The Eastern Alps are usually defined as the area east of a line from Lake Constance and the Alpine Rhine valley, up to the Splügen Pass at the Alpine divide , and down the Liro River to Lake Como in the south. The peaks and mountain passes are lower than the Western Alps , while the range itself is broader and less arched.
84-592: Kreuzjoch (German: cross col ) is the name of many summits and several mountain passes, predominantly in the Eastern Alps . Summits: Mountain passes: Eastern Alps The Eastern Alps include the eastern parts of Switzerland (mainly Graubünden ), all of Liechtenstein , and most of Austria from Vorarlberg to the east, as well as parts of extreme Southern Germany ( Upper Bavaria ), northwestern Italy ( Lombardy ), northeastern Italy ( Trentino-Alto Adige/Südtirol , Veneto and Friuli-Venezia Giulia ) and
168-455: A Mohs hardness of 2 to 4, dense limestone can have a crushing strength of up to 180 MPa . For comparison, concrete typically has a crushing strength of about 40 MPa. Although limestones show little variability in mineral composition, they show great diversity in texture. However, most limestone consists of sand-sized grains in a carbonate mud matrix. Because limestones are often of biological origin and are usually composed of sediment that
252-457: A bloom of cyanobacteria or microalgae . However, stable isotope ratios in modern carbonate mud appear to be inconsistent with either of these mechanisms, and abrasion of carbonate grains in high-energy environments has been put forward as a third possibility. Formation of limestone has likely been dominated by biological processes throughout the Phanerozoic , the last 540 million years of
336-823: A drainage basin that covers an area of 14,109 km (5,448 sq mi). It risesin the Hohe Tauern national park of the Central Eastern Alps in Austria with its source being 1,898 m (6,227 ft) above sea level. It is a tributary of the Drava and subsequently the Danube . The important rivers in Tyrol are the Adige , Inn , and Drau (or Drava ). The important river in Carinthia
420-434: A carbonate rock outcrop can be estimated in the field by etching the surface with dilute hydrochloric acid. This etches away the calcite and aragonite, leaving behind any silica or dolomite grains. The latter can be identified by their rhombohedral shape. Crystals of calcite, quartz , dolomite or barite may line small cavities ( vugs ) in the rock. Vugs are a form of secondary porosity, formed in existing limestone by
504-612: A central quartz grain or carbonate mineral fragment. These likely form by direct precipitation of calcium carbonate onto the ooid. Pisoliths are similar to ooids, but they are larger than 2 mm in diameter and tend to be more irregular in shape. Limestone composed mostly of ooids is called an oolite or sometimes an oolitic limestone . Ooids form in high-energy environments, such as the Bahama platform, and oolites typically show crossbedding and other features associated with deposition in strong currents. Oncoliths resemble ooids but show
588-449: A change in environment that increases the solubility of calcite. Dense, massive limestone is sometimes described as "marble". For example, the famous Portoro "marble" of Italy is actually a dense black limestone. True marble is produced by recrystallization of limestone during regional metamorphism that accompanies the mountain building process ( orogeny ). It is distinguished from dense limestone by its coarse crystalline texture and
672-949: A composition reflecting the organisms that produced them and the environment in which they were produced. Low-magnesium calcite skeletal grains are typical of articulate brachiopods , planktonic (free-floating) foraminifera, and coccoliths . High-magnesium calcite skeletal grains are typical of benthic (bottom-dwelling) foraminifera, echinoderms , and coralline algae . Aragonite skeletal grains are typical of molluscs , calcareous green algae , stromatoporoids , corals , and tube worms . The skeletal grains also reflect specific geological periods and environments. For example, coral grains are more common in high-energy environments (characterized by strong currents and turbulence) while bryozoan grains are more common in low-energy environments (characterized by quiet water). Ooids (sometimes called ooliths) are sand-sized grains (less than 2mm in diameter) consisting of one or more layers of calcite or aragonite around
756-412: A considerable fraction of the limestone bed. At depths greater than 1 km (0.62 miles), burial cementation completes the lithification process. Burial cementation does not produce stylolites. When overlying beds are eroded, bringing limestone closer to the surface, the final stage of diagenesis takes place. This produces secondary porosity as some of the cement is dissolved by rainwater infiltrating
840-483: A drop of dilute hydrochloric acid is dropped on it. Dolomite is also soft but reacts only feebly with dilute hydrochloric acid, and it usually weathers to a characteristic dull yellow-brown color due to the presence of ferrous iron. This is released and oxidized as the dolomite weathers. Impurities (such as clay , sand, organic remains, iron oxide , and other materials) will cause limestones to exhibit different colors, especially with weathered surfaces. The makeup of
924-621: A few million years, as this is the most stable form of calcium carbonate. Ancient carbonate formations of the Precambrian and Paleozoic contain abundant dolomite, but limestone dominates the carbonate beds of the Mesozoic and Cenozoic . Modern dolomite is quite rare. There is evidence that, while the modern ocean favors precipitation of aragonite, the oceans of the Paleozoic and middle to late Cenozoic favored precipitation of calcite. This may indicate
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#17328723367801008-455: A few thousand years. As rainwater mixes with groundwater, aragonite and high-magnesium calcite are converted to low-calcium calcite. Cementing of thick carbonate deposits by rainwater may commence even before the retreat of the sea, as rainwater can infiltrate over 100 km (60 miles) into sediments beneath the continental shelf. As carbonate sediments are increasingly deeply buried under younger sediments, chemical and mechanical compaction of
1092-731: A good portion of northern Slovenia ( Upper Carniola and Lower Styria ). In the south the range is bound by the Italian Padan Plain ; in the north the valley of the Danube River separates it from the Bohemian Massif . The easternmost spur is formed by the Vienna Woods range, with the Leopoldsberg overlooking the Danube and the Vienna basin , which is the transition zone to the arch of
1176-490: A high percentage of the mineral dolomite , CaMg(CO 3 ) 2 . Magnesian limestone is an obsolete and poorly-defined term used variously for dolomite, for limestone containing significant dolomite ( dolomitic limestone ), or for any other limestone containing a significant percentage of magnesium . Most limestone was formed in shallow marine environments, such as continental shelves or platforms , though smaller amounts were formed in many other environments. Much dolomite
1260-435: A limestone sample except in thin section and are less common in ancient limestones, possibly because compaction of carbonate sediments disrupts them. Limeclasts are fragments of existing limestone or partially lithified carbonate sediments. Intraclasts are limeclasts that originate close to where they are deposited in limestone, while extraclasts come from outside the depositional area. Intraclasts include grapestone , which
1344-466: A lower Mg/Ca ratio in the ocean water of those times. This magnesium depletion may be a consequence of more rapid sea floor spreading , which removes magnesium from ocean water. The modern ocean and the ocean of the Mesozoic have been described as "aragonite seas". Most limestone was formed in shallow marine environments, such as continental shelves or platforms . Such environments form only about 5% of
1428-525: A lower diversity of organisms and a greater fraction of silica and clay minerals characteristic of marls . The Green River Formation is an example of a prominent freshwater sedimentary formation containing numerous limestone beds. Freshwater limestone is typically micritic. Fossils of charophyte (stonewort), a form of freshwater green algae, are characteristic of these environments, where the charophytes produce and trap carbonates. Limestones may also form in evaporite depositional environments . Calcite
1512-523: A mechanism for dolomitization, with one 2004 review paper describing it bluntly as "a myth". Ordinary seawater is capable of converting calcite to dolomite, if the seawater is regularly flushed through the rock, as by the ebb and flow of tides (tidal pumping). Once dolomitization begins, it proceeds rapidly, so that there is very little carbonate rock containing mixed calcite and dolomite. Carbonate rock tends to be either almost all calcite/aragonite or almost all dolomite. About 20% to 25% of sedimentary rock
1596-448: A plausible source of mud. Another possibility is direct precipitation from the water. A phenomenon known as whitings occurs in shallow waters, in which white streaks containing dispersed micrite appear on the surface of the water. It is uncertain whether this is freshly precipitated aragonite or simply material stirred up from the bottom, but there is some evidence that whitings are caused by biological precipitation of aragonite as part of
1680-696: A protected piece of upland forestry in Austria. The Pasterze Glacier a protected piece of mountain glacier in Austria. The ranges are subdivided by several deeply indented river valleys, mostly running east–west, including the Inn , Salzach , Enns , Adige , Drava , and Mur valleys. According to the traditional Alpine Club classification of the Eastern Alps (AVE) widely used by Austrian and German mountaineers , these mountain chains comprise several dozen smaller mountain groups, each assigned to four larger regions: For
1764-449: A radial rather than layered internal structure, indicating that they were formed by algae in a normal marine environment. Peloids are structureless grains of microcrystalline carbonate likely produced by a variety of processes. Many are thought to be fecal pellets produced by marine organisms. Others may be produced by endolithic (boring) algae or other microorganisms or through breakdown of mollusc shells. They are difficult to see in
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#17328723367801848-560: Is also favored on the seaward margin of shelves and platforms, where there is upwelling deep ocean water rich in nutrients that increase organic productivity. Reefs are common here, but when lacking, ooid shoals are found instead. Finer sediments are deposited close to shore. The lack of deep sea limestones is due in part to rapid subduction of oceanic crust, but is more a result of dissolution of calcium carbonate at depth. The solubility of calcium carbonate increases with pressure and even more with higher concentrations of carbon dioxide, which
1932-482: Is an uncommon mineral in limestone, and siderite or other carbonate minerals are rare. However, the calcite in limestone often contains a few percent of magnesium . Calcite in limestone is divided into low-magnesium and high-magnesium calcite, with the dividing line placed at a composition of 4% magnesium. High-magnesium calcite retains the calcite mineral structure, which is distinct from dolomite. Aragonite does not usually contain significant magnesium. Most limestone
2016-402: Is carbonate rock, and most of this is limestone. Limestone is found in sedimentary sequences as old as 2.7 billion years. However, the compositions of carbonate rocks show an uneven distribution in time in the geologic record. About 95% of modern carbonates are composed of high-magnesium calcite and aragonite. The aragonite needles in carbonate mud are converted to low-magnesium calcite within
2100-474: Is clusters of peloids cemented together by organic material or mineral cement. Extraclasts are uncommon, are usually accompanied by other clastic sediments, and indicate deposition in a tectonically active area or as part of a turbidity current . The grains of most limestones are embedded in a matrix of carbonate mud. This is typically the largest fraction of an ancient carbonate rock. Mud consisting of individual crystals less than 5 μm (0.20 mils) in length
2184-416: Is commonly white to gray in color. Limestone that is unusually rich in organic matter can be almost black in color, while traces of iron or manganese can give limestone an off-white to yellow to red color. The density of limestone depends on its porosity, which varies from 0.1% for the densest limestone to 40% for chalk. The density correspondingly ranges from 1.5 to 2.7 g/cm . Although relatively soft, with
2268-420: Is controlled largely by the amount of dissolved carbon dioxide ( CO 2 ) in the water. This is summarized in the reaction: Increases in temperature or decreases in pressure tend to reduce the amount of dissolved CO 2 and precipitate CaCO 3 . Reduction in salinity also reduces the solubility of CaCO 3 , by several orders of magnitude for fresh water versus seawater. Near-surface water of
2352-545: Is converted to low-magnesium calcite. Diagenesis is the likely origin of pisoliths , concentrically layered particles ranging from 1 to 10 mm (0.039 to 0.394 inches) in diameter found in some limestones. Pisoliths superficially resemble ooids but have no nucleus of foreign matter, fit together tightly, and show other signs that they formed after the original deposition of the sediments. Silicification occurs early in diagenesis, at low pH and temperature, and contributes to fossil preservation. Silicification takes place through
2436-591: Is covered by forest (lagly beech, fir, and spruce) and the amount of forested land is still increasing. Mount Peca or Mount Raduha is in the eastern part of Kamnik–Savinja Alps of northern Slovenia . The Alpine Rhine has as its source the Swiss canton of Grisons, which flows through the Chur Rhine Valley, or Grisonian Rhine Valley ( German : Churer Rheintal, or Bündner Rheintal ) and Vorarlberg Rhine Valley ( German : Voralberger Rheintal ). It later forms
2520-503: Is deposited close to where it formed, classification of limestone is usually based on its grain type and mud content. Most grains in limestone are skeletal fragments of marine organisms such as coral or foraminifera . These organisms secrete structures made of aragonite or calcite, and leave these structures behind when they die. Other carbonate grains composing limestones are ooids , peloids , and limeclasts ( intraclasts and extraclasts [ ca ] ). Skeletal grains have
2604-460: Is described as coquinite . Chalk is a soft, earthy, fine-textured limestone composed of the tests of planktonic microorganisms such as foraminifera, while marl is an earthy mixture of carbonates and silicate sediments. Limestone forms when calcite or aragonite precipitate out of water containing dissolved calcium, which can take place through both biological and nonbiological processes. The solubility of calcium carbonate ( CaCO 3 )
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2688-617: Is described as micrite . In fresh carbonate mud, micrite is mostly small aragonite needles, which may precipitate directly from seawater, be secreted by algae, or be produced by abrasion of carbonate grains in a high-energy environment. This is converted to calcite within a few million years of deposition. Further recrystallization of micrite produces microspar , with grains from 5 to 15 μm (0.20 to 0.59 mils) in diameter. Limestone often contains larger crystals of calcite, ranging in size from 0.02 to 0.1 mm (0.79 to 3.94 mils), that are described as sparry calcite or sparite . Sparite
2772-462: Is distinguished from micrite by a grain size of over 20 μm (0.79 mils) and because sparite stands out under a hand lens or in thin section as white or transparent crystals. Sparite is distinguished from carbonate grains by its lack of internal structure and its characteristic crystal shapes. Geologists are careful to distinguish between sparite deposited as cement and sparite formed by recrystallization of micrite or carbonate grains. Sparite cement
2856-543: Is located in was probably inhabited in the early Stone Age . Several surviving pre-Roman place names exist in and about the city. In the 4th century Chur also became the seat of the first Christian bishopric north to the Alps . Despite a legend assigning its foundation to a legendary British king, St Lucius, the first known bishop is one Asinio in AD 451. In the 6th century the Slavs settled
2940-710: Is mountainous. and the highest point of Liechtenstein is the Vordere Grauspitz (Vordergrauspitz) mountain with an altitude of 2599m above sea level. The Falknishorn, at 2452 meters above sea level, is the 5th highest mountain in Liechtenstein and represents the southernmost point of the country. The area known as the Liechtenstein-Graubünden-Vorarlberg border triangle is around the Naafkopf mountain that reaches 2570m above sea level. In addition to
3024-560: Is one of the first minerals to precipitate in marine evaporites. Most limestone is formed by the activities of living organisms near reefs, but the organisms responsible for reef formation have changed over geologic time. For example, stromatolites are mound-shaped structures in ancient limestones, interpreted as colonies of cyanobacteria that accumulated carbonate sediments, but stromatolites are rare in younger limestones. Organisms precipitate limestone both directly as part of their skeletons, and indirectly by removing carbon dioxide from
3108-473: Is otherwise chemically fairly pure, with clastic sediments (mainly fine-grained quartz and clay minerals ) making up less than 5% to 10% of the composition. Organic matter typically makes up around 0.2% of a limestone and rarely exceeds 1%. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragments (such as sponge spicules, diatoms , or radiolarians ). Fossils are also common in limestone. Limestone
3192-472: Is produced by decaying organic matter settling into the deep ocean that is not removed by photosynthesis in the dark depths. As a result, there is a fairly sharp transition from water saturated with calcium carbonate to water unsaturated with calcium carbonate, the lysocline , which occurs at the calcite compensation depth of 4,000 to 7,000 m (13,000 to 23,000 feet). Below this depth, foraminifera tests and other skeletal particles rapidly dissolve, and
3276-514: Is secondary dolomite, formed by chemical alteration of limestone. Limestone is exposed over large regions of the Earth's surface, and because limestone is slightly soluble in rainwater, these exposures often are eroded to become karst landscapes. Most cave systems are found in limestone bedrock. Limestone has numerous uses: as a chemical feedstock for the production of lime used for cement (an essential component of concrete ), as aggregate for
3360-562: Is the Drau (or Drava ). The important river in Slovenia is the Sava . Triglav National Park was founded in 1981. It was originally set out in 1924 on a smaller scale and scrapped between 1944 and 1961. The mountains of the canton include part of a thrust fault that was declared a geologic UNESCO World Heritage Site , under the name Swiss Tectonic Arena Sardona , in 2008. The Vienna Woods are
3444-558: Is the Piz Buin , whose rocky peak of 3,312 m (10,866 ft). The Silvretta Alps cut across Tirol and Vorarlberg (both in Austria), and Graubünden (Switzerland). Mount Sulzfluh is well frequented by climbers and is situated in the Rätikon range of the Alps , on the border between Austria and Switzerland . On the eastern side is a mountain path, of grade T4, allowing non-climbers to reach
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3528-606: Is today Ticino was settled by the Lepontii, a Celtic tribe. Later, probably around the reign of Augustus, it became part of the Roman Empire . In ancient times, the region had long been inhabited by the Celts before it became part of the ancient Roman provinces of Raetia and Noricum . There were two Celtic tribes settled in the future Vorarlberg area: the Raeti in the highlands, and
3612-700: The Carpathian Mountains . The highest mountain in the Eastern Alps is Piz Bernina at 4,049 m (13,284 ft) in the Bernina Group of the Western Rhaetian Alps in Switzerland. The sole four-thousander of the range, its name is taken from the Bernina Pass and was given in 1850 by Johann Coaz , who also made the first ascent. The rocks composing Piz Bernina are diorites and gabbros , while
3696-838: The Karawanks mountain range of the Southern Limestone Alps and contains both the Meža Valley down to the confluence with the Drava Valley ( Dravska dolina ) and the Municipality of Jezersko south of the Seeberg Saddle mountain pass, totalling 478 km (185 sq mi): Austrian and Slovenian Carinthia has a very diverse landscape, with predominance of hilly and mountainous terrain of Pleistocene oragins and later scuptedby by former glaciers. Over 2/3s of Slovenian Carinthia
3780-859: The Limes and caused widespread devastation of Roman cities and settlements in the Crisis of the Third Century . The Roman Empire succeeded in re-establishing the Rhine as the border, but it was now a frontier province. The late Roman influx from the north by the Alemanni also influenced the makeup of the Principality of Liechtenstein and is also evidenced by the remains of a Roman fort at Schaan . Roman villas have been excavated in Schaanwald and Nendeln . The area that Innsbruck
3864-681: The Vindelici in the lowlands, i.e. the Lake Constance region and the Rhine Valley prior to the Romans conquered Vorarlberg area. Rome conquered the area of the future Municipality of Schellenberg in 15BCE. Most of the lands of the region were once part of a Roman province called Raetia , which was established in 15 BCE. The current capital of Graubünden, Chur , was known as Curia in Roman times. The area
3948-505: The 2817 metre summit. There are six known caves in the limestone mountain, with lengths between 800 and 3000 or more yards, all with entrances on the Eastern side, in Switzerland. Mount Grauspitz ( Vorder Grauspitze or Vorder Grauspitz on some maps) is the highest summit of the Rätikon, located on the border between Liechtenstein and Switzerland . About half of Liechtenstein's territory
4032-496: The Earth's history. Limestone may have been deposited by microorganisms in the Precambrian , prior to 540 million years ago, but inorganic processes were probably more important and likely took place in an ocean more highly oversaturated in calcium carbonate than the modern ocean. Diagenesis is the process in which sediments are compacted and turned into solid rock . During diagenesis of carbonate sediments, significant chemical and textural changes take place. For example, aragonite
4116-570: The Eastern Alps. The first signs of humans living in the area of present-day Liechtenstein can be dated back to the Middle Paleolithic era. Neolithic farming settlements appeared in the valleys around 5300 BCE. A Bronze Age settlement at the site goes back as far as the Pfyn culture (3900–3500 BCE), making Chur one of the oldest settlements in Switzerland . In ancient times, the area of what
4200-604: The Großglockner and the adjacent Pasterze Glacier has been a special protection area within the High Tauern National Park since 1986. Other high Tyrolian mountains include Königspitze (3,851 m), Monte Cevedale (3,769 m), and Wildspitze (3,768 m). Crossing Tyrol, on the border between North and South Tyrol, runs the main chain of the Alps . The city of Innsbruck is in the broad valley between high mountains of
4284-528: The Italian border from Frulia into Slovenia's Municipality of Bovec. The highest mountain is Mt. Triglav 2,864 m (9,396 ft). The High Tauern mountain range in which Mt Grossglockner , 3,797 m (12,457.35 ft) lies, separates Carentania from the state of Salzburg in the northwest. To the northeast and to the east beyond the Pack Saddle mountain pass is the state of Styria . Carinthia lies in
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#17328723367804368-724: The Rhine River. In 926 more Magyar raiders attacked the abbey and the nearby town of St Gallen. The Lordship of Schellenberg was constituted in the 9th century by Charlemagne . Limestone Limestone ( calcium carbonate CaCO 3 ) is a type of carbonate sedimentary rock which is the main source of the material lime . It is composed mostly of the minerals calcite and aragonite , which are different crystal forms of CaCO 3 . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as
4452-430: The accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite , a closely related rock, which contains
4536-524: The area , and the local dioceses collapsed. This is shown in archaeological culture . A Slavic language group was established in the area. The Alpine Slavs , who are reckoned to be ancestors of present-day Slovenes, also settled in the easternmost mountainous areas of Friuli , known as the Friulian Slavia , as well in as the Karst Plateau and the area north and south of Gorizia . At this time, Chur
4620-434: The base of roads, as white pigment or filler in products such as toothpaste or paint, as a soil conditioner , and as a popular decorative addition to rock gardens . Limestone formations contain about 30% of the world's petroleum reservoirs . Limestone is composed mostly of the minerals calcite and aragonite , which are different crystal forms of calcium carbonate ( CaCO 3 ). Dolomite , CaMg(CO 3 ) 2 ,
4704-657: The beds. This may include the formation of vugs , which are crystal-lined cavities within the limestone. Diagenesis may include conversion of limestone to dolomite by magnesium-rich fluids. There is considerable evidence of replacement of limestone by dolomite, including sharp replacement boundaries that cut across bedding. The process of dolomitization remains an area of active research, but possible mechanisms include exposure to concentrated brines in hot environments ( evaporative reflux ) or exposure to diluted seawater in delta or estuary environments ( Dorag dolomitization ). However, Dorag dolomitization has fallen into disfavor as
4788-462: The border between Switzerland to the west and Liechtenstein and later Austria to the east. The Mur ( German pronunciation: [ˈmuːɐ̯] ) or Mura ( Slovene pronunciation: [ˈmúːɾa] ; Croatian: [mǔːra] ; Hungarian: [ˈmurɒ] ; Prekmurje Slovene : Müra or Möra ) is a 464 kilometres (288 mi). long river in Central Europe with
4872-557: The breakdown of these regions into mountain groups see the List of mountain groups in the Alpine Club classification of the Eastern Alps . The Swiss Alpine Club (SAC) has a slightly different classification of the ranges, based on the political borders in the canton of Graubünden. In Italy the 1926 Partizione delle Alpi concept is quite common, recently superseded by the SOIUSA attempt to combine
4956-462: The depositional fabric of carbonate rocks. Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles, based on criteria such as whether the grains were originally in mutual contact, and therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of
5040-469: The deposits are highly porous, so that they have a spongelike texture, they are typically described as tufa . Secondary calcite deposited by supersaturated meteoric waters ( groundwater ) in caves is also sometimes described as travertine. This produces speleothems , such as stalagmites and stalactites . Coquina is a poorly consolidated limestone composed of abraded pieces of coral , shells , or other fossil debris. When better consolidated, it
5124-647: The different approaches. Other specific, especially hydrographical arrangements are also in use. The Alps comprise four main nappe systems: During the Würm glaciation , the Eastern Alps were drier than the Western Alps , with the contiguous ice shield ending in the region of the Niedere Tauern in Austria . This allowed many species to survive the ice age in the Eastern Alps where they could not survive elsewhere. For that reason, many species of plants are endemic to
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#17328723367805208-406: The earth's oceans are oversaturated with CaCO 3 by a factor of more than six. The failure of CaCO 3 to rapidly precipitate out of these waters is likely due to interference by dissolved magnesium ions with nucleation of calcite crystals, the necessary first step in precipitation. Precipitation of aragonite may be suppressed by the presence of naturally occurring organic phosphates in
5292-745: The fall of the Ostrogothic Kingdom in 553, the Germanic tribe of the Lombards invaded Italy via the Tyrol and founded the Lombard Kingdom of Italy , which no longer included all of Tyrol, but only its southern part. The northern part of Tyrol came under the influence of the Bavarii , while the west was probably part of Alamannia . Most of Tyrol came under the control of the Duchy of Bavaria (created c. 555) while
5376-399: The first refers to the grains and the second to the cement. For example, a limestone consisting mainly of ooids, with a crystalline matrix, would be termed an oosparite. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample. Robert J. Dunham published his system for limestone in 1962. It focuses on
5460-572: The formation of distinctive minerals from the silica and clay present in the original limestone. Two major classification schemes, the Folk and Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks . Based on composition, there are three main components: allochems (grains), matrix (mostly micrite), and cement (sparite). The Folk system uses two-part names;
5544-429: The geologic record are called bioherms . Many are rich in fossils, but most lack any connected organic framework like that seen in modern reefs. The fossil remains are present as separate fragments embedded in ample mud matrix. Much of the sedimentation shows indications of occurring in the intertidal or supratidal zones, suggesting sediments rapidly fill available accommodation space in the shelf or platform. Deposition
5628-619: The massif in general is composed of granites ( Piz Corvatsch , Piz Palü ). Excepting other peaks in the Bernina range, the next highest is the Ortler at 3,905 m (12,812 ft) in Italian South Tyrol and third the Großglockner , which stands on the border of Carinthia & East Tyrol in Austria, at 3,798 m (12,461 ft), the highest mountain of Austria. The region around
5712-410: The ocean basins, but limestone is rarely preserved in continental slope and deep sea environments. The best environments for deposition are warm waters, which have both a high organic productivity and increased saturation of calcium carbonate due to lower concentrations of dissolved carbon dioxide. Modern limestone deposits are almost always in areas with very little silica-rich sedimentation, reflected in
5796-734: The peaks of the Alpine chain, which belong to the Limestone Alps, two inselbergs , Fläscherberg (1135 meters above sea level .) in the south and Eschnerberg (698 m) in the north, rise from the Rhine Valley and belong to the Helvetic cover or flysch zone of the Alps. A sandstone mountain belt called the Flyschzone runs along the Northern Margin of the Limestone Alps and used to be part
5880-426: The reaction: Fossils are often preserved in exquisite detail as chert. Cementing takes place rapidly in carbonate sediments, typically within less than a million years of deposition. Some cementing occurs while the sediments are still under water, forming hardgrounds . Cementing accelerates after the retreat of the sea from the depositional environment, as rainwater infiltrates the sediment beds, often within just
5964-482: The relative purity of most limestones. Reef organisms are destroyed by muddy, brackish river water, and carbonate grains are ground down by much harder silicate grains. Unlike clastic sedimentary rock, limestone is produced almost entirely from sediments originating at or near the place of deposition. Limestone formations tend to show abrupt changes in thickness. Large moundlike features in a limestone formation are interpreted as ancient reefs , which when they appear in
6048-647: The rest remained under the Lombards. By the 590s AD, today's East Tyrol and Carinthia had come to be referred to in historical sources as Provincia Sclaborum (the Country of Slavs). The territory settled by Slavs, however, was also inhabited by remnants of the indigenous Romanised Celtic and Pannonian population, who preserved the Christian faith and helped convert the Slavs of Carantania . From 623 to 658 Slavic peoples between
6132-460: The rock. The Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright (1992). It adds some diagenetic patterns to the classification scheme. Travertine is a term applied to calcium carbonate deposits formed in freshwater environments, particularly waterfalls , cascades and hot springs . Such deposits are typically massive, dense, and banded. When
6216-479: The sediments increases. Chemical compaction takes place by pressure solution of the sediments. This process dissolves minerals from points of contact between grains and redeposits it in pore space, reducing the porosity of the limestone from an initial high value of 40% to 80% to less than 10%. Pressure solution produces distinctive stylolites , irregular surfaces within the limestone at which silica-rich sediments accumulate. These may reflect dissolution and loss of
6300-662: The sediments of the ocean floor abruptly transition from carbonate ooze rich in foraminifera and coccolith remains ( Globigerina ooze) to silicic mud lacking carbonates. In rare cases, turbidites or other silica-rich sediments bury and preserve benthic (deep ocean) carbonate deposits. Ancient benthic limestones are microcrystalline and are identified by their tectonic setting. Fossils typically are foraminifera and coccoliths. No pre-Jurassic benthic limestones are known, probably because carbonate-shelled plankton had not yet evolved. Limestones also form in freshwater environments. These limestones are not unlike marine limestone, but have
6384-653: The so-called North Chain in the Karwendel Alps ( Hafelekarspitze , 2,334 metres or 7,657 feet) to the north and Patscherkofel (2,246 m or 7,369 ft) and Serles (2,718 m or 8,917 ft) to the south. The name "Innsbruck" means 'bridge over the Inn'. Vorarlberg 's notable mountain ranges include the Silvretta, the Rätikon, the Verwall and the Arlberg. The highest mountain
6468-730: The submereded sea bed of the Tethys Ocean . The chain also includes the Klippenzone and Steinitzer Wald . Liechtenstein lies entirely within the Rhaetikon and is thus allotted either to the Eastern Alps (two-part division of the Alps ) or to the Central Alps (three-part division of the Alps) depending on how its geology classified. The Rätikon mountain range, in the Central Eastern Alps , derives its name from Raetia . The Julian Alps cross
6552-519: The upper Elbe River and the Karawanks mountain range. They united under the leadership of King Samo (Kralj Samo). Carantania, (AKA: Carentania, Slovene: Karantanija, German: Karantanien, in Old Slavic *Korǫtanъ), was a former Alpine Slavic (Alpska Slovanščina) \proto-Slovenian principality that emerged from Samo's Empire in the second half of the 7th century, in the territory of present-day southern Austria and north-eastern Slovenia. Carantania
6636-533: The water by photosynthesis and thereby decreasing the solubility of calcium carbonate. Limestone shows the same range of sedimentary structures found in other sedimentary rocks. However, finer structures, such as lamination , are often destroyed by the burrowing activities of organisms ( bioturbation ). Fine lamination is characteristic of limestone formed in playa lakes , which lack the burrowing organisms. Limestones also show distinctive features such as geopetal structures , which form when curved shells settle to
6720-553: The water. Although ooids likely form through purely inorganic processes, the bulk of CaCO 3 precipitation in the oceans is the result of biological activity. Much of this takes place on carbonate platforms . The origin of carbonate mud, and the processes by which it is converted to micrite, continue to be a subject of research. Modern carbonate mud is composed mostly of aragonite needles around 5 μm (0.20 mils) in length. Needles of this shape and composition are produced by calcareous algae such as Penicillus , making this
6804-691: Was absorbed into the Frankish Empire in 745. The province of Lower Rhaetia was formed in 814. The Frankish March of Carinthia , created within the Carolingian Empire in 889. The city of Chur suffered several invasions: by the Magyars in 925–926, when the cathedral was destroyed, and by the Saracens (940 and 954), but afterwards it flourished thanks to its location, where the roads from several major Alpine transit routes come together and continue down
6888-686: Was also conquered by the Franks . After the fall of the Western Roman Empire , Ticino was ruled by the Ostrogoths , the Lombards and the Franks . The Alemanni or Alamanni , were a confederation of Germanic tribes on the Upper Rhine River. Eastern Switzerland, Vorarlberg and Liechtenstein was under the Alemanni and 73% of Liechtenstein's current population still speak the native Alemannic dialect of German at home as of 2022. After
6972-560: Was later part of the diocese of Chur . A Roman road crossed Liechtenstein from south to north, traversing the Alps by the Splügen Pass and following the right bank of the Rhine at the edge of the floodplain, for long uninhabited because of periodic flooding. Some Roman villas have been excavated in Schaanwald and Nendeln . Nearly 2,000 years later, some of the population of Graubünden still speak Romansh which has descended from Vulgar Latin . By 259, Alamanni tribes had overrun
7056-416: Was likely deposited in pore space between grains, suggesting a high-energy depositional environment that removed carbonate mud. Recrystallized sparite is not diagnostic of depositional environment. Limestone outcrops are recognized in the field by their softness (calcite and aragonite both have a Mohs hardness of less than 4, well below common silicate minerals) and because limestone bubbles vigorously when
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