Paradox Valley
Encyclopedia
Paradox Valley is a basin
located in Montrose County
in the U.S. state
of Colorado
. The dry, sparsely populated valley is named after the apparently paradox
ical course of the Dolores River
—instead of flowing down the length of the valley, the river cuts across the middle. The valley is the site of a Bureau of Reclamation
salinity
-control project which has caused thousands of earthquakes, and is the proposed location of a new uranium
mill
which would be the first built in the United States in over 25 years.
, about 50 miles (80.5 km) south of the city of Grand Junction
. The La Sal Range
of Utah rises in the northwest. Colorado State Highway 90
follows Paradox Valley on its way from Naturita
to the Utah
state line, crossing the historic Dolores River Bridge
near the small unincorporated town of Bedrock
. The town of Paradox
lies a few miles north of the highway. Elevations on the valley floor range from about 5000 feet (1,524 m) at the Dolores River to nearly 6000 feet (1,828.8 m) at the southeast end. Steep parallel sandstone
and shale
walls bound the valley to the northeast and southwest.
The valley was named in 1875 by geologist and surveyor Albert Charles Peale, after he noted that the Dolores River
had a "desire to perform strange and unexpected things" in the area. Instead of flowing down the valley, the river emerges from a narrow gap in one wall, cuts perpendicularly across the middle, and exits through another gap. As a consequence of this unusual geography, the valley cannot be easily irrigated
by the Dolores River, but springs and streams fed by snowmelt from the La Sal Range support farming in the northwestern third
Near the center of the valley, the town of Bedrock experiences average highs ranging from 45 °F (7.2 °C) in December to 96 °F (35.6 °C) in July. Average lows range from 13 °F (-10.6 °C) in December to 54 °F (12.2 °C) in July. An average of 11 inches (27.9 cm) of precipitation, including 9 inches (22.9 cm) of snow, fall annually at Bedrock.
of Paradox Valley can be explained by salt tectonics
. The valley is a collapsed anticline
, a type of geological fold
. About 300 million years ago, during the middle Pennsylvanian
period, high pressures on lands to the northeast caused underlying salt
deposits to flow towards where the valley is today. The salt encountered a buried fault-block ridge
and was deflected upwards, penetrating the overlying rock strata
and forming a salt dome
. The salt may not have actually been exposed on the surface, but groundwater entering the top of the dome dissolved the underlying salt beds, allowing the center to collapse, forming what is today Paradox Valley. This process took place over about 150 million years, a long enough time for the Dolores River to downcut
into the land and maintain its ancient course
. The same process also created the Moab Valley (Spanish Valley
) to the west, itself cut crosswise in a similar fashion by the Colorado River
.
The Paradox Formation
, a geological formation containing salt
, gypsum
, anhydrite
, shale
, sandstone
, and limestone
, is named after exposures found in Paradox Valley. The Paradox Basin
, a geologic province
throughout which the Paradox Formation is found, also bears the name of the valley.
. An 1868 treaty created a reservation
for the Utes over much of western Colorado, including Paradox Valley. Squatters began grazing cattle
in the valley as early as 1877, in violation of the treaty. By 1881, the Utes had been forced out of the area, and in 1882 the United States Congress
officially opened the land to settlement. Springs and streams allowed farming in the northwest end of the valley, and the mid-1890s discovery of copper
at the future site of the Cashin Mine near the town of Bedrock brought in a further influx of settlers. The valley and the surrounding plateau would soon become an important source of radioactive materials, including radium
and uranium
. In 1913, the New York Times identified carnotite
mines near Paradox Valley as the source of "the greatest radium ore deposits in the world". Production of radium ceased in 1922 when richer deposits were found in the Belgian Congo
, but production of uranium and vanadium
continued throughout most of the century.
beds up to 14000 feet (4,267.2 m) thick still underlie Paradox Valley. The Dolores River, a tributary of the Colorado River
, naturally picks up about 100,000-200,000 tons of salt annually on its way through the valley. In the 1980s, the United States Bureau of Reclamation
began construction of a pumping facility known as the Paradox Valley Unit. The PVU, a part of the wider Colorado River Basin Salinity Control Project, became fully operational in 1996 and collects saline
groundwater
from 12 shallow wells along the Dolores River. The system then dilutes the brine
with water and a corrosion inhibitor
and transports it to a high-pressure injection well
, where it is deposited 14000 to 16000 ft (4,267.2 to 4,876.8 m) deep into Precambrian
and Paleozoic
rocks. A 2001 study found that the total salt reaching the Dolores had declined by about 90%, although this may have been the result of a period of low precipitation during the measurement period. As of 2009, the PVU removes about 113,000 tons of salt annually from Paradox Valley.
The injection well of the Paradox Valley Unit has induced
thousands of earthquakes, including at least 4,000 prior to the year 2001. Most were below the threshold of human detection, but at least 15 have been over 2.5 in magnitude, the largest being a 4.3 magnitude quake on May 27, 2000. The PVU suspended operations for 28 days following this quake, but later resumed injections at a lower rate. Further earthquakes have been linked with the operation, including a 3.9 magnitude quake in 2004.
-based Energy Fuels Incorporated, has proposed the construction of a uranium
mill
in the southeast end of Paradox Valley. Called the Piñon Ridge Mill, it would be capable of processing 500 tons of uranium ore per day. If approved, it will be the first uranium mill built in the United States in over 25 years.
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
located in Montrose County
Montrose County, Colorado
Montrose County is the 17th most populous of the 64 counties of the State of Colorado of the United States. The county population was 41,276 at U.S. Census 2010. The county was named for its county seat, the City of Montrose...
in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
. The dry, sparsely populated valley is named after the apparently paradox
Paradox
Similar to Circular reasoning, A paradox is a seemingly true statement or group of statements that lead to a contradiction or a situation which seems to defy logic or intuition...
ical course of the Dolores River
Dolores River
The Dolores River is a tributary of the Colorado River, approximately 250 mi long, in the U.S. states of Colorado and Utah....
—instead of flowing down the length of the valley, the river cuts across the middle. The valley is the site of a Bureau of Reclamation
United States Bureau of Reclamation
The United States Bureau of Reclamation , and formerly the United States Reclamation Service , is an agency under the U.S...
salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
-control project which has caused thousands of earthquakes, and is the proposed location of a new uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
mill
Mineral processing
In the field of extractive metallurgy, mineral processing, also known as mineral dressing or ore dressing, is the process of separating commercially valuable minerals from their ores.-History:...
which would be the first built in the United States in over 25 years.
Geography and climate
Paradox Valley trends northwest-southeast and measures about 3 to 5 mi (4.8 to 8 km) wide and 25 miles (40.2 km) long. It lies along the extreme western edge of ColoradoColorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, about 50 miles (80.5 km) south of the city of Grand Junction
Grand Junction, Colorado
The City of Grand Junction is the largest city in western Colorado. It is a city with a council–manager government form that is the county seat and the most populous city of Mesa County, Colorado, United States. Grand Junction is situated west-southwest of the Colorado State Capitol in Denver. As...
. The La Sal Range
La Sal Range
The La Sal Mountains are located in Grand and San Juan counties, near the eastern border of the state of Utah, and rising above the town of Moab. This range is part of the Manti-La Sal National Forest and the southern Rocky Mountains. The maximum elevation is at Mount Peale, reaching 12,721 feet ...
of Utah rises in the northwest. Colorado State Highway 90
Colorado State Highway 90
State Highway 90 is a long state highway at the western edge of Colorado.-Route description:SH 90 begins in the west at the border with Utah where it becomes Utah State Route 46 which continues westward to meet U.S. Highway 191 about twenty miles south of Moab, UT...
follows Paradox Valley on its way from Naturita
Naturita, Colorado
Naturita is a Statutory Town in Montrose County, Colorado, United States. The population was 635 at the 2000 census.-Geography:Naturita is located at ....
to the Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
state line, crossing the historic Dolores River Bridge
Dolores River Bridge
The Dolores River Bridge is a through truss bridge spanning the Dolores River near Bedrock, Colorado. It carries State Highway 90 and is listed on the National Register of Historic Places ....
near the small unincorporated town of Bedrock
Bedrock, Colorado
Bedrock is an unincorporated town and U.S. Post Office in Montrose County, Colorado, United States. The ZIP Code of the Bedrock Post Office is 81411.-History:The town of Bedrock was established in 1883. The Bedrock Post Office opened on November 8, 1883...
. The town of Paradox
Paradox, Colorado
Paradox is an unincorporated town and a U.S. Post Office located in Montrose County, Colorado, United States. The Paradox Post Office has the ZIP Code 81429.-Geography:Paradox is located in Paradox Valley at ....
lies a few miles north of the highway. Elevations on the valley floor range from about 5000 feet (1,524 m) at the Dolores River to nearly 6000 feet (1,828.8 m) at the southeast end. Steep parallel sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
and shale
Shale
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...
walls bound the valley to the northeast and southwest.
The valley was named in 1875 by geologist and surveyor Albert Charles Peale, after he noted that the Dolores River
Dolores River
The Dolores River is a tributary of the Colorado River, approximately 250 mi long, in the U.S. states of Colorado and Utah....
had a "desire to perform strange and unexpected things" in the area. Instead of flowing down the valley, the river emerges from a narrow gap in one wall, cuts perpendicularly across the middle, and exits through another gap. As a consequence of this unusual geography, the valley cannot be easily irrigated
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
by the Dolores River, but springs and streams fed by snowmelt from the La Sal Range support farming in the northwestern third
Near the center of the valley, the town of Bedrock experiences average highs ranging from 45 °F (7.2 °C) in December to 96 °F (35.6 °C) in July. Average lows range from 13 °F (-10.6 °C) in December to 54 °F (12.2 °C) in July. An average of 11 inches (27.9 cm) of precipitation, including 9 inches (22.9 cm) of snow, fall annually at Bedrock.
Geology
The apparent paradoxParadox
Similar to Circular reasoning, A paradox is a seemingly true statement or group of statements that lead to a contradiction or a situation which seems to defy logic or intuition...
of Paradox Valley can be explained by salt tectonics
Salt tectonics
500px|thumb|rightSalt tectonics is concerned with the geometries and processes associated with the presence of significant thicknesses of evaporites containing rock salt within a stratigraphic sequence of rocks...
. The valley is a collapsed anticline
Anticline
In structural geology, an anticline is a fold that is convex up and has its oldest beds at its core. The term is not to be confused with antiform, which is a purely descriptive term for any fold that is convex up. Therefore if age relationships In structural geology, an anticline is a fold that is...
, a type of geological fold
Fold (geology)
The term fold is used in geology when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation. Synsedimentary folds are those due to slumping of sedimentary material before it is lithified. Folds in rocks vary in...
. About 300 million years ago, during the middle Pennsylvanian
Pennsylvanian
The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly . As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain...
period, high pressures on lands to the northeast caused underlying salt
Halite
Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...
deposits to flow towards where the valley is today. The salt encountered a buried fault-block ridge
Fault-block mountain
Fault-block landforms are formed when large areas of bedrock are widely broken up by faults creating large vertical displacements of continental crust....
and was deflected upwards, penetrating the overlying rock strata
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
and forming a salt dome
Salt dome
A salt dome is a type of structural dome formed when a thick bed of evaporite minerals found at depth intrudes vertically into surrounding rock strata, forming a diapir....
. The salt may not have actually been exposed on the surface, but groundwater entering the top of the dome dissolved the underlying salt beds, allowing the center to collapse, forming what is today Paradox Valley. This process took place over about 150 million years, a long enough time for the Dolores River to downcut
Downcutting
Downcutting, also called erosional downcutting or downward erosion or vertical erosion is a geological process that deepens the channel of a stream or valley by removing material from the stream's bed or the valley's floor. How fast downcutting occurs depends on the stream's base level, which is...
into the land and maintain its ancient course
Entrenched river
An entrenched river is a river that is confined to a canyon or gorge, usually with a relatively narrow width and little or no flood plain, and often with meanders worn into the landscape...
. The same process also created the Moab Valley (Spanish Valley
Spanish Valley, Utah
Spanish Valley is a census-designated place in San Juan County, Utah, in the United States. As of the 2000 census, the CDP population was 181. But on almost all maps of the area, and especially in local usage, the name identifies the geographic valley that extends south of the city of Moab...
) to the west, itself cut crosswise in a similar fashion by the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
.
The Paradox Formation
Paradox formation
The Paradox formation consists of gypsum, anhydrite, and salt, interbedded with shale, sandstone, and limestone. It is the oldest rock exposed in several anticlines in eastern Utah and western Colorado...
, a geological formation containing salt
Halite
Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...
, gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
, anhydrite
Anhydrite
Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the...
, shale
Shale
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...
, sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
, and limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
, is named after exposures found in Paradox Valley. The Paradox Basin
Paradox Basin
The Paradox Basin is an asymmetric foreland basin located mostly in southeast Utah and southwest Colorado, but extending into northeast Arizona and northwest New Mexico. The basin is a large elongate northwest to southeast oriented depression formed during the late Paleozoic Era...
, a geologic province
Geologic province
A geologic or geomorphic province is a spatial entity with common geologic or geomorphic attributes. A province may include a single dominant structural element such as a basin or a fold belt, or a number of contiguous related elements...
throughout which the Paradox Formation is found, also bears the name of the valley.
History
Paradox Valley was within the historical domain of the Ute tribeUte Tribe
The Ute are an American Indian people now living primarily in Utah and Colorado. There are three Ute tribal reservations: Uintah-Ouray in northeastern Utah ; Southern Ute in Colorado ; and Ute Mountain which primarily lies in Colorado, but extends to Utah and New Mexico . The name of the state of...
. An 1868 treaty created a reservation
Indian reservation
An American Indian reservation is an area of land managed by a Native American tribe under the United States Department of the Interior's Bureau of Indian Affairs...
for the Utes over much of western Colorado, including Paradox Valley. Squatters began grazing cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
in the valley as early as 1877, in violation of the treaty. By 1881, the Utes had been forced out of the area, and in 1882 the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
officially opened the land to settlement. Springs and streams allowed farming in the northwest end of the valley, and the mid-1890s discovery of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
at the future site of the Cashin Mine near the town of Bedrock brought in a further influx of settlers. The valley and the surrounding plateau would soon become an important source of radioactive materials, including radium
Radium
Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226,...
and uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
. In 1913, the New York Times identified carnotite
Carnotite
Carnotite is a potassium uranium vanadate radioactive mineral with chemical formula: K222·3H2O. The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present.-Occurrence:...
mines near Paradox Valley as the source of "the greatest radium ore deposits in the world". Production of radium ceased in 1922 when richer deposits were found in the Belgian Congo
Belgian Congo
The Belgian Congo was the formal title of present-day Democratic Republic of the Congo between King Leopold II's formal relinquishment of his personal control over the state to Belgium on 15 November 1908, and Congolese independence on 30 June 1960.-Congo Free State, 1884–1908:Until the latter...
, but production of uranium and vanadium
Vanadium
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery gray, ductile and malleable transition metal. The formation of an oxide layer stabilizes the metal against oxidation. The element is found only in chemically combined form in nature...
continued throughout most of the century.
Paradox Valley Unit
Near-surface saltHalite
Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...
beds up to 14000 feet (4,267.2 m) thick still underlie Paradox Valley. The Dolores River, a tributary of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
, naturally picks up about 100,000-200,000 tons of salt annually on its way through the valley. In the 1980s, the United States Bureau of Reclamation
United States Bureau of Reclamation
The United States Bureau of Reclamation , and formerly the United States Reclamation Service , is an agency under the U.S...
began construction of a pumping facility known as the Paradox Valley Unit. The PVU, a part of the wider Colorado River Basin Salinity Control Project, became fully operational in 1996 and collects saline
Saline water
Saline water is a general term for water that contains a significant concentration of dissolved salts . The concentration is usually expressed in parts per million of salt....
groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
from 12 shallow wells along the Dolores River. The system then dilutes the brine
Brine
Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...
with water and a corrosion inhibitor
Corrosion inhibitor
A corrosion inhibitor is a chemical compound that, when added to a liquid or gas, decreases the corrosion rate of a material, typically a metal or an alloy. The effectiveness of a corrosion inhibitor depends on fluid composition, quantity of water, and flow regime...
and transports it to a high-pressure injection well
Injection well
An injection well is a vertical pipe in the ground into which water, other liquids, or gases are pumped or allowed to flow.-Waste disposal: One application is waste water disposal, in which treated waste water is injected into the ground between impermeable layers of rocks to avoid polluting fresh...
, where it is deposited 14000 to 16000 ft (4,267.2 to 4,876.8 m) deep into Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
and Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
rocks. A 2001 study found that the total salt reaching the Dolores had declined by about 90%, although this may have been the result of a period of low precipitation during the measurement period. As of 2009, the PVU removes about 113,000 tons of salt annually from Paradox Valley.
The injection well of the Paradox Valley Unit has induced
Induced seismicity
Induced seismicity refers to typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on the Earth's crust. Most induced seismicity is of an extremely low magnitude...
thousands of earthquakes, including at least 4,000 prior to the year 2001. Most were below the threshold of human detection, but at least 15 have been over 2.5 in magnitude, the largest being a 4.3 magnitude quake on May 27, 2000. The PVU suspended operations for 28 days following this quake, but later resumed injections at a lower rate. Further earthquakes have been linked with the operation, including a 3.9 magnitude quake in 2004.
Piñon Ridge Mill
Energy Fuels Resources Corporation, a subsidiary of TorontoToronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
-based Energy Fuels Incorporated, has proposed the construction of a uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
mill
Mineral processing
In the field of extractive metallurgy, mineral processing, also known as mineral dressing or ore dressing, is the process of separating commercially valuable minerals from their ores.-History:...
in the southeast end of Paradox Valley. Called the Piñon Ridge Mill, it would be capable of processing 500 tons of uranium ore per day. If approved, it will be the first uranium mill built in the United States in over 25 years.
External links
- Upstream and downstream water quality data from the United States Geological SurveyUnited States Geological SurveyThe United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...