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Gray Hill, Monmouthshire
Gray Hill ( cy, Mynydd Llwyd) is a hill immediately to the north of the village of Llanvair Discoed, Monmouthshire, South Wales, rising to above sea level. Location Gray Hill is on the eastern side of Wentwood Reservoir opposite Mynydd Alltir Fach which sits on the western side of the reservoir. Wentwood rises behind these two hills. The nearest large village or town is Caerwent. The summit of the hill has views over the Caldicot Levels and Severn estuary, as well as inland. Geology Geologically the hill forms a detached part of a longer north and west-facing sandstone scarp which runs roughly northeast through Monmouthshire from Llandevaud to the Wye valley south of Monmouth. Gray Hill is formed from various sandstones of the Old Red Sandstone (or 'ORS') which were laid down during the Devonian period. The northern and western slopes and the lower southern slopes are formed by the lower ORS Brownstones Formation. Unconformably overlying these rocks are the upper ORS Qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sept08gh2 025
A sept is a division of a family, especially of a Scottish or Irish family. The term is used in both Scotland and Ireland, where it may be translated as ''sliocht'', meaning "progeny" or "seed", which may indicate the descendants of a person (for example, ''Sliocht Bhriain Mhic Dhiarmada'', "the descendant of Brian MacDermott"). The word may derive from the Latin ''saeptum'', meaning "enclosure" or "fold", or via an alteration of "sect". Family branches ''Síol'' is a Gaelic word meaning "progeny" or "seed" that is used in the context of a family or clan with members who bear the same surname and inhabited the same territory,"Septs of Ireland" Irish Septs Association. as a manner of distinguishing one group from another; a family called ''Mac an Bháird'' ( |
Old Red Sandstone
The Old Red Sandstone is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the northeastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the ancient continent of Euramerica, Euramerica/Laurussia. In Britain it is a lithostratigraphy, lithostratigraphic unit (a sequence of rock strata) to which Stratigraphy, stratigraphers accord Geological unit#Lithostratigraphic units, supergroup status and which is of considerable importance to early paleontology. For convenience the short version of the term, ORS is often used in literature on the subject. The term was coined to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain. Sedimentology The Old Red Sandstone describes a suite of sedimentary rocks deposited in a variety of environments during the Devonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medieval
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern history, modern period. The medieval period is itself subdivided into the Early Middle Ages, Early, High Middle Ages, High, and Late Middle Ages. Population decline, counterurbanisation, the collapse of centralized authority, invasions, and mass migrations of tribes, which had begun in late antiquity, continued into the Early Middle Ages. The large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze Age
The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second principal period of the three-age system proposed in 1836 by Christian Jürgensen Thomsen for classifying and studying ancient societies and history. An ancient civilization is deemed to be part of the Bronze Age because it either produced bronze by smelting its own copper and alloying it with tin, arsenic, or other metals, or traded other items for bronze from production areas elsewhere. Bronze is harder and more durable than the other metals available at the time, allowing Bronze Age civilizations to gain a technological advantage. While terrestrial iron is naturally abundant, the higher temperature required for smelting, , in addition to the greater difficulty of working with the metal, placed it out of reach of common use until the end o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neolithic
The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of settlement. It began about 12,000 years ago when farming appeared in the Epipalaeolithic Near East, and later in other parts of the world. The Neolithic lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BC), marked by the development of metallurgy, leading up to the Bronze Age and Iron Age. In other places the Neolithic followed the Mesolithic (Middle Stone Age) and then lasted until later. In Ancient Egypt, the Neolithic lasted until the Protodynastic period, 3150 BC.Karin Sowada and Peter Grave. Egypt in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severn Estuary
The Severn Estuary ( cy, Aber Hafren) is the estuary of the River Severn, flowing into the Bristol Channel between South West England and South Wales. Its high tidal range, approximately , means that it has been at the centre of discussions in the UK regarding renewable energy. Geography Definitions of the limits of the Severn Estuary vary. At the upstream boundary, the tidal limit of the river is at Gloucester. Downstream, the International Hydrographic Organization places the boundary between the estuary and the open sea of the Bristol Channel at a line between Sand Point, Somerset (immediately north of Weston-super-Mare) and Lavernock Point (immediately south of Penarth in south Wales). This definition is used by the Severn Estuary Partnership and Visit England. A narrower definition adopted for navigation purposes by some maps includes only the area downstream of the Second Severn Crossing near Severn Beach, South Gloucestershire. The definition used on Admiralty Chart SC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stone Circle
A stone circle is a ring of standing stones. Most are found in Northwestern Europe – especially in Britain, Ireland, and Brittany – and typically date from the Late Neolithic and Early Bronze Age, with most being built from 3000 BC. The best known examples include those at the henge monument at Avebury, the Rollright Stones, and elements within the ring of standing stones at Stonehenge. Scattered examples exist from other parts of Europe. Later, during the Iron Age, stone circles were built in southern Scandinavia. Stone circles are usually grouped in terms of the shape and size of the stones, the span of their radius, and their population within the local area. Although many theories have been advanced to explain their use, usually related to providing a setting for ceremony or ritual, no consensus exists among archaeologists regarding their intended function. Their construction often involved considerable communal effort, including specialist tasks such as planning, quar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standing Stone
A menhir (from Brittonic languages: ''maen'' or ''men'', "stone" and ''hir'' or ''hîr'', "long"), standing stone, orthostat, or lith is a large human-made upright rock (geology), stone, typically dating from the European middle Bronze Age. They can be found individually as monoliths, or as part of a group of similar stones. Menhirs' size can vary considerably, but they often taper toward the top. They are widely distributed across Europe, Africa and Asia, but are most numerous in Western Europe; particularly in Ireland, Great Britain, and Brittany, where there are about 50,000 examples, and northwestern France, where there are some 1,200 further examples. Standing stones are usually difficult to date. They were constructed during many different periods across pre-history as part of the larger megalithic cultures in Europe and near areas. Some menhirs stand next to buildings that have an early or current religious significance. One example is the South Zeal Menhir in Devon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval of geologic time not represented is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-bearing sandstone can be changed into quartzite through metamorphism, usually related to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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