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59-434: The Kivach Reserve covers lake and forest territory just to the northwest of Lake Onega , where the terrain is rockier and more rugged than along the main shores of the lake. The Suna River runs through the reserve, over a ridge of Precambrian Diabase to create the waterfall for which the reserve is best known. The waterfall is diminished from its former size due to the construction of a dam upstream. The reserve's terrain

118-480: A thin section using a method like the Gazzi-Dickinson Method . This yields the relative percentages of quartz, feldspar, and lithic grains and the amount of clay matrix. The composition of a sandstone can provide important information on the genesis of the sediments when used with a triangular Q uartz, F eldspar, L ithic fragment ( QFL diagrams ). However, geologist have not been able to agree on

177-692: A 200-metre-thick (660 ft) layer covering the Baltic Shield which consists of granite , gneiss and greenstone . The retreat of the Ice Age glaciers formed the Littorina Sea . Its level was first 7–9 m (23–30 ft) higher than at present, but it gradually lowered, thereby decreasing the sea area and forming several lakes in the Baltic region. Lake Onega has a surface area of 9,891 km (3,819 sq mi) without islands and

236-640: A giant crayfish . In the northern part lies a large Zaonezhye Peninsula ( Заонежье ); south of it, is the Big Klimenetsky ( Большой Клименецкий ) island. To the west of them lies the deep (deeper than 100 m [330 ft]) Greater Onega ( Большое Онего ) area containing the Kondopozhskaya ( Кондопожская губа , depth up to 78 m [256 ft]), Ilem-Gorskaya (42 m [138 ft]), Lizhemskoy (82 m [269 ft]) and Unitskoy (44 m [144 ft]) bays. To

295-478: A sandstone goes through as the degree of kinetic processing of the sediments increases. Dott's (1964) sandstone classification scheme is one of many such schemes used by geologists for classifying sandstones. Dott's scheme is a modification of Gilbert's classification of silicate sandstones, and it incorporates R.L. Folk's dual textural and compositional maturity concepts into one classification system. The philosophy behind combining Gilbert's and R. L. Folk's schemes

354-522: A sea than a lake; waves of 2–3 metres (6 ft 7 in – 9 ft 10 in) are not uncommon and may even reach 5 m (16 ft). The lake freezes near the coast and bays in late November and December and around mid-January in its center. Thawing starts in April in the tributaries and reaches the lake in May. Water in the deep parts is clear, with the visibility up to 7–8 m (23–26 ft). In

413-462: A set of boundaries separating regions of the QFL triangle. Visual aids are diagrams that allow geologists to interpret different characteristics of a sandstone. For example, a QFL chart can be marked with a provenance model that shows the likely tectonic origin of sandstones with various compositions of framework grains. Likewise, the stage of textural maturity chart illustrates the different stages that

472-529: A summer church with 22 domes, a winter church with nine domes, and a belfry . The pogost was included in the list of UNESCO World Heritage sites in 1990. In the summer, there are daily boat connections to the island from Petrozavodsk. Another attraction of the lake are the Onega petroglyphs (rock engravings). They are located on the eastern coast of the lake and date back to between the 4th and 2nd millennia BC. There are about 1,200 petroglyphs scattered over

531-445: A twofold classification: Cement is what binds the siliciclastic framework grains together. Cement is a secondary mineral that forms after deposition and during burial of the sandstone. These cementing materials may be either silicate minerals or non-silicate minerals, such as calcite. Sandstone that becomes depleted of its cement binder through weathering gradually becomes friable and unstable. This process can be somewhat reversed by

590-465: A volume of 291 km (70 cu mi); its length is about 245 km (152 mi) and width about 90 km (56 mi). It is the second largest lake in Europe, and the 18th largest lake by area in the world. Its southern banks are mostly low and continuous, whereas northern banks are rocky and rugged. They contain numerous elongated bays resulting in the lake's outline appearing similar to

649-677: Is stormwater runoff and 16% is melioration -related drainage. This drainage contains 810 tonnes (890 tons) of phosphorus and 17,000 tonnes (19,000 tons) of nitrogen ; 280 and 11,800 tonnes (310 and 13,010 tons) respectively of these elements are removed through the River Svir whereas the rest accumulates in the lake. Ships and motor boats (about 8,000 units) bring oil pollution at the level of about 830 tonnes (910 tons) per navigation year, as well as phenols (500 kg [1,100 lb]), lead (100 kg [220 lb]) and oxides of sulfur , nitrogen, and carbon . The lake basin

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708-469: Is 40–50 m (130–160 ft) deep. All the shores there are rocky. The average depth of the lake is 30 m (98 ft), and the deepest spot of 127 m (417 ft) is located in the northern part. The average depth is 50–60 m (160–200 ft) in the middle and rises to 20–30 m (66–98 ft) in the southern part. The bottom has a very uneven profile, it is covered with silt , and contains numerous trenches of various size and shape in

767-837: Is a distinction that can be recognized in the field . In turn, the distinction between an orthoquartzite and a metaquartzite is the onset of recrystallization of existing grains. The dividing line may be placed at the point where strained quartz grains begin to be replaced by new, unstrained, small quartz grains, producing a mortar texture that can be identified in thin sections under a polarizing microscope. With increasing grade of metamorphism, further recrystallization produces foam texture , characterized by polygonal grains meeting at triple junctions, and then porphyroblastic texture , characterized by coarse, irregular grains, including some larger grains ( porphyroblasts .) Sandstone has been used since prehistoric times for construction, decorative art works and tools. It has been widely employed around

826-641: Is a major source of granite , marble and black schist in Russia which have been exploited in the area since the early 18th century. Also advanced is metallurgy, especially in the Petrozavodsk area which produces about 25% of industrial products of Karelia . Water level of the lake is controlled by the Nizhnesvirskaya ( Нижнесвирская ГЭС , "Lower Svir") and Verkhnesvirskaya ( Верхнесвирская ГЭС , "Upper Svir") hydroelectric power plants. The former

885-578: Is characterized by long cold winters, and short, cool summers. As a strict nature reserve, the Kivach Reserve is mostly closed to the general public. There is, however, a "public excursion zone" that is open year round to public tourists for visits to the waterfall, a nature museum, and a monument to fallen soldiers of the Great Patriotic War . Trails in the public zone have informational signs and basic facilities. The main office

944-550: Is composed of quartz or feldspar , because they are the most resistant minerals to the weathering processes at the Earth's surface. Like uncemented sand , sandstone may be imparted any color by impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Because sandstone beds can form highly visible cliffs and other topographic features, certain colors of sandstone have become strongly identified with certain regions, such as

1003-468: Is covered with dense virgin forests. Major tree types are coniferous , but also common are lime (linden) , elm and European alder . Common mammals include elks , brown bears , wolves , red foxes , European hares , blue hares , red squirrels , lynxes , pine martens , European badgers , as well as American muskrats and minks which were introduced to the area in the early 20th century. About 200 bird species from 15 families have been observed in

1062-479: Is found in three main types: rocky ridges (the highest point is 160 meters above sea level), hilly glacial moraines, and Quaternary glacial-lake plains. Kivach is located in the Scandinavian and Russian taiga ecoregion, which covers Northern Europe between tundra in the north and temperate mixed forests in the south. It is covers parts of Norway, Sweden, Finland and the northern part of European Russia, being

1121-634: Is gradually increasing, especially in the northwestern and northern parts which contain the industrial facilities of Petrozavodsk, Kondopoga and Medvezhyegorsk. About 80% of the population and more than 90% of industry of the basin are concentrated in these areas. The pollution from these three cities amount to about 190 million cubic metres (6.7 billion cubic feet) of sewage and drainage water and 150 tonnes (170 short tons) of emissions per year. Human activity results in about 315 million cubic metres (11.1 billion cubic feet) of drain water per year, of which 46% are industrial and household water, 25%

1180-545: Is in June–August and the lowest is in March–April. Rivers bring 15.6 km (3.7 cu mi) of water per year to the lake, that is up to 74% of the water balance; the rest is provided by precipitation . Most of the lake water (84% or 17.6 km  [4.2 cu mi] per year) outflows via a single river, Svir , and the remaining 16% evaporates from the lake surface. There are frequent storms more characteristic of

1239-513: Is in the town of Kivach. Lake Onega Lake Onega ( / oʊ ˈ n ɛ ɡ ə / ; also known as Onego ; Russian : Оне́жское о́зеро , romanized :  Onezhskoe ozero , IPA: [ɐˈnʲɛʂskəɪ ˈozʲɪrə] ; Finnish : Ääninen, Äänisjärvi ; Livvi : Oniegujärvi ; Veps : Änine, Änižjärv ) is a lake in northwestern Russia, on the territory of the Republic of Karelia , Leningrad Oblast and Vologda Oblast . It belongs to

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1298-523: Is likely formed during eogenesis. Deeper burial is accompanied by mesogenesis , during which most of the compaction and lithification takes place. Compaction takes place as the sand comes under increasing pressure from overlying sediments. Sediment grains move into more compact arrangements, ductile grains (such as mica grains) are deformed, and pore space is reduced. In addition to this physical compaction, chemical compaction may take place via pressure solution . Points of contact between grains are under

1357-453: Is no regular passenger service on the lake, there are several tourist trips per day along the routes of Petrozavodsk–Kizhi, Petrozavodsk–Velikaya Guba and Petrozavodsk–Shala. They are run by hydrofoil and motor ships and are used for passenger transport as well. In addition, passenger ships go on the route Petrozavodsk – Shala. Sailing is a popular activity on the lake and there is a sailing club in Petrozavodsk. Since 1972, every year at

1416-431: Is redeposited in the unstrained pore spaces. Mechanical compaction takes place primarily at depths less than 1,000 meters (3,300 ft). Chemical compaction continues to depths of 2,000 meters (6,600 ft), and most cementation takes place at depths of 2,000–5,000 meters (6,600–16,400 ft). Unroofing of buried sandstone is accompanied by telogenesis , the third and final stage of diagenesis. As erosion reduces

1475-484: Is relatively cold, with temperatures below 0 °C (32 °F) for half of the year and average summer temperatures of about 16 °C (61 °F). The catchment area of 51,540 km (19,900 sq mi) drains into the lake via 58 rivers and more than 110 tributaries, including the Shuya , Suna , Vodla , Vytegra and Andoma . The only outgoing Svir , which marks the southern boundary of Karelia, runs from

1534-443: Is that it is better able to "portray the continuous nature of textural variation from mudstone to arenite and from stable to unstable grain composition". Dott's classification scheme is based on the mineralogy of framework grains, and on the type of matrix present in between the framework grains. In this specific classification scheme, Dott has set the boundary between arenite and wackes at 15% matrix. In addition, Dott also breaks up

1593-597: The 20 km (12 mi) area including several capes, such as Besov Nos (see map above). The engravings are 1–2 mm (0.04–0.08 in) deep and depict animals, people, boats and geometrical shapes of circular and crescent shapes. In 2021, the petroglyphs were inscribed on the UNESCO World Heritage List for its significant artistic qualities that testify the creativity of the Stone Age. Many other historical monuments are scattered around

1652-628: The Circular Square and a gymnasium building (built in 1790). The embankment of Lake Onega contains a series of sculptures, many of which were presented as gifts from the twin cities. Kondopoga has been known since 1495 and (before its destruction in 2018) contained the Uspenskaya (Assumption) Church from 1774. This 42-metre-tall (138 ft) edifice was the tallest wooden church of the Russian North . There are two carillons in

1711-469: The Finnish forces and was a place of busy military activities. The main attraction of the lake is the island of Kizhi in the northern part of the lake, which is a State Historical, Architectural and Ethnographic Preservation Area. There are 89 wooden architectural monuments of the 15th to 20th centuries on the island. The most remarkable of those is Kizhi Pogost of the early 18th century which consists of

1770-491: The application of tetraethyl orthosilicate (Si(OC 2 H 5 ) 4 ) which will deposit amorphous silicon dioxide between the sand grains. The reaction is as follows. Pore space includes the open spaces within a rock or a soil. The pore space in a rock has a direct relationship to the porosity and permeability of the rock. The porosity and permeability are directly influenced by the way the sand grains are packed together. Sandstones are typically classified by point-counting

1829-571: The basin of the Baltic Sea , and is the second-largest lake in Europe after Lake Ladoga , slightly smaller than Lebanon . The lake is fed by about 50 rivers and is drained by the Svir . There are about 1,650 islands on the lake. They include Kizhi , which hosts a historical complex of 89 Orthodox churches and other wooden structures of the 15th–20th centuries. The complex includes a UNESCO World Heritage Site , Kizhi Pogost . The eastern shores of

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1888-515: The bays, the visibility may decrease to about a meter. The water is fresh, with a salinity of 35 mg/L. This is relatively low for a lake and is about 1 + 1 ⁄ 2 times lower than in the other large lake of the area, Lake Ladoga . The maximum surface water temperature is 20–24 °C (68–75 °F) on the open lake and 24–27 °C (75–81 °F) in the bays. The deep waters are much colder, from 2–2.5 °C (36–36 °F) in winter to 4–6 °C (39–43 °F) in summer. Weather

1947-518: The city, with 23 and 18 bells, also there is an indoor ice sports arena accommodating 1,850 spectators and a Palace of Arts with an organ . The town of Medvezhyegorsk was founded in 1916 and from 1931 became the construction base of the White Sea – Baltic Canal. Between 1703–1710 and 1766–1769 a factory was operating on the site of the city. During the World War II this area was occupied by

2006-473: The common minerals most resistant to weathering processes at the Earth's surface, as seen in the Goldich dissolution series . Framework grains can be classified into several different categories based on their mineral composition: Matrix is very fine material, which is present within interstitial pore space between the framework grains. The nature of the matrix within the interstitial pore space results in

2065-456: The depositional environment, older sand is buried by younger sediments, and it undergoes diagenesis . This mostly consists of compaction and lithification of the sand. Early stages of diagenesis, described as eogenesis , take place at shallow depths (a few tens of meters) and are characterized by bioturbation and mineralogical changes in the sands, with only slight compaction. The red hematite that gives red bed sandstones their color

2124-407: The depth of burial, renewed exposure to meteoric water produces additional changes to the sandstone, such as dissolution of some of the cement to produce secondary porosity . Framework grains are sand-sized (0.0625-to-2-millimeter (0.00246 to 0.07874 in) diameter) detrital fragments that make up the bulk of a sandstone. Most framework grains are composed of quartz or feldspar , which are

2183-446: The different types of framework grains that can be present in a sandstone into three major categories: quartz, feldspar, and lithic grains. When sandstone is subjected to the great heat and pressure associated with regional metamorphism , the individual quartz grains recrystallize, along with the former cementing material, to form the metamorphic rock called quartzite . Most or all of the original texture and sedimentary structures of

2242-578: The east and Svir in the west. The canal was part of the Mariinsk Canal System , a forerunner of the Volga–Baltic Waterway , and aimed to create a quiet pass for boats avoiding the stormy waters of the lake. It is around 50 m (160 ft) wide, and lies between 10 m (33 ft) and 2 km (1.2 mi) from the shores of the lake. The canal is not used for active navigation at present. There are about 1650 islands in

2301-646: The end of July the lake has hosted the largest regatta in Russia (" Онежская парусная регата ") which is the Russian Open Championship in the Russian class of Cruisers Yachts "Open800". The regatta has international status. The largest city on the lake is Petrozavodsk – the capital of Republic of Karelia (about 270,000 citizens) – founded in 1703 by Peter I to exploit the natural ore deposits. The city contains several remarkable Neoclassical buildings from Catherine II 's reign, including

2360-433: The greatest strain, and the strained mineral is more soluble than the rest of the grain. As a result, the contact points are dissolved away, allowing the grains to come into closer contact. Lithification follows closely on compaction, as increased temperatures at depth hasten deposition of cement that binds the grains together. Pressure solution contributes to cementing, as the mineral dissolved from strained contact points

2419-442: The hardness of individual grains, uniformity of grain size and friability of their structure, some types of sandstone are excellent materials from which to make grindstones , for sharpening blades and other implements. Non-friable sandstone can be used to make grindstones for grinding grain, e.g., gritstone . A type of pure quartz sandstone, orthoquartzite, with more of 90–95 percent of quartz, has been proposed for nomination to

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2478-608: The lake basin. Lake Onega features a large variety of fish and water invertebrates , including relicts of the glacial period such as lamprey . There are about 47 fish species from 13 families; they include sturgeon , landlocked salmon , brown trout , European smelt , grayling , roaches , Crucian carp , whitefishes , char , pike , European cisco , common dace , silver bream , carp bream , sabre carp , spined loach , wels catfish , European eel , rudd , ide , gudgeon , pike-perch , European perch , ruffe and burbot . The lake area used to be clean but pollution

2537-406: The lake contain about 1,200 petroglyphs (rock engravings) dated to the 4th–2nd millennia BC, which have also been inscribed as a UNESCO World Heritage Site . The major cities on the lake are Petrozavodsk , Kondopoga and Medvezhyegorsk . The lake is of glacial-tectonic origin and is a small remnant of a larger body of water which existed in this area during an Ice Age . In geologic terms,

2596-528: The lake is rather young, formed – like almost all lakes in northern Europe – through the carving activity of the inland ice sheets in the latter part of the last ice age , about 12,000 years ago: In the Paleozoic Era (400–300 million years ago) the entire territory of the modern basin of the lake was covered with a shelf sea lying near the ancient, near-equatoric Baltic continent. Sediments at that time – sandstone , sand, clay and limestone – form

2655-558: The lake with a total area of about 250 km (97 sq mi). Whereas the most famous is Kizhi , which contains historical wooden churches of the 18th century, the largest island is Big Klimenetsky with an area of 147 km (57 sq mi). It contains a few settlements, a school and an 82 m (269 ft) hill. Other large islands are Big Lelikovsky and Suysari. The lake banks are low and are flooded with raising water level. They are therefore swampy and are rich in reed, hosting ducks, geese and swans. The coastal region

2714-518: The lake. They include the Dormition Monastery ( ru ) on the cape Muromsky, on the eastern shore of the lake. The monastery was founded in 1350, closed in 1918 and revived in 1991. Sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks . Most sandstone

2773-410: The largest ecoregion in Europe. The ecoregion is characterized by coniferous forests dominated by Pinus sylvestris (in drier locations), often with an understory of Juniperus communis, Picea abies and Picea obovata and a significant admixture of Betula pubescens and Betula pendula. The climate of Kivach is Humid continental climate, cool summer ( Köppen climate classification (Dfc) ). This climate

2832-493: The much lower temperatures and pressures associated with diagenesis of sedimentary rock, but diagenesis has cemented the rock so thoroughly that microscopic examination is necessary to distinguish it from metamorphic quartzite. The term orthoquartzite is used to distinguish such sedimentary rock from metaquartzite produced by metamorphism. By extension, the term orthoquartzite has occasionally been more generally applied to any quartz-cemented quartz arenite . Orthoquartzite (in

2891-464: The narrow sense) is often 99% SiO 2 with only very minor amounts of iron oxide and trace resistant minerals such as zircon , rutile and magnetite . Although few fossils are normally present, the original texture and sedimentary structures are preserved. The typical distinction between a true orthoquartzite and an ordinary quartz sandstone is that an orthoquartzite is so highly cemented that it will fracture across grains, not around them. This

2950-506: The northern part. The trenches are separated by large shallow banks. Such bottom structure is favorable for fish, and the banks are used for commercial fishing. The water level is stabilized by the Verhnesvirskaya hydropower plant and varies by only 0.9–1.5 m (2 ft 11 in – 4 ft 11 in) over the year. It rises due to the spring flood which lasts 1 + 1 ⁄ 2 to 2 months. The highest water level

3009-638: The product of physical and chemical weathering of bedrock. Weathering and erosion are most rapid in areas of high relief, such as volcanic arcs , areas of continental rifting , and orogenic belts . Eroded sand is transported by rivers or by the wind from its source areas to depositional environments where tectonics has created accommodation space for sediments to accumulate. Forearc basins tend to accumulate sand rich in lithic grains and plagioclase . Intracontinental basins and grabens along continental margins are also common environments for deposition of sand. As sediments continue to accumulate in

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3068-712: The red rock deserts of Arches National Park and other areas of the American Southwest . Rock formations composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs . Quartz-bearing sandstone can be changed into quartzite through metamorphism , usually related to tectonic compression within orogenic belts . Sandstones are clastic in origin (as opposed to either organic , like chalk and coal , or chemical , like gypsum and jasper ). The silicate sand grains from which they form are

3127-502: The same as those of Onega Lake. Its construction raised the water level of the lake by 0.5 m (20 in). The lake contains a well-developed navigation system which is part of the Volga–Baltic Waterway and White Sea – Baltic Canal , connecting the basins of Baltic , Caspian and the northern seas. These canals allow water transport of goods from the lake to the countries from Germany to Iran; most traffic goes to Finland, Sweden, Germany and Denmark. The Onega Canal running along

3186-417: The sandstone are erased by the metamorphism. The grains are so tightly interlocked that when the rock is broken, it fractures through the grains to form an irregular or conchoidal fracture. Geologists had recognized by 1941 that some rocks show the macroscopic characteristics of quartzite, even though they have not undergone metamorphism at high pressure and temperature. These rocks have been subject only to

3245-654: The southern shore of the lake there is not used at present. Cargo on Lake Onega amounts to 10–12 million tonnes per year with about 10,300 ship voyages. Lake shores contain two ports (Petrozavodsk and Medvezhyegorsk), 5 wharves (Kondopoga, Povenets, Shala, Vytegra and Ascension ( Вознесенье )) and 41 piers. Fishery is an important activity on the lake. About 17 species are being fished commercially, mostly European cisco , smelt , whitefishes , roaches , burbot , pike-perch , perch , ruffe , carp bream , lake salmon , pike and somewhat less ide , graylings , common dace , common bleak and crucian carp . Whereas there

3304-422: The southwest of Greater Onega lies Petrozavodskoye Onego ( Петрозаводское Онего ) containing the large Petrozavodsk and small Yalguba and Pinguba bays. To the east of Zaonezhye there is a bay, northern part of which is called Povenetsky Bay and the southern part is Zaonezhsky Bay. There, deep sections alternate with banks and islands which split the bay into several parts. The southernmost part of them, Lesser Onega,

3363-629: The southwestern shore of Lake Onega to Lake Ladoga and continues as the Neva to the Gulf of Finland . The White Sea–Baltic Canal runs through the lake from the White Sea to the Baltic Sea . The Volga–Baltic Waterway connects Onega Lake with the Volga , Caspian Sea and Black Sea . The Onega Canal , which follows the southern banks of the lake, was built in 1818–1820 and 1845–1852 between Vytegra in

3422-626: The world in constructing temples, churches, homes and other buildings, and in civil engineering . Although its resistance to weathering varies, sandstone is easy to work. That makes it a common building and paving material, including in asphalt concrete . However, some types that have been used in the past, such as the Collyhurst sandstone used in North West England , have had poor long-term weather resistance, necessitating repair and replacement in older buildings. Because of

3481-439: Was built between 1927 and 1938 and has a peak power of 99 MW. The construction of Verkhnesvirskaya plant started in 1938, but was interrupted by World War II and could only be resumed in 1947. The plant was completed in 1952 and provided 160 MW of electric power. The associated with the plant Verkhnesvirsk Reservoir has an area of 9,930 km (3,830 sq mi) and volume of 260 km (62 cu mi), i.e. almost

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