Constraints on the origin of zonation of the granite complexes in the Fichtelgebirge (Germany and Czech Republic): evidence from a gravity and geochemical study

Compositional zoning of granitic plutons is a common feature, but the spatial variation of zoning is rarely studied in detail. It is suggested that important additional information can emerge if the compositional zoning is regarded with relation to the root zones, i.e. with the granite shape at depth. A combined geochemical and gravity investigation was performed on the Hercynian Fichtelgebirge granites, which are composed of an older intrusive complex and younger intrusive complex. It is suggested that the complex zonation patterns of the Fichtelgebirge granite complexes reflect interactions between the rate of magma output which is partly governed by their rheological properties and the rate of deformation which provides the room for the magma to be emplaced.