I have had the opportunity to work work with some amazing talent at the USGS, and support some fascinating projects. From the Alaskan muskeg to the dry playas of the Mojave Desert, I have been able to search for, recover, and describe some really cool geologic records.
have spent numerous summers working on collecting sediment from lakes; The Great Salt Lake, Bear Lake, high altitude lakes in Colorado, Crevice lake in Yellowstone, and remote ponds, surrounded by grizzlies, near Yakutat, Alaska. Using Kullenburg, Uwitec, Livingston and other systems I have helped develop records of vegetation change and landscape evolution from the bottoms of these lakes. Most recently I have been able to utilize hydraulic systems to extract records from the dry playa lakes in the desert southwest. Exploring the sedimentological records of these systems, and trying to fathom the changes that the Earth's surface goes through has fully gathered my attention.
Education and Certifications
1993 B.S., Environmental Studies, University of Nebraska at Omaha
2014 M.A., Geography, University of Denver
Science and Products
Quaternary Hydroclimate Records of Spring Ecosystems
Paleohydrology of Desert Wetlands
Data release for Evidence of glacial activity during MIS 4 in the Rocky Mountains, Colorado, USA
Data release for Evidence of humans in North America during the Last Glacial Maximum
Long-term annual aeolian dust deposition data from seven locations in southeastern Utah
Holocene paleohydrology from alpine lake sediment, Emerald Lake, Wasatch Plateau of central Utah, USA
Evidence of glacial activity during MIS 4 in the Rocky Mountains, Colorado, USA
Evidence for humans in North America during the Last Glacial Maximum
Late Quaternary paleohydrology of desert wetlands and pluvial lakes in the Soda Lake basin, central Mojave Desert, California (USA)
Desert wetlands record hydrologic variability within the Younger Dryas chronozone, Mojave Desert, USA
Activation of a small ephemeral lake in southern Jordan during the last full glacial period and its paleoclimatic implications
Active tectonics of the northern Mojave Desert: The 2017 Desert Symposium field trip road log
Late quaternary changes in lakes, vegetation, and climate in the Bonneville Basin reconstructed from sediment cores from Great Salt Lake: Chapter 11
Description and Analytical Results for Deposited Dust Samples from a Two-Year Monitoring Program Near Deer Trail, Colorado, USA, 2006-2007
Science and Products
- Science
Quaternary Hydroclimate Records of Spring Ecosystems
Desert springs and wetlands are among the most biologically productive, diverse, and fragile ecosystems on Earth. They are home to thousands of rare, endemic, and endangered plants and animals and reflect the availability and health of emergent groundwater. Despite the ecological importance of these wetlands, our knowledge of how they might respond to predicted future climate change is limited...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 geologic... - Data
Data release for Evidence of glacial activity during MIS 4 in the Rocky Mountains, Colorado, USA
The Ziegler Reservoir fossil site near Snowmass Village, Colorado (USA) provides a rare opportunity to examine environmental conditions in the Rocky Mountains during marine isotope stage (MIS) 4 (71-57 ka). Although recognized as a global-scale cold event, MIS 4 is typically absent from Rocky Mountain glacial chronologies because the geologic evidence was either covered or destroyed during the subData release for Evidence of humans in North America during the Last Glacial Maximum
Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. Questions remain about when and how people migrated, where they originated, and how their arrival affected the established fauna and landscape. Here, we present evidence from excavated surfaces in White Sands National Park (New Mexico, United States), where multiple in situ human fooLong-term annual aeolian dust deposition data from seven locations in southeastern Utah
These data are annual aeolian dust deposition calculations from vertical deposition at seven locations near the vicinity of Moab, Utah covering the period from 1999 to 2020. Data were collected by the U.S. Geological Survey Geosciences and Environmental Change Science Center (Denver, Colorado) and Southwest Biological Science Center (Moab, Utah) to "monitor sediment characteristics at sites select - Publications
Holocene paleohydrology from alpine lake sediment, Emerald Lake, Wasatch Plateau of central Utah, USA
Holocene sediments at Emerald Lake in central Utah (3090 m asl) document the paleohydroclimatic history of the western Upper Colorado River headwater region. Multi-proxy analyses of sediment composition, mineralogy, and stable isotopes of carbonate (δ18O and δ13C) show changes in effective moisture for the past ca. 10,000 years at millennial to decadal timescales. Emerald Lake originated as a shalEvidence of glacial activity during MIS 4 in the Rocky Mountains, Colorado, USA
The Ziegler Reservoir fossil site near Snowmass Village, Colorado, provides a rare opportunity to examine environmental conditions in the Rocky Mountains during marine isotope stage (MIS) 4 (71–57 ka). Although recognized as a global-scale cold event, MIS 4 is typically absent from Rocky Mountain glacial chronologies because the geologic evidence was covered or destroyed during the subsequent, andEvidence for humans in North America during the Last Glacial Maximum
Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. When, how, and from where did people migrate, and what were the consequences of their arrival for the established fauna and landscape are enduring questions. Here, we present evidence from excavated surfaces of in situ human footprints from White Sands National Park (New Mexico, USA)Late Quaternary paleohydrology of desert wetlands and pluvial lakes in the Soda Lake basin, central Mojave Desert, California (USA)
Sediment cores taken near extant springs along the western margin of Soda Lake playa, as well as from the playa center, reveal dramatic hydrologic changes that occurred in the central Mojave Desert during the late Quaternary. Results of stratigraphic, chronologic, physical, chemical, and microfossil analyses of seven cores, ranging in length from 5 to 23 m, help refine the timing and character ofDesert wetlands record hydrologic variability within the Younger Dryas chronozone, Mojave Desert, USA
One of the enduring questions in the field of paleohydrology is how quickly desert wetland ecosystems responded to past episodes of abrupt climate change. Recent investigations in the Las Vegas Valley of southern Nevada have revealed that wetlands expanded and contracted on millennial and sub-millennial timescales in response to changes in climate during the late Quaternary. Here, we evaluate geolActivation of a small ephemeral lake in southern Jordan during the last full glacial period and its paleoclimatic implications
Playas, or ephemeral lakes, are one of the most common depositional environments in arid and semiarid lands worldwide. Playa deposits, however, have mostly been avoided as paleoclimatic archives because they typically contain exceptionally low concentrations of organic material, making 14C dating difficult. Here, we describe a technique for concentrating organic matter in sediments for radiocarbonActive tectonics of the northern Mojave Desert: The 2017 Desert Symposium field trip road log
The 2017 Desert Symposium field trip will highlight recent work by the U.S. Geological Survey geologists and geophysicists, who have been mapping young sediment and geomorphology associated with active tectonic features in the least well-known part of the eastern California Shear Zone (ECSZ). This area, stretching from Barstow eastward in a giant arc to end near the Granite Mountains on the southLate quaternary changes in lakes, vegetation, and climate in the Bonneville Basin reconstructed from sediment cores from Great Salt Lake: Chapter 11
Sediment cores from Great Salt Lake (GSL) provide the basis for reconstructing changes in lakes, vegetation, and climate for the last ~ 40 cal ka. Initially, the coring site was covered by a shallow saline lake and surrounded by Artemisia steppe or steppe-tundra under a cold and dry climate. As Lake Bonneville began to rise (from ~ 30 to 28 cal ka), Pinus and subalpine conifer pollen percentages iDescription and Analytical Results for Deposited Dust Samples from a Two-Year Monitoring Program Near Deer Trail, Colorado, USA, 2006-2007
Biosolids reclaimed from municipal wastewater have been applied since 1993 on nonirrigated farmland and rangeland east of Deer Trail, Colo., by Metro Wastewater Reclamation District of Denver. The U.S. Geological Survey has monitored ground water at this site since 1993, and began monitoring the biosolids, soils, and stream sediments in 1999. To investigate the possible effects of airborne dust bl