Salt Glaciers, Zagros Mountains, Southern Iran, Iran

A salt glacier is a rare flow of salt that is created when a rising diapir in a salt dome breaches the surface of the Earth. The name ‘salt A salt glacier was given to this phenomenon due to the similarity of movement when compared with ice glaciers. The causes of these formations is primarily due to salt's unique properties and its surrounding geologic environment. A rising body of salt is referred to as a diapir; which rises to the surface and feeds the salt glacier. Salt structures are usually composed of halite, anhydrite, gypsum and clay minerals. Clays may be brought up with the salt, turning it dark. These salt flows are rare on earth. In a more recent discovery, scientists have found that they also occur on Mars, but are composed of sulfates.

The salt glaciers of the Zagros Mountains in Iran are halite whereas the salt glacier of Lüneburg Kalkberg, Germany is composed of gypsum and carbonate minerals. Ancient flows have been preserved in various rock records by sedimentation. Late Triassic salt glaciers repeatedly flowed onto a basin in Germany and were buried with sediment to create a series of preserved glaciers. Miocene glaciers flowed into sheets in the northern Gulf of Mexico and were similarly preserved by overriding sediment.

The sources of salt glaciers are salt deposits. Over time sediments, rock and debris cover the deposit causing layers to build up over the salt. Due to its crystalline structure, salt remains at the same density while the sediment above begins to compress and become denser. The density contrast is the mechanism in which salt begins to rise. Diapirs rise and pierce the surface allowing the salt to flow because of gravity. Piercing the overburden is crucial for salt glaciers to form, and can occur in three ways. Active diapirism develops as the rising salt itself pushes and forces the overburden upward and sideways. Passive diapirism occurs when the salt always remains near the surface and the sediment builds up around it rather than over it. Reactive diapirism is the result of regional extension caused by rifting. The overburden becomes weak and thin which allows the salt body to travel upwards.

Salt glaciers are a frequent topic in salt tectonics, which is the study of salt causing deformation and its leading cause is differential loading. Differential loading can be caused by displacement, gravitational and thermal gradients. Other tectonics may cause salt deposit uplift. The strength of the overburden and drag of the salt deposit boundary are the two factors that will slow and prevent salt flow and it will only move if the salt forces exceed the resistant forces. 

 

The structure of a salt glacier is much like that of an ice glacier. Salt glaciers on average may only advance a few meters per year. Salt will continue to flow on the surface if sedimentation, erosion and disintegration rates are slow and thus will have little impact. Salt glaciers move faster as precipitation increases; however too much precipitation may dissolve the salt. Salt glaciers may also leave behind features such as moraines.

Salt glaciers are mostly found in arid areas, where they will be preserved due to the dry climatic conditions. Southern Iran hosts the majority of salt glaciers and the most active salt glacier in the world. The Kuh-e-Namak salt glacier is located in southeast Iran. This salt feature is composed of two salt glaciers and the larger one is 50–100 m thick and 3,000 m long. The summit of the feature is around 1,600 m above sea level.

Salt glaciers provide observable and tangible evidence demonstrating salt movement which allows scientists to further understand movement that occurs beneath the Earth's surface. New studies of salt glaciers can help improve the understanding how salt tectonics work and how they influence the surrounding landscape. Salt structures often have petroleum traps, which contain much of the oil in use today. The traps are also being studied to serve as potential storage vessels for waste and fuels.

The White Cliffs of Dover, Kent, England

The White Cliffs of Dover, part of the North Downs formation, is the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of 350 feet (110 m), owes its striking appearance to its composition of chalk accented by streaks of black flint. The cliffs, on both sides of the town of Dover in Kent, stretch for eight miles (13 km). A section of coastline encompassing the cliffs was purchased by the National Trust in 2016.

The cliffs are part of the Dover to Kingsdown Cliffs Site of Special Scientific Interest and Special Area of Conservation. The cliffs are part of the coastline of Kent in England between approximately 51°06′N 1°14′E and 51°12′N 1°24′E, at the point where Great Britain is closest to continental Europe. On a clear day they are visible from the French coast. The chalk cliffs of the Alabaster Coast of Normandy in France are part of the same geological system. The White Cliffs are at one end of the Kent Downs designated Area of Outstanding Natural Beauty.In 1999 a sustainable National Trust visitor centre was built in the area. The Gateway building, designed by van Heyningen and Haward Architects, houses a restaurant, an information centre on the work of the National Trust, and details of local archaeology, history and landscape.

About 70 million years ago Great Britain and much of Europe were submerged under a great sea. The sea bottom was covered with white mud formed from fragments of coccoliths, the skeletons of tiny algae that floated in the surface waters and sank to the bottom during the Cretaceous period and, together with the remains of bottom-living creatures, formed muddy sediments. It is thought that the sediments were deposited very slowly, probably half a millimetre a year, equivalent to about 180 coccoliths piled one on top of another. Up to 500 metres of sediments were deposited in some areas. The weight of overlying sediments caused the deposits to become consolidated into chalk.

Subsequent earth movements related to the formation of the Alps raised the sea-floor deposits above sea level. Until the end of the last glacial period, the British Isles were part of continental Europe, linked by the unbroken Weald-Artois Anticline, a ridge that acted as a natural dam to hold back a large freshwater pro-glacial lake, now submerged under the North Sea. The land masses remained connected until between 450,000 and 180,000 years ago when at least two catastrophic glacial lake outburst floods breached the anticline and destroyed the ridge that connected Britain to Europe. A land connection across the southern North Sea existed intermittently at later times when periods of glaciation resulted in lower sea levels. At the end of the last glacial period, around 10,000 years ago, rising sea levels finally severed the last land connection.

 

The cliffs' chalk face shows horizontal bands of dark-coloured flint which is composed of the remains of sea sponges and siliceous planktonic micro-organisms that hardened into the microscopic quartz crystals. Quartz silica filled cavities left by dead marine creatures which are found as flint fossils, especially the internal moulds of Micraster echinoids. Several different ocean floor species such as brachiopods, bivalves, crinoids, and sponges can be found in the chalk deposits, as can sharks' teeth. In some areas, layers of soft, grey chalk known as a hardground complex can be seen. Hardgrounds are thought to reflect disruptions in the steady accumulation of sediment when sedimentation ceased and/or the loose surface sediments were stripped away by currents or slumping, exposing the older hardened chalk sediment. A single hardground may have been exhumed 16 or more times before the sediments were compacted and hardened to form chalk.

The cliffs have been eroding slowly but in the past 150 years they have been eroding ten times faster than they did before.The change is likely due to the construction of sea walls and groynes, the loss of beaches beneath the cliffs, and stronger storms hitting the coastline due to climate change and the rise of CO2 in the ocean. Scientists say that the English Channel has eaten away at the cliffs at a rate of 8.7 inches to just over a foot per year. A thousand years ago, that rate was three-quarters of an inch to 2.3 inches per year. Over the years, the cliffs began to crumble as well and there have been sudden cliff falls due to the erosion of the chalk. In 2001, a large chunk of the cliff edge, as large as a football pitch, fell into the Channel. Another large section collapsed on 15 March 2012.

A possible Iron Age hillfort has been discovered at Dover, on the site of the later castle. The area was also inhabited during the Roman period, when Dover was used as a port. A lighthouse survives from this era, one of a pair at Dover which helped shipping navigate the port. It is likely the area around the surviving lighthouse was inhabited in the early medieval period as archaeologists have found a Saxon cemetery here, and the church of St Mary in Castro was built next to the lighthouse in the 10th or 11th century. It is thought that the Old English name for Britain, Albion, was derived from the latin albus (meaning 'white') as an allusion to the white cliffs. Dover Castle, the largest castle in England, was founded in the 11th century. It has been described as the "Key to England" owing to its defensive significance throughout history. The castle was founded by William the Conqueror in 1066 and rebuilt for Henry II, King John, and Henry III. This expanded the castle to its current size, taking its curtain walls to the edge of the cliffs. During the First Barons' War the castle was held by King John's soldiers and besieged by the French between May 1216 and May 1217. The castle was also besieged in 1265 during the Second Barons' War. In the 16th century, cannons were installed at the castle, but it became less important militarily as Henry VIII had built artillery forts along the coast. Dover Castle was captured in 1642 during the Civil War when the townspeople climbed the cliffs and surprised the royalist garrison, giving a symbolic victory against royal control. Towards the end of the war many castles were slighted, but Dover was spared.

 

The castle had renewed importance from the 1740s as the development of heavy artillery made capturing ports an important part of warfare. During the Napoleonic Wars, in particular, the defences were remodelled and a series of tunnels were dug into the cliff to act as barracks, adding space for an extra 2,000 soldiers. The tunnels mostly lay abandoned until the Second World War.

South Foreland Lighthouse is a Victorian-era lighthouse on the South Foreland in St. Margaret's Bay, which was once used to warn ships approaching the nearby Goodwin Sands. Goodwin Sands is a 10-mile-long (16 km) sandbank at the southern end of the North Sea lying six miles (10 km) off the Deal coast. The area consists of a layer of fine sand approximately 82 ft (25 m) deep resting on a chalk platform belonging to the same geological feature that incorporates the White Cliffs of Dover. More than 2,000 ships are believed to have been wrecked on the Goodwin Sands because they lie close to the major shipping lanes through the Straits of Dover. It went out of service in 1988 and is now owned by the National Trust for Places of Historic Interest or Natural Beauty.
Second World War.

The cliffs have great symbolic value in Britain because they face towards continental Europe across the narrowest part of the English Channel, where invasions have historically threatened and against which the cliffs form a symbolic guard. The National Trust calls the cliffs "an icon of Britain", with "the white chalk face a symbol of home and wartime defence." Because crossing at Dover was the primary route to the continent before the advent of air travel, the white line of cliffs also formed the first or last sight of Britain for travellers. During the Second World War, thousands of allied troops on the little ships in the Dunkirk evacuation saw the welcoming sight of the cliffs. In the summer of 1940, reporters gathered at Shakespeare Cliff to watch aerial dogfights between German and British aircraft during the Battle of Britain.

Vera Lynn, known as "The Forces' Sweetheart" for her 1942 wartime classic " The White Cliffs of Dover" celebrated her 100th birthday in 2017. That year she led a campaign for donations to buy 170 acres (0.7 km2) of land atop Dover's cliffs when it was feared that they might be sold to developers; the campaign met its target after only three weeks. The National Trust, which owns the surrounding areas, plans to return the land to a natural state of chalk grassland and preserve existing military structures from the Second World War.

Dover Museum was founded in 1836. Shelled from France in 1942 during the Second World War, the museum lost much of its collections, including nearly all its natural history collections. Much of the surviving material was left neglected in caves and other stores until 1946. In 1948 a temporary museum was opened and in 1991 a new museum of three storeys, built behind its original Victorian façade, was opened. In 1999, a new gallery on the second floor centred on the Dover Bronze Age Boat was opened.

 

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Komodo Islands ( Island of Pink Sand and Komodo Dragon), Republic of Indonesia

Komodo Islands is one of the 17,508 islands that comprise the Republic of Indonesia. The island is particularly notable as the habitat of the Komodo dragon, the largest lizard on Earth, which is named after the island. Komodo Island has a surface area of 390 square kilometres and a human population of over two thousand. The people of the island are descendants of former convicts who were exiled to the island and who have mixed with Bugis from Sulawesi. The people are primarily adherents of Islam but there are also Christian and Hindu congregations. Komodo is part of the Lesser Sunda chain of islands and forms part of the Komodo National Park. In addition, the island is a popular destination for diving. Administratively, it is part of the East Nusa Tenggara Indonesia. 

It lies between the substantially larger neighboring islands Sumbawa to the west and Flores to the east. Komodo Island is home to the Komodo Dragon, the largest lizard on earth. The Pink Beach Komodo Island is located at the western end of the large island of Flores in the Nusa Tenggara region of East Indonesia.

The earliest stories (among Westerners) of a dragon-like animal existing in the region circulated widely and attracted considerable attention. But no Westerner visited the island to check the story until official interest was sparked in the early 1910s by stories from Dutch sailors based in Flores in East Nusa Tenggara about a mysterious creature. The creature was allegedly a dragon which inhabited a small island in the Lesser Sunda Islands.

The Dutch sailors reported that the creature measured up to seven metres (twenty-three feet) in length with a large body and mouth which constantly breathed fire. It burnt them and so they could not continue the investigation. It was believed then that the odd creature could fly. Hearing the reports, Lieutenant Steyn van Hensbroek, an official of the Dutch Colonial Administration in Flores, planned a trip to Komodo Island to continue the search himself. He armed himself, and accompanied by a team of soldiers, he landed on the island. After a few days, Hensbroek managed to kill one of the lizards to investigate.

Van Hensbroek took the dragon to headquarters where measurements were taken. It was approximately 2.1 metres (6.9 feet) long, with a shape very similar to that of a lizard. More samples were then photographed by Peter A. Ouwens, the Director of the Zoological Museum and Botanical Gardens in Bogor, Java. The records that Ouwens made are the first reliable documentation of details about what is now called the Komodo dragon (or Komodo monitor).

Ouwens was keen to obtain additional samples. He recruited hunters who killed two dragons measuring 3.1 metres and 3.35 metres as well as capturing two pups, each measuring less than one metre. Ouwens carried out studies on the samples and concluded that the Komodo dragon was not a flame-thrower but was a type of monitor lizard. Research results were published in 1912. Ouwens named the giant lizard Varanus komodoensis. Realizing the significance of the dragons on Komodo Island as an endangered species, the Dutch government issued a regulation on the protection of the lizards on Komodo Island in 1915.

In 1926, W. Douglas Burden, F.J. Defoisse, and Emmett Reid Dunn collected specimens for the American Museum of Natural History. Burden's chapter "The Komodo Dragon", in Look to the Wilderness, describes the expedition, the dragon's habitat and its behavior. The Komodo dragon became something of a living legend. In the decades since the Komodo was discovered, various scientific expeditions from a range of countries have carried out field research on the dragons on Komodo Island.

Komodo has a human population of over two thousand, spread out over the island and in the main Komodo village. The native population of Komodo, the Komodo people, has been extinct since the 1980s. The present day people of the island are descendants of former convicts who were exiled to Komodo and who have mixed with Bugis from Sulawesi. The population is primarily adherents of Islam but there are also Christian and Hindu congregations.

Komodo is part of the Lesser Sundas deciduous forests ecoregion. The island is also a popular destination for diving and it has been included into the controversial New7Wonders of Nature list since November 11, 2011.

Komodo contains a beach with "pink" sand, one of only seven in the world. The sand appears pink because it is a mixture of white sand combined with red sand, formed from pieces of Foraminifera. 

A Labuan Bajo is the jumping off point for trips into the UNESCO World Heritage Site of Komodo National Park, Komodo Island, Rinca Island and Komodo Island Pink Beach. Pink Beach Komodo Island can only be accessed by boat from the nearest town of Labuan Bajo.

Pink sand beaches, the sand gets is beautiful pink tint from thousands of pieces of broken red coral, shells and calcium carbonate left behind by tiny marine creatures, with red outer casings, known as foraminifera.  The broken fragments all combined with the fine, white sand to produce a unique cotton-candy coloured beach.