Publication Date:
2019-06-14
Description:
The Neogene evolution of the European Alps was characterized by the exhumation of crystalline basement, the so-called external crystalline massifs. Their exhumation presumably controlled the evolution of relief, distribution of drainage networks and generation of sediment in the Central Alps. However, due to the absence of suitable proxies, the timing of their surficial exposure, and thus the initiation of sediment supply from these areas, are poorly constrained. The northern alpine foreland basin preserves the Oligocene to Miocene sedimentary record of tectonic and climatic adjustments in the hinterland. This contribution analyses the provenance of 25 to 14 My-old alluvial fan deposits by means of detrital garnet chemistry. Unusually grossular- and spessartine-rich garnets are found to be unique proxies for identifying detritus from the external crystalline massifs. In the foreland basin, these garnets are abundant in 14 My-old deposits, thus providing a minimum age for the surficial exposure of the crystalline basement.
Electronic ISSN:
1869-9537
Topics:
Geosciences
Permalink