Moel Ysgyfarnogod is a mountain in Snowdonia, North Wales and is the northernmost of the Rhinogydd. Rhinog Fawr lies directly south, it overlooks Llyn Trawsfynydd, from the summit it is possible to see the towns of Porthmadog and Blaenau Ffestiniog. It may be climbed from Talsarnau in the west. To the north-west of the summit, on an area of moorland and rocky outcrops, lies Bryn Cader Faner, an ancient stone circle, it is one of the finest examples of a Bronze Age cairn in Britain, has rocky standing stones along its circumference. Www.geograph.co.uk: photos of Moel Ysgyfarnogod and surrounding area A Walk up Moel Ysgyfarnogod From Trawsfynydd with photos
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of small particules and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes; the particles that form a sedimentary rock are called sediment, may be composed of geological detritus or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, transported to the place of deposition by water, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and piling up on the floor of water bodies. Sedimentation may occur as dissolved minerals precipitate from water solution; the sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 8% of the total volume of the crust.
Sedimentary rocks are only a thin veneer over a crust consisting of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata; the study of sedimentary rocks and rock strata provides information about the subsurface, useful for civil engineering, for example in the construction of roads, tunnels, canals or other structures. Sedimentary rocks are important sources of natural resources like coal, fossil fuels, drinking water or ores; the study of the sequence of sedimentary rock strata is the main source for an understanding of the Earth's history, including palaeogeography and the history of life. The scientific discipline that studies the properties and origin of sedimentary rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps with other disciplines in the Earth sciences, such as pedology, geomorphology and structural geology. Sedimentary rocks have been found on Mars. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical sedimentary rocks, chemical sedimentary rocks, a fourth category for "other" sedimentary rocks formed by impacts and other minor processes.
Clastic sedimentary rocks are composed of other rock fragments that were cemented by silicate minerals. Clastic rocks are composed of quartz, rock fragments, clay minerals, mica. Clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions: gravel and mud; the classification of clastic sedimentary rocks parallels this scheme. This tripartite subdivision is mirrored by the broad categories of rudites and lutites in older literature; the subdivision of these three broad categories is based on differences in clast shape, grain size or texture. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel. Sandstone classification schemes vary but most geologists have adopted the Dott scheme, which uses the relative abundance of quartz and lithic framework grains and the abundance of a muddy matrix between the larger grains.
Composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks. All other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Quartz sandstones have >90% quartz grains Feldspathic sandstones have <90% quartz grains and more feldspar grains than lithic grains Lithic sandstones have <90% quartz grains and more lithic grains than feldspar grainsAbundance of muddy matrix material between sand grains When sand-sized particles are deposited, the space between the grains either remains open or is filled with mud. "Clean" sandstones with open pore space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes. Six sandstone names are possible using the descriptors for grain composition and the amount of matrix. For example, a quartz arenite would be composed of quartz grains and have little or no clayey matrix between the grains, a lithic wacke would have abundant lithic grains and abundant muddy matrix, etc.
Although the Dott classification scheme is used by sedimentologists, common names like greywacke and quartz sandstone are still used by non-specialists and in popular literature. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles; these fine-grained particles are transported by turbulent flow in water or air, deposited as the flow calms and the particles settle out of suspension. Most authors presently
The Rhinogydd are a range of mountains located east of Harlech in North Wales. The name Rhinogydd derives from the names of two of the more famous peaks, Rhinog Fawr and Rhinog Fach, although the greatest elevation in the range is reached by Y Llethr, 756 m. Foel Penolau, the northernmost summit of the range, was promoted to a Hewitt in 2018 due to a new survey; the Rhinogydd are notably rocky and heather-clad towards the northern end of the range around Rhinog Fawr, Rhinog Fach and towards Moel Ysgyfarnogod. The southern end, around Y Llethr and the Ysgethin Valley has a softer, grassy character. A population of feral goats are in the range. Over 30 km ² are protected as a Special Area of a National Nature Reserve; the Rhinogydd are formed of hard sedimentary rocks of Cambrian age which occur as a major anticlinal structure known to geologists as the Harlech Dome. This structure which originated during the Caledonian Orogeny extends from Cadair Idris in the south to Blaenau Ffestiniog in the north.
Its erosion by successive ice ages has left the peaks of the Rhinogydd visible today. The core of the area is formed from the hard-wearing greywackes of the Rhinog Formation; the formation contains and is overlain by some siltstones and mudstones which form a broken zone of softer scenery around the periphery of the area's rugged core. In places, swarms of dolerite dykes cut through the country rocks in a northwest-southeast direction. Much of the lower ground is mantled by a legacy of the last ice age; the geology of the area was first characterised by Adam Sedgwick and Roderick Murchison in 1835. The Geological Survey began work in the area in 1846 and their first maps were published in 1855. With the discovery of gold in the area in 1846, the state of geological knowledge increased dramatically. At least a dozen major publications appeared between 1844 and 1939; the Rhinogydd are far less well known than the areas in the north of the Snowdonia National Park, such as the Glyderau and the Snowdon massif itself.
This is due to the rugged nature of the landscape in the Rhinogydd and the fame of Snowdon as the highest peak in Wales. The Rhinog mountains are popular with hillwalkers looking for a more isolated, wilder walking experience; the peaks of the range are most accessed from the west side. Two valleys - Cwm Nantcol and Cwm Bychan - lead deep into the mountains and may be reached from the village of Llanbedr; the most popular walking route in this area begins at the Roman Steps at 52°51′16.76″N 4°0′18.43″W, which leads from Cwm Bychan through Bwlch Tyddiad and around Rhinog Fawr. Despite the name, these steps are not Roman and are in fact the well preserved remains of a medieval packhorse trail leading from Chester to Harlech Castle. At the top of the Roman Steps, the route curves around the eastern end of Rhinog Fawr and enters Cwm Nantcol via Bwlch Drws Ardudwy. A different path leads from Cwm Nantcol, passing around the western end of Rhinog Fawr back to Cwm Bychan via Gloywlyn, completing a circular route that can be completed in a day.
The range contains the following Marilyns: Y Llethr 756 m Rhinog Fawr 720 m Y Garn 629 m Moel Ysgyfarnogod 623 m Moelfre 589 mthe following Hewitts: Rhinog Fach 712 m Diffwys 750 m Foel Penolau 614 mand the following Nuttalls: Crib-y-rhiw 670 m Diffwys West Top 642 m Time Out - Wales. The new Umbria? 9 Walks in the Rhinog Mountains
Ordnance Survey is the national mapping agency of the United Kingdom which covers the island of Great Britain. Since 1 April 2015 part of Ordnance Survey has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership; the Ordnance Survey Board remains accountable to the Secretary of State for Business and Industrial Strategy. It is a member of the Public Data Group; the agency's name indicates its original military purpose, to map Scotland in the wake of the Jacobite rising of 1745. There was a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Ordnance Survey mapping is classified as either "large-scale" or "small-scale"; the Survey's large-scale mapping comprises 1:2,500 maps for 1:10,000 more generally. These large scale maps are used in professional land-use contexts and were available as sheets until the 1980s, when they were digitised. Small-scale mapping for leisure use includes the 1:25,000 "Explorer" series, the 1:50,000 "Landranger" series and the 1:250,000 road maps.
These are still available in traditional sheet form. Ordnance Survey maps remain in copyright for fifty years after their publication; some of the Copyright Libraries hold complete or near-complete collections of pre-digital OS mapping. The origins of the Ordnance Survey lie in the aftermath of the Jacobite rising of 1745, defeated by forces loyal to the government at the Battle of Culloden in 1746. Prince William, Duke of Cumberland realised that the British Army did not have a good map of the Scottish Highlands to locate Jacobite dissenters such as Simon Fraser, 11th Lord Lovat so that they could be put on trial. In 1747, Lieutenant-Colonel David Watson proposed the compilation of a map of the Highlands to help to subjugate the clans. In response, King George II charged Watson with making a military survey of the Highlands under the command of the Duke of Cumberland. Among Watson's assistants were William Roy, Paul Sandby and John Manson; the survey was produced at a scale of 1 inch to 1000 yards and included "the Duke of Cumberland's Map", now held in the British Library.
Roy had an illustrious career in the Royal Engineers, rising to the rank of General, he was responsible for the British share of the work in determining the relative positions of the French and British royal observatories. This work was the starting point of the Principal Triangulation of Great Britain, led to the creation of the Ordnance Survey itself. Roy's technical skills and leadership set the high standard. Work was begun in earnest in 1790 under Roy's supervision, when the Board of Ordnance began a national military survey starting with the south coast of England. Roy's birthplace near Carluke in South Lanarkshire is today marked by a memorial in the form of a large OS trig point. By 1791 the Board received the newer Ramsden theodolite, work began on mapping southern Great Britain using a five-mile baseline on Hounslow Heath that Roy himself had measured. In 1991 Royal Mail marked the bicentenary by issuing a set of postage stamps featuring maps of the Kentish village of Hamstreet. In 1801 the first one-inch-to-the-mile map was published, detailing the county of Kent, with Essex following shortly afterwards.
The Kent map was published and stopped at the county border, while the Essex maps were published by Ordnance Survey and ignore the county border, setting the trend for future Ordnance Survey maps. In the next 20 years about a third of England and Wales was mapped at the same scale under the direction of William Mudge, as other military matters took precedence, it took until 1823 to re-establish a relationship with the French survey made by Roy in 1787. By 1810 one inch to the mile maps of most of the south of England were completed, but they were withdrawn from sale between 1811 and 1816 because of security fears. By 1840 the one-inch survey had covered all of Wales and all but the six northernmost counties of England, it was hard work: Major Thomas Colby, the longest-serving Director General of Ordnance Survey, walked 586 miles in 22 days on a reconnaissance in 1819. In 1824, Colby and most of his staff moved to Ireland to work on a six-inches-to-the-mile valuation survey; the survey of Ireland, county by county, was completed in 1846.
The suspicions and tensions it caused in rural Ireland are the subject of Brian Friel's play Translations. Colby was not only involved in the design of specialist measuring equipment, he established a systematic collection of place names, reorganised the map-making process to produce clear, accurate plans. Place names were recorded in "Name Books", a system first used in Ireland; the instructions for their use were: The persons employed on the survey are to endeavour to obtain the correct orthography of the names of places by diligently consulting the best authorities within their reach. The name of each place is to be inserted as it is spelt, in the first column of the name book and the various modes of spelling it used in books, writings &c. are to be inserted in the second column, with the authority placed in the third column opposite to each. Whilst these procedures produced excellent results, mistakes were made: for instance, the Pilgrims Way in the North Downs labelled the wrong route
Calluna vulgaris is the sole species in the genus Calluna in the flowering plant family Ericaceae. It is a low-growing perennial shrub growing to 20 to 50 centimetres tall, or to 1 metre and taller, is found in Europe and Asia Minor on acidic soils in open sunny situations and in moderate shade, it is the dominant plant in most heathland and moorland in Europe, in some bog vegetation and acidic pine and oak woodland. It is tolerant of grazing and regenerates following occasional burning, is managed in nature reserves and grouse moors by sheep or cattle grazing, by light burning. Calluna was separated from the related genus Erica by Richard Anthony Salisbury, who devised the generic name Calluna from the Greek Kallyno, "beautify, sweep clean", in reference to its traditional use in besoms; the specific epithet vulgaris is Latin for'common'. Calluna is differentiated from Erica by its corolla and calyx each being in four parts instead of five. Calluna has small scale-leaves borne in opposite and decussate pairs, whereas those of Erica are larger and in whorls of 3-4, sometimes 5.
The flowers emerge in late summer. They are terminal in racemes with sepal-like bracts at the base with a superior ovary, the fruit a capsule. Unlike Erica, Calluna sometimes sports double flowers. Calluna is sometimes referred to as Summer heather to distinguish it from winter or spring flowering species of Erica. Calluna is native to Europe, the Faroe Islands, the Azores, it has been introduced into many other places worldwide with suitable climates, including North America, New Zealand and the Falkland Islands. Despised until the 19th century for its associations with the most rugged rural poverty, heather's growth in popularity may be paralleled with the vogue for alpine plants, it is a popular ornamental plant in gardens and for landscaping, in lime-free areas where it will thrive, but has defeated many a gardener on less acid soil. There are many named cultivars, selected for variation in flower colour and for different foliage colour and growing habits. Different cultivars have flower colours ranging from white, through pink and a wide range of purples, including reds.
The flowering season with different cultivars extends from late July to November in the northern hemisphere. The flowers may turn brown but still remain on the plants over winter, this can lead to interesting decorative effects. Cultivars with ornamental foliage are selected for reddish and golden leaf colour. A few forms can be silvery grey. Many of the ornamental foliage forms change colour with the onset of winter weather increasing in intensity of colour; some forms are grown for distinctive young spring foliage. Cultivars include ‘Beoley Crimson’, ‘Boskoop’, ‘Cuprea’,'Firefly',‘Long White’; the following cultivars have gained the Royal Horticultural Society's Award of Garden Merit: Heather is an important food source for various sheep and deer which can graze the tips of the plants when snow covers low-growing vegetation. Willow grouse and red grouse feed on the young seeds of this plant. Both adult and larva of the heather beetle feed on it, can cause extensive mortality in some instances.
The larvae of a number of Lepidoptera species feed on the plant, notably the small emperor moth Saturnia pavonia. Heather was used to dye wool yellow and to tan leather. With malt, heather is an ingredient in gruit, a mixture of flavourings used in the brewing of heather-beer during the Middle Ages before the use of hops. Thomas Pennant wrote in A Tour in Scotland that on the Scottish island of Islay "ale is made of the young tops of heath, mixing two thirds of that plant with one of malt, sometimes adding hops". From time immemorial heather has been used for making besoms, a practice recorded in "Buy Broom Buzzems" a song written by William Purvis from Newcastle-upon-Tyne, England. Heather honey is a valued product in moorland and heathland areas, with many beehives being moved there in late summer. Not always as valued as it is today, it was dismissed as mel improbum by Dioscurides. Heather honey has a characteristic strong taste, an unusual texture, for it is thixotropic, being a jelly until stirred, when it becomes a syrup like other honey, but sets again to a jelly.
This makes the extraction of the honey from the comb difficult, it is therefore sold as comb honey. White heather is regarded in Scotland as being lucky, a tradition brought from Balmoral to England by Queen Victoria and sprigs of it are sold as a charm and worked into bridal bouquets. Heather stalks are used by a small industry in Scotland as a raw material for sentimental jewellery; the stalks are stripped of bark, dyed in bright colours and compressed with resin. Calluna vulgaris herb has been used in the traditional Austrian medicine internally as tea for treatment of disorders of the kidneys and urinary tract; the plant was introduced to New Zealand and has become an invasive weed in some areas, notably the Tongariro National Park in the North Island and the Wilderness Reserve in the South Island, overgrowing native plants. Heather beetles have been released to stop the heather, with preliminary trials successful to date; the shoots of Calluna vulgaris contain the phenolic compounds chlorogenic acid, its 3-O-glucoside, 3-O-galactoside and 3-O-arabinoside.
Heather is seen as iconic of Scotland. When poems like
Y Llethr is the highest mountain in the Rhinogydd range of Snowdonia, in north Wales. The summit consists of a flat grassy top marked only by a small cairn; the summit is more in keeping with its southern flanks than its rugged northern approach. The shortest route to the summit goes from the valley of Cwm Nantcol in the west, either directly or via Bwlch Drws Ardudwy and over the mountain of Rhinog Fach. To the south lies the mountain of Diffwys, to the south-east lies the mountain of Y Garn, to the north lies Rhinog Fach and to the west lies the hill of Moelfre
A mountain is a large landform that rises above the surrounding land in a limited area in the form of a peak. A mountain is steeper than a hill. Mountains are formed through tectonic forces or volcanism; these forces can locally raise the surface of the earth. Mountains erode through the action of rivers, weather conditions, glaciers. A few mountains are isolated summits. High elevations on mountains produce colder climates than at sea level; these colder climates affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains tend to be used less for agriculture and more for resource extraction and recreation, such as mountain climbing; the highest mountain on Earth is Mount Everest in the Himalayas of Asia, whose summit is 8,850 m above mean sea level. The highest known mountain on any planet in the Solar System is Olympus Mons on Mars at 21,171 m. There is no universally accepted definition of a mountain.
Elevation, relief, steepness and continuity have been used as criteria for defining a mountain. In the Oxford English Dictionary a mountain is defined as "a natural elevation of the earth surface rising more or less abruptly from the surrounding level and attaining an altitude which to the adjacent elevation, is impressive or notable."Whether a landform is called a mountain may depend on local usage. Mount Scott outside Lawton, Oklahoma, USA, is only 251 m from its base to its highest point. Whittow's Dictionary of Physical Geography states "Some authorities regard eminences above 600 metres as mountains, those below being referred to as hills." In the United Kingdom and the Republic of Ireland, a mountain is defined as any summit at least 2,000 feet high, whilst the official UK government's definition of a mountain, for the purposes of access, is a summit of 600 metres or higher. In addition, some definitions include a topographical prominence requirement 100 or 500 feet. At one time the U.
S. Board on Geographic Names defined a mountain as being 1,000 feet or taller, but has abandoned the definition since the 1970s. Any similar landform lower. However, the United States Geological Survey concludes that these terms do not have technical definitions in the US; the UN Environmental Programme's definition of "mountainous environment" includes any of the following: Elevation of at least 2,500 m. Using these definitions, mountains cover 33% of Eurasia, 19% of South America, 24% of North America, 14% of Africa; as a whole, 24% of the Earth's land mass is mountainous. There are three main types of mountains: volcanic and block. All three types are formed from plate tectonics: when portions of the Earth's crust move and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features; the height of the feature makes it either a hill or, if steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.
Volcanoes are formed when a plate is pushed at a mid-ocean ridge or hotspot. At a depth of around 100 km, melting occurs in rock above the slab, forms magma that reaches the surface; when the magma reaches the surface, it builds a volcanic mountain, such as a shield volcano or a stratovolcano. Examples of volcanoes include Mount Pinatubo in the Philippines; the magma does not have to reach the surface in order to create a mountain: magma that solidifies below ground can still form dome mountains, such as Navajo Mountain in the US. Fold mountains occur when two plates collide: shortening occurs along thrust faults and the crust is overthickened. Since the less dense continental crust "floats" on the denser mantle rocks beneath, the weight of any crustal material forced upward to form hills, plateaus or mountains must be balanced by the buoyancy force of a much greater volume forced downward into the mantle, thus the continental crust is much thicker under mountains, compared to lower lying areas.
Rock can fold either asymmetrically. The upfolds are anticlines and the downfolds are synclines: in asymmetric folding there may be recumbent and overturned folds; the Balkan Mountains and the Jura Mountains are examples of fold mountains. Block mountains are caused by faults in the crust: a plane; when rocks on one side of a fault rise relative to the other, it can form a mountain. The uplifted blocks are block horsts; the intervening dropped blocks are termed graben: these can be small or form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range Province of Western North America and the Rhine valley; these areas occur when the regional stress is extensional and the crust is thinned. During and following uplift, mountains are subjected to the agents of erosion which wear the uplifted area down. Erosion causes the surface of mountains to be younger than the rocks that form the mountains themselves. Glacial processes produce characteristic landforms, such as pyramidal peaks, knife-edge arêtes, bowl-shaped cirques that can contai