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Fossil Lake (Oregon)
Fossil Lake (designated by the Bureau of Land Management as Fossil Lake Area of Critical Environmental Concern) is a dry lakebed in the remote high desert country of northern Lake County in the U.S. state of Oregon. During the Pleistocene epoch, Fossil Lake and the surrounding basin were covered by an ancient lake. Numerous animals used the lake resources. Over time, the remains of many of these animals became fossilized in the lake sediments. As a result, Fossil Lake has been an important site for fossil collection and scientific study for well over a century. Over the years, paleontologists have found the fossil remains of numerous mammals as well as bird and fish species there. Some of these fossils are 2 million years old. Location Fossil Lake is located in a remote area of northern Lake County, Oregon. It is from the unincorporated community of Christmas Valley by road. Fossil Lake is approximately southeast of Bend and north of Lakeview in straight- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake County, Oregon
Lake County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 8,160. Its county seat is Lakeview. The county is named after the many lakes found within its boundaries, including Lake Abert, Summer Lake, Hart Lake, and Goose Lake. Lake County is in the high desert region known as the Oregon Outback, on the northwestern edge of the Great Basin. The county is generally divided between the communities around Lakeview and Paisley to the south and the communities around Christmas Valley, Fort Rock, and Silver Lake to the north. Its economy consists largely of agriculture and natural resource management and extraction. It is home to many large cattle ranches, hay farms, and timber holdings (both public and private), as well as several frontier towns and early 20th-century homesteads. Although lumber was once a primary economic driver in Lake County, today only one mill remains, at Lakeview. History Pre-Columbian Pre-Clovis era c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.Jackson, J.A., J. Mehl, and K. Neuendorf (2005) ''Glossary of Geology'' American Geological Institute, Alexandria, Virginia. 800 pp. McPhie, J., M. Doyle, and R. Allen (1993) ''Volcanic Textures A guide to the interpretation of textures in volcanic rocks'' Centre for Ore Deposit and Exploration Studies, University of Tasmania, Hobart, Tasmania..198 pp. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium. Floodplain alluvium can be highly fertile, and supported some of the earliest human civilizations. Definitions The present consensus is that "alluvium" refers to loose sediments of all types deposited by running water in floodplains or in alluvial fans or related landforms. However, the meaning of the term has varied considerably since it was first defined in the French dictionary of Antoine Furetière, posthumously published in 1690. Drawing upon concepts from Roman law, Furetière defined ''alluvion'' (the F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolian Processes
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacustrine Plain
A lacustrine plain or lake plain is a plain formed due to the past existence of a lake and its accompanying sediment accumulation. Lacustrine plains can be formed through one of three major mechanisms: glacial drainage, differential uplift, and inland lake creation and drainage. Lake plains can have various uses depending on where and how they form. Over time, in regions where a lake once existed, as water drains or evaporates from the lake, the deposited sediments are left behind, resulting in a level plain of land where the lake once existed. The soil of the plain may constitute fertile and productive farmland due to the previous accumulation of lacustrine sediments; in other cases, it may become a wetland or a desert. Background Lacustrine plains are plains formed when lakes filled with sediments are drained. There are several reasons why drainage might occur, but in all cases the water in the lake is lost, leaving behind a level land of sediments. The resulting plain is an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christmas Valley Sand Dunes
The Christmas Valley Sand Dunes are a natural sand dune complex covering of public lands east of Christmas Valley in Lake County, Oregon, United States, about southeast of Bend. The area is accessible via the Christmas Valley National Back Country Byway. The dunes are up to high. It is the largest inland shifting sand dune system in the Pacific Northwest. The dunes are composed mostly of ash and pumice from the eruption of Mount Mazama that formed Crater Lake 7,000 years ago.Christmas Valley Sand Dunes: Area of Critical Environmental Concern (PDF) brochure from the BLM Approximately of dunes are open to vehicles. Administration The Christmas Valley Sand Dunes area is administered by Bureau of Land Management. ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swale (landform)
A swale is a shady spot, or a sunken or marshy place. In US usage in particular, it is a shallow channel with gently sloping sides. Such a swale may be either natural or human-made. Artificial swales are often infiltration basins, designed to manage water runoff, filter pollutants, and increase rainwater infiltration. Bioswales are swales that involve the inclusion of plants or vegetation in their construction, specifically. On land This swale concept has also been popularized as a rainwater harvesting Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit (well, shaft, or borehole), aquifer, or a reservoir ... and soil conservation strategy by Bill Mollison, David Holmgren, and other advocates of permaculture. In this context it is usually a water-harvesting ditch on contour, also called a ''contour Bunding, bund''. Swales as used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lost Forest Research Natural Area
The Lost Forest Research Natural Area is a designated forest created by the Bureau of Land Management to protect an ancient stand of ponderosa pine in the remote high desert county of northern Lake County, in the south central area of the U.S. state of Oregon. Lost Forest is an isolated area of pine trees separated from the nearest contiguous forest land by forty miles of arid desert. There are no springs or surface water in Lost Forest, and much of the southwest portion of the natural area is covered by large shifting sand dunes that are slowly encroaching on the forest. Geology Lost Forest is located at the northeastern corner of the Christmas Lake Basin in south central Oregon. The bedrock beneath the area was created by basalt flows laid down during the Pliocene and Pleistocene epochs. After a period of intense faulting during the middle Pleistocene, a large basin area was created by erosion and sedimentation. This basin filled with water during the wet climatic periods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ponderosa Pine
''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the most widely distributed pine species in North America.Safford, H.D. 2013. Natural Range of Variation (NRV) for yellow pine and mixed conifer forests in the bioregional assessment area, including the Sierra Nevada, southern Cascades, and Modoc and Inyo National Forests. Unpublished report. USDA Forest Service, Pacific Southwest Region, Vallejo, CA/ref> ''Pinus ponderosa'' grows in various erect forms from British Columbia southward and eastward through 16 western U.S. states and has been successfully introduced in temperate regions of Europe, and in New Zealand. It was first documented in modern science in 1826 in eastern Washington near present-day Spokane (of which it is the official city tree). On that occasion, David Douglas misidenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caliche (mineral)
Caliche () is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions, including in central and western Australia, in the Kalahari Desert, in the High Plains of the western United States, in the Sonoran Desert, Chihuahuan Desert and Mojave Desert of North America, and in eastern Saudi Arabia at Al-Hasa. Caliche is also known as calcrete or kankar (in India). It belongs to the duricrusts. The term ''caliche'' is Spanish and is originally from the Latin ''calx'', meaning lime. Caliche is generally light-colored, but can range from white to light pink to reddish-brown, depending on the impurities present. It generally occurs on or near the surface, but can be found in deeper subsoil deposits, as well. Layers vary from a few inches to feet thick, and multiple layers can exist in a single location. A caliche lay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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