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Highwood Mountains
The Highwood Mountains are an island range (sub-range of the Rockies entirely surrounded by prairie) which cover approximately 4,659 km2 (1,799 sq mi) of the Central Montana Alkalic Province in north central Montana in the U.S. They are in Chouteau, Judith Basin and Cascade counties and lie east of Great Falls and Benton Lake National Wildlife Refuge, at the northern end of the Lewis and Clark National Forest. The mountains were included in Highwood Mountains National Forest until 1908, when the unit became part of Lewis and Clark National Forest. Nearby are Highwood, Montana and the Missouri River above the mouth of the Marias River. The highest point in the Highwood Mountains is Highwood Baldy at 2338 meters (7670 ft). The area is an Eocene volcanic complex and is rich in potash. Many of the extrusive rocks and some of the dike rocks contain abundant phenocrysts of a clear analcime that appears to be primary. Pseudoleucite is an abundant constituent of many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Montana Alkalic Province
The central Montana Alkalic Province is located in the United States in central Montana. Montana is bordered by Idaho, Wyoming, North Dakota, South Dakota, and Canada to the north. Central Montana is unique when compared to the rest of the Rocky Mountains due to its east-west trend of tectonic features, including thrust fault zones, anticlines, and domes. The area of tectonic activity experienced conditions of plastic deformation, which affected the whole region. The Montana Alkalic Province consist of Cretaceous intrusions of monzonite and syenite as well as Cambrian limestone, sandstone, and siltstone. Most of the sedimentary rocks are a result of deposition from a terrestrial fluvial environment. Deposition included more than 13,000 feet of clastics that were later uplifted. The peak of this uplifting occurred during the Devonian. Deposition, uplift, and traps of carbonate shales have made central Montana prime for small-scale oil and gas production. Other geologic formations in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrusive Rock
Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contrast, intrusive rock refers to rocks formed by magma which cools below the surface.Jain, Sreepat (2014). ''Fundamentals of Physical Geology''. New Delhi, India: Springer. . The main effect of extrusion is that the magma can cool much more quickly in the open air or under seawater, and there is little time for the growth of crystals. Sometimes, a residual portion of the matrix fails to crystallize at all, instead becoming a natural glass like obsidian. If the magma contains abundant volatile components which are released as free gas, then it may cool with large or small vesicles (bubble-shaped cavities) such as in pumice, scoria, or vesicular basalt. Other examples of extrusive rocks are rhyolite and andesite. Texture The textur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landforms Of Chouteau County, Montana
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, structure stratification, rock exposure, and soil type. Gross physical features or landforms include intuitive elements such as berms, cliffs, hills, mounds, peninsulas, ridges, rivers, valleys, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Montana
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface and the processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their Geochronology, absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Ranges Of Montana
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and climate, mountains t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Mountain Ranges In Montana
This is a list of mountain ranges in the state of Montana. Montana is the fourth largest state in the United States and is well known for its mountains. The name "Montana" is Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ... for "Mountain". Representative James Mitchell Ashley (Republican Party (United States), R-Ohio), suggested the name when legislation organizing the territory was passed by the United States Congress in 1864. Ashley noted that a mining camp in the Colorado Territory had already used the name, and Congress agreed to use the name for the new territory. According to the United States Board on Geographic Names, there are at least 100 named mountain ranges and sub-ranges in Montana. However, mountain ranges have no official boundaries, and there is no offic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riparian Areas
A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a riparian zone. The word ''riparian'' is derived from Latin '' ripa'', meaning " river bank". Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. Riparian zones are important in ecology, environmental resource management, and civil engineering because of their role in soil conservation, their habitat biodiversity, and the influence they have on terrestrial and semiaquatic fauna as well as aquatic ecosystems, including grasslands, woodlands, wetlands, and even non-vegetative areas. Riparian zones may be natural or engineered for soil stabilization or restoration. These zones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highwood Mountains Montana Southeast Face 17 , a wood in north-east France, sce ...
Highwood may refer to: People * Sidney Highwood (1896–1975), World War I flying ace Places Canada * Highwood, Calgary, a neighbourhood in Calgary, Alberta * Highwood (electoral district), a provincial electoral district in Alberta * Highwood River, a river in Alberta United Kingdom * Highwood, Devon * Highwood, Dorset * Highwood, Essex * Highwood, Hampshire * Highwood, Wokingham, a Local Nature Reserve * Highwood, Worcestershire United States * Highwood, Illinois * Highwood, Montana * Highwood, Wisconsin * Highwood, Hamden, a neighborhood in the town of Hamden, Connecticut Philippines * Highwood, Batangas, Philippines See also * Highwood, hymn tune by R.R. Terry. * High Wood The Attacks on High Wood, near Bazentin le Petit in the Somme ''département'' of northern France, took place between the British Fourth Army and the German 1st Army during the Battle of the Somme. After the Battle of Bazentin Ridge on 14 Ju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meltwater Channel
A meltwater channel (or sometimes a glacial meltwater channel) is a channel cut into ice, bedrock or unconsolidated deposits by the flow of water derived from the melting of a glacier or ice-sheet. The channel may form on the surface of, within, beneath, along the margins of or downstream from the ice mass. Accordingly it would be referred to as supraglacial, englacial, subglacial, lateral (or ice-marginal) or proglacial. Different forms of subglacial channel are described in glaciological literature including Nye or N-channels, Röthlisberger or R-channels and Hooke or H-channels. Tunnel valley is a related term descriptive of subglacial channels. Some examples of tunnel valleys in northwest England have also been described as iceways. The depositional landforms known as kames and eskers may often be found in association with meltwater channels. An urstromtal is a proglacial or ice-marginal channel common in Germany and Poland formed during various of the Pleistocene gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shonkin Sag
The Shonkin Sag is a prehistoric fluvioglacial landform located along the northern edge of the Highwood Mountains in the state of Montana in the United States. The Sag is a river channel formed by the Missouri River and glacial meltwater pouring from Glacial Lake Great Falls. It is one of the most famous prehistoric meltwater channels in the world. Location and size Shonkin Sag is located in central Montana. It begins south of Highwood, Montana, (about east of the city of Great Falls, Montana, Great Falls) and runs in an easterly direction for about until it reaches the Judith River."Societies and Academies: Geological Society of Washington." ''Science (journal), Science.'' May 7, 1895, p. 559-560. It varies from to in width and is about deep. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust. Geological significance Igneous and metamorphic rocks make up 90–95% of the top of the Earth's crust by volume. Igneous rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucite
Leucite (from the Greek word ''leukos'' meaning white) is a rock-forming mineral of the feldspathoid group, silica-undersaturated and composed of potassium and aluminium tectosilicate KAlSi2O6. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system. Optical investigations have since proved the crystals to be still more complex in character, and to consist of several orthorhombic or monoclinic individuals, which are optically biaxial and repeatedly twinned, giving rise to twin-lamellae and to striations on the faces. When the crystals are raised to a temperature of about 500 °C they become optically isotropic and the twin-lamellae and striations disappear, although they reappear when the crystals are cooled again. This pseudo-cubic character of le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
