau Formation (Late Cretaceous)

Provenance of sands and sandstones is evaluated by statistical analysis of heavy mineral data: source rocks are distinguished by the modeling of lithological end members from detrital heavy mineral distributions using the version of extended Q-mode factor analysis of Klovan and Miesch (1976). Two examples demonstrate this: a) Heavy mineral data from modern river sands of the Moldanubian region (Bohemian Massif, central Europe) in the northern part of Austria show that the end-member modeling estimates exactly the known source rocks. b) Modeling of Late Cretaceous heavy mineral distributions of the Austroalpine Gosau Formation confirms and clarifies a plate tectonic model of the Alps by Frisch (1979). The end members describe source rocks by variable combinations of different heavy minerals, thus, the frame of the sample space can be fitted optimally on the data structure. The generally small number of end members facilitates a clear representation of results. Plate tectonic setting of source areas can be inferred by comparing the end-member configuration to a simple tetrahedral graph which contains possible sources of clastic sediments for different stages of a plate tectonic cycle.