All Publications

The Harney Basin is a closed river basin in southeastern Oregon. Surface water in the basin is used for a variety of social, economic, and ecological benefits. While some surface water uses compete with one another, others are complementary or jointly produce multiple beneficial outcomes. The objective of this study is to conduct a baseline economic assessment of surface water in the Basin as it r

Basalt lava fields, some decorated with scoria ‘cinder’ cones, are scattered around the Mojave Desert. Most basalt fields are short-lived, but the Cima volcanic field is unique in having eruptions that span ~7.5 m.y., including the youngest eruption in the Mojave Desert at ~12 ka. Xenolith-bearing basalts that include both mantle and deep crustal rocks are known in several fields. All basalt fi

The southwestern part of the Cima volcanic field in the Mojave National Monument, California, contains many of the youngest basaltic cinder cones and lava flows in the field (Wilshire and others, 2002). In 2014 the Hyperspectral Thermal Emission Spectrometer (HyTES) collected a swath of data across this area. This summary describes the HyTES instrument, data, and images, and compares two standar

Wilderness areas in the Mojave Desert, California, are remote and rugged terrain, but they contain important geology for understanding faults of the eastern California shear zone (ECSZ), and remote sensing offers techniques that can optimize mapping. The Bristol–Granite Mountain fault zone (BGMFZ) is the easternmost fault of the ECSZ with the Marble, Bristol, and Old Dad mountains on either side o

Baseflow is the portion of streamflow that comes from groundwater and subsurface sources. Although baseflow is essential for sustaining streams during low flow and drought periods, we have little information about how and why it has changed over large regions of the continental United States. The objective of this study was to evaluate how changes in the climate system have affected observed month

Preliminary interpretation of new and updated incision rates in western Grand Canyon shows the effects of Quaternary faulting, which dampens river incision rates in the footwalls and amplifies them in the hanging walls of normal faults. In the reach between Lava Falls and Diamond Creek in western Grand Canyon, about 178 to 225 river miles downstream from Lees Ferry, the river crosses the neotecton

The Arctic Ocean has experienced orbital and millennial-scale climate oscillations over the last 500 kilo-annum (ka) involving massive changes in global sea level and components of the Arctic cryosphere, including sea-ice cover, land-based ice sheets and ice shelves. Although these climate events are only partially understood, micropaleontological studies utilizing ostracodes and benthic foraminif

Humans are profoundly affecting the planet, and human-caused, or anthropogenic, climate change is the most visible manifestation of this today. In the graph above, from the National Oceanic and Atmospheric Administration, trends in atmospheric carbon dioxide (CO2) are shown from the present (at far right) back through several ice age cycles, to eight hundred thousand years ago (800 kyBCE, or thous

Native across the Old World tropics from Africa to Southeast Asia and Australia, Lygodium microphyllum (Cav.) R. Br. (Old World Climbing Fern) is one of the most invasive plant species threatening South Florida ecosystems (Rodgers et al. 2014). This invasive fern was first collected as a naturalized plant in South Florida in the late 1960s (Beckner 1968). Subsequent populations were observed in th

The discovery of multiple deformed and metamorphosed sedimentary successions in southwestern Laurentia that have depositional ages between ca. 1.50 and 1.45 Ga marked a turning point in our understanding of the Mesoproterozoic tectonic evolution of the continent and its interactions with formerly adjacent cratons. Detrital zircon U-Pb ages from metasedimentary strata and igneous U-Pb zircon ages f

The New Idria serpentinite body in the Coast Ranges of California is a diapir that resulted from the interaction of the migrating Mendocino trench-ridge-transform fault triple junction, transpression, metasomatic fluids, and previously subducted oceanic crust and mantle. Northward propagation of the San Andreas fault progressively eliminated the original subduction zone, allowing seawater to penet

The Ogallala aquifer is the primary source of water for agricultural and municipal purposes in the Texas Panhandle. Because most of the groundwater in the Texas Panhandle is withdrawn from the Ogallala aquifer, information on the quality of groundwater in the Ogallala aquifer in this part of Texas is useful for resource characterization. During 2012–13, the U.S. Geological Survey in cooperation wi