Geyserite rock formations around Tihany
Most of the hot springs on the peninsula can be found in the area between Belső-tó (Inner Lake) and Szarkádi-erdő (Szarkad forest). After the extinction of the volcanoes that were active a few million years ago, the heat of the molten rock (magma) trapped in the depth was still heating its surroundings for thousands of centuries. High temperature gases (carbon and sulphur dioxide) coming from the molten basalt streamed upwards through the rock fractures and mixed with the underground waters. These hot waters occluded the gases and thus became agressive, dissolving calcium, silica, magnesium and iron from sedimentary rocks (red sandstone, dolomite, limestone, pannonian sand) and depositing them on the surface in the form of hot spring cones. This miscellaneous rock is called geyserite.
