In the neogene (Upper Tertiary beginning 26 million years ago) period, tectonic activity increased again - just as the Alpine orogeny (Alps, Carpathians etc.) slowly came to an end. In that time, parts of this and other older massifs (such as the Bohemian-Moravian Highlands or Bohemian Massif in the Alpine foothills) sometimes ended up underneath younger rock. In the Upper Miocene (10 million years ago), molten basalt broke through in northern Upper Palatinate as the Eger Graben was being formed. Through erosion, the remains of former diatremes have been uncovered and may be seen e.g. on the Rauher Kulm or at Parkstein near Weiden. Basaltic surface layers, i.e. extensive flows of low-viscosity lava, are visible e. g. on the Teichelberg near Pechbrunn. These basaltic nappes should not however be confused with the formation of tectonic layers.