[EN]
Siva Brada (Grey Beard) repesents an unique area of the youngest travertine pile of the so called Spis Travertines. Up to now the processes that were giving features to this countryside since the end of Tertiary period are fading here. We can see here contemporary rising of travertine by precipitating from mineral water containing calcium carbonate. The age of Siva Brada is about 10,000 years old and now is the most threatened travertine pile in Slovakia.
Travertine forms piles with round shoulders at springs of Ca(HCO3)2-rich mineral waters. Travertine deposits are scattered over the territory of the Liptovska Depression (Lucky, Besenova, Sliace), in the Spis Upland (Drevenik, Ganovce, Siva Brada, Vysne Ruzbachy) and in many other places, generally along tectonic faults that facilitate the occurrence of mineral springs.
Travertine precipitate from the water rich in Ca(HCO3)2. Before that, however, precipitation water enriched by the atmospheric carbon dioxide seeps into carbonate rocks and dissolves them. The dissolution is still enhanced by carbon dioxide of the juvenile postvolcanic origin. Then, water rises to the surface pushed by "gas lift" – the pressure of CO2. The influence of temperature and pressure decreases in combination with the presence of algae result in the precipitation of CaCO3 around the mineral or thermal spring. New and new CaCO3 layers build up around the spring thus eventually giving rise to travertine piles of considerable dimensions, sometimes with a small crater on their tops. The rate of deposition increases with the temperature of water, or alternatively, when biotic material accelerates the process of precipitation. The organisms like the mentioned algae, macrophytes, bryophytes, cyanobacteria and others colonizing the surface of travertine are giving travertine its distinctive porosity.
Travertine was a very important building material for housing and representative buildings since the Middle Ages. Rich deposits of aged, dried and hardened travertine were mined by the Romans. The largest building in the world constructed mostly of travertine is the Colosseum in Rome.
On the top of the Siva Brada hill stands Chapel of the Holy Cross. Two mineral springs were described on the top of the hill already in the 17th century. Soon the Spis canonry found a spa for its monks where the deseases of skin, rheumatism and digestive problems were healed. The spa ceased to exists in 1930's. Today there are still 12 active mineral springs on the hill. Only few steps from the chapel you can find one of them with noisy bubbling of carbon dioxide.
Welling and eruption of this kind of mineral water creates conditions for the existence of halophytes. Saline sites are very unique and fast vanishing biotopes in Europe. Siva Brada represents one of the most spacious and best preserved areas of this type in Slovakia.
On the way from parking here you cannot miss a small travertine knoll with spring on top connected to the nothern rim of the hill. (N 49° 00.426 E 020° 43.391) In 1956 a borehole was drilled intended to supply neighbouring spa with mineral water. It's 132 m deep but the first manifestations of erupting groundwater were registered at a depth of 119.8 m. The original height of the geyser eruptions appeared for about two minutes three times a day was 15 m. The volume of one eruption was about 1000 l. The travertine knoll was created by this geyser. But the eruptions became weaker till they disappeared and since the original borehole casing was removed in 1990's the place gives the impression of natural spring.
The typical reason of sudden release of the groundwater e.g. in Iceland is the hot water vapour but the principle of this geyser is different. The carbon dioxide, massively present in the deep groundwater of the Carpathians, gradually creates bubbles in the water present within the borehole until it causes a substantial drop in hydrostatic pressure. Subsequently, the entire volume from the accumulation area is pushed out by the hydrostatic pressure of inflowing groundwater. The space is then gradually filled up by new inflowing groundwater, which is again penetrated by CO2, and the whole cycle is repeated.
In order to complete this cache you must take a (since 2011 optional!) photo of you or your GPS in front of the chapel, attach it to the log and send me answers (EN, CZ or SK) to the following questions through my geocaching profile:
1) What is the height above sea level on top of the pile? The online sources differ, I want the exact value from picture on the information board of the nature foot trail (N 49° 00.453 E 020° 43.430) near the parking. Estimate also the height of the pile itself.
2) What is the gas and it's chemical formula which helps to lift the mineral water to the surface?
The found logs without correct answers sent within 24 hours after posting the log can be deleted without further warning. If you want me to confirm the answers, don't hide your e-mail address in the message.
[CZ]
Nepouzivejte novy Message Center, ten nectu a otazky budou povazovany za neodpovezene!!! K uznani logu mi musite poslat e-mailem pres profil odpovedi (EN, CZ nebo SK) na nasledujici otazky:
1) Jaka je nadmorska vyska na vrcholku kopce? Online zdroje se lisi, chci presny udaj z obrazku na informacni tabuli naucne stezky (N 49° 00.453 E 020° 43.430) u parkoviste. Odhadnete take vysku samotne travertinove kupy.
2) Jaky plyn (nazev a chemicky vzorec) pomaha mineralni vode v gejziru vystoupat na povrch?
Prosim vyfotte sebe nebo svou GPS pred kaplickou na vrcholku kupy a pripojte foto k vasemu logu.
Logy bez spravnych odpovedi zaslanych do 24 hodin od zapsani logu mohou byt bez dalsiho varovani okamzite smazany. Jestlize si prejete potvrdit spravnost odpovedi, neskryvejte v odesilane zprave pres profil svou e-mailovou adresu.
Wikipedia.org, Poznaj a chran.sk
Listing seen since 15-10-2009: 
times.