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Gibson Knott
Gibson Knott is a fell in the English Lake District, an intermediate height on the ridge between Greenburn and Far Easedale in the Central Fells. Topography The spine of the Central Fells runs on a north-south axis with the highpoint at High Raise. A complex system of daleheads to the east of this apex resolves itself into Calf Crag, a broad-topped ridge featuring a number of rocky tops. This ridge then splits into two arms about the head of Greenburn, the southern branch running on to Gibson Knott and Helm Crag. Between Calf Crag and Helm Crag the ridge narrows to perhaps a hundred yards in width, gradually curving to the south east on its one and a half mile course. There are several tops on this section, Gibson Knott being halfway along. The southern face above Far Easedale is rocky, Horn Crag being the principal feature. The northern side drops more gradually to the upper gathering grounds of Greenburn Bottom. There is little loss of height going westward from the summ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helm Crag
Helm Crag is a fell in the English Lake District situated in the Central Fells to the north of Grasmere. Despite its low height it sits prominently at the end of a ridge, easily seen from the village. This, combined with the distinctive summit rocks which provide the alternative name 'The Lion and the Lamb', makes it one of the most recognised hills in the District. Alfred Wainwright wrote of Helm Crag that "The virtues of Helm Crag have not been lauded enough. It gives an exhilarating little climb, a brief essay in real mountaineering, and, in a region where all is beautiful, it makes a notable contribution to the natural charms and attractions of Grasmere."A. Wainwright, ''A Pictorial Guide to the Lake Fells, Book 3, The Central Fells'', (London: Frances Lincoln, 2003), Helm Crag p.2 Topography A rocky ridge curves east and then south east from Calf Crag, passing over Gibson Knott and the depression of Bracken Hause, before ending at Helm Crag where it falls steeply on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcaniclastic
Volcaniclastics are geologic materials composed of broken fragments (clasts) of volcanic rock. These encompass all clastic volcanic materials, regardless of what process fragmented the rock, how it was subsequently transported, what environment it was deposited in, or whether nonvolcanic material is mingled with the volcanic clasts. The United States Geological Survey defines volcaniclastics somewhat more narrowly, to include only rock composed of volcanic rock fragments that have been transported some distance from their place of origin. In the broad sense of the term, volcaniclastics includes pyroclastic rocks such as the Bandelier Tuff; cinder cones and other tephra deposits; the basal and capping breccia that characterize ʻaʻā lava flows; and lahars and debris flows of volcanic origin.Vincent 2000, pp.27-28 Volcaniclastics make up more of the volume of many volcanoes than do lava flows. Volcaniclastics may have contributed as much as a third of all sedimentation in the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cairn
A cairn is a man-made pile (or stack) of stones raised for a purpose, usually as a marker or as a burial mound. The word ''cairn'' comes from the gd, càrn (plural ). Cairns have been and are used for a broad variety of purposes. In prehistoric times, they were raised as markers, as memorials and as burial monuments (some of which contained chambers). In modern times, cairns are often raised as landmarks, especially to mark the summits of mountains. Cairns are also used as trail markers. They vary in size from small stone markers to entire artificial hills, and in complexity from loose conical rock piles to elaborate megalithic structures. Cairns may be painted or otherwise decorated, whether for increased visibility or for religious reasons. A variant is the inuksuk (plural inuksuit), used by the Inuit and other peoples of the Arctic region of North America. History Europe The building of cairns for various purposes goes back into prehistory in Eurasia, ranging in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, ''tuffaceous sandstone''). Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa in guidebooks and in television programmes. Volcanic ash The material that is expelled in a volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lapilli
Lapilli is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. ''Lapilli'' (singular: ''lapillus'') is Latin for "little stones". By definition lapilli range from in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material with particles less than 2 mm in diameter is referred to as volcanic ash. Formation Lapilli are spheroid-, teardrop-, dumbbell- or button-shaped droplets of molten or semi-molten lava ejected from a volcanic eruption that fall to earth while still at least partially molten. These granules are not accretionary, but instead the direct result of liquid rock cooling as it travels through the air. Lapilli tuffs are a very common form of volcanic rock typical of rhyolite, andesite and dacite pyroclastic eruptions, where thick layers of lapilli can be deposited during a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dacitic
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz. Dacite is relatively common, occurring in many tectonic settings. It is associated with andesite and rhyolite as part of the subalkaline tholeiitic and calc-alkaline magma series. Composition Dacite consists mostly of plagioclase feldspar and quartz with biotite, hornblende, and pyroxene ( augite or enstatite). The quartz appears as rounded, corroded phenocrysts, or as an element of the ground-mass. The plagioclase in dacite ranges from oligoclase to andesine and labradorite. Sanidine occurs, although in small proportions, in some dacites, and when abundant gives rise to rocks that form transitions to the rhyolites. The relative proportions of feldspars and quartz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, pp.381-382 Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock ( clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is defined a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claystone
Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone, slate, and shale. Most of the particles of which the stone is composed are less than and are too small to study readily in the field. At first sight, the rock types appear quite similar; however, there are important differences in composition and nomenclature. There has been a great deal of disagreement involving the classification of mudrocks. A few important hurdles to their classification include the following: # Mudrocks are the least understood and among the most understudied sedimentary rocks to date. # Studying mudrock constituents is difficult due to their diminutive size and susceptibility to weathering on outcrops. # And most importantly, scientists accept more than one classification scheme. Mudrocks make up 50% of the sedimentary rocks in the geologic record and are easily the most widespread deposits on Earth. Fine sedimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calf Crag
Calf Crag is a fell in the English Lake District, on the eastern side of the High Raise massif. Topography The spine of the Central Fells runs on a north–south axis with the high point at High Raise. A complex system of daleheads to the east of this apex resolves itself into Calf Crag, a broad-topped ridge featuring a number of rocky tops. Calf Crag is bounded by Wythburndale to the north and by its upper gathering grounds to the west. Far Easedale lies to the south while the head of Greenburn forms the eastern face, both of these sides being craggy. The Wyth Burn flows north east into Thirlmere while Far Easedale Gill and Green Burn descend to the River Rothay and ultimately to Windermere. Calf Crag thus stands on the main north-south watershed of the Lakeland Fells. The summit plateau, about a mile across, sends two narrow eastern ridges to the north and south of Greenburn Bottom. The former leads to Steel Fell, while the southern spur passes over Gibson Knott before endi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Wainwrights
Wainwrights are the 214 English peaks (known locally as ''fells'') described in Alfred Wainwright's seven-volume ''Pictorial Guide to the Lakeland Fells'' (1955–66). They all lie within the boundary of the Lake District National Park in Cumbria, and all but one (Castle Crag) are over in height. Over two million copies of the ''Pictorial Guides'' have been sold since their publication. In 1974, Wainwright published a supplementary volume ''The Outlying Fells of Lakeland'' (1974), which includes another 116 summits (described in 56 walks); these are the Wainwright Outlying Fells. Summiting all of the Wainwrights is a popular form of peak bagging in the Lake District, along with the Birketts. Because both lists are based on historical books, unlike, for example, the Munros, their constituents remain fixed, regardless of revisions to height or other metrics. In this regard, they are similar to the Scottish lowlands, Donalds. There are 214 Wainwrights, of which 209 are also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Raise (Langdale)
High Raise is a fell in the Central Fells of the English Lake District, not to be confused with another High Raise situated in the Far Eastern Fells. High Raise is one of the most spectacular mountains in the district; with a height of 762 metres (2,500 ft) it is the highest point in the central fells of Lakeland. High Raise is in fact commonly regarded as the most central mountain in the district and this position gives a fine viewpoint to admire the surrounding mountains and beyond. All of England's 3,000-foot (914 m) mountains (Skiddaw, Helvellyn and the Scafells) can be well seen from the summit while the more distant views include the Three Peaks in the Yorkshire Dales (37 miles / 60 km) and Morecambe Bay (25 miles / 40 km). Summit The summit itself, which is also known as High White Stones due to a smattering of grey boulders in the vicinity of the highest point, has an Ordnance Survey column and a large cairn which also doubles as a wind sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fell
A fell (from Old Norse ''fell'', ''fjall'', "mountain"Falk and Torp (2006:161).) is a high and barren landscape feature, such as a mountain or Moorland, moor-covered hill. The term is most often employed in Fennoscandia, Iceland, the Isle of Man, parts of northern England, and Scotland. Etymology The English word "fell" comes from Old Norse ''fell'' and ''fjall'' (both forms existed). It is cognate with Danish language, Danish ''fjeld'', Faroese language, Faroese ''fjall'' and ''fjøll'', Icelandic language, Icelandic ''fjall'' and ''fell'', Norwegian language, Norwegian ''fjell'' with Norwegian dialects, dialects ''fjøll'', ''fjødd'', ''fjedd'', ''fjedl'', ''fjill'', ''fil(l)'', and ''fel'', and Swedish language, Swedish ''fjäll'', all referring to mountains rising above the Tree line, alpine tree line.Bjorvand and Lindeman (2007:270–271). British Isles In northern England, especially in the Lake District and in the Pennines, Pennine Dale (origin), Dales, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
