A5014140224- Geochemistry and Geologic Mapping
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Water Quality and Resources Studies
- Geological Studies and Exploration
- Groundwater and Isotope Geochemistry
- Geology and Paleoclimatology Research
- Climate change and permafrost
- Polar Research and Ecology
- Hydrocarbon exploration and reservoir analysis
- Geological and Geochemical Analysis
- Radioactive element chemistry and processing
- Archaeology and Natural History
- Methane Hydrates and Related Phenomena
- Mining and Gasification Technologies
- Marine and coastal ecosystems
- Cryospheric studies and observations
- Analytical chemistry methods development
- Mercury impact and mitigation studies
- Heavy metals in environment
- Groundwater flow and contamination studies
- Smart Materials for Construction
- Geochemistry and Elemental Analysis
- Soil Carbon and Nitrogen Dynamics
- Metal Extraction and Bioleaching
United States Geological Survey
2005-2023
U.S. Geological Survey, Alaska Science Center
2010
Alaska Department of Natural Resources
1999
Denver Federal Center
1999
AbstractAttempts to understand how communities assemble following a disturbance are challenged by the difficulty of determining relative importance stochastic and deterministic processes. Biological legacies, which result from organisms that survive disturbance, can favour processes in community assembly improve predictions successional trajectories. Recently disturbed ecosystems often so rapidly colonized propagules role biological legacies is obscured. We studied on remote volcanic island...
Summary In A ugust 2008, K asatochi volcano erupted and buried a small island in pyroclastic deposits fine ash; since then, microbes, plants birds have begun to re‐colonize the initially sterile surface. Five years post‐eruption, bacterial 16S r RNA gene fungal internal transcribed spacer (ITS) copy numbers extracellular enzyme activity ( EEA ) potentials were one two orders of magnitude greater materials with organic matter OM inputs relative those without, despite minimal accumulation...
A mass of snow and ice 400‐m‐wide 105‐m‐thick began melting in the summit crater Mount Chiginagak volcano sometime between November 2004 early May 2005, presumably owing to increased heat flux from hydrothermal system, or possibly magma intrusion degassing. In an estimated 3.8 × 10 6 m 3 sulfurous, clay‐rich debris acidic water, with accompanying aerosol component, exited through a tunnel at base glacier that breaches south rim. Over 27 km downstream, waters flood inundated important salmon...
The 7–8 August 2008 eruption of Kasatochi Island volcano blanketed the island in newly generated pyroclastic deposits and deposited ash into ocean onto nearby islands. Concentrations water soluble Fe, Cu, Zn determined from a 1:20 deionized leachate were sufficient to provide short-term fertilization surface ocean. thicker concavities at bases steeper slopes thinner on steep ridge crests. By summer 2009, secondary erosion had exposed pre-eruption soils along gulley walls gully bottoms...
First posted September 3, 2019 For additional information, contact: Director, Geology, Geophysics and Geochemistry Science CenterU.S. Geological SurveyBox 25046, MS-973Denver, CO 80225-0046 The Alaska Geochemical Database Version 3.0 (AGDB3) contains new geochemical data compilations in which each geologic material sample has one “best value” determination for analyzed species, greatly improving speed efficiency of use. Like the 2.0 before it, AGDB3 was created designed to compile integrate...
First posted June 21, 2016 For additional information, contact: Center DirectorUSGS Central Mineral and Environmental Resources Science Box 25046, MS-973 Denver Federal Denver, CO 80225-0046http://minerals.cr.usgs.gov A rich legacy of geochemical data produced since the early 1960s covers great expanse Alaska; careful treatment such may provide significant revealing maps that be used for landscape geochemistry, mineral resource exploration, geoenvironmental investigations over large areas....
Geochemical patterns are presented for 23 elements, ash yield, and pH in soils other unconsolidated surficial materials from 265 collection sites throughout Alaska. This is a new presentation of data originally published 1988 released now with additional interpretation based on landscape geochemical principles (such as the effects regional groups, climate, vegetation) that influence observed areal patterns. The interpretations applied to subjects involving ecosystems soil-forming processes...
Thick accumulations of ice, called "aufeis," form during winter along stream and river valleys in arctic subarctic regions. In high-gradient alpine streams, aufeis forms mostly as a result ground-water discharge into the channel. The ice occludes this discharge, perturbing steady-state condition, causing an incremental rise local water table until occurs higher on bank above previously formed ice. Successive freezing onlapping layers can lead to several meters thick. location extent streams...
First posted August 12, 2019 For additional information, contact: Alaska Science Center staffU.S. Geological Survey4210 University Dr.Anchorage, AK 99508Alaska Mineral ResourcesAlaska Soils collected along a predominately north-south transect in were used to evaluate regional differences the soil mineralogy and geochemistry context of geotectonic framework for Alaska. The approximately 1,395-kilometer-long followed Dalton, Elliott, Richardson Highways from near Prudhoe Bay Valdez. Sites...
First posted February 23, 2015 For additional information, contact: Alaska Science Center staffU.S. Geological Survey4210 University Dr.Anchorage, AK 99508Alaska This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated potential and certainty are mapped for six selected deposit groups: (1) rare earth element (REE) deposits associated with peralkaline carbonatitic intrusive...
A systematic water-quality study of the Fortymile River and many its major tributaries in eastern Alaska was conducted June 1997 1998.Surface-water samples were collected for chemical analyses to establish regional baseline geochemistry values evaluate possible environmental effects suction-dredge placer gold mining bulldozer-operated (commonly referred as "cat mining").In general, water quality is very good, with low total dissolved solids only two cases which concentration any element...
First posted June 29, 2021 Revised October 28, For additional information, contact: Director,Alaska Science CenterU.S. Geological Survey4210 University DriveAnchorage, Alaska 99508 Several comprehensive, data-driven geographic information system (GIS) analyses were conducted to assess prospectivity for lode gold in Alaska. These use available geospatial datasets of lithologic, geochemical, mineral occurrence, and geophysical data build models recognizing different types deposits within...
First posted May 26, 2020 For additional information, contact: Director,Alaska Science CenterU.S. Geological Survey4210 University DriveAnchorage, Alaska 99508 A recent U.S. Survey data compilation of stream-sediment geochemistry for contains decades analyses collected under numerous Federal and State programs. The compiled were determined by various analytical methods. Some samples reanalyzed a different method than the original, resulting in some elements having concentrations reported...
Stream water was collected at 30 sites within the Tangle Lakes area of Delta mineral belt in Alaska. Sampling focused on streams near ultramafic rocks Fish Lake intrusive complex south Eureka Creek and Complex east Fourteen Mile Lake, as well those deformed metasedimentary, metavolcanic, Specimen drainage drainages Glacier. Major, minor, trace elements were analyzed aqueous samples for this reconnaissance geochemistry effort. The lithologic differences study are reflected major-ion chemistry...
We report the chemical analysis for water and sediment collected from Big Delta B-2 quadrangle. These data are part of a study located in quadrangle that focused on integration geology bedrock geochemistry with biogeochemistry water, sediments, soil, vegetation. The discovery Pogo lode gold deposit northwest corner was impetus this study. objectives were to create geologic map, evaluate geochemical influence signature surficial environment, define landscape-level predevelopment baselines....