The Tiglian , also referred to as the Tegelen , is a temperate complex stage in the glacial history of Northern Europe. It is preceded by the Praetiglian (stage). The stage was introduced by Zagwijn in 1957 based on geological formations in Tegelen in southern Netherlands. Originally, it was thought to be part of a sequence of glacials and interglacials, namely Praetiglian (cold), Tiglian (warm), Eburonian (cold), Waalian (warm), Menapian (cold), and Bavelian (warm).
31-739: The Praetiglian and Tiglian are today regarded as corresponding to the Biber stage in the glacial history of the Alps and to the Gelasian (2.6-1.8 million years ago) in the global division of the Quaternary period. Deep sea core samples have identified approximately 40 marine isotope stages (MIS 103 – MIS 64) during the Gelasian. Thus, there have probably been about 20 glacial cycles of varying intensity during Praetiglian and Tiglian. The dominant trigger
62-791: A water gap may occur. In these, erosion from a stream occurs faster than mountain uplift, resulting in a gorge or valley that runs through a mountain range from low-lying country on one side to similar country on the other. Examples of such water gaps include the Manawatū Gorge in New Zealand and the Cumberland Narrows in Maryland . The removal of mass from a region will be isostatically compensated by crustal rebound. If we take into consideration typical crustal and mantle densities, erosion of an average 100 meters of rock across
93-527: A broad, uniform surface will cause the crust to isostatically rebound about 85 meters and will cause only a 15-meter loss of mean surface elevation. An example of isostatic uplift is post-glacial rebound following the melting of ice sheets . The Hudson Bay region of Canada, the Great Lakes of Canada and the United States, and Fennoscandia are currently undergoing gradual rebound as a result of
124-508: A more modest uplift over a large region. Perhaps the most extreme form of orogenic uplift is a continental-continental crustal collision. In this process, two continents are sutured together, and large mountain ranges are produced. The collision of the Indian and Eurasian plates is a good example of the extent to which orogenic uplift can reach. Heavy thrust faulting (of the Indian plate beneath
155-463: A relatively small role, and high peak formation can be more attributed to tectonic processes. Direct measures of the elevation change of the land surface can only be used to estimate erosion or bedrock uplift rates when other controls (such as changes in mean surface elevation, volume of eroded material, timescales and lags of isostatic response, variations in crustal density) are known. In a few cases, tectonic uplift can be seen in coral islands . This
186-482: Is an upper limit to vertical mountain growth). Although the raised surfaces of mountain ranges mainly result from crustal thickening, there are other forces at play that are responsible for the tectonic activity. All tectonic processes are driven by gravitational force when density differences are present. A good example of this would be the large-scale circulation of the Earth's mantle . Lateral density variations near
217-738: Is believed to be the 41 000 year Milankovitch cycles of axial tilt. Gravels ascribed to Biber (also called the Highland Gravel or Oldest Gravel ( Ältester Deckenschotter ) occur northwest of Augsburg as the Stauffenberg Gravel ( Stauffenberg-Schotter ), as well as northeast as the Hohenried Gravel ( Hohenrieder Schotter ) and southwest of Augsburg as the Stauden Plateau Gravel ( Schotter der Stauden-Platte ). Also included are isolated gravels of
248-469: Is believed to be the 41 000 year Milankovitch cycles of axial tilt. The Gelasian of Northern Europe has subsequently been subdivided as follows: This glaciology article is a stub . You can help Misplaced Pages by expanding it . Biber (geology) Biber or the Biber Complex ( German : Biber-Komplex ) is a timespan approximately 2.6–1.8 million years ago in the glacial history of
279-679: Is evidenced by the presence of various oceanic islands composed entirely of coral , which otherwise appear to be volcanic islands . Examples of such islands are found in the Pacific, notably the three phosphate islets of Nauru , Makatea , and Banaba , as well as Maré and Lifou in New Caledonia ; Fatu Huku in the Marquesas Islands ; and Henderson Island in the Pitcairn Islands . The uplift of these islands
310-452: Is known to be sensitive to temperature and rainfall. The magnitude of the exhumation a rock has been subjected to may be inferred from geothermobarometry (measuring previous pressure and temperature history of a rock or assemblage). Knowing the pressure and temperature history of a region can yield an estimate of the ambient geothermal gradient and bounds on the exhumation process; however, geobarometric/geothermometric studies do not produce
341-404: Is proportional to the rate of increase of average surface height. The highest rates of working against gravity are required when the thickness of the crust (not the lithosphere) changes. Lithospheric flexure is the process by which the lithosphere bends under the action of forces such as the weight of a growing orogeny or changes in ice thickness related to glaciation. The lithosphere rests on
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#1732773334395372-450: Is specified. Molnar and England identify three kinds of displacement to which the term "uplift" is applied: This simple equation relates the three kinds of displacement: The term geoid is used above to mean mean sea level and makes a good frame of reference. A given displacement within this frame of reference allows one to quantify the amount of work being done against gravity. Measuring uplift and exhumation can be tricky. Measuring
403-409: Is the result of the movement of oceanic tectonic plates. Sunken islands or guyots with their coral reefs are the result of crustal subsidence as the oceanic plate carries the islands to deeper or lower oceanic crust areas. The word "uplift" refers to displacement contrary to the direction of the gravity vector, and displacement is only defined when the object being displaced and the frame of reference
434-500: The Alps . Biber corresponds to the Gelasian age in the international geochronology , which since 2009 is regarded as the first age of the Quaternary period. Deep sea core samples have identified approximately 20 glacial cycles of varying intensity during Biber. In 1953, Schaefer defined the Biber glaciation ( German : Biber-Kaltzeit ), Biber Glacial ( Biber-Glazial ), or Biber Ice Age ( Biber-Eiszeit ) from gravel landforms of
465-714: The Hochfirst near Mindelheim and the Stoffersberg near Landsberg am Lech . There may also be gravels in the Sundgau from the Biber ice age. Uplift (geology) Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics . While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal thickening (such as mountain building events), changes in
496-487: The asthenosphere , a viscous layer that in geological time scales behaves like a fluid. Thus, when loaded, the lithosphere progressively reaches an isostatic equilibrium. For example, the lithosphere on the oceanward side of an oceanic trench at a subduction zone will curve upwards due to the elastic properties of the Earth's crust. Orogenic uplift is the result of tectonic-plate collisions and results in mountain ranges or
527-524: The Eurasian plate) and folding are responsible for the suturing together of the two plates. The collision of the Indian and Eurasian plates produced the Himalayas and is also responsible for crustal thickening north into Siberia . The Pamir Mountains , Tian Shan , Altai , Hindu Kush , and other mountain belts are all examples of mountain ranges formed in response to the collision of the Indian with
558-815: The Eurasian plate. The Ozark Plateau is a broad uplifted area which resulted from the Permian Ouachita Orogeny to the south in the states of Arkansas , Oklahoma , and Texas . Another related uplift is the Llano Uplift in Texas, a geographical location named after its uplift features. The Colorado Plateau which includes the Grand Canyon is the result of broad tectonic uplift followed by river erosion . When mountains rise slowly, either due to orogenic uplift or other processes (e.g., rebound after glaciation ), an unusual feature known as
589-814: The Stauden Plateau in the area of the Iller-Lech Plateau and in the Aindling terrace sequence , by grouping together the so-called Middle and Upper Cover Gravels or Deckenschotter . This corresponded to the Staufenberg Gravel Terrace on the Iller-Lech Plateau, identified in 1974 by Scheunenpflug, and the so-called High Gravels ( Hochschottern ) of the Aindling region. The rich crystalline sedimentary facies ( Kristallinreiche Liegendfazies ), that Löscher distinguished in 1976 in
620-759: The Swiss cover gravel glaciations ( Deckenschotter-Vergletscherungen ). The 2016 version of the detailed stratigraphic table by the German Stratigraphic Commission firmly places Biber in the Gelasian and gives a correspondence to Pre-Tegelen and Tegelen in the glacial geology of northern Europe. There is continuity between Biber and the glacial cycles of the following Danube stage Deep sea core samples have identified approximately 40 marine isotope stages (MIS 103 – MIS 64) during Biber. Thus, there have probably been about 20 glacial cycles of varying intensity during Biber. The dominant trigger
651-602: The area of the Rhine Glacier of the western Riß-Iller Plateau may also be paralleled with these glacial landforms. The gravels in the Iller-Lech region ascribed to the Biber glaciation are generally heavily weathered and originate from the Northern Limestone Alps . Löscher's Kristallinreiche Liegendfazies , by contrast, originates from the bedrock of the molasse zone. The term Biber glaciation
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#1732773334395682-410: The density distribution of the crust and underlying mantle , and flexural support due to the bending of rigid lithosphere . Tectonic uplift results in denudation (processes that wear away the earth's surface) by raising buried rocks closer to the surface. This process can redistribute large loads from an elevated region to a topographically lower area as well – thus promoting an isostatic response in
713-468: The depositions assessed as Biber-related also exist in the Alpine region. It is possible that there were tectonic influences perhaps in the wake of the uplift phases of the Alps. The succession and appearance of the gravel bodies makes it possible that during their formation there were several periods of alternating fluvial erosion and accumulation . The Biber cold period at least corresponds partly with
744-451: The melting of ice sheets 10,000 years ago. Crustal thickening, which for example is currently occurring in the Himalayas due to the continental collision between the Indian and the Eurasian plates, can also lead to surface uplift; but due to the isostatic sinking of thickened crust, the magnitude of surface uplift will only be about one-sixth of the amount of crustal thickening. Therefore, in most convergent boundaries , isostatic uplift plays
775-559: The other; evidence of this process can be seen in preserved ophiolitic nappes (preserved in the Himalayas ) and in rocks with an inverted metamorphic gradient . The preserved inverted metamorphic gradient indicates that nappes were actually stacked on top of each other so quickly that hot rocks did not have time to equilibrate before being thrust on top of cool rocks. The process of nappe stacking can only continue for so long, as gravity will eventually disallow further vertical growth (there
806-461: The period between 1.6 and 1.8 million years ago, in the latter case it would roughly correspond to MIS 96 to 100, and would therefore have taken place about 2.4 to 2.588 million years ago. The correlation was fraught with problems however due to the fact that the corresponding depositions in the Netherlands were probably not governed by climatic changes. Similar doubts on climatic grounds for
837-404: The region of denudation (which can cause local bedrock uplift). The timing, magnitude, and rate of denudation can be estimated by geologists using pressure-temperature studies. Crustal thickening has an upward component of motion and often occurs when continental crust is thrust onto continental crust. Basically nappes (thrust sheets) from each plate collide and begin to stack one on top of
868-417: The surface (such as the creation, cooling, and subduction of oceanic plates ) also drive plate motion. The dynamics of mountain ranges are governed by differences in the gravitational energy of entire columns of the lithosphere (see isostasy ). If a change in surface height represents an isostatically compensated change in crustal thickness, the rate of change of potential energy per unit surface area
899-690: The uplift of a point requires measuring its elevation change – usually geoscientists are not trying to determine the uplift of a singular point but rather the uplift over a specified area. Accordingly, the change in elevation of all points on the surface of that area must be measured, and the rate of erosion must be zero or minimal. Also, sequences of rocks deposited during that uplift must be preserved. Needless to say, in mountain ranges where elevations are far above sea level these criteria are not easily met. Paleoclimatic restorations though can be valuable; these studies involve inferring changes in climate in an area of interest from changes with time of flora/fauna that
930-612: Was not part of the traditional four-stage glaciation schema of the Alps by Albrecht Penck and Eduard Brückner , but was named after the Biberbach river north of Augsburg in 1953 by Ingo Schaefer, based on the naming system of the traditional Penck schema. Its type region is the Stauden Plateau in the Iller-Lech Plateaux and the Staufenberg Gravel Terrace in the area of Aindling . The Biber glaciation
961-653: Was thought to be followed by the Biber-Danube interglacial and the Danube glacial . The absolute timing and the connexion with the glacial classification of North Germany and the Netherlands has been problematic. The Biber glacial was thought to correlate either to the Eburonian complex or the Pre-Tiglian complex in the Netherlands. In the former case it would correspond to MIS 56 to 62, which would place it in