Large volumes of volcanic rock, considered a product of stratovolcanos, significantly changed by metamorphism, are present in the Gemeric. Basic volcanism is recognized in the Carboniferous and Permian rock. Among the Permian rock the Ipoltica Group of the Hronic nappe is best known. The lower part of the group is called the Malužiná Formation. It is characteristic of synsedimentary dacite to andesite volcanism in the lower part and andesitic-basalts close to the Tholeitic type in the upper part. Nodules of hydrothermal agate are common in the cavities of these rocks, widely known as the melaphyres. According to some authors, Permian volcanism in Hronic has polyphase linear character. Mesozoic volcanic processes are more distinct and known from all zones of the Western Carpathians. There are Triassic effusives in the rock of Fatric and Hronic of the Malá Fatra Mts. and Nízke Tatry Mts. Picrites are known around Banská Bystrica. Cretaceous těšínites (subvolcanic alcalic gabbro) were found in the Slesian zone of the Flysch Belt. Remnants of destructed ophiolites with N-MORB basalts in the upper part are present in the rock of the Meliatic. Post nappe volcanic activity in the Carpathians is simply called Neovolcanism. It took place from the Neogene (Lower Badenian) to the Quaternary, mostly in the internal portion of the Carpathian arc (on a smaller scale also in the external Carpathians). Three main phases of the volcanic activity are distinguished:  The occurrence of metamorphosed crystalline rock in the Western Carpathians is known from the Tatric, Veporic, Gemeric, and Zemplinic zones. Existing research has clearly demonstrated traces of the Hercynian and Alpine orogeny. Although some authors suggest the possible presence of the older Cadomian or Caledonian metamorphic cycles, existence of the Precambrian metamorphic cycles was not confirmed because of the later metamorphic overprint. Caledonian metamorphism has not been clearly proved, but some signs are present in amphibolites of the Malé Karpaty Mts. (about 395 million years old) or the granite of Sihla type in the Veporic (about 370–380 million years old).