The Cambrian Period was the first geological period of the Paleozoic Era, of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago to the beginning of the Ordovician Period 485.4 mya and its subdivisions, and its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latinised form of Cymru, the Welsh name for Wales, as a result, our understanding of the Cambrian biology surpasses that of some periods. The rapid diversification of lifeforms in the Cambrian, known as the Cambrian explosion, most of the continents were probably dry and rocky due to a lack of vegetation. Shallow seas flanked the margins of several continents created during the breakup of the supercontinent Pannotia, the seas were relatively warm, and polar ice was absent for much of the period. The United States Federal Geographic Data Committee uses a barred capital C ⟨Є⟩ character similar to the capital letter Ukrainian Ye ⟨Є⟩ to represent the Cambrian Period, the proper Unicode character is U+A792 Ꞓ LATIN CAPITAL LETTER C WITH BAR.
Despite the long recognition of its distinction from younger Ordovician Period rocks and older Supereon Precambrian rocks, the base of the Cambrian lies atop a complex assemblage of trace fossils known as the Treptichnus pedum assemblage. Pedum in Namibia and Newfoundland, and possibly, in the western USA, the stratigraphic range of T. pedum overlaps the range of the Ediacaran fossils in Namibia, and probably in Spain. The Cambrian Period followed the Ediacaran Period and was followed by the Ordovician Period, the Cambrian is divided into four epochs and ten ages. Currently only two series and five stages are named and have a GSSP, because the international stratigraphic subdivision is not yet complete, many local subdivisions are still widely used. In some of these subdivisions the Cambrian is divided into three epochs with locally differing names – the Early Cambrian, Middle Cambrian and Furongian, rocks of these epochs are referred to as belonging to the Lower, Middle, or Upper Cambrian.
Trilobite zones allow biostratigraphic correlation in the Cambrian, each of the local epochs is divided into several stages. The International Commission on Stratigraphy list the Cambrian period as beginning at 541 million years ago, the lower boundary of the Cambrian was originally held to represent the first appearance of complex life, represented by trilobites. The recognition of small shelly fossils before the first trilobites, and Ediacara biota substantially earlier and this formal designation allowed radiometric dates to be obtained from samples across the globe that corresponded to the base of the Cambrian. Early dates of 570 million years ago quickly gained favour, though the used to obtain this number are now considered to be unsuitable. A more precise date using modern radiometric dating yield a date of 541 ±0.3 million years ago, most continental land was clustered in the Southern Hemisphere at this time, but was drifting north. Large, high-velocity rotational movement of Gondwana appears to have occurred in the Early Cambrian, the sea levels fluctuated somewhat, suggesting there were ice ages, associated with pulses of expansion and contraction of a south polar ice cap.
In Baltoscandia a Lower Cambrian transgression transformed large swathes of the Sub-Cambrian peneplain into a epicontinental sea, the Earth was generally cold during the early Cambrian, probably due to the ancient continent of Gondwana covering the South Pole and cutting off polar ocean currents
The Paleozoic Era is the earliest of three geologic eras of the Phanerozoic Eon, from 541 to 252.17 million years ago. It is the longest of the Phanerozoic eras, and is subdivided into six periods, the Cambrian, Silurian, Carboniferous. The Paleozoic comes after the Neoproterozoic era of the Proterozoic and is followed by the Mesozoic, the Paleozoic was a time of dramatic geological and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earths history, known as the Cambrian explosion, arthropods, anapsids, synapsids and diapsids all evolved during the Paleozoic. Life began in the ocean but eventually transitioned onto land, and by the late Paleozoic, Great forests of primitive plants covered the continents, many of which formed the coal beds of Europe and eastern North America. Towards the end of the era, sophisticated diapsids and synapsids were dominant, the Paleozoic Era ended with the largest extinction event in the history of Earth, the Permian–Triassic extinction event.
The effects of this catastrophe were so devastating that it took life on land 30 million years into the Mesozoic Era to recover, recovery of life in the sea may have been much faster. The Paleozoic era began and ended with supercontinents and in between were the rise of mountains along the margins, and flooding and draining of shallow seas between. At its start, the supercontinent Pannotia broke up, paleoclimatic studies and evidence of glaciers indicate that central Africa was most likely in the polar regions during the early Paleozoic. During the early Paleozoic, the huge continent Gondwana formed or was forming, by mid-Paleozoic, the collision of North America and Europe produced the Acadian-Caledonian uplifts, and a subduction plate uplifted eastern Australia. There are six periods in the Paleozoic Era, Ordovician, Devonian, the Cambrian spans from 541 million years to 485 million years and is the first period of the Paleozoic era of the Phanerozoic. The Cambrian marked a boom in evolution in an event known as the Cambrian explosion in which the largest number of creatures evolved in any period of the history of the Earth.
Creatures like algae evolved, but the most ubiquitous of that period were the armored arthropods, almost all marine phyla evolved in this period. During this time, the supercontinent Pannotia begins to break up, the Ordovician spanned from 485 million years to 443 million years ago. The Ordovician is a time in Earths history in many of the biological classes still prevalent today evolved, such as primitive fish, cephalopods. The most common forms of life, were trilobites, more importantly, the first arthropods went ashore to colonize the empty continent of Gondwana. By the end of the Ordovican, Gondwana was at the pole, early North America had collided with Europe. Glaciation of Africa resulted in a drop in sea level
In earth science, erosion is the action of surface processes that remove soil, rock, or dissolved material from one location on the Earths crust, transport it away to another location. Eroded sediment or solutes may be transported just a few millimetres, the rates at which such processes act control how fast a surface is eroded. Feedbacks are possible between rates of erosion and the amount of eroded material that is carried by, for example. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, while erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the rate of erosion in the region. Excessive erosion causes both on-site and off-site problems, on-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers.
In some cases, the end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of bodies, as well as sediment-related damage to roads. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, and the surface runoff which may result from rainfall, produces four types of soil erosion, splash erosion, sheet erosion, rill erosion. Splash erosion is generally seen as the first and least severe stage in the erosion process. In splash erosion, the impact of a falling raindrop creates a crater in the soil. The distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rate is greater than the rate at which water can infiltrate into the soil.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope, sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a few centimetres or less and this means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow
The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period and it once reached elevations similar to those of the Alps and the Rocky Mountains before naturally occurring erosion. The Appalachian chain is a barrier to east-west travel, as it forms a series of alternating ridgelines, definitions vary on the precise boundaries of the Appalachians. A common variant definition does not include the Adirondack Mountains, which belong to the Grenville Orogeny and have a different geological history from the rest of the Appalachians. The range covers parts of the islands of Saint Pierre and Miquelon, the system is divided into a series of ranges, with the individual mountains averaging around 3,000 ft. The highest of the group is Mount Mitchell in North Carolina at 6,684 feet, the term Appalachian refers to several different regions associated with the mountain range.
Most broadly, it refers to the mountain range with its surrounding hills. The Ouachita Mountains in Arkansas and Oklahoma were originally part of the Appalachians as well, the name was soon altered by the Spanish to Apalachee and used as a name for the tribe and region spreading well inland to the north. Pánfilo de Narváezs expedition first entered Apalachee territory on June 15,1528, now spelled Appalachian, it is the fourth-oldest surviving European place-name in the US. After the de Soto expedition in 1540, Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance of Apalchen is on Diego Gutierrezs map of 1562, the name was not commonly used for the whole mountain range until the late 19th century. A competing and often more popular name was the Allegheny Mountains, Alleghenies, in the early 19th century, Washington Irving proposed renaming the United States either Appalachia or Alleghania. In U. S. dialects in the regions of the Appalachians.
In northern parts of the range, it is pronounced /ˌæpəˈleɪtʃᵻnz/ or /ˌæpəˈleɪʃᵻnz/, the third syllable is like lay. There is often debate between the residents of the regions as to which pronunciation is the more correct one. Elsewhere, a commonly accepted pronunciation for the adjective Appalachian is /ˌæpəˈlætʃiən/, the whole system may be divided into three great sections, The northern section runs from the Canadian province of Newfoundland and Labrador to the Hudson River. The Monteregian Hills, which cross the Green Mountains in Quebec, are unassociated with the Appalachians, The central section goes from the Hudson Valley to the New River running through Virginia and West Virginia. Southern, The southern section runs from the New River onwards and it consists of the prolongation of the Blue Ridge, which is divided into the Western Blue Ridge Front and the Eastern Blue Ridge Front, the Ridge-and-Valley Appalachians, and the Cumberland Plateau
Chert is a fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline silica. Depending on its origin, it can contain either microfossils, small macrofossils, Chert occurs as oval to irregular nodules in greensand, limestone and dolostone formations as a replacement mineral, where it is formed as a result of some type of diagenesis. Where it occurs in chalk or marl, it is usually called flint and it occurs in thin beds, when it is a primary deposit. Thick beds of chert occur in marine deposits. These thickly bedded cherts include the novaculite of the Ouachita Mountains of Arkansas, the banded iron formations of Precambrian age are composed of alternating layers of chert and iron oxides. Chert occurs in deposits and is known as diatomaceous chert. Diatomaceous chert consists of beds and lenses of diatomite which were converted during diagenesis into dense, in petrology the term chert is used to refer generally to all rocks composed primarily of microcrystalline, cryptocrystalline and microfibrous quartz.
The term does not include quartzite, chalcedony is a microfibrous variety of quartz. Strictly speaking, the flint is reserved for varieties of chert which occur in chalk. Among non-geologists, the distinction between flint and chert is often one of quality - chert being lower quality than flint, among petrologists, chalcedony is sometimes considered separately from chert due to its fibrous structure. Since many cherts contain both microcrystalline and microfibrous quartz, it is difficult to classify a rock as completely chalcedony. The cryptocrystalline nature of chert, combined with its above average ability to resist weathering, recrystallization, for example, The 3.2 Ga chert of the Fig Tree Formation in the Barbeton Mountains between Swaziland and South Africa preserved non-colonial unicellular bacteria-like fossils. The Gunflint Chert of western Ontario preserves not only bacteria and cyanobacteria but believed to be ammonia-consuming and some that resemble green algae. The Apex Chert of the Pilbara craton, Australia preserved eleven taxa of prokaryotes, the Bitter Springs Formation of the Amadeus Basin, Central Australia, preserves 850 Ma cyanobacteria and algae.
The Rhynie chert of Scotland has remains of a Devonian land flora, in prehistoric times, chert was often used as a raw material for the construction of stone tools. Like obsidian, as well as some rhyolites, felsites and this results in conchoidal fractures, a characteristic of all minerals with no cleavage planes. When a chert stone is struck against an iron-bearing surface sparks result and this makes chert an excellent tool for starting fires, and both flint and common chert were used in various types of fire-starting tools, such as tinderboxes, throughout history. Cherts are subject to problems when used as concrete aggregates, deeply weathered chert develops surface pop-outs when used in concrete that undergoes freezing and thawing because of the high porosity of weathered chert
Gneiss is a common distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. The foliations are characterized by alternating darker and lighter colored bands, the word gneiss comes from the Middle High German verb gneist. It has occurred in English since at least 1757, gneissic rocks are usually medium- to coarse-foliated, they are largely recrystallized but do not carry large quantities of micas, chlorite or other platy minerals. Gneisses that are metamorphosed igneous rocks or their equivalent are termed granite gneisses, diorite gneisses, gneiss rocks may be named after a characteristic component such as garnet gneiss, biotite gneiss, albite gneiss, etc. Orthogneiss designates a gneiss derived from a rock, and paragneiss is one from a sedimentary rock. Gneissose rocks have properties similar to gneiss, gneiss appears to be striped in bands, called gneissic banding. The banding is developed under high temperature and pressure conditions, the minerals are arranged into layers that appear as bands in cross section.
The appearance of layers, called compositional banding, occurs because the layers, the darker bands have relatively more mafic minerals. The lighter bands contain relatively more felsic and these forces stretch out the rock like a plastic, and the original material is spread out into sheets. Another cause of banding is metamorphic differentiation, which separates different materials into different layers through chemical reactions, not all gneiss rocks have detectable banding. In kyanite gneiss, crystals of kyanite appear as random clumps in what is mainly a plagioclase matrix, henderson gneiss is found in North Carolina and South Carolina, US, east of the Brevard Shear Zone. It has deformed into two sequential forms, the second, more warped, form is associated with the Brevard Fault, and the first deformation results from displacement to the southwest. Most of the Outer Hebrides of Scotland have a formed from Lewisian gneiss. In addition to the Outer Hebrides, they form basement deposits on the Scottish mainland west of the Moine Thrust and on the islands of Coll and Tiree.
These rocks are igneous in origin, mixed with metamorphosed marble and mica schist with intrusions of basaltic dikes. Gneisses of Archean and Proterozoic age occur in the Baltic Shield, in antiquity, gneisses were utilized in architectural construction. They were used to erect the Sphinx of Taharqo in the Nile Valley, list of rock types Blatt and Robert J. Tracy. Petrology, Igneous and Metamorphic, 2nd ed. Freeman, mcKirdy, Roger Crofts and John Gordon
Bonne Bay /ˈbɒni/ is a bay in Newfoundland, Canada. It is located on the side of Newfoundland and separates Great Northern Peninsula from the rest of the island. It is a part of Gros Morne National Park, Bonne Bay has a population of about 7000 people. It is separated into two sections, Inner Bonne Bay and Outer Bonne Bay, Inner Bonne Bay consists of two arms, one which is South which has wooded coves and beach landings. Outer Bonne Bay consists of the entrance to the fjord of Bonne Bay, Bonne Bay was carved out approximately 10,000 years ago by two large glaciers in each one of the arms. The glaciers came together in the part of the Bay
Long Range Mountains
The Long Range Mountains are a series of mountains along the west coast of the Canadian island of Newfoundland. They form the northernmost section of the Appalachian chain on the seaboard of North America. In 2003 it was announced that the International Appalachian Trail would be extended through the Long Range Mountains, the Great Northern Peninsula of Western Newfoundland contains the Highlands, the largest external basement massif of the Grenville Orogeny in the Appalachian Orogen. This Precambrian basement is known as the Long Range Inlier, Long Range Complex or Basement Gneiss Complex, the Long Range Swarm are mafic dikes within the range, with an age of about 605 Ma. Running along the Gulf of St. Lawrence, the range includes the sections, Anguille Mountains, Lewis Hills
Parks Canada, known as the Parks Canada Agency, is an agency of the Government of Canada run by a chief executive who answers to the Minister of the Environment. Parks Canada manages 38 National Parks, three National Marine Conservation Areas,171 National Historic Sites, and one National Landmark, the agency administers lands and waters set aside as potential national parklands, including eight National Park Reserves and one National Marine Conservation Area Reserve. The Canadian Register of Historic Places is supported and managed by Parks Canada, in collaboration with provincial and territorial governments, the agency is the working arm of the national Historic Sites and Monuments Board, which recommends National Historic Sites and Persons. Parks Canada was established on May 19,1911, as the Dominion Parks Branch under the Department of the Interior, the services activities are regulated under the provisions of the Canada National Parks Act, which was enacted in 1930, and amended in 2000.
To mark the 150th anniversary of Confederation in 2017, Parks Canada is offering free passes to national parks, the Parks Canada Agency was established as a separate service entity in 1998, and falls under the responsibility of Environment Canada. Before 2003, Parks Canada fell under the jurisdiction of the Department of Canadian Heritage, from 1979 to 1994, Parks Canada was part of the Department of Environment, and before it was part of the Department of Indian and Northern Affairs, and the Department of the Interior. With the organizational shifts and political leadership in Canada, the priorities of Parks Canada have shifted over the years more towards conservation, starting in the 1960s, Parks Canada has moved to decentralize its operations. S. C. Marie Canal, Saint-Ours Canal, Chambly Canal, Sainte-Anne-de-Bellevue Canal, Carillon Canal, Lachine Canal, the Department of Canadian Heritage, which runs federal Museums and more cultural affairs, falls under the control of the Minister of Heritage.
They are designated under section 18 of the Canada National Parks Act and have the authority of peace officers and they carry firearms and have access to other use of force options. The Minister may designate provincial and local enforcement officers under section 19 of the Act for the purpose of enforcing laws within the specified parks and these officers have the power of peace officers only in relation to the Act. In May 2012, it was reported that Park Wardens may be designated to enforce certain wildlife acts administered by Environment Canada. Should the designations go ahead it would only be for Park Wardens that are stationed near existing migratory bird sanctuaries, historical Analysis of Parks Canada and Banff National Park, 1968–1995 List of legislation for which Parks Canada is responsible Lothian, W. F. A History of Canadas National Parks Volumes I-IV Lothian, W. F, a Brief History of Canadas National Parks Lothian, W. F. Histoire des parcs nationaux du Canada Volumes I-IV Lothian, W.
F, a Century of Parks Canada, 1911–2011, Free eBook Parks Canada article in the Canadian Encyclopedia National Parks of Canada Electronic Library
International Union for Conservation of Nature
The International Union for Conservation of Nature is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in gathering and analysis, field projects, lobbying. IUCNs mission is to influence and assist societies throughout the world to conserve nature and to ensure that any use of resources is equitable. Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to equality, poverty alleviation. Unlike other international NGOs, IUCN does not itself aim to mobilize the public in support of nature conservation and it tries to influence the actions of governments and other stakeholders by providing information and advice, and through lobbying and partnerships. The organization is best known to the public for compiling and publishing the IUCN Red List. IUCN has a membership of over 1200 governmental and non-governmental organizations, some 11,000 scientists and experts participate in the work of IUCN commissions on a voluntary basis.
It employs approximately 1000 full-time staff in more than 60 countries and its headquarters are in Gland, Switzerland. IUCN has observer and consultative status at the United Nations, and plays a role in the implementation of several conventions on nature conservation. It was involved in establishing the World Wide Fund for Nature, in the past, IUCN has been criticized for placing the interests of nature over those of indigenous peoples. In recent years, its relations with the business sector have caused controversy. It was previously called the International Union for Protection of Nature, establishment In 1947, the Swiss League for the Protection of Nature organised an international conference on the protection of nature in Brunnen. It is considered to be the first government-organized non-governmental organization, the initiative to set up the new organisation came from UNESCO and especially from its first Director General, the British biologist Julian Huxley. At the time of its founding IUPN was the international organisation focusing on the entire spectrum of nature conservation Early years.
Its secretariat was located in Brussels and its first work program focused on saving species and habitats and applying knowledge, advancing education, promoting international agreements and promoting conservation. Providing a solid base for conservation action was the heart of all activities. IUPN and UNESCO were closely associated and they jointly organized the 1949 Conference on Protection of Nature. In preparation for this conference a list of endangered species was drawn up for the first time
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable, shale is characterized by breaks along thin laminae or parallel layering or bedding less than one centimeter in thickness, called fissility. Mudstones, on the hand, are similar in composition. Before the mid 19th century, the slate, shale. In the context of underground mining, shale was frequently referred to as slate well into the 20th century. Non-fissile rocks of similar composition but made of smaller than 0.06 mm are described as mudstones or claystone. Rocks with similar sizes but with less clay and therefore grittier are siltstones. Shale is the most common sedimentary rock, shales are typically composed of variable amounts of clay minerals and quartz grains and the typical color is gray. Addition of variable amounts of minor constituents alters the color of the rock, black shale results from the presence of greater than one percent carbonaceous material and indicates a reducing environment.
Black shale can be referred to as black metal, red and green colors are indicative of ferric oxide, iron hydroxide, or micaceous minerals. Clays are the constituent of shales and other mudrocks. The clay minerals represented are largely kaolinite and illite, clay minerals of Late Tertiary mudstones are expandable smectites whereas in older rocks especially in mid- to early Paleozoic shales illites predominate. The transformation of smectite to illite produces silica, calcium, magnesium and these released elements form authigenic quartz, calcite, ankerite and albite, all trace to minor minerals found in shales and other mudrocks. Shales and mudrocks contain roughly 95 percent of the matter in all sedimentary rocks. However, this amounts to less than one percent by mass in an average shale, black shales, which form in anoxic conditions, contain reduced free carbon along with ferrous iron and sulfur. Pyrite and amorphous iron sulfide along with carbon produce the black coloration, the process in the rock cycle which forms shale is called compaction.
The fine particles that compose shale can remain suspended in long after the larger particles of sand have deposited. Shales are typically deposited in very slow moving water and are found in lakes and lagoonal deposits, in river deltas, on floodplains
It is a texturally immature sedimentary rock generally found in Palaeozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume, the term greywacke can be confusing, since it can refer to either the immature aspect of the rock or the fine-grained component of the rock. Geologists now attribute its formation to submarine avalanches or strong turbidity currents and these actions churn sediment and cause mixed-sediment slurries, in which the rocks may exhibit a variety of sedimentary features. They occur in association with black shales of deep sea origin, greywackes are mostly grey, yellow or black, dull-colored sandy rocks which may occur in thick or thin beds along with shales and limestones. Among other minerals found in them are biotite, tourmaline, apatite, hornblende, sphene, the cementing material may be siliceous or argillaceous and is sometimes calcareous. As a rule greywackes are not fossiliferous, but organic remains may be common in the finer beds associated with them and their component particles are usually not very rounded or polished, and the rocks have often been considerably indurated by recrystallization, such as the introduction of interstitial silica.
In some districts the greywackes are cleaved, but they show phenomena of this much less perfectly than the slates. Some varieties include feldspathic greywacke, which is rich in feldspar, and lithic greywacke and their essential features are their gritty character and their complex composition. By increasing metamorphism, greywackes frequently pass into mica-schists, chloritic schists, Greywacke zone Torlesse Greywacke This article incorporates text from a publication now in the public domain, Hugh, ed. Greywacke. National Park Service site Presidio Franciscan Greywacke/Shales