The data presented here are from hand held X-ray fluorescence measurements from clean faces of sediment in trenches of the Aztec Drinking Water Reservoir #1. Sediments were analyzed at approximately the mid-point between the top and bottom depths.

The data presented here are from hand held X-ray fluorescence measurements on wet and dry composite samples. The composite samples are from 10 cm sections of sediment trenches in the Aztec Drinking Water Reservoir #1. Samples were analyzed to evaluate chemistry of the reservoir sediments.

The data presented here are from acid digested sediments from 10 cm composites at different depths in trenches of the Aztec Drinking Water Reservoir #1.

These data provide the initial field observations of reservoir sediments including grain size, color, bioturbation, redox indicators, and reaction with hydrogen peroxide and hydrochloric acid.

This dataset contains the results of batch experiments to evaluate the mobility of major and trace elements from the Aztec Drinking Water Reservoir #1 sediments. The sediments were exposed to 3 different environmentally relevant reagents, deionized water, bicarbonate, and acetic acid.

The elemental concentration over time of sediments from four trenches from the Aztec drinking water reservoir #1. The source of water to the reservoir is the Animas River, which has historical mining sites in the watershed. In order to evaluate the geochemical record in the sediments, several types of data were collected. Bulk chemical analysis of sediments with depth in the reservoir as well as X-ray fluorescence measurements provide information about the sediment total chemistry. Batch experiments where sediments are reacted with different reagents provide information about the mobility of major and trace elements from the sediments into the reservoir water or environment. Sediment field descriptions provide information about the grain size, degree of sorting, redox conditions, and reaction with hydrochloric acid or hydrogen peroxide.

These data were collected using field portable (handheld) X-ray fluorescence (pXRF) equipped with a 4-watt Ta/Au X-ray tube. Samples of surficial alluvium, rock, and archived core material from existing auger- or sonic-drilled monitoring wells in Hinkley Valley and the adjoining Water Valley, 140 kilometers (km) northeast of Los Angeles, California, were measured as part of an investigation of naturally-occurring and anthropogenic hexavalent chromium, Cr(VI), concentrations in local groundwater. Surficial alluvium samples were collected from small stream channels draining distinct geologic units, or from previously mapped river deposits, and generally consisted of silt, sand, and granules to small pebbles. Twigs and other detritus were removed prior to measurement. Rocks were collected from outcrops or from colluvium eroded from nearby outcrops and were broken to expose fresh surfaces whenever possible. Core material was measured within the screened interval of wells sampled for water-quality as part of the study, along with additional core material from other intervals of geologic or lithologic interest to the study. Some measurements of core material were made on materials from selected geologic settings including oxide-rich zones formed near lithologic and redox contacts, groundwater discharge deposits, and weathered bedrock. Measurements were made on 155 samples of alluvium and rock, and archived core material from 69 monitoring well sites, located over an approximately 200 square km area between March 2015 and May 2018. Measurements on National Institute of Standards and Technology (NIST) and U.S. Geological Survey standard reference materials (available in a separate child page associated with https://doi.org/10.5066/P9CU0EH3) indicated the pXRF was sufficiently accurate for chromium and selected trace elements for the intended purpose of the dataset. Standard reference material indicated a need to adjust instrument beam times to optimize measurements of chromium. Measurements on a silica dioxide blank showed consistent clean (few to no measurable elements) data.

These data contain concentrations of select trace elements in samples collected on the flood plain from flood deposits from the December 2015 flood and underlying soils. All samples were analyzed by x-ray fluorescence.

Rio Tinto, Spain, is an example of a fluvial system strongly influenced by acid rock and acid mine drainage. During the spring of 2018 and 2019, samples of stream waters and mine waters, biofilms, sediments, and rocks, were collected in the field by Aubrey Zerkle. These samples were analyzed for comprehensive geochemistry, including Cr isotope geochemistry, anions and cations. Mineralogical analysis was conducted on powdered sediments and rocks.

Sediment traps were deployed in tributaries to the San Juan River during 2021 and 2022. These traps collected sediment during storm events that typically occur as monsoonal convective storms from June to September. Because of the rural nature of the watershed, sediment traps were collected every 3 weeks so the sediment collected is a composite of that time period. The date listed is the date the trap was collected. This dataset includes the chemical concentrations of the sediment samples. Major ions are reported in weight percentage, while all other elements are reported in parts per million. Samples were fused at 750°C with sodium peroxide and the fusion cake dissolved in a dilute nitric acid. The resulting solution was analyzed by ICP-OES and ICP-MS. This method was done to include all of the rare earth elements. Results from this method may differ slightly from the results in the 49-element analysis because of the differences in digestion procedure. The 60 element dataset includes aluminum, calcium, iron, potassium, magnesium, phosphorous, sulfur, silicon, titanium, silver, arsenic, boron, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, dysprosium, erbium, europium, gallium, gadolinium, germanium, hafnium, holmium, indium, lanthanum, lithium, lutetium, manganese, molybdenum, niobium, neodymium, nickel, lead, praseodymium, rubidium, antimony, scandium, selenium, samarium, tin, strontium, tantalum, terbium, tellurium, thorium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zircon.