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Sgurr Beag Thrust
The Sgurr Beag Thrust is an important tectonic structure within the Neoproterozoic metasedimentary rock sequences of the Scottish Highlands. The thrust, or similar structures correlated with it, form the boundary between rocks of the Glennfinnan Group and the underlying Morar Group. It divides the Wester Ross Supergroup from the Loch Ness Supergroup. The history of this structure remains poorly understood although it is thought to be at least partly of Caledonian age. Extent The Sgurr Beag Thrust was identified as a zone of high strain in the western part of the Highlands and was originally called the "Sgurr Beag Slide". It is currently interpreted to extend from the Morvern peninsula in the southwest (with a possible extension onto the Isle of Mull), to the Dornoch Firth where it disappears beneath the Old Red Sandstone. It is often marked by the presence of inliers of Lewisian basement, which are found in its hanging-wall (structurally above the fault plane). In eastern Suthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonic
Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that constitute the Earth's outer shell interact with each other. Tectonics also provide a framework for understanding the earthquake and volcanic belts that directly affect much of the global population. Tectonic studies are important as guides for economic geologists searching for fossil fuels and ore deposits of metallic and nonmetallic resources. An understanding of tectonic principles is essential to geomorphologists to explain erosion patterns and other Earth surface features. Main types of tectonic regime Extensional tectonics Extensional tectonics is associated with the stretching and thinning of the crust or the lithosphere. This type of tectonics is fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isle Of Mull
The Isle of Mull ( gd, An t-Eilean Muileach ) or just Mull (; gd, Muile, links=no ) is the second-largest island of the Inner Hebrides (after Skye) and lies off the west coast of Scotland in the council area of Argyll and Bute. Covering , Mull is the fourth-largest island in Scotland and Great Britain. From 2001 to 2020, the population has gradually increased: during 2020 the populace was estimated to be 3,000, in the 2011 census it was approximately 2,800, and in 2001, it was measured at 2,667 people. It has the eighth largest Island population in Scotland. In the summer, these numbers are augmented by an influx of many tourists. Much of the year-round population lives in the colourful main settlement of Tobermory. There are two distilleries on the island: the Tobermory distillery, formerly named Ledaig, produces single malt Scotch whisky and another, opened in 2019 and located in the vicinity of Tiroran, which produces Whitetail Gin. Mull is host to numerous sport ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Devonian
The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonian series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, which lasted until the Middle Devonian began, . During this time, the first ammonoids appeared, descending from bactritoid nautiloids. Ammonoids during this time period were simple and differed little from their nautiloid counterparts. These ammonoids belong to the order Agoniatitida, which in later epochs evolved to new ammonoid orders, for example Goniatitida and Clymeniida. This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ... Era. Reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grampian Orogeny
The Caledonian orogeny was a mountain-building era recorded in the northern parts of the British Isles, the Scandinavian Mountains, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly 490–390 million years ago ( Ma). It was caused by the closure of the Iapetus Ocean when the continents and terranes of Laurentia, Baltica and Avalonia collided. The orogeny is named for Caledonia, the Latin name for Scotland. The term was first used in 1885 by Austrian geologist Eduard Suess for an episode of mountain building in northern Europe that predated the Devonian period. Geologists like Émile Haug and Hans Stille saw the Caledonian event as one of several episodic phases of mountain building that had occurred during Earth's history. Current understanding has it that the Caledonian orogeny encompasses a number of tectonic phases that can laterally be diachron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knoydartian Orogeny
The Knoydartian Orogeny is a Tonian (early Neoproterozoic) tectonic and metamorphic event, or group of events, that is recognised in the rocks of the Wester Ross and Loch Ness supergroups of the Scottish Highlands. It is dated to about 820–725 Ma (million years ago), predating the deposition of the Cryogenian to Cambrian Dalradian Supergroup. It is named after Knoydart, one of the localities where the event was first recognised. Identification Evidence for a Precambrian event affecting Moine rocks (as then understood) came from the identification of a set of "older" pegmatites, thought to predate Caledonian tectonic and metamorphic effects, in a number of localities, including Morar and Knoydart, in the 1960s. The terms "Morarian" and Knoydartian" were both used to describe this event. It was dated to about 740 Ma (million years ago). As more dating was carried out on samples covering a larger geographical area, using techniques with significantly greater precision, the full a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basement (geology)
In geology, basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at the surface, but often they are buried under miles of rock and sediment. The basement rocks lie below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. In the same way, the sediments or sedimentary rocks on top of the basement can be called a "cover" or "sedimentary cover". Crustal rocks are modified several times before they become basement, and these transitions alter their composition. Continental crust Basement rock is the thick foundation of ancient, and oldest, metamorphic and igneous rock that forms the crust of continents, often in the form of granite. Basement rock is contrasted to overlying sedimentary rocks which are laid down on top of the basement rocks after the continent was formed, such as sandstone and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inlier
An inlier is an area of older rocks surrounded by younger rocks. Inliers are typically formed by the erosion of overlying younger rocks to reveal a limited exposure of the older underlying rocks. Faulting or folding may also contribute to the observed outcrop pattern. A classic example from Great Britain is that of the inlier of folded Ordovician and Silurian rocks at Horton in Ribblesdale in North Yorkshire which are surrounded by the younger flat-lying Carboniferous Limestone. The location has long been visited by geology students and experts. Another example from South Wales is the Usk Inlier in Monmouthshire where Silurian age rocks are upfolded amidst Old Red Sandstone rocks of Devonian age. A similar outcrop pattern which results from movement on a thrust fault followed by erosion may be termed a window. Conversely an outlier is an area of younger rock surrounded by older rocks. An outlier is typically formed when sufficient erosion of surrounding rocks has taken plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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/Laurussia. In Britain it is a lithostratigraphic unit (a sequence of rock strata) to which stratigraphers accord 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 but extending back into the late Silurian and on into the earliest part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dornoch Firth
The Dornoch Firth ( gd, Caolas Dhòrnaich, ) is a firth on the east coast of Highland, in northern Scotland. It forms part of the boundary between Ross and Cromarty, to the south, and Sutherland, to the north. The firth is designated as a national scenic area, one of 40 such areas in Scotland. The national scenic area covers 15,782 ha in total, of which 4,240 ha is the marine area of the firth below low tide. A review of the national scenic areas by Scottish Natural Heritage in 2010 commented: Together with Loch Fleet it is a designated as a Special Protection Area (SPA) for wildlife conservation purposes. Additionally, together with Morrich More, it has the designation of Special Area of Conservation (SAC). The total SPA hosts significant populations of the following birds: *Breeding season: osprey (''Pandion haliaetus'') *Overwintering: bar-tailed godwit (''Limosa lapponica''), greylag goose (''Anser anser''), wigeon (''Anas penelope''), curlew (''Numenius arquata''), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morvern
Morvern, historically also spelt Morven, is a peninsula and traditional district in the Highlands, on the west coast of Scotland. It lies south of the districts of Ardgour and Sunart, and is bounded on the north by Loch Sunart and Glen Tarbert, on the south east by Loch Linnhe and on the south west by the Sound of Mull. The name is derived from the Gaelic ''A' Mhorbhairne'' (the Sea-Gap). The highest point is the summit of the Corbett Creach Bheinn which reaches in elevation. Administratively Morvern is now part of the ward management area of Lochaber, in Highland council area. It forms part of the traditional shire and current registration county of Argyll. Morvern is approximately in area, with a current population of about 320. Prehistory and archaeology In 2010, forestry planting by the then Forestry Commission Scotland let to the discovery of a Mesolithic stone tool scatter. Subsequent archaeology excavations also found evidence that people in the Bronze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_-_geograph.org.uk_-_286814.jpg "Click for more on -> Dornoch Firth")