Pamukkale, meaning "cotton castle" in Turkish, is a natural site in Denizli in southwestern Turkey. The area is famous for a carbonate mineral left by the">Scheffel, Richard L.. Natural Wonders of the World. United States of America: Reader's Digest Association, Inc. p. 286. ISBN 978-0-89577-087-5.</ref> It is located in Turkey's Inner Aegean region, in the River Menderes valley, which has a temperate climate for most of the year. The ancient Greco-Roman city of Hierapolis was built on top of the white "castle", in total about 2,700 metres long, 600 m wide and 160 m high, it can be seen from the hills on the opposite side of the valley in the town of Denizli, 20 km away. Known as Pamukkale or ancient Hierapolis, this area has been drawing the weary to its thermal springs since the time of Classical antiquity; the Turkish name refers to the surface of the shimmering, snow-white limestone, shaped over millennia by calcium-rich springs. Dripping down the vast mountainside, mineral-rich waters foam and collect in terraces, spilling over cascades of stalactites into milky pools below.
Legend has it. Tourism is and has been a major industry in the area for thousands of years, due to the attraction of the thermal pools; as as the mid-20th century, hotels were built over the ruins of Hierapolis, causing considerable damage. An approach road was built from the valley over the terraces, motor bikes were allowed to go up and down the slopes; when the area was declared a World Heritage Site, the hotels were demolished and the road removed and replaced with artificial pools. Overshadowed by natural wonder, Pamukkale’s well-preserved Roman ruins and museum have been remarkably underestimated and unadvertised. Aside from a small footpath running up the mountain face, the terraces are all off-limits, having suffered erosion and water pollution at the feet of tourists. Pamukkale's terraces are made of travertine, a sedimentary rock deposited by water from the hot springs. In this area, there are 17 hot water springs in which the temperature ranges from 35 °C to 100 °C; the water that emerges from the spring is transported 320 metres to the head of the travertine terraces and deposits calcium carbonate on a section 60 to 70 metres long covering an expanse of 24 metres to 30 metres.
When the water, supersaturated with calcium carbonate, reaches the surface, carbon dioxide de-gasses from it, calcium carbonate is deposited. Calcium carbonate is deposited by the water as a soft gel which crystallizes into travertine. In this museum, alongside historical artifacts from Hierapolis, there are artifacts from Laodiceia, Tripolis and other towns of the Lycos valley. In addition to these, the museum has a large section devoted to artifacts found at Beycesultan Hüyük that includes some of the most beautiful examples of Bronze Age craft. Artifacts from the Caria and Lydia regions are on display in this museum; the museum’s exhibition space consists of three closed areas of the Hierapolis Bath and the open areas in the eastern side which are known to have been used as the library and gymnasium. The artifacts in open exhibition space are marble and stone. Hierapolis is broken down into ruins. Pamukkale is a tourist attraction, it is recognized as a World Heritage Site together with Hierapolis.
Hierapolis-Pamukkale was made a World Heritage Site in 1988. The underground volcanic activity which causes the hot springs forced carbon dioxide into a cave, called the Plutonium, which here means "place of the god Pluto"; this cave was used for religious purposes by priests of Cybele, who found ways to appear immune to the suffocating gas. Tadpoles can be found in the pools; the hotels built in the 1960s were demolished as they were draining the thermal waters into their swimming pools and caused damage to the terraces. The water supply to the hotels is restricted in an effort to preserve the overall site and to allow deposits to regenerate. Access to the terraces is not allowed and visitors are asked to follow the pathway; the village of Pamukkale has two sister cities: Eger, Hungary Las Vegas, United States These locations are well-known for their travertine formations: Egerszalók in Hungary Badab-e Surt in Iran Mammoth Hot Springs in the USA Pink and White Terraces in New Zealand Hierve el Agua in Mexico The White Whale in Italy - Bagni San Filippo Baishuitai in China Garmchashma in Tajikistan Tatev in Armenia Terme di Saturnia in Italy Huanglong Scenic and Historic Interest Area, A similar UNESCO world heritage travertine cascade in China.
Dolok Tinggi Raja in Simalungun Sumatra Indonesia Pamukkale official site Pamukkale travel guide from Wikivoyage Pamukkale - spherical panorama 360 degree UNESCO World Heritage site datasheet The Marble Stairs of Heaven on Earth: Pamukkale Pamukkale Travel Guide Photos and first hand account of visit including Hierapolis and Cleopatra's pool Visiting the Cotton Castle – Geobeats.com on Youtube Video from Pamukkale
The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and with the end of the Paleolithic age used in archaeology; the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, the Gelasian, Middle Pleistocene and Upper Pleistocene. In addition to this international subdivision, various regional subdivisions are used. Before a change confirmed in 2009 by the International Union of Geological Sciences, the time boundary between the Pleistocene and the preceding Pliocene was regarded as being at 1.806 million years Before Present, as opposed to the accepted 2.588 million years BP: publications from the preceding years may use either definition of the period. Charles Lyell introduced the term "Pleistocene" in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today.
This distinguished it from the older Pliocene epoch, which Lyell had thought to be the youngest fossil rock layer. He constructed the name "Pleistocene" from the Greek πλεῖστος, pleīstos, "most", καινός, kainós, "new"; the Pleistocene has been dated from 2.588 million to 11,700 years BP with the end date expressed in radiocarbon years as 10,000 carbon-14 years BP. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell; the end of the Younger Dryas has been dated to about 9640 BC. The end of the Younger Dryas is the official start of the current Holocene Epoch. Although it is considered an epoch, the Holocene is not different from previous interglacial intervals within the Pleistocene, it was not until after the development of radiocarbon dating, that Pleistocene archaeological excavations shifted to stratified caves and rock-shelters as opposed to open-air river-terrace sites. In 2009 the International Union of Geological Sciences confirmed a change in time period for the Pleistocene, changing the start date from 1.806 to 2.588 million years BP, accepted the base of the Gelasian as the base of the Pleistocene, namely the base of the Monte San Nicola GSSP.
The IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75° 06' N 42° 18' W; the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils: Discoaster pentaradiatus and Discoaster surculus; the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age; the revised definition of the Quaternary, by pushing back the start date of the Pleistocene to 2.58 Ma, results in the inclusion of all the recent repeated glaciations within the Pleistocene. The modern continents were at their present positions during the Pleistocene, the plates upon which they sit having moved no more than 100 km relative to each other since the beginning of the period.
According to Mark Lynas, the Pleistocene's overall climate could be characterized as a continuous El Niño with trade winds in the south Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, other El Niño markers. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places, it is estimated. In addition, a zone of permafrost stretched southward from the edge of the glacial sheet, a few hundred kilometres in North America, several hundred in Eurasia; the mean annual temperature at the edge of the ice was −6 °C. Each glacial advance tied up huge volumes of water in continental ice sheets 1,500 to 3,000 metres thick, resulting in temporary sea-level drops of 100 metres or more over the entire surface of the Earth. During interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions.
The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene; the Andes were covered in the south by the Patagonian ice cap. There were glaciers in New Tasmania; the current decaying glaciers of Mount Kenya, Mount Kilimanjaro, the Ruwenzori Range in east and central Africa were larger. Glaciers existed to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one; the Cordilleran ice sheet covered the North American northwest. The Fenno-Scandian ice sheet rested including much of Great Britain. Scattered domes stretched across Siberi
Sediment is a occurring material, broken down by processes of weathering and erosion, is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation and if buried, may become sandstone and siltstone. Sediments are most transported by water, but wind and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian deposition. Glacial moraine deposits and till are ice-transported sediments. Sediment can be classified based on its grain composition. Sediment size is measured on a log base 2 scale, called the "Phi" scale, which classifies particles by size from "colloid" to "boulder". Composition of sediment can be measured in terms of: parent rock lithology mineral composition chemical make-up.
This leads to an ambiguity in which clay can be used as a composition. Sediment is transported based on the strength of the flow that carries it and its own size, volume and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more to fall through the flow. Rivers and streams carry sediment in their flows; this sediment can be in a variety of locations within the flow, depending on the balance between the upwards velocity on the particle, the settling velocity of the particle. These relationships are shown in the following table for the Rouse number, a ratio of sediment fall velocity to upwards velocity. Rouse = Settling velocity Upwards velocity from lift and drag = w s κ u ∗ where w s is the fall velocity κ is the von Kármán constant u ∗ is the shear velocity If the upwards velocity is equal to the settling velocity, sediment will be transported downstream as suspended load. If the upwards velocity is much less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling and saltating.
If the upwards velocity is higher than the settling velocity, the sediment will be transported high in the flow as wash load. As there are a range of different particle sizes in the flow, it is common for material of different sizes to move through all areas of the flow for given stream conditions. Sediment motion can create self-organized structures such as ripples, dunes, or antidunes on the river or stream bed; these bedforms are preserved in sedimentary rocks and can be used to estimate the direction and magnitude of the flow that deposited the sediment. Overland flow can transport them downslope; the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion. If overland flow is directly responsible for sediment entrainment but does not form gullies, it is called "sheet erosion". If the flow and the substrate permit channelization, gullies may form.
The major fluvial environments for deposition of sediments include: Deltas Point bars Alluvial fans Braided rivers Oxbow lakes Levees Waterfalls Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust. Glaciers carry a wide range of sediment sizes, deposit it in moraines; the overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation. This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow; this equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, due to small obstacles. Erosion and deposition can be regional. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise.
Seas and lakes accumulate sediment over time. The sediment can consist of terrigenous material, which originates on land, but may be deposited in either terrestrial, marine, or lacustrine environments, or of sediments originating in the body of water. Terrigenous material is supplied by nearby rivers and streams or reworked marine sediment. In the mid-ocean, the exoskeletons of dead organisms are responsible for sediment accumulation. Deposited sediments are the source of sedimentary rocks, which can contain fossils of
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxyhydroxides. Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, are used by humans, e.g. as iron ores, catalysts, in thermite and hemoglobin. Common rust is a form of iron oxide. Iron oxides are used as inexpensive, durable pigments in paints and colored concretes. Colors available are in the "earthy" end of the yellow/orange/red/brown/black range; when used as a food coloring, it has E number E172. Oxide of FeIIFeO: iron oxide, wüstite FeO2: iron dioxide Mixed oxides of FeII and FeIIIFe3O4: Iron oxide, magnetite Fe4O5 Fe5O6 Fe5O7 Fe25O32 Fe13O19 Oxide of FeIIIFe2O3: iron oxide α-Fe2O3: alpha phase, hematite β-Fe2O3: beta phase γ-Fe2O3: gamma phase, maghemite ε-Fe2O3: epsilon phase iron hydroxide iron hydroxide, akaganéite, feroxyhyte, ferrihydrite, or 5 Fe 2 O 3 ⋅ 9 H 2 O, better recast as FeOOH ⋅ 0.4 H 2 O high-pressure FeOOH schwertmannite green rust Several species of bacteria, including Shewanella oneidensis, Geobacter sulfurreducens and Geobacter metallireducens, metabolically utilize solid iron oxides as a terminal electron acceptor, reducing Fe oxides to Fe containing oxides.
Under conditions favoring iron reduction, the process of iron oxide reduction can replace at least 80% of methane production occurring by methanogenesis. This phenomenon occurs in a nitrogen-containing environment with low sulfate concentrations. Methanogenesis, an Archaean driven process, is the predominate form of carbon mineralization in sediments at the bottom of the ocean. Methanogenesis completes the decomposition of organic matter to methane; the specific electron donor for iron oxide reduction in this situation is still under debate, but the two potential candidates include either Titanium or compounds present in yeast. The predicted reactions with Titanium serving as the electron donor and phenazine-1-carboxylate serving as an electron shuttle is as follows: Ti-cit + CO2 + 8H+ → CH4 + 2H2O + Ti + cit ΔE = –240 + 300 mV Ti-cit + PCA → PCA + Ti + cit ΔE = –116 + 300 mV PCA + Fe3 → Fe2+ + PCA ΔE = –50 + 116 mV Note: cit = citrate. Titanium is oxidized to Titanium; the reduced form of PCA can reduce the iron hydroxide.
On the other hand when airborne, iron oxides have been shown to harm the lung tissues of living organisms by the formation of hydroxyl radicals, leading to the creation of alkyl radicals. The following reactions occur when Fe2O3 and FeO, hereafter represented as Fe3+ and Fe2+ iron oxide particulates accumulate in the lungs. O2 + e− → O2• –The formation of the superoxide anion is catalyzed by a transmembrane enzyme called NADPH oxidase; the enzyme facilitates the transport of an electron across the plasma membrane from cytosolic NADPH to extracellular oxygen to produce O2• –. NADPH and FAD are bound to cytoplasmic binding sites on the enzyme. Two electrons from NADPH are transported to FAD which reduces it to FADH2. One electron moves to one of two heme groups in the enzyme within the plane of the membrane; the second electron pushes the first electron to the second heme group so that it can associate with the first heme group. For the transfer to occur, the second heme must be bound to extracellular oxygen, the acceptor of the electron.
This enzyme can be located within the membranes of intracellular organelles allowing the formation of O2• – to occur within organelles. 2O2• – + 2 H+ → H2O2 + O2 The formation of hydrogen peroxide can occur spontaneously when the environment has a lower pH at pH 7.4. The enzyme superoxide dismutase can catalyze this reaction. Once H2O2 has been synthesized, it can diffuse thro
Mammoth Hot Springs
Mammoth Hot Springs is a large complex of hot springs on a hill of travertine in Yellowstone National Park adjacent to Fort Yellowstone and the Mammoth Hot Springs Historic District. It was created over thousands of years as hot water from the spring cooled and deposited calcium carbonate; because of the huge amount of geothermal vents, travertine flourishes. Although these springs lie outside the caldera boundary, their energy has been attributed to the same magmatic system that fuels other Yellowstone geothermal areas; the hot water that feeds Mammoth comes from Norris Geyser Basin after traveling underground via a fault line that runs through limestone and parallel to the Norris-to-Mammoth road. The limestone from rock formations along the fault is the source of the calcium carbonate. Shallow circulation along this corridor allows Norris' superheated water to cool before surfacing at Mammoth at about 170 °F. Algae living in the warm pools have tinted the travertine shades of brown, orange and green.
Thermal activity here is extensive both over distance. The thermal flows show much variability with some variations taking place over periods ranging from decades to days. Terrace Mountain at Mammoth Hot Springs is the largest known carbonate-depositing spring in the world; the most famous feature at the springs is a series of travertine terraces. The terraces have been deposited by the spring over many years but, due to recent minor earthquake activity, the spring vent has shifted, rendering the terraces dry; the Mammoth Terraces extend all the way from the hillside, across the Parade Ground, down to Boiling River. The Mammoth Hotel, as well as all of Fort Yellowstone, is built upon an old terrace formation known as Hotel Terrace. There was some concern when construction began in 1891 on the fort site that the hollow ground would not support the weight of the buildings. Several large sink holes can be seen out on the Parade Ground; this area has been thermally active for several thousand years.
The Mammoth area exhibits much evidence of glacial activity from the Pinedale Glaciation. The summit of Terrace Mountain is covered with glacial till, thereby dating the travertine formation there to earlier than the end of the Pinedale Glaciation. Several thermal kames, including Capitol Hill and Dude Hill, are major features of the Mammoth Village area. Ice-marginal stream beds are in evidence in the small, narrow valleys where Floating Island Lake and Phantom Lake are found. In Gardner Canyon one can see the old, sorted gravel bed of the Gardner River covered by unsorted glacial till. Geothermal areas of Yellowstone
Abbasabad County is a county on the Caspian Sea, in Mazandaran Province of northern Iran. The county was detached from Tonekabon County and established in 2009; the capital of the county is Abbasabad. At the 2006 census, the county's population was 45,589, in 12,694 families; the county is subdivided into two districts: Salman Shahr District. The county has three cities: Abbasabad and Salman Shahr