Geochemical and mineralogical analyses of uranium ores from the Hack II and Pigeon deposits, solution-collapse breccia pipes, Grand Canyon region, Mohave and Coconino Counties, Arizona, USA
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This data release compiles the whole-rock geochemistry, X-ray diffraction, and electron microscopy analyses of samples collected from the uranium ore bodies of two mined-out deposits in the Grand Canyon region of northwestern Arizona - the Hack II and Pigeon deposits. The samples are grab samples of ore collected underground at each mine by the U.S. Geological Survey (USGS) during the mid-1980s, while each mine was active. The Hack II and Pigeon mines were remediated after their closure, so these data, analyses of samples in the archives of the USGS, are provided as surviving, although limited representations of these ore bodies. The Hack II and Pigeon deposits are similar to numerous other uranium deposits hosted by solution-collapse breccia pipes in the Grand Canyon region of northwest Arizona. The uranium-copper deposits occur within matrix-supported columns of breccia (a "breccia pipe") that formed by solution and collapse of sedimentary strata (Wenrich, 1985; Alpine, 2010). The regions north and south of the Grand Canyon host hundreds of solution-collapse breccia pipes (Van Gosen and others, 2016). Breccia refers to the broken rock that fills these features, and pipe refers to their vertical, pipe-like shape. The breccia pipes average about 300 ft (90 m) in diameter and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The breccia fragments are blocks and pieces of rock units that have fallen downward, now resting below their original stratigraphic level. In contrast to many other types of breccia pipes, there are no igneous rocks associated with the northwestern Arizona breccia pipes, nor have igneous processes contributed to their formation. Many of these breccia pipes contain concentrated deposits of uranium, copper, arsenic, barium, cobalt, lead, molybdenum, nickel, antimony, strontium, vanadium, and zinc minerals (Wenrich, 1985), which is reflected in this data set. The Hack II and Pigeon mines were two of thirteen breccia pipe deposits in the Grand Canyon region mined for uranium from the 1950s to present (2020) (Alpine, 2010; Van Gosen and others, 2016). While hundreds of breccia pipes in the region have been identified (Van Gosen and others, 2016), six decades of exploration across the region has found that most are not mineralized or substantially mineralized, and only a small percentage of the breccia pipes contain economic uranium deposits. The most recent mining operation in a breccia pipe deposit in the region is the Canyon mine, located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona. In 2018, Energy Fuels completed a mine shaft and other mining facilities at the Canyon deposit, a copper- uranium-bearing breccia pipe (Van Gosen and others, 2020); however, this mining operation is currently (2020) inactive, awaiting higher market prices for uranium oxide. The Hack II deposit is one of four breccia pipes mined in Hack Canyon near its intersection with Robinson Canyon (Chenoweth, 1988; Otton and Van Gosen, 2010), approximately 30 miles (48 km) southwest of Fredonia and 9 miles (14.5 km) north-northwest of Kanab Creek. Hack Canyon incised and exposed part of the "Hacks" (or "Hack Canyon") breccia pipe, which was discovered and mined as a surface mine in the early 1900s for copper and silver. The original Hacks mine and adjacent Hack I deposit were later mined underground for uranium from 1950 to 1954 (Chenoweth, 1988). The Hack II deposit was discovered in the late 1970s along Hack Canyon about 1 mile (1.6 km) upstream of the Hacks and Hack I mines. The Hack II mine is located at latitude 36.58219 north, longitude -112.81059 west (datum of WGS84). Mining began at Hack II in 1981 and ended in May 1987. The USGS collected the ore samples reported in this data release in 1984 from underground exposures in the Hack II mine while it was in operation. Reclamation of the four mines in
Mineralogical analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona, USA
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This data release compiles the X-ray diffraction and electron microscopy analyses of drill core samples collected by the U.S. Geological Survey that were selected to typify the uranium-copper ore bodies of the Canyon deposit. The deposit is hosted by a solution-collapse breccia pipe, in which mineralization exists from about 650 to 2,100 ft (200 to 640 m) below the surface (Mathisen and others, 2017), located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona, at latitude 35.88333 North, longitude -112.09583 West (datum WGS 1984). Energy Fuels Inc., owner and operator of the property, has conducted extensive drilling into the Canyon deposit that delineated the extent and uranium and copper content of the ore bodies. Mining facilities, including a shaft, have been developed by Energy Fuels at the deposit. As of October 2020, they await favorable economic conditions to resume mining operations and recover the ore. On a site visit in February 2018, Energy Fuels generously allowed the authors (U.S. Geological Survey geologists) to examine and sample drill cores of mineralized portions of the Canyon deposit. Thirty-five samples were collected, which were chosen primarily as representative intervals of high-grade uranium, copper, and associated sulfide mineralization. An earlier-published data release (Van Gosen and others, 2020) provides the geochemical analyses of the 35 samples for 63 elements. X-ray diffraction (XRD) analyses were performed on 28 of these samples to examine their mineralogy. The raw data from these XRD analyses are also provided in Van Gosen and others (2020). This data release provides a mineralogical interpretation of the XRD data. This data release summarizes the mineralogy of the drill core samples, based on interpretation of the XRD analyses (28 samples) and observations by scanning electron microscopy. From the XRD data, mineralogy was determined using specialized software and user interpretation of the software's selections, which are detailed in the section on process description below. Polished thin sections cut from 21 of the Canyon drill core samples were examined using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) to identify the ore minerals and observe their relationships at high magnification. The EDS vendor's auto identification algorithm was used for peak assignments; the user did not attempt to verify every peak identification. The spectra for each EDS measurement are provided in separate documents in Portable Data Format (pdf), one document for each of the 21 samples that were examined by SEM-EDS. The interpreted mineral phase(s), which is based solely on the judgement of the user, is given below each spectrum. XRD and SEM-EDS analyses identified uraninite (U oxide) as the uranium ore mineral, which is intergrown with at least a dozen identified sulfide minerals, within a gangue matrix of mainly quartz and lesser amounts of clay minerals, dolomite, calcite, barite, and potassium feldspar. The Canyon deposit is similar to numerous other uranium deposits hosted by solution-collapse breccia pipes in the Grand Canyon region of northwest Arizona. The uranium-copper deposits occur within matrix-supported, vertical columns of breccia (a "breccia pipe") that formed by solution and collapse of sedimentary strata (Wenrich, 1985; Alpine, 2010). The breccia pipes average about 300 ft (90 m) in diameter and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The regions north, south, and east of the Grand Canyon host hundreds of solution-collapse breccia pipes (Van Gosen and others, 2016). Six decades of exploration across the region has found that most of these breccia pipes are not mineralized or substantially mineralized, and only a small percentage of the breccia pipes contain ore-grade uranium deposits. The mineralized breccia
Mineralogical analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona, USA
공공데이터포털
This data release compiles the X-ray diffraction and electron microscopy analyses of drill core samples collected by the U.S. Geological Survey that were selected to typify the uranium-copper ore bodies of the Canyon deposit. The deposit is hosted by a solution-collapse breccia pipe, in which mineralization exists from about 650 to 2,100 ft (200 to 640 m) below the surface (Mathisen and others, 2017), located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona, at latitude 35.88333 North, longitude -112.09583 West (datum WGS 1984). Energy Fuels Inc., owner and operator of the property, has conducted extensive drilling into the Canyon deposit that delineated the extent and uranium and copper content of the ore bodies. Mining facilities, including a shaft, have been developed by Energy Fuels at the deposit. As of October 2020, they await favorable economic conditions to resume mining operations and recover the ore. On a site visit in February 2018, Energy Fuels generously allowed the authors (U.S. Geological Survey geologists) to examine and sample drill cores of mineralized portions of the Canyon deposit. Thirty-five samples were collected, which were chosen primarily as representative intervals of high-grade uranium, copper, and associated sulfide mineralization. An earlier-published data release (Van Gosen and others, 2020) provides the geochemical analyses of the 35 samples for 63 elements. X-ray diffraction (XRD) analyses were performed on 28 of these samples to examine their mineralogy. The raw data from these XRD analyses are also provided in Van Gosen and others (2020). This data release provides a mineralogical interpretation of the XRD data. This data release summarizes the mineralogy of the drill core samples, based on interpretation of the XRD analyses (28 samples) and observations by scanning electron microscopy. From the XRD data, mineralogy was determined using specialized software and user interpretation of the software's selections, which are detailed in the section on process description below. Polished thin sections cut from 21 of the Canyon drill core samples were examined using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) to identify the ore minerals and observe their relationships at high magnification. The EDS vendor's auto identification algorithm was used for peak assignments; the user did not attempt to verify every peak identification. The spectra for each EDS measurement are provided in separate documents in Portable Data Format (pdf), one document for each of the 21 samples that were examined by SEM-EDS. The interpreted mineral phase(s), which is based solely on the judgement of the user, is given below each spectrum. XRD and SEM-EDS analyses identified uraninite (U oxide) as the uranium ore mineral, which is intergrown with at least a dozen identified sulfide minerals, within a gangue matrix of mainly quartz and lesser amounts of clay minerals, dolomite, calcite, barite, and potassium feldspar. The Canyon deposit is similar to numerous other uranium deposits hosted by solution-collapse breccia pipes in the Grand Canyon region of northwest Arizona. The uranium-copper deposits occur within matrix-supported, vertical columns of breccia (a "breccia pipe") that formed by solution and collapse of sedimentary strata (Wenrich, 1985; Alpine, 2010). The breccia pipes average about 300 ft (90 m) in diameter and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The regions north, south, and east of the Grand Canyon host hundreds of solution-collapse breccia pipes (Van Gosen and others, 2016). Six decades of exploration across the region has found that most of these breccia pipes are not mineralized or substantially mineralized, and only a small percentage of the breccia pipes contain ore-grade uranium deposits. The mineralized breccia
Geochemical and X-ray diffraction analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona
공공데이터포털
This data release compiles the major and trace element analytical results of drill core samples that typify the uranium-copper ore bodies of the Canyon deposit, located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona. The Canyon deposit lies from about 750 to 2,000 ft (230 to 610 m) below the surface at latitude 35.88333 North, longitude -112.09583 West (datum WGS 1984). Energy Fuels, owners and operators of the property, has conducted extensive drilling into the Canyon deposit, which has defined the extent and characteristics of the ore bodies, leading to mine development. On a site visit in February 2018, Energy Fuels generously allowed the authors (U.S. Geological Survey geologists) to examine and sample drill cores of mineralized portions of the Canyon deposit, focused primarily on intervals of high-grade uranium and associated mineralization. This data release provides the analytical results of 35 samples of drill core collected during the visit by the authors. Additionally, X-ray Diffraction analyses were performed on 28 of these samples to examine their mineralogy. These samples and their geochemistry reflect the variation of base-metal sulfide and uranium oxide mineralization within ore zones of the Canyon deposit. The ore mineralogy, and thus rock chemistry, can vary over short intervals (centimeters). However, although their concentrations vary, the group of metals that occur together is generally consistent. The 35 samples were analyzed for 63 elements by a laboratory contracted by the USGS. Concentrations for 58 elements were measured by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Additionally, total carbon, carbonate carbon (inorganic carbon), total sulfur, mercury, and selenium concentrations were determined using other element-specific analytical techniques (described below). From this suite of 35 samples, 28 were analyzed by X-ray Diffraction to determine their mineralogy. The X-ray Diffraction scan results are provided in the data file named "Canyon_deposit_drill_core_samples_XRD.csv". The Canyon uranium-copper deposit occurs within a matrix-supported column of breccia (a "breccia pipe") that is similar to numerous other uranium-bearing breccia pipes of the Grand Canyon region of northwest Arizona. These uranium deposits occur in unusual features described as solution-collapse breccia pipes, or simply breccia pipes (Wenrich, 1985; Alpine, 2010). The regions north and south of the Grand Canyon host hundreds of breccia pipes that were formed by solution and collapse (Van Gosen and others, 2016). Breccia refers to the broken rock that fills these features, and pipe refers to the vertical, pipe-like shape of these features. The breccia pipes average about 300 ft (90 m) in diameter, and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The breccia fragments that form the pipes are consistently blocks and pieces of rock units found below their normal position in the wall rock; that is, all rocks within the breccia column have fallen downward and are never found above their original level. In contrast to many other types of breccia pipes, there are no igneous rocks associated with the northwestern Arizona breccia pipes, nor have igneous processes contributed to their formation. Many of these breccia pipes contain concentrated deposits of uranium, arsenic, copper, silver, lead, zinc, cobalt, and nickel minerals (Wenrich, 1985), as is reflected in this data set. Subsequent to the primary episodes of solution and collapse (breccia pipe formation), base-metal mineralization was deposited in the breccia pipes, primarily as sulfide phases, and principally in the stratigraphic levels of the Coconino Sandstone, Hermit Formation, and Esplanade Sandstone (Wenrich, 1985; Alpine, 2010). In the Canyon breccia pipe,
Geochemical and X-ray diffraction analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona
공공데이터포털
This data release compiles the major and trace element analytical results of drill core samples that typify the uranium-copper ore bodies of the Canyon deposit, located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona. The Canyon deposit lies from about 750 to 2,000 ft (230 to 610 m) below the surface at latitude 35.88333 North, longitude -112.09583 West (datum WGS 1984). Energy Fuels, owners and operators of the property, has conducted extensive drilling into the Canyon deposit, which has defined the extent and characteristics of the ore bodies, leading to mine development. On a site visit in February 2018, Energy Fuels generously allowed the authors (U.S. Geological Survey geologists) to examine and sample drill cores of mineralized portions of the Canyon deposit, focused primarily on intervals of high-grade uranium and associated mineralization. This data release provides the analytical results of 35 samples of drill core collected during the visit by the authors. Additionally, X-ray Diffraction analyses were performed on 28 of these samples to examine their mineralogy. These samples and their geochemistry reflect the variation of base-metal sulfide and uranium oxide mineralization within ore zones of the Canyon deposit. The ore mineralogy, and thus rock chemistry, can vary over short intervals (centimeters). However, although their concentrations vary, the group of metals that occur together is generally consistent. The 35 samples were analyzed for 63 elements by a laboratory contracted by the USGS. Concentrations for 58 elements were measured by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Additionally, total carbon, carbonate carbon (inorganic carbon), total sulfur, mercury, and selenium concentrations were determined using other element-specific analytical techniques (described below). From this suite of 35 samples, 28 were analyzed by X-ray Diffraction to determine their mineralogy. The X-ray Diffraction scan results are provided in the data file named "Canyon_deposit_drill_core_samples_XRD.csv". The Canyon uranium-copper deposit occurs within a matrix-supported column of breccia (a "breccia pipe") that is similar to numerous other uranium-bearing breccia pipes of the Grand Canyon region of northwest Arizona. These uranium deposits occur in unusual features described as solution-collapse breccia pipes, or simply breccia pipes (Wenrich, 1985; Alpine, 2010). The regions north and south of the Grand Canyon host hundreds of breccia pipes that were formed by solution and collapse (Van Gosen and others, 2016). Breccia refers to the broken rock that fills these features, and pipe refers to the vertical, pipe-like shape of these features. The breccia pipes average about 300 ft (90 m) in diameter, and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The breccia fragments that form the pipes are consistently blocks and pieces of rock units found below their normal position in the wall rock; that is, all rocks within the breccia column have fallen downward and are never found above their original level. In contrast to many other types of breccia pipes, there are no igneous rocks associated with the northwestern Arizona breccia pipes, nor have igneous processes contributed to their formation. Many of these breccia pipes contain concentrated deposits of uranium, arsenic, copper, silver, lead, zinc, cobalt, and nickel minerals (Wenrich, 1985), as is reflected in this data set. Subsequent to the primary episodes of solution and collapse (breccia pipe formation), base-metal mineralization was deposited in the breccia pipes, primarily as sulfide phases, and principally in the stratigraphic levels of the Coconino Sandstone, Hermit Formation, and Esplanade Sandstone (Wenrich, 1985; Alpine, 2010). In the Canyon breccia pipe,
Surface Materials Data from Breccia-Pipe Uranium Mine and Reference Sites, Arizona, USA
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This data release includes elemental analysis of soil samples collected at breccia-pipe uranium mines, at one undeveloped breccia-pipe uranium deposit, and at a reference site in northern Arizona. Samples were collected near the Arizona 1, Canyon, Kanab North, and Pinenut uranium mines, over the EZ2 breccia-pipe uranium deposit, and at the Little Robinson Tank reference site. Samples were collected around the Arizona 1 mine after active mining had ceased during July 2015; around and within the mine yard at the Canyon mine during mine-development activity and before active mining occurred in June 2013; around and within the mine yard at the Kanab North mine during reclamation and before reclamation was completed in June 2016; around the Pinenut mine during active mining in October 2014; directly over the EZ2 deposit before any development activity occurred during November 2015; and at the Little Robinson Tank reference site during November 2015. This data release includes data for four different types of soil samples: (type 1) incremental soil samples where more than 30 equally-spaced subsamples were collected and composited over a limited areal extent termed a decision unit and depicted generally as a trapezoidal-shaped polygon mapped within a mine yard, or surrounding a mine site; (type 2) incremental soil samples where more than 30 subsamples were collected and composited over a roughly two dimensional linear or sinuous mapped pattern following roads also termed a decision unit; (type 3) discrete integrated soil samples (Bern and others, 2019 use the term “point” for these samples) where more than 30 subsamples were collected within fenced exclosures (generally about 3 meters square) containing Big Springs Number Eight dust sampling equipment; and (type 4) integrated soil samples comprised of at least 10 subsamples collected from underneath plywood cover boards used to collect herpetofauna. Incremental samples (types 1 and 2) were collected in triplicate from the soil surface from 0-5 centimeters (cm) depth using a Multi-Incremental Sampling Tool (MIST) collecting approximately the same volume for each subsample subject to slight variation due to variable soil conditions. The volume of soil represented by each type 1 and 2 sample is termed a decision unit (DU), the areal extent of which is defined by a mapped polygonal or sinuous or linear area, and the depth of which is the 5 cm that is sampled by the MIST. Each subsample of each triplicate incremental sample was passed through a 2-millimeter sieve and composited into a clean 19-liter bucket, with each completed triplicate sample transferred to double zip-top bags for transfer to the laboratory. Integrated samples (types 3 and 4) were collected using a plastic soil scoop to collect soil from 0-5 cm depth and were composited into double zip-top plastic bags for transfer to the laboratory. Data are divided into two different data tables based upon type: types 1 and 2 are in T1_DUSamples.csv; types 3 and 4 are in T2_BSNESamples.csv. The file DataDictionary_v1.csv defines all table headings and abbreviations. Sample preparation and analytical techniques are described in the metadata file. This data release also includes location information for the approximate center points of the incremental sample polygons and linear features (decision units) and for the discrete integrated samples. Note, locations for incremental samples for decision units (sample types 1 and 2) are the approximate center of the geographical area (polygon, linear, or sinuous feature) over which the sample was collected. As such, the elemental values represent average concentrations for the sample volume collected over the entire geographic area and depth of 0-5 centimeters of each decision unit, and do not represent concentrations that would be measured in a discrete sample collected at that central location.
Atmospheric fallout radionuclide data and geochemical data for soil cores from four uranium mine sites, Mohave County, Arizona, April 2022
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The data represent sediment depth profiles of gamma-emitting radionuclides and major, minor, and trace elements in native soil locations around four mineralized sites in Mohave County, Arizona. The four sites represent breccia pipe uranium deposits in the Grand Canyon Region in various lifecycle stages of mining: EZ2 complex (exploration), Arizona 1 mine (standby), Pinenut mine (closed, pre-reclamation), and Kanab North Mine (reclaimed). Gamma spectroscopy determinations were made using high-purity germanium well detectors for analysis of cesium-137 (Cs-137), lead-210 (Pb-210), lead-214 (Pb-214), and bismuth-214 (Bi-214). Major, minor, and trace element determinations were made for using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) for analysis of aluminum (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), sodium (Na), phosphorus (P), sulfur (S), titanium (Ti), silver (Ag), arsenic (As), barium (Ba), beryllium (Be), bismuth (Bi), cadmium (Cd), cerium (Ce), cobalt (Co), chromium (Cr), cesium (Cs), copper (Cu), gallium (Ga), hafnium (Hf), indium (In), lanthanum (La), lithium (Li), lutetium (Lu), manganese (Mn), molybdenum (Mo), niobium (Nb), nickel (Ni), lead (Pb), rubidium (Rb), antimony (Sb), scandium (Sc), selenium (Se), tin (Sn), strontium (Sr), tantalum (Ta), terbium (Tb), tellurium (Te), thorium (Th), thallium (Tl), uranium (U), vanadium (V), tungsten (W), yttrium (Y), ytterbium (Yb), zinc (Zn), and zirconium (Zr). The data were collected to assess the potential of fallout radionuclides (Cs-137 and unsupported Pb-210) to help understand the distribution of subsurface contaminants related to mining activity. The Pb-210, Pb-214, and Bi-214 data can be used to calculate Ra-226 and unsupported Pb-210.
Atmospheric fallout radionuclide data for soil cores from four uranium mine sites, Mohave County, Arizona, November 2018
공공데이터포털
The data represent sediment depth profiles of gamma-emitting radionuclides cesium-137 (Cs-137), lead-210 (Pb-210), lead-214 (Pb-214), and bismuth-214 (Bi-214) in native soil locations around four mineralized sites in Mohave County, Arizona. The four sites represent breccia pipe uranium deposits in the Grand Canyon Region in various lifecycle stages of mining: EZ2 complex (exploration), Arizona 1 mine (standby), Pinenut mine (closed, pre-reclamation), and Kanab North Mine (reclaimed). The data were collected to assess the potential of fallout radionuclides (Cs-137 and unsupported Pb-210) to help understand the distribution of subsurface contaminants related to mining activity. Gamma spectroscopy determinations were performed on archive samples from November 2018 that were collected during a previous investigation, which is cited below. The Pb-210, Pb-214, and Bi-214 data can be used to calculate Ra-226 and excess (unsupported) Pb-210. Additional information about the collection of sediment cores and soil-profile measurements can be found in Kauble, R.K., Andraski, B.J., Green, C.T., and Walton-Day, K., 2021, Soil sample data for four uranium mine sites, Mohave County, Arizona, April and November 2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9B8I7KC.