Geology Reports⌕ Search
Home/Archive/USGS

USGS · sim2976

Alteration Map Showing Major Faults and Veins and Associated Water-Quality Signatures of the Animas River Watershed Headwaters Near Silverton, Southwest Colorado

Dana J. Bove·Douglas B. Yager·M. Alisa Mast·J. Brad Dalton
View original source ↗Export metadata ↓

Abstract

This map was produced to provide hard-copy and digital data for alteration assemblages in the historical mining area centered on the Tertiary San Juan and Silverton calderas. The data have direct application to geoenvironmental and mineral exploration objectives. This dataset represents alteration mapping for the upper Animas River watershed near Silverton, Colorado. The map is based on detailed 1:12,000-scale field mapping, X-ray diffraction (XRD) analysis, mineral mapping by remote sensing (AVIRIS) data, and 1:24,000-scale aerial photographic interpretation. Geologic structures were compiled and generalized from multiple published and unpublished sources (Burbank and Luedke, 1964; Steven and others, 1974; Luedke and Burbank 1975a, b; Lipman, 1976; Luedke and Burbank, 1987; Luedke, 1996) (see Index Map). Unpublished mapping of the Ironton quadrangle by D.J. Bove and J.P. Kurtz in 1997-1999 was included.

Explore related subjects

Scientific Investigations MapReport

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dana J. Bove, Douglas B. Yager, M. Alisa Mast, J. Brad Dalton. 2007. Alteration Map Showing Major Faults and Veins and Associated Water-Quality Signatures of the Animas River Watershed Headwaters Near Silverton, Southwest Colorado. https://doi.org/10.3133/sim2976

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Altitude of the potentiometric surface and depth to water in the Mississippi River Valley alluvial aquifer, spring 2024

Potentiometric-surface and depth-to-water maps for spring 2024 were created for the Mississippi River Valley alluvial aquifer using groundwater-altitude data from 1,151 wells completed in the Mississippi River Valley alluvial aquifer and from the altitude of the top of the water surface in area rivers from 160 U.S. Geological Survey and U.S. Army Corps of Engineers streamgages. The potentiometric-surface and depth-to-water maps for 2024 were created to support investigations to characterize the Mississippi River Valley alluvial aquifer as part of the U.S. Geological Survey Water Availability and Use Science Program. Sufficient data were available to map the potentiometric surface and depth to water of the Mississippi River Valley alluvial aquifer for spring 2024 for about 83 percent of the aquifer area. The potentiometric contours ranged from 0 to 330 feet (ft) above the North American Vertical Datum of 1988. The regional direction of the groundwater gradient was generally to the south-southwest, except in areas of groundwater-altitude depressions, where the groundwater gradient direction was into the depression, and near rivers, where the groundwater gradient direction was either from the aquifer to the river or from the river into the aquifer. Groundwater depressions in the potentiometric-surface map are in the lower one-half of the Cache region and in most of the Grand Prairie and Delta regions. Depth to water by well in the Mississippi River Valley alluvial aquifer in spring 2024 ranged from 0.27 ft above land surface to 145.65 ft below land surface.

Arkansas, Illinois, Kentucky, Louisiana, Mississip↗
USGS2026

Color-Shaded Relief Bathymetry of Lake Chelan, Washington

In 2023, the U.S. Geological Survey (USGS) completed a 3-week field operation in Lake Chelan, Washington, the third deepest lake in the conterminous United States, to acquire sediment cores, high-resolution bathymetry data, and chirp sub-bottom profiles. The high-resolution bathymetry displayed in this map publication was collected using a Norbit Winghead i67-curved array multibeam system; raw data were cleaned and gridded (3 by 3 meters [m]) in the Teledyne CARIS software. In some locations where the slopes of Lake Chelan are near-vertical, multibeam returns were sparse, resulting in artifacts resembling holes that appear as grey dots within the color-shaded bathymetric relief. Although the 2023 bathymetric mapping of Lake Chelan resulted in similar morphometric characteristics to previous hydrographic campaigns (table 1; Kendra and Singleton, 1987; Pelletier and others, 1989), these new data provide a much more detailed understanding of the two physiographic basins that comprise Lake Chelan: the deeper (as deep as 445.8 m [fig. 1]; previously reported as 453 m) and narrower (1–2 kilometers [km] wide) Lucerne Basin to the north, and the shallower (as deep as 127.8 m [fig. 1]), and wider (2–3 km wide) Wapato Basin to the south. With this detailed imaging of Lake Chelan, we find pervasive morphological evidence of slope failure and mass-transport deposits (MTDs) in at least 89 locations within the lake and 63 subaqueous deltas (fig. 2). The deeper Lucerne Basin is dominated by steep slopes and numerous subaqueous deltas fed by steep fluvial catchments, whereas the Wapato Basin contains numerous landslide scarps, scars, and debris aprons along the more gently sloping lake margins, and abundant relict kettle structures from the Pleistocene deglaciation. Lake Chelan’s geomorphic, geophysical, and sediment data contain important records of glacial retreat and advance, regional volcanic eruptions, and earthquakes that generate ground motions severe enough to induce landslides recorded in the sediment as MTDs. The epicenter of the 1872 Washington State Earthquake (M 6.5–7.2; Bakun and others, 2002; Brocher and others, 2017; Sherrod and others, 2021) is along the Spencer Canyon Fault, near the southern end of Lake Chelan. Shaking from this earthquake was strong enough to affect local aquifers, induce liquefaction of unconsolidated sediments, produce large seiches (Brocher and others, 2018), and likely cause landslides within Lake Chelan.

Washington↗