Reconstruction of the Landeskrone Scoria Cone in the Lusatian Volcanic Field, Eastern Germany — Long-term degradation of volcanic edifices and implications for landscape evolution

Abstract

Remnants of numerous monogenetic volcanoes are preserved in the Central European Volcanic Province (CEVP). The Landeskrone Hill, a monogenetic scoria cone in the Lusatian Volcanic Field, is reconstructed here. This was done using measurements of the dip of columnar jointing of lava lake basalts and the detailed mapping of the volcaniclastic rocks. The reconstruction implies a large scoria cone and a lava lake; filling the crater with a thickness of more than 110m. Volcanic activity was characterized by strombolian eruptions possibly after an opening phreatomagmatic phase. A scoria cone was developed in an initial maar-diatreme volcano. A late phreatomagmatic phase could explain the unusual modified crater of the scoria cone. The conduit was emptied and so the crater was widened in this late eruption stage. An increased magma flux probably induced a change in the eruptive style and, finally, the crater was filled in a single event by a lava lake. This effusive phase completed the multi-stage volcano development.The 34Ma-old volcano is an excellent example for the persistence of relicts of monogenetic volcanoes over a long period of time. There are some other remnants of monogenetic scoria cones that survived degradation processes in the area. With respect to the present surface, the reconstruction of the paleosurface implies low uplift and erosion rates of about 3mm/ka since the Oligocene. These denudation values support and expand on the previously published fission track data (prior to the Upper Cretaceous) and glacial-sedimentological data on neotectonic movements since the Middle Pleistocene. The erosion rate estimated by physical volcanological data implies stagnation of tectonic uplift from the Upper Paleogene to the Middle Neogene and a reactivation of tectonic movement for the Lusatian Massif in the Middle Pleistocene. Thus, the reconstructed edifice provides a powerful tool for the study of landscape evolution by clearly defining the characteristics of the paleosurfaces at certain times.