Adam M Hudson
Biography
I am a geochemist and geologist specializing in lakes, wetlands, and soils, with a focus on carbonates. I am particularly interested in what isotopes in carbonates can say about the geologic history of these types of environments. My main research goal is to understand what affects water availability in arid regions. I have done research in Tibet, the Andes, and the western United States. My current research is focused in the US Great Basin, Alaska, and the southern Rocky Mountains.
Science and Products
Denali National Park Geohazards Geologic Mapping
Denali National Park (DENA) is a major draw for tourism and recreation and a major economic engine for central Alaska. However, the geologic forces that created the steep landscape of DENA also make it prone to geologic hazards (geohazards) like landslides, debris flows, and earthquakes. DENA has only one major road, called the ‘Park Road’, that serves nearly all of its infrastructure.
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Geologic Framework of the Intermountain West
The Geologic Framework of the Intermountain West project was launched with the goal of producing a new digital geologic map database and 3D geologic model of a transect from the Rio Grande rift to the Basin and Range, based on a synthesis of existing geologic maps with new targeted new mapping, subsurface data, and other data sets. This database will integrate disparate map data, resolve...
Serving the U.S. Geological Survey’s geochronological data
Geochronological data provide essential information necessary for understanding the timing of geologic processes and events, as well as quantifying rates and timescales key to geologic mapping, mineral and energy resource and hazard assessments. The USGS’s National Geochronological Database (NGDB) contains over 30,000 radiometric ages, but no formal update has occurred in over 20 years. This...
Denver Radiogenic Isotope Lab
Radiogenic isotopes are daughter nuclides derived from natural decay of radioactive parent nuclides. They are useful for determining radiometric ages of rocks, minerals, and soils, and can be used as natural tracers of lithologic, hydrologic, and biologic materials.
Paleohydrology of Desert Wetlands
Springs and wetlands are among the most highly threatened ecosystems on Earth. Although geographically limited, they support more than 20% of all the threatened and endangered species in the United States. Scientists from the U.S. Geological Survey are examining the rock record to determine how springs and wetlands responded to abrupt climate change during prehistoric times and the recent...
Data release for Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
This dataset includes tables of He-isotopic data used to calculate surface exposure ages for samples of basalt, and U- and Th-isotopic data used to calculate uranium-series age estimates (230Th/U method) and initial 234U/238U activity ratios for samples of pedogenic carbonate formed in soils on alluvial fans in the San Luis Valley, Colorado, USA.
Data release for Isotopic constraints on middle Pleistocene cave evolution, paleohydrologic flow, and environmental conditions from Fitton Cave speleothems, Buffalo National River, Arkansas (KIG'17)
This dataset accompanies publication 'Isotopic constraints on middle Pleistocene cave evolution, paleohydrologic flow, and environmental conditions from Fitton Cave speleothems, Buffalo National River, Arkansas', to be published as a USGS Scientific Investigations Report associated with the 2017 USGS Karst Interest Group meeting in San Antonio, TX.
Assessing geohazards to the Denali National Park road with geologic mapping
Denali National Park (DENA) is home to iconic and breathtaking landscapes surrounding the tallest mountain range in North America, the Alaska Range. The park, which covers 6 million acres, is a major draw for tourism and recreation, making it an important economic engine for central Alaska. However, the geologic forces that created the beautiful,...
Hudson, Adam M.; Ruleman, Chester A.; Capps, Denny MMiddle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
The Rio Grande is the fourth longest river in North America extending over 3,000 km from the Rocky Mountains to the Gulf of Mexico. The Pleistocene evolution of this river from individual subbasins into a coalesced fluvial system has been long debated. Herein, we constrain the middle Pleistocene evolution of the northernmost and largest Rio Grande...
Ruleman, Chester A.; Hudson, Adam M.; Thompson, Ren A.; Miggins, Daniel P.; Paces, James; Goehring, Brent M.North-south dipole in winter hydroclimate in the western United States during the last deglaciation
During the termination of the last glacial period the western U.S. experienced exceptionally wet conditions, driven by changes in location and strength of the mid-latitude winter storm track. The distribution of modern winter precipitation is frequently characterized by a north-south wet/dry dipole pattern, controlled by interaction of the storm...
Hudson, Adam M.; Hatchett, Benjamin J.; Quade, Jay; Boyle, Douglas P.; Bassett, Scott D.; Ali, Guleed; De los Santos, Marie G.Establishing chronologies for alluvial-fan sequences with analysis of high-resolution topographic data: San Luis Valley, Colorado, USA
On active alluvial fans, debris-flow deposits and frequent avulsions produce a rough topographic surface. As is the case in many initially rough landforms produced by catastrophic processes, the topography of alluvial fans is progressively smoothed, producing textural differences useful in establishing relative age criteria for fans. Here, we...
Johnstone, Samuel A.; Hudson, Adam M.; Nicovich, Sylvia; Ruleman, Chester A.; Sare, Robert M.; Thompson, Ren A.Isotopic characterization of late Neogene travertine deposits at Barrancas Blancas in the eastern Atacama Desert, Chile
Here we explore the potential of spring-related, surface and subsurface carbonates as an archive of paleoenvironmental change at Barrancas Blancas, located in the broadest and driest sector of the Atacama Desert at 24.5°S. From these deposits we present a new stable isotopic record of paleoenvironmental conditions over portions of the past ~ ...
Quade, J.; Rasbury, E.T.; Huntington, K.W.; Hudson, Adam M.; Vonhof, H.; Anchukaitis, K.; Betancourt, Julio L.; Latorre, C.; Pepper, M.Stable C, O and clumped isotope systematics and 14C geochronology of carbonates from the Quaternary Chewaucan closed-basin lake system, Great Basin, USA: Implications for paleoenvironmental reconstructions using carbonates
Isotopic compositions of lacustrine carbonates are commonly used for dating and paleoenvironmental reconstructions. Here we use carbonate δ13C and δ18O, clumped (Δ47), and 14C compositions to better understand the carbonate isotope system in closed-basin lakes and trace the paleohydrologic and temperature evolution in the Chewaucan closed-basin...
Hudson, Adam M.; Quade, Jay; Ali, Guleed; Boyle, Douglas P.; Bassett, Scott; Huntington, Katharine W.; De los Santos, Marie G.; Cohen, Andrew S.; Lin, Ke; Wang, XiangfengPreliminary geologic map of the Big Costilla Peak area, Taos County, New Mexico, and Costilla County, Colorado
This map covers the Big Costilla Peak, New Mex.&nash;Colo. quadrangle and adjacent parts of three other 7.5 minute quadrangles: Amalia, New Mex.–Colo., Latir Peak, New Mex., and Comanche Point, New Mex. The study area is in the southwesternmost part of that segment of the Sangre de Cristo Mountains known as the Culebra Range; the Taos Range...
Fridrich, Christopher J.; Shroba, Ralph R.; Hudson, Adam M.Preliminary Geologic Map of the Vermejo Peak area, Colfax and Taos Counties, New Mexico and Las Animas and Costilla Counties, Colorado
This geologic map covers four 7.5-minute quadrangles-The Wall, NM-CO (New Mexico-Colorado), Vermejo Park, NM-CO, Ash Mountain, NM, and Van Bremmer Park, NM. The study area straddles the boundary between the eastern flank of the Sangre de Cristo Mountains and the western margin of the Raton Basin, with about two-thirds of the map area in the basin...
Fridrich, Christopher J.; Shroba, Ralph R.; Pillmore, Charles L.; Hudson, Adam M.