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Lewisian Complex
The Lewisian complex or Lewisian gneiss is a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane and the North Atlantic Craton. These rocks are of Archaean and Paleoproterozoic age, ranging from 3.0–1.7 billion years ( Ga). They form the basement on which the Torridonian and Moine Supergroup sediments were deposited. The Lewisian consists mainly of granitic gneisses with a minor amount of supracrustal rocks. Rocks of the Lewisian complex were caught up in the Caledonian orogeny, appearing in the hanging walls of many of the thrust faults formed during the late stages of this tectonic event. Distribution The main outcrops of the Lewisian complex are on the islands of the Outer Hebrides, including Lewis, from which the complex takes its name. It is also exposed on several islands of the Inner Hebrides, small islands north of the Scottish mainland and forms a coastal strip on the mainland from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular ''klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is referred to as a ''blind thrust'' fault. Because of the lack of surface evidence, blind thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhinns Complex
The Rhinns complex is a deformed Palaeoproterozoic igneous complex that is considered to form the basement to the Colonsay Group of metasedimentary rocks. The largest outcrop of the complex is on the Rhinns of Islay, from where the complex gets its name. It has also been recognised in three other inliers extending to the southwest as far as Inishtrahull, off the north coast of Donegal. Distribution The Rhinns complex has been recognised in a series of four outcrops that form inliers within younger cover sequences of the Dalradian Supergroup and the Colonsay Group. The most easterly of these exposures is on the islands of Colonsay, where the complex consists of strongly retrogressed orthogneisses, although the correlation of this outcrop with the Rhinns complex has been questioned on the basis of new radiometric dating and Hf isotope analyses. On the Rhinns of Islay, gneisses of the Rhinns complex lie unconformably beneath the Colonsay Group, which is correlated with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Glen Fault
The Great Glen Fault is a strike-slip fault that runs through the Great Glen in Scotland. The fault is mostly inactive today, but occasional moderate tremors have been recorded over the past 150 years. Location Aligned northeast to southwest, the Great Glen Fault extends further southwest in a straight line through Loch Linnhe and the Firth of Lorne, and then on into northwestern Ireland, directly through Lough Swilly, Donegal Bay and Clew Bay as the Leannan Fault. To the northeast the fault connects to the Walls Boundary Fault and the associated Melby Fault and Nestings Fault, before becoming obscured by the effects of Mesozoic rifting to the north of Shetland. The fault continues on the North American side of the North Atlantic Ocean, but is no longer part of a contiguous fault, as the complete fault was broken when the Mid-Atlantic Ridge formed 200 million years ago. The North American side of the fault runs through the length of northwestern Newfoundland, Canada, as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocarbon Exploration
Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particularly petroleum and natural gas, in the Earth using petroleum geology. Exploration methods Visible surface features such as oil seeps, natural gas seeps, pockmarks (underwater craters caused by escaping gas) provide basic evidence of hydrocarbon generation (be it shallow or deep in the Earth). However, most exploration depends on highly sophisticated technology to detect and determine the extent of these deposits using exploration geophysics. Areas thought to contain hydrocarbons are initially subjected to a gravity survey, magnetic survey, passive seismic or regional seismic reflection surveys to detect large-scale features of the sub-surface geology. Features of interest (known as ''leads'') are subjected to more detailed seismic surveys which work on the principle of the time it takes for reflected sound waves to travel thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Of The Hebrides
The Sea of the Hebrides ( gd, An Cuan Barrach, ) is a small, partly sheltered section of the North Atlantic Ocean, indirectly off the southern part of the north-west coast of Scotland. To the east are the mainland of Scotland and the northern Inner Hebrides (including Skye and the Small Isles); to the west are the southern Outer Hebrides islands, principally South Uist, Eriskay, and Barra. To the north is the Little Minch, a channel connecting it with the Minch. The Sea of the Hebrides forms part of the Inner Seas off the West Coast of Scotland, as defined by the International Hydrographic Organization, and part of the Seas west of Scotland as far as fisheries management is concerned. Ending on 30 August 2019, the Scottish Government consulted on a proposal to designate the Sea of the Hebrides a Marine Protected Area (MPA). The designation was confirmed in December 2020. The designated area of the MPA covers , mainly to protect the area's population of basking shar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minches
The Minch ( gd, An Cuan Sgitheanach, ', ', '), also called North Minch, is a strait in north-west Scotland, separating the north-west Highlands and the northern Inner Hebrides from Lewis and Harris in the Outer Hebrides. It was known as ("Scotland's fjord/firth") in Old Norse. The Lower Minch (), also known as the Little Minch, is the Minch's southern extension, separating Skye from the lower Outer Hebrides: North Uist, Benbecula, South Uist, Barra etc. It opens into the Sea of the Hebrides. The Little Minch is the northern limit of the Sea of the Hebrides. Geography The Minch and Lower Minch form part of the Inner Seas off the West Coast of Scotland, as defined by the International Hydrographic Organization. The Minch ranges from wide and is approximately long. It is believed to be the site of the biggest meteorite ever to hit the British Isles. The Lower Minch is about wide. In June 2010 Eilidh Macdonald became the first person to swim across it from Waternish Poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shetland
Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the northeast of Orkney, from mainland Scotland and west of Norway. They form part of the border between the Atlantic Ocean to the west and the North Sea to the east. Their total area is ,Shetland Islands Council (2012) p. 4 and the population totalled 22,920 in 2019. The islands comprise the Shetland constituency of the Scottish Parliament. The local authority, the Shetland Islands Council, is one of the 32 council areas of Scotland. The islands' administrative centre and only burgh is Lerwick, which has been the capital of Shetland since 1708, before which time the capital was Scalloway. The archipelago has an oceanic climate, complex geology, rugged coastline, and many low, rolling hills. The largest island, known as " the Mainland", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Wrath
Cape Wrath ( gd, Am Parbh, known as ' in Lewis) is a cape in the Durness parish of the county of Sutherland in the Highlands of Scotland. It is the most north-westerly point in mainland Britain. The cape is separated from the rest of the mainland by the Kyle of Durness and consists of of moorland wilderness known as the Parph. The first road was built in 1828 by the lighthouse commission across the Parph/Durness. This road connects a passenger ferry that crosses the Kyle of Durness with the buildings on the peninsula. Much of the cape is owned by the Ministry of Defence and is used as a military training area, including as live firing range. Areas of it are also designated as a Site of Special Scientific Interest, a Special Protection Area, a Special Area of Conservation and a Special Landscape Area. Etymology The name Cape Wrath is derived from Old Norse ' ("turning point"), accordingly, ''wrath'' is pronounced (''a'' as in ''cat''), [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loch Torridon
Loch Torridon ( gd, Loch Thoirbheartan) is a sea loch on the west coast of Scotland in the Northwest Highlands. The loch was created by glacial processes and is in total around 15 miles (25 km) long. It has two sections: Upper Loch Torridon to landward, east of Rubha na h-Airde Ghlaise, at which point it joins Loch Sheildaig; and the main western section of Loch Torridon proper. Loch a' Chracaich and Loch Beag are small inlets on the southern shores of the outer Loch, which joins the Inner Sound between the headlands of Rubha na Fearna to the south and Red Point to the north. The name ''Thoirbhearta'' has a similar root to '' Tarbert'' and indicates a place where boats were dragged overland. Islands The islets in the loch include: * in Loch Shieldaig: Eilean an Inbhire Bhàin, Eilean Dùghaill and Shieldaig Island. * in Upper Loch Torridon: Eilean à Chaoil, Eilean Cnapach, both of which are tidal. * in outer Loch Torridon: Eilean Mòr, Eilean Tioram, Sgeir Ghlas, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Hebrides
The Inner Hebrides (; Scottish Gaelic: ''Na h-Eileanan a-staigh'', "the inner isles") is an archipelago off the west coast of mainland Scotland, to the south east of the Outer Hebrides. Together these two island chains form the Hebrides, which experience a mild oceanic climate. The Inner Hebrides comprise 35 inhabited islands as well as 44 uninhabited islands with an area greater than . Skye, Mull, and Islay are the three largest, and also have the highest populations. The main commercial activities are tourism, crofting, fishing and whisky distilling. In modern times the Inner Hebrides have formed part of two separate local government jurisdictions, one to the north and the other to the south. Together, the islands have an area of about , and had a population of 18,948 in 2011. The population density is therefore about . There are various important prehistoric structures, many of which pre-date the first written references to the islands by Roman and Greek authors. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isle Of Lewis
The Isle of Lewis ( gd, Eilean Leòdhais) or simply Lewis ( gd, Leòdhas, ) is the northern part of Lewis and Harris, the largest island of the Western Isles or Outer Hebrides archipelago in Scotland. The two parts are frequently referred to as if they were separate islands. The total area of Lewis is . Lewis is, in general, the lower-lying part of the island: the other part, Harris, is more mountainous. Due to its larger area and flatter, more fertile land, Lewis contains three-quarters of the population of the Western Isles, and the largest settlement, Stornoway. The island's diverse habitats are home to an assortment of flora and fauna, such as the golden eagle, red deer and seal, and are recognised in a number of conservation areas. Lewis has a Presbyterian tradition and a rich history. It was once part of the Norse Kingdom of the Isles. Today, life is very different from elsewhere in Scotland, with Sabbath observance, the Scottish Gaelic language and peat cutting re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
