ABOUT REPUBLICAN UNIQUE STONES MUSEUM

In Lithuania "Mosedis" and stones are synonymous. The museum is famous not only within Lithuania, but internationally. Here, one can familiarize oneself with Lithuania's geology.

Designed as an open air concept, the museum was established in 1965 by Vaclovas Intas. It was the first type of its kind. Even before 1965, Vaclovas Intas began collecting distinct rocks, transporting them back to his farm, even though the Mosedis area is abundant in stones. Authors, journalists and environmentalists lobbied for the establishment of a unique stone museumpark. Landscape architects Ruta and Alphonse Kiskis, were commissioned to oversee the museum's construction, while Genovaite Prakapaite prepared the dendrological aspect. Geology and Mineralogy professor, Algirdas Gaigalas, PHD, presides as the museum's academic chairman and Vaclovas Intas as its director. Since 1979, the museum has been managed by the national environmental protection organizations.

A path leads one from the parking lot to a restored windmill. Inside, there is an exposition of rock fragments displayed by classification, geological maps and rare rocks.

Outside the windmill, one enters the museum's outdoor exposition, situated on a terrace that covers eight hectares of the Bartuva valley. The site is continually tended to and updated with newlyfound rocks from Lithuania.

The rocks are sorted out according to their origins and laid out in a geographical order: Eastern, Central and Western Finland, Finland Bay, Aland island, Bothnian Bay, Central and Northern Sweden boulders. They reached Lithuania during the last ice age between 700 000 and 13 000 years ago.

Further subdivided into smaller groups; the rocks are dug into the ground, half exposed, creating a natural rocky landscape.

A path composed of Jotnian sandstone slabs connects the various expositions. The slabs have multicoloured1 coarse chagreen surfaces. They were formed in Scandinavia, 0.6 billion years ago, from brittle sands that adhered and hardened over time.

At times, it is possible to see ripples on the slabs' surfaces created by either water currents, waves or wind. From these ripples it is possible to determine the water current's direction or wind's velocity and direction, which brought these sands.

Mosedis has amassed a large Vyborgite (south-eastern Finland) rapakivi, or boulder, collection. Translated from Finnish, rapakivi in Lithuanian, means "rotting stone", as the decay and sunken ovoid rings are evident. Ovoids are oval, egg-sized crystals of potassium feldspar. They are encompassed by rings composed of: oligoclase or quartz grains, mica and layers of homblende minerals. In some instances, large rapakivi have several generations of ovoids found within one another: that is, within a large ovoid, a smaller one is found. On the actual rapakivi, one can find various coloured mossand lichen among them: green, greenish, yellowish. The moss is selective of the type of rapakivi it will grow on most often it will choose potassium and sodium feldspars.

Another interesting museum exposition is that of Finnish boulders composed of thin layers. They are staurolitic crystal slate stone originating from Tomasjarvi, Finland. While it decays, on the surface regular staurolites form, often with crystals with cross-like features, nicknamed "twins".

As well at the museum-park, there are green-grey rocks in which greyand almost black crystals, needle-like in appearance, are indispersed.

Geologists refer to rocks with such compositions as diabases. Selection of these boulders originated from Finland's south-west region, Satakunta. From afar, the Satakunta's diabases placement on the lawn leaves an impression of grazing flock of sheep.

Aland rapakivi and granite boulders are for the most part, oval, ball like or weathered to a smooth, round shape. This, compared to gneisses, migmatites and other metamorphic rocks, carved out by rushing water, result in sculpture like qualities: gods and mythical figures. In darker gneiss and migmatite boulders, one can often see veins of older granite, pegmatite and quartz, that meander through the boulders in a snake like manner. Consequently, their name "snake stones". It is impossible to describe their elaborateness; one must witness it themselves.

Mosedis' geological substructure reveals compression and run oft marks. They originated in the boulders while being subjected to the earth's inner core's (11-15 km. deep) intense pressure and high temperatures. At times the gneisses' run off features are disrupted by cracks or boudinage structures, characteristic of rhomboedroe fragments; both resulting from compression during the rocks' formation. Here as well, one finds breccia composed of jagged pieces of amphibolites, gabbro and diabase, that have been cemented into the granite, the result of being subjected to the earth's inner core's intense pressure.

One area of the outdoor exposition, typical for northern Sweden's countryside, is blanketed by various multicoloured granite boulders. Particularly impressive is the pegmatite: a red, spotted granite, whose elaborate features are reminiscent of a hieroglyphic script. Pegmatites are large, red, feldspar crystals with quartz growths. Consequently, their hieroglyphic appearance. The academic term for pegmatites with quartz growths is "writing pegmatite"; for the lay person it is known as "horse teeth".

Another of the museum's features is its large collection of the Baltic Sea boulders. Among them: red and brown porphyries, various sandstones, diabases and prenitic mandelstones.

Granite rocks comprise the largest collection at the museum. They include: red, grey, brown and other coloured boulders, with large feldspar and quartz crystals. As well, granite contains mica, amphibolites and other dark coloured minerals. People, interested in geology, are particularly interested in seeing the decaying granite boulders that crumble, upon being touched. Such stones are called "rotten stones". In them, are thin layers of golden mica. Seeing such a boulder, many believe that they have found a stone containing gold. This proves the proverb, "all that glitters is not gold". The golden glittering mineral is called a biotite.

At the museum, one can view the boulders' previous and current applications. For example, similar sized stones placed in such a manner to create a fence demonstrates an old farmer's custom demarcating one's fields. In comparison, platter like stones were used to form altars, used by pagans, that are scattered throughout the museum's Bartuva island. As well, on the other side of the river, on a terrace, one can view how pagans utilized rocks in their burial grounds.

The museum's exhibits are useful tools in academic research. The stones are nonliving monuments of Lithuania's nature, witnesses of the ice age, who have been managed by attentive, caring, undaunted Lithuanian environmentalists.

Prof. dr. Algirdas GAIGALAS