Only the abundance of hot springs that contain hydrogen sulfide, is a remnant of the old volcanic activity. Pays special attention to broad development are rich in silica trahitovyh lavas. This group of rocks called the Roth and liparite. Along with powerful streams of glassy obsidian found on Lipari and grainy trachytes. Especially the enormous growth reaches here pumice. This glassy, ??but very porous rock that resembles a sponge or thick foam, riddled with numerous voids and has a gray, much less black. Pumice in Europe, as well as most of the other volcanoes is rich in silica volcanic glass. On the islands of the southern seas as Cohen observed and rich in silica glass puzyristye so-called basaltic pumice. Due to numerous air voids pumice floating on the water, but the way, until, until all the air expelled. Not surprisingly, this volcanic product is carried away by sea currents and wind away from their place of education and deposited in remote areas. After a large eruption Konzegvina in Nicaragua, the ship ran Conway at 7 ° 26 '. sh. and 104 ° 45 'west. debt, from Greenwich to the great masses of floating pumice, at a distance of 1100 English miles from the eruption of the ship met with a broad band of pumice that covered the sea for 40 miles. This wonderful breed, found mainly among the loose product of many volcanoes, rare in lava flows found on Lipari in large numbers and takes a prominent part in the structure of the island. Almost all of that pumice, which refers to European trade, thrown eruptions near Cape Bianco on Lipari. Like Stromboli Volcano has not stopped more activity, but its eruptions are very rare. As far as we know, they started from 475 the year before P. X. Relatively strong eruption, accompanied by lava, separated by long intervals of moderate activity, expressed the release of ash. Last bblynoe eruption of belongs to the 1771 At this time, stood out from the northern side of the cone obsidian flow Petrekotte. After that, the volcano entered into a period of activity that is characteristic solfataram, and only occasionally throws ashes. Allocated to them gases mainly consist of water vapor, hydrochloric acid and hydrogen sulfide, which blended ammonium chloride (sal ammoniac), boric acid, and probably some other gases, what are the nitrogen and carbon dioxide. Useful substances secreted by fumaroles, extracted very simple way; hole fumaroles fall asleep loose rocks, ashes, etc.; gases passing through them, to allocate alum, sulfur, ammonium chloride and boric acid. After some time, mass, covering the hole, collected and delivered to the factories for processing. In 1873, the eruption of stones and ash, which lasted 44 days, since the volcano emerged from his calm state. Eruption followed more often, and industry, yutivshayasya inside the crater must now confine the outer slopes. Even more increased activity manifested in the mountains of the period from August 3, 1888 to March 22, 1890, ie within one year and eight months. It was interrupted only by short pauses of 5 to 30 or even 40 minutes. During the winter months has increased the number of eruptions, which should be attributed to lower atmospheric pressure at this time of year. Eruptions were accompanied by a muffled roar of varying strength, but without any significant earthquakes, and powerful electric discharges in the crater, sometimes there is an allocation of huge masses of steam mixed with ash, lapilli and huge volcanic bombs. Past consisted of a porous mass of the central and wool-covered bark cracks. Apparently, they left the deepest parts of the crater in poluzastyvshem condition and covered with a kind of cracks due to expansion within them of gases and vapors. Inside, many bombs were included pieces of ancient lava. Fresh lava is not poured during the eruption. After March 22, 1890 Volcano again joined his usual stage solfatary. Greater attention should be paid yavleyiya that accompanied this eruption. On the island of Lipari, at places Piano Grekke and Bagno Secco, new fumaroles, and not far from the coast of the island Salina, in the area Skonkasso, which was considered by the people place underwater eruptions were much stronger emission of gas. A number of facts of the past pointed to the existence of a submarine eruption near Volcano. Existing now Volkanello peninsula with three small craters appeared in 183, to P. X. with an underwater eruption, he was first an independent island and only later - reportedly - in 1570 - joined with the Volcano. But this phenomenon is not restricted. November 29, 1888 near Volcano deeply moved by the sea and threw pumice. In this same place a few days earlier, was torn underwater telegraph cable in the time of the eruption on 13 March and in September 1889 and in the same area cable was damaged twice. Changes experienced by a volcano during an eruption, limited to filling the crater, the bottom of which lay on the first 130 meters below the lowest and 246 m below the highest part of the ring. But the prehistoric eruption of how to judge the structure of the island itself - made, apparently, very big changes. Like Vesuvius, the crater is surrounded by a broad semi-circular shaft in the way the Somme, but he is not in the center of the shaft, and move a few outside in the direction where the ring is interrupted. The southeastern part of the island is a similar volcanic shaft, cut the above-mentioned ring. This structure came as a result of moving the center of the eruption along the main crack. The existence of two small craters on the northern side of the modern cone of the volcano and the position of the crater Volkanelo also indicate a shift of the center of eruption to the north, however, recently denied such a distinguished expert on this group of islands, as prof. Mercalli. Another group of Italian volcanic island located west of the Gulf of Gaeta; it - Pontinskie islands: Ponza, Ventotene, Palmarola, Tsannone and San Stefano, all of whom have been investigated Scrope, and more recently, objective-acter. In contrast, as described so far the cases we are dealing here not with the latest volcanic terrain, and with the remnants and ruins of the Tertiary volcanoes. In Italy there is a set of ancient volcanoes. Among them we should mention the towering among the Lombard plain Evganeyskie hills and widespread basalts in the vicinity of Verona and Vicenza. The latter form numerous spurs, extending into the region of the Southern Alps, namely in the river valley Echa (South Tyrol): all these traces of volcanic activity related to the earliest days of the Tertiary period.
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