Misplaced Pages

#622377

43-449: The Fatra-Tatra Area is from the northern side bounded by Pieniny Klippen Belt . Mountains of the area are located in two ranges. The external range consists of Hainburg Hills , Malé Karpaty (Pezinok part), Považský Inovec , Strážovské vrchy , Malá Fatra , Tatras ( Western , High and Belianske Tatry ). Inner range consists of Tribeč , Žiar , Veľká Fatra , Chočské vrchy , Ďumbier part of Nízke Tatry and massif of Smrekovica in

86-470: 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

129-478: 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

172-459: 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

215-445: 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

258-462: A very complex geological structure. It is a narrow (only 0.4 to 19 km) and extremely long (about 600 km) north banded zone of extreme shortening and sub-vertical strike-slip fault zone, with complex geological history, where only fragments of individual strata and facies are preserved. The Pieniny Klippen Belt is considered one of the main tectonic sutures of the Carpathians and forms

301-498: 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 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

344-837: 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

387-745: Is a result of two main phases during the Alpine orogeny . The oldest phase is called the Laramide phase or Jarmuta phase and occurred in the Cretaceous and Paleogene periods. It caused thrusting of the nappes . The second phase is called the Savian or Helvetian phase. It was induced by subduction of the Northern Penninic ocean and caused the formation of the Carpathian Flysch Belt . The Pieniny Klippen Belt

430-678: Is covered with younger deposits, for example in the Podhale basin in Poland, or in the Vihorlat Mountains in Slovakia. Klippes , which are the most characteristic features of the belt, are Jurassic to lower Cretaceous lenses - rigid blocks of limestone , tectonically separated from their unknown substratum. These blocks are also cropping out in tectonic windows in the overlying middle Cretaceous to Paleogene sediments. Strong tectonic deformation

473-490: Is divided into numerous tectonic units, but only few of them occur throughout the entire belt. The oldest rocks of the Klippen belt are Middle Jurassic to upper Cretaceous . They are in normal stratigraphical positions, with only minor hiatus . Large scale crustal shortening caused rocks of different tectonic units and origin to be thrusted over each other and now lying juxtaposed. These tectonic units are: The Czorsztyn unit has

SECTION 10

#1732851330623

516-523: 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

559-629: Is not exactly known. Choč Nappe is considered as rootless nappe. After the end of main Eo-Alpine orogenic movement, the area of Western Carpathians was still not so mountainous. In the Paleogene subsidence along the normal faults caused formation of grabens - intra-mountain Inner Carpathian Paleogene Basin and horsts present day mountain ranges. In the Neogene, further orogene movement in

602-431: 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

645-443: 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

688-568: The Branisko . The southern boundary of Area is the Čertovica line , south of which is the Vepor Belt . The Tatra-Fatra Belt consists of Tatric alpine crystalline basement and its autochthonous sedimentary cover, over which the Subtatric nappes ( Fatric and Hronic ) were thrust. The name core mountains is derived from the structural element, resistant crystalline basement rocks , preserved in

731-855: The Middle Jurassic to Lowermost Cretaceous an elevated continental ribbon called the Czorsztyn Ridge evolved due to the thermal uplift and continental break-up at the southern side of the Czorsztyn Ridge. Rifting resulted in the opening of basinal area called the Kysuca basin or Vahic Ocean (South Penninic or Piemont ocean equivalent) to the south of the Oravic area. In the Upper Jurassic entire Oravic domain began to thermally subside. Since Lowermost Cretaceous time probably an asymmetrical rifting affected

774-823: The Upper Cretaceous to Paleocene the Vahic Ocean began to close. The Oravic units were detached from its subducting basement and formed a fold and thrust belt . After first phase of folding and thrusting sedimentation of turbiditic sequences was restored. Whole area was again deformed in second phase of orogeny in the Upper Paleogene to Lower Miocene when sinistral transpression and amalgamation with hinterland part of closed Magura Ocean caused formation of typical "klippen" tectonic style due to counterclockwise rotation of ALCAPA microplate. During this times several subduction related calc-alcaline volcanoes locally evolved in

817-619: The greenschist and amphibolite facies (forming large amount of paragneisses and amphibolites , only locally orthogneisses , phyllites and mica schists ). Regional and contact metamorphism was induced also by intrusions of granites , which accompanied the Hercynian collision (generally in the Carboniferous ). Basement rocks were later exposed due to erosion and at the end of the Paleozoic affected by marine transgression that lasted till

860-498: 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

903-696: The Tatric. These nappes are generally composed of limestone , marl , dolomite and less by sandstones and slates . The lower nappes is called Krížna Nappe (or the Fatric ) and the upper is Choč Nappe (or the Hronic ). Krížňa Nappe is dominantly composed of rock, that were formed in the Zliechov basin. It was situated in the Fatric area between the Tatric and Veporic units. Fatric had

SECTION 20

#1732851330623

946-491: 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

989-648: The area to the North of the Czorsztyn Ridge where a Magura basin (North Penninic or Valais Ocean equivalent) started to evolve. During the Middle Cretaceous thermal subsidence of the Czorsztyn Ridge caused its development into a pelagic high. In Turonian times frontal elements of the Fatric Nappe System of the Inner Western Carpathians were emplaced onto the southern parts of the Vahic Ocean. In

1032-592: The area. Later sinistral transtension and lateral extension modified the structure of the belt during the Late Miocene and Pliocene . Extensional deformation on the eastern and western edge of the belt interacted with development of the Vienna and Transcarpathian basin . After the marine regression at the end of Miocene younger marls and turbidites were eroded faster than more competent Jurassic limestones forming distinctly looking klippes. Sandstone Sandstone

1075-600: The boundary between the Outer (externides a thin-skin thrustbelt) and Central Western Carpathians (internal thick-skin thrustbelt). The Pieniny Klippen Belt emerges from beneath the Neogene sediments of the Vienna basin near Podbranč in western Slovakia and continues eastward to Poland , where it bends and returns to Slovakia in the area of Pieniny . The klippen belt then continues to Ukraine and ends in Romania . In some places it

1118-468: 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

1161-534: The core of horsts , often forming the highest peaks of the mountains. The basement of the core mountains is formed by the Tatric Unit, which is composed of dominantly hercynian metamorphic and igneous rocks and locally also a sedimentary cover of various thickness. In the Paleozoic clastic and volcanoclastic sediments deposited in the area, but later during Hercynian orogeny , sediments were metamorphosed in

1204-540: The crystalline schists and granites of the Tatric. Similar fold and thrust model of origin is known from the other areas of alpine system. In the English terminology, similar model is called Fault-block mountain , it is typical in the area of Basin and Range . Pieniny Klippen Belt The Pieniny Klippen Belt is in geology a tectonically and orographically remarkable zone in the Western Carpathians , with

1247-456: 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

1290-407: 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

1333-446: 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

Fatra-Tatra Area - Misplaced Pages Continue

1376-504: The end of Mesozoic . During this period sedimentary rocks , known as Tatric cover units , deposited. They generally consists of clastic and carbonate rocks . In the Upper Cretaceous area of Tatric Unit, was affected by Eo-Alpine of Alpine Orogeny , that caused movement of large masses of rocks to the North and Northeast. To the South of the Tatric area a 2 superficial nappes , so called Subtatric Nappes , were detached and thrust over

1419-459: The external part of Carpathian arc caused formation of back-arc Pannonian Basin . Northern branches of Pannonian Basin were penetrating the Tatra-Fatra Area and formed inter-mountain basins. Simultaneously with the immersion of the horsts, ongoing and intense erosion is denuding the mountains and supplies the basin with clastic sediments. Among all of the rocks, the most erosion resistant were

1462-433: 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

1505-442: 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

1548-483: 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 the red rock deserts of Arches National Park and other areas of the American Southwest . Rock formations composed of sandstone usually allow

1591-493: 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

1634-464: 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

1677-638: 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

1720-478: The same basement as the Veporic unit and is considered as former northern part of Veporic, but later during the thrusting its substratum was consumed and subducted. Surface occurrences of Fatric basement remained only as a remnants in the northern part of Veporic Veľký Bok Unit and few other areas. Choč Nappe, was thrust from the southern area, but its roots were probably consumed entirely, so its paleogeographic position

1763-417: 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

Fatra-Tatra Area - Misplaced Pages Continue

1806-766: The shallowest marine facies. Together with smaller continental slope units and the deep marine Kysuca unit it forms a continental domain called the Oravicum , which is geometrically equivalent to the Briançonnais microcontinent in the Western and Central Alps. Reconstruction of the older phases of development is not possible because of absence of pre- triassic rocks. The development of Pieniny Klippen Belt started on passive margin of European platform in Lower Jurassic with rifting and tectonic subsidence of Oravic unit. During

1849-612: 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

#622377