summit of mount etna, sicily

above acidity african and black caldera caught crater distant dormant emanating etna eurasian extrusive felsic flow gabbro gas gases gasses geological geology hephaestus hiking igneous ignimbrite italy komatiite landscape lateral lava level mafic magmatic mongibello mount nature peak peridotite pyroclastic rim rock rocks sea sediment sicily slopes summit trail trails tree typhon ultramafic uninhabited view volcanic volcano zeus