USGS Science⌕ Search

SEARCH · USGS Science

Results for “Map”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,261 records · Page 70Linked to original sources
USGS2014

Bedrock geologic and structural map through the western Candor Colles region of Mars

The Candor Colles are a population of low, conical hills along the southeast flank of Ceti Mensa, in west Candor Chasma, within the Valles Marineris system of Mars (fig. 1). Ceti Mensa and the adjacent Candor Mensa are mounds of layered sedimentary deposits and are the most prominent landforms within west Candor Chasma. Prior to the arrival of the Mars Reconnaissance Orbiter (MRO) in orbit around Mars in 2006 (Zurek and Smrekar, 2007), geologic maps of the area utilized the relatively low resolution Viking Orbiter photomosaics (20–150 m/pixel). Geologic maps covering west Candor Chasma were created at scales of 1:15,000,000 for the western equatorial region of Mars (Scott and Tanaka, 1986), 1:2,000,000 for the Valles Marineris region (Witbeck and others, 1991), and 1:500,000 for the far eastern part of west Candor Chasma (Mars Transverse Mercator quadrangle–05072; Lucchitta, 1999). Previous structural mapping in west Candor Chasma at scales of less than 1:24,000 (Okubo and others, 2008; Okubo, 2010) employed digital terrain models (DTMs), with 1-m post spacings, derived from stereo MRO High Resolution Imaging Science Experiment (HiRISE) imagery (McEwen and others, 2010) and focused on examining the relative timing between deposition of the youngest unit of the layered deposits in this area (unit Avme of Witbeck and others, 1991) relative to regional faulting related to chasma formation. These previous mapping efforts on the southwest flank of Ceti Mensa demonstrated that unit Avme is not deformed by faults attributed to formation of the chasma. Studies of other layered deposits (primarily unit Hvl, but also including units Avme, Avsl, Avsd, and Avfs; Witbeck and others, 1991) exposed along the southeast flank of Ceti Mensa using a High-Resolution Stereo Camera (HRSC) digital terrain model (DTM) (50 m/pixel) refined the local stratigraphy and revealed evidence for syntectonic deposition of these deposits (Fueten and others, 2006, 2008; Jaumann and others, 2007; Birnie and others, 2012). Layered deposits such as those that constitute Ceti Mensa are widespread throughout the interior regions of Valles Marineris (Witbeck and others, 1991). These sedimentary deposits have been variously interpreted as eolian sediments (Nedell and others, 1987), hyaloclastic debris (Chapman and Tanaka, 2001; Komatsu and others, 2004), lacustrine or fluvial sediment (Dromart and others, 2007; Mangold and others, 2008; Metz and others, 2009), pyroclastic deposits (Hynek and others, 2003), evaporites (Mangold and others, 2008; Andrews-Hanna and others, 2010), or various combinations thereof. Recent analysis of data from the MRO Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) shows that these sediments consist primarily of hydrated sulfates (Murchie and others, 2009a,b). Further, hydrologic modeling indicates that spring-fed lakes likely occurred within the chasma (Andrews-Hanna and others, 2010). These recent findings point to a scenario in which the layered deposits accumulated as sequences of evaporites precipitating in hypersaline lakes, with contemporaneous trapping of eolian dust and sand, diagenesis, and iron-cycling, interspersed with periods of eolian and fluvial erosion (Murchie and others, 2009a). Water vapor released from these lakes may have also driven localized precipitation of snow and accumulation of layered deposits on the adjacent plateaus (Kite and others, 2011a,b). This scenario is in contrast to recent alternative interpretations that the layered deposits formed within the chasma through weathering of dust-rich ice deposits (Niles and Michalski, 2009; Michalski and Niles, 2012). The structure and geology of the layered deposits in the Candor Colles region corresponding to units Avfs, Avme, and Hvl of Witbeck and others (1991) are reevaluated in this 1:18,000-scale map. The objectives herein are to gather high-resolution structural measurements to (1) refine the previous unit boundaries in this area established by Witbeck and others (1991), (2) revise the local stratigraphy where necessary, (3) characterize bed forms to help constrain depositional processes, and (4) determine the styles and extent of deformation to better inform reconstructions of the local post-depositional geologic history.

Scientific Investigations Map↗
USGS2014

Geologic map of the west-central Buffalo National River region, northern Arkansas

This map summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus region of northern Arkansas. Geologically, the region lies on the southern flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically, the map area spans the Springfield Plateau, a topographic surface generally held up by Mississippian cherty limestone and the higher Boston Mountains to the south, held up by Pennsylvanian rocks. The Buffalo River flows eastward through the map area, enhancing bedrock erosion of an approximately 1,600-ft- (490-m-) thick sequence of Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks that have been mildly deformed by a series of faults and folds. Quaternary surficial units are present as alluvial deposits along major streams, including a series of terrace deposits from the Buffalo River, as well as colluvium and landslide deposits mantling bedrock on hillslopes. This report provides a geologic map database of the map area that improves understanding of the regional geologic framework and its influence on the regional groundwater flow system. Furthermore, additional edits were made to the Ponca and Jasper quadrangles in the following ways: new control points on important contacts were obtained using modern GPS; recent higher resolution elevation data allowed further control on placement of contacts; some new contacts were added, in particular the contact separating the upper and lower Everton Formation.

Arkansas↗
USGS2015

Seismic-hazard maps for the conterminous United States, 2014

The maps presented here provide an update to the 2008 data contained in U.S Geological Survey Scientific Investigations Map 3195 ( http://pubs.usgs.gov/sim/3195/ ).Probabilistic seismic-hazard maps were prepared for the conterminous United States for 2014 portraying peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with probabilities of exceedance of 10 percent in 50 years and 2 percent in 50 years. All of the maps were prepared by combining the hazard derived from spatially smoothed historical seismicity with the hazard from fault-specific sources. The acceleration values contoured are the random horizontal component. The reference site condition is firm rock, defined as having an average shear-wave velocity of 760 m/s in the top 30 meters corresponding to the boundary between NEHRP (National Earthquake Hazards Reduction program) site classes B and C. This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. The grid of points was contoured to produce the final representation of the seismic hazard. These maps are intended to summarize the available quantitative information about seismic ground motion hazard for the conterminous United States from geologic and geophysical sources.

Scientific Investigations Map↗
USGS2015

Geologic map of the Alamosa 30’ × 60’ quadrangle, south-central Colorado

The Alamosa 30'× 60' quadrangle is located in the central San Luis Basin of southern Colorado and is bisected by the Rio Grande. The Rio Grande has headwaters in the San Juan Mountains of Colorado and ultimately discharges into the Gulf of Mexico 3,000 kilometers (km) downstream. Alluvial floodplains and associated deposits of the Rio Grande and east-draining tributaries, La Jara Creek and Conejos River, occupy the north-central and northwestern part of the map area. Alluvial deposits of west-draining Rio Grande tributaries, Culebra and Costilla Creeks, bound the Costilla Plain in the south-central part of the map area. The San Luis Hills, a northeast-trending series of flat-topped mesas and hills, dominate the landscape in the central and southwestern part of the map and preserve fault-bound Neogene basin surfaces and deposits. The Precambrian-cored Sangre de Cristo Mountains rise to an elevation of nearly 4,300 meters (m), almost 2,000 m above the valley floor, in the eastern part of the map area. In total, the map area contains deposits that record surficial, tectonic, sedimentary, volcanic, magmatic, and metamorphic processes over the past 1.7 billion years.

Colorado↗
USGS2015

Flood-inundation maps for South Fork Peachtree Creek from the Brockett Road bridge to the Willivee Drive bridge, DeKalb County, Georgia

Digital flood-inundation maps for a 5.3-mile reach of South Fork Peachtree Creek that extends from about 500 feet above the Brockett Road bridge to the Willivee Drive bridge were developed by the U.S. Geological Survey (USGS) in cooperation with DeKalb County, Georgia. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation , depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage at South Fork Peachtree at Casa Drive, near Clarkston, Georgia (02336152). Real-time stage information from this USGS streamgage may be obtained at http://waterdata.usgs.gov/ and can be used in conjunction with these maps to estimate near real-time areas of inundation. The National Weather Service (NWS) is incorporating results from this study into the Advanced Hydrologic Prediction Service (AHPS) flood-warning system ( http://water.weather.gov/ahps/ ). A one-dimensional step-backwater model was developed using the U.S. Army Corps of Engineers HEC–RAS software for South Fork Peachtree Creek and was used to compute flood profiles for a 5.3-mile reach of South Fork Peachtree Creek. The model was calibrated using the most current (2015) stage-discharge relation at the USGS streamgage South Fork Peachtree at Casa Drive, near Clarkston, Georgia (02336152). The hydraulic model was then used to simulate 13 water-surface profiles at 0.5-foot intervals at the South Fork Peachtree Creek near Clarkston streamgage. The profiles ranged from just above bankfull stage (6.0 feet) to approximately 3.21 feet above the highest recorded water level (12.0 feet). The simulated water-surface profiles were then combined with a geographic information system digital elevation model—derived from light detection and ranging data having a 5.0-foot horizontal resolution—to delineate the area flooded at each 0.5-foot interval of stream stage. The availability of these flood-inundation maps, when combined with real-time stage information from USGS streamgages, provides emergency management personnel and residents with critical information during flood-response activities, such as evacuations and road closures, in addition to post-flood recovery efforts.

Georgia↗
USGS2016

Geologic map of the Rio Rico and Nogales 7.5’ quadrangles, Santa Cruz County, Arizona

The Rio Rico and Nogales (Arizona) 1:24,000-scale quadrangles are located in the Basin and Range Province of southern Arizona, and the southern edge of the map is the international border with Sonora, Mexico. The major urban area is Nogales, a bi-national city known as “the gateway to Mexico.” Rocks exposed in the map area range in age from Jurassic through Quaternary. Major physiographic, geologic, and hydrologic features in the map area include the southern San Cayetano Mountains, Grosvenor Hills, and Sonoita Creek in the northern part, and Mount Benedict and the Mount Benedict horst block in the southcentral part. The horst block is bounded by the Santa Cruz River on the east and Nogales Wash on the west. The objectives of our mapping were to define the geologic framework for the Nogales area and the upper Santa Cruz basin to support ongoing multidisciplinary projects. This new work will improve understanding of the Nogales Formation to more fully assess its groundwater resource potential. We significantly revised the Miocene Nogales Formation based on geologic mapping combined with new geochronologic, geophysical, and petrographic studies.

Arizona↗
USGS2016

Bedrock geologic map of the Hartland and North Hartland quadrangles, Windsor County, Vermont, and Sullivan and Grafton Counties, New Hampshire

The bedrock geology of the 7.5-minute Hartland and North Hartland quadrangles, Vermont-New Hampshire, consists of highly deformed and metamorphosed lower Paleozoic metasedimentary, metavolcanic, and metaplutonic rocks of the Bronson Hill anticlinorium (BHA) and the Connecticut Valley trough (CVT). Rocks of the Orfordville anticlinorium on this map occupy the western part of the broader BHA. In the BHA, the Ordovician Ammonoosuc Volcanics and graphitic, sulfidic metapelite of the Partridge Formation are intruded by Ordovician plutonic rocks of the Oliverian Plutonic Suite. The Ordovician rocks are collectively referred to as the Bronson Hill arc. The Ordovician rocks are overlain by the Silurian to Devonian Clough, Fitch, and Littleton Formations. On this map, rocks of the CVT occupy the eastern part of the broader CVT. In the CVT in Vermont, the Silurian to Devonian Shaw Mountain, Waits River, and Gile Mountain Formations form an unconformable autochthonous to parautochthonous cover sequence on the pre-Silurian rocks of the Rowe-Hawley zone above Precambrian basement rocks of the Mount Holly Complex. On this map, however, only the Waits River and Gile Mountain Formations are exposed. Syn- to postmetamorphic rocks include quartz veins and Cretaceous dikes of the White Mountain Igneous Suite. Rocks of the BHA occur in a thrust sheet floored by the Monroe fault, which carried a deformed section of plutonic rocks, Ammonoosuc Volcanics, Partridge Formation, Clough Quartzite, and the Fitch and Littleton Formations. The Monroe thrust sheet placed the BHA rocks over the CVT during an early Acadian F 1 nappe-stage event prior to peak metamorphism at lower amphibolite facies conditions. Upper and lower plate truncations, mylonite, and local mélange characterize the Monroe fault. F 2 doming deformed the Monroe thrust sheet, folded earlier isograds, and created the Meriden antiform and Lebanon dome. Lower greenschist facies (Acadian to Alleghanian) faults such as the Sumner Falls shear zone truncated peak-metamorphic assemblages, isograds, and older F 1 folds and faults. Late-stage F 3 folds show preferred left-lateral rotation sense and are probably related to late dome-stage Alleghanian deformation or motion along lower greenschist facies faults. The youngest deformation is characterized by Mesozoic brittle faulting and spatially associated kink bands along the Ammonoosuc fault zone, followed by subsequent jointing. Currently major economic natural resource activities are related to aggregate quarrying in the Ammonoosuc Volcanics at Twin State Sand and Gravel in Hartford, Vt., and Lebanon Crushed Stone in Lebanon, N.H. This report consists of sheets 1 and 2 as well as an online geographic information systems database that includes contacts of bedrock geologic units, faults, outcrops, structural geologic information, and photographs. Sheet 2 of this report shows three cross sections, a tectonic map, and two brittle features maps that show measured outcrop-scale strike and dip results with summary stereonets and rose diagrams.

New Hampshire, Vermont↗
USGS2017

Streamflow distribution maps for the Cannon River drainage basin, southeast Minnesota, and the St. Louis River drainage basin, northeast Minnesota

Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02. Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface-water appropriations. Presented streamflow distribution maps are foundational work intended to support the development of additional streamflow distribution maps that include statistical constraints on the selected flow conditions.

Minnesota↗
USGS2020

Geologic map of the northern Harrat Rahat volcanic field, Kingdom of Saudi Arabia

Harrat Rahat, in the west-central part of the Kingdom of Saudi Arabia, is the largest of 15 Cenozoic harrats (Arabic for “volcanic field”) distributed on the Arabian plate. It extends more than 300 km north-south and 50 to 75 km east-west, and it covers an area of approximately 20,000 km 2 , has a volume of approximately 2,000 km 3 , and encompasses more than 900 observable vents. Volcanism commenced around 10 Ma and has continued into historic time, the most recent eruption occurring in 1256 C.E. Volcanic products are dominated by alkali basalt and hawaiite lava flows, with subordinate mugearite lava flows, as well as benmoreite and trachyte lava flows, domes, and pyroclastic flows. This geologic map distinguishes 239 eruptive units that cover an area of 3,340 km 2 in northern Harrat Rahat and the adjacent city of Al-Madinah. Results are presented as a geologic map of the study area at 1:75,000 scale and of smaller regions of particular interest at 1:25,000 scale, along with interpretive text. Most units are basaltic lava flows that erupted from the broadly north-northwest-trending main vent axis that constructed the topographic crest of the volcanic field. This 300- to 400-m-high vent axis, which has a width of 6 to 10 km, lies in the eastern one-third of northern Harrat Rahat. Basalt and hawaiite lava flows can extend as far as 27 km from their vents, but most are 10 to 15 km long. Evolved products such as mugearites, benmoreites, and trachytes are less extensive; the trachytic pyroclastic flows extend as far as 9 km from their source vents, although most only reach 4 to 6 km. Vents of the evolved products are restricted to the main vent axis or its flanks. No volcanic rocks older than 1.2 Ma are exposed in the map area, and about 90 percent of the exposed volcanic rocks erupted during the past 570 thousand years. As depicted on the geologic maps, eruption ages and field relations define 12 eruptive stages for northern Harrat Rahat for the past 1.2 million years. Other important geochronological findings include (1) several late Pleistocene lava flows near Al-Madinah, which previously were interpreted as Holocene from archeological evidence; (2) the eruption age of a cluster of cinder cones and small lava flows in the western outskirts of Al-Madinah (previously ascribed to an eruption in 641 C.E.) is actually 13.3±1.9 ka, close to the Pleistocene-Holocene boundary; and (3) only two Holocene eruptions have been identified in the map area, those of the historically described basalt of Al Labah in 1256 C.E. and the dome and pyroclastic flows of the trachyte of Um Rgaibah at 4.2±5.2 ka.

Scientific Investigations Map↗
USGS2020

Geologic map of the greater Portland metropolitan area and surrounding region, Oregon and Washington

The Portland-Vancouver-Hillsboro Metropolitan Area (metro area) has great scenic, natural, and cultural resources and is the major economic hub of Oregon. The metro area is subject to a variety of geologic hazards. Underthrusting of the oceanic plate along the Cascadia plate boundary fault, or megathrust, deforms the leading edge of North America and produces earthquakes on the megathrust and in the overlying plate. Rising magma from the deeper parts of the subduction zone produces active volcanoes that form the Cascades Arc, including Mount Hood and Mount St. Helens visible from Portland. Both volcanism and strong ground-shaking from earthquakes have impacted the metro area, most recently in the 1980 eruptions of Mount St. Helens and the 1993 magnitude (M) 5.7 Scotts Mills earthquake. Great offshore earthquakes as large as M 9 on the Cascadia megathrust have shaken the metro area every 500 years or so, most recently in 1700. Giant floods have inundated the metro area, from the ice age Missoula floods about 20,000 to 15,000 years ago to the flood generated by collapse of the Bridge of the Gods landslide dam on the Columbia River around 1421–1447 A.D. Geologic resources of the metro area include the southern part of the Mist Natural Gas Storage Field in the northwest corner of the map area, the Columbia South Shore Well Field aquifer in the Portland Basin, the Columbia River Basalt aquifer of the Tualatin Basin, and the Tualatin Basin Aquifer Storage and Recovery projects. The metro area includes several well-known American Viticultural Areas in the western part of the map area and numerous transportation, electrical transmission, and pipeline corridors. We created this map to provide a uniform, modern geologic database for the greater Portland metro area to better understand its tectonic setting, active faults, volcanoes, landslide hazards, and distribution of geologic materials and resources. Information in this database will be used to improve seismic hazard and resource assessments in this economically important region. NOTE: The sheet 1 map was divided into two parts—sheet 1 (north) and sheet 1 (south)—to facilitate printing and plotting the map.

Oregon, Washington↗
USGS2020

Surficial geologic map of the Spirit Mountain SE and part of the Spirit Mountain NE 7.5' quadrangles, Nevada and Arizona

This geologic map includes a trove of stratigraphic and geomorphic information that chronicles the inception and evolution of the lower Colorado River. The map area is located near the south end of the Lake Mead National Recreation Area about 80 km (50 mi) downstream from Hoover Dam. It spans parts of northwestern Arizona and southern Nevada near the south end of Cottonwood Valley. The map includes the Spirit Mountain SE 7.5' quadrangle and the southern part of the Spirit Mountain NE 7.5' quadrangle. The map area contains well-exposed Neogene and Quaternary strata and associated geomorphic features that record and are critical in dating the arrival of the Colorado River in the early Pliocene and the subsequent history of the river and its landscape through the Holocene. The valley is bounded on the west by the Newberry Mountains (Nevada) and on the east by the Black Mountains (Arizona) and includes part of Lake Mohave, a reservoir created by the completion of Davis Dam in 1951. This map does not include the geology of the reservoir floor and focuses only on surficial deposits.

Arizona, Nevada↗
USGS2023

Geologic map of the source region of Shalbatana Vallis, Mars

Xanthe Terra is a high-standing cratered plain located southeast of Lunae Planum and south of Chryse Planitia in the western equatorial region of Mars. It contains landforms shaped by diverse geologic processes, including various scales of channels and valleys, chaotic terrains, delta fan deposits, and landslides. An extensive outflow channel system is located within Xanthe Terra and the surrounding circum-Chryse region, including Shalbatana and Ravi Valles, thought to have formed by catastrophic flooding during the Hesperian to Amazonian Periods. The study region within Xanthe Terra is defined by Mars Transverse Mercator (MTM) quadrangles 00042 and 00047 (2.5° to −2.5° N, 310° to 320° E) and includes Orson Welles crater (124.5 km diameter, the source region for Shalbatana Vallis), the southernmost portion of Shalbatana Vallis, Aromatum Chaos (the source region for Ravi Vallis), the westernmost portion of Ravi Vallis, and the source area of Nanedi Valles. The Mars Odyssey Thermal Emission Image System (THEMIS) IR daytime mosaic (100 m/pixel) was used as the primary base map. We constructed the geologic map of the source region of Shalbatana Vallis at 1:750,000 scale. We defined 16 geologic units in the map area, which we divided into the following groups: plains units, channel units, crater units, chaos units, flow units, and surficial units. Mapped linear features include ridge crests, scarp crests, channels, crests of crater rims, crests of buried or degraded crater rims, graben traces, grooves, troughs, and faults. Surface features include secondary crater chains and dark ejecta material. The geologic history of the map region can be summarized as follows. During the Noachian Period, ancient highland materials in the Xanthe Terra region, including lava and any ancient sedimentary units present, were reworked by impacts during the heavy bombardment. In particular, the impact that formed a basin that later underwent widespread resurfacing, likely as a combination of lava flows, reworked crater materials, and sedimentary deposits resulting in the flat-lying, smooth plains of Chryse Planitia. The Hesperian Period was characterized by the impact that formed Orson Welles crater and the subsequent formation of Shalbatana Vallis, as well as Aromatum Chaos and Ravi Vallis. During this period, depressions were filled with smooth material that was subsequently modified by collapse, subsidence, and flooding. Water filled and overflowed the tops of Orson Welles crater and other depressions. The Amazonian Period was characterized by ongoing collapse, as well as the formation of flow and surficial materials, including a lava flow that extends from Aromatum Chaos.

Scientific Investigations Map↗
USGS2024

Geomorphic map of the Umatilla River corridor, Oregon

This map portrays the distribution of landforms along the Umatilla River in northeastern Oregon and covers a corridor 127 kilometers long from the confluence of the Umatilla River with the Columbia River upstream to Meacham Creek. The map encompasses the valley bottom and extends about 1 kilometer up the adjoining hillslopes. Map data are intended to support water quality and fisheries enhancement efforts pursuant to the First Foods, a resource-management approach that focuses on traditionally gathered foods including water, fish, big game, roots, and berries and calls attention to the reciprocity between people and the foods upon which humans depend. The Umatilla River drains about 6,300 square kilometers on the northwest slope of the Blue Mountains in northeast Oregon. Most of the drainage basin is underlain by Miocene basalt flows of the Columbia River Basalt Group. Younger, weakly lithified, late Miocene and early Pliocene gravel deposits of local origin (for example, McKay Formation) are mapped in a few places. Upland surfaces are mantled with windborne silt (loess) correlative with deposits elsewhere known as the Palouse Formation. Surfaces below an elevation of about 340 meters were inundated repeatedly by large Pleistocene glacial outburst floods, most emanating from glacial Lake Missoula in western Montana. In backflooded areas such as the lower Umatilla River valley, Missoula floods deposited extensive slack-water silt. Areas mapped as open water, active channel and tie channel, flood basin, valley bottom, and modified land constitute the geomorphic floodplain: the area subject to occasional inundation by the Umatilla River. Deposits and landforms within the floodplain are inset into Missoula flood deposits and hence postdate the 20–15-kilo-annum Missoula floods. Some floodplain deposits are no more than a few centuries old, as indicated by substantial erosion and deposition during the Umatilla River flood of February 2020, the largest since systematic measurements began in October 1903. Deposits and landforms of the floodplain are transient features within the longer-term incision of the Umatilla River into mid-Miocene flood basalts and younger gravel of the McKay Formation.

Oregon↗
USGS2025

Geologic map of the Buckner 7.5-Minute quadrangle, Louisa County, Virginia

The Buckner 7.5-minute quadrangle straddles three terrane boundaries in the Piedmont Physiographic Province in central Virginia: the Chopawamsic terrane, the Elk Hill Complex, and the Goochland terrane. In much of the map area, the Elk Hill Complex separates the Chopawamsic and Goochland terranes. Rocks of the Chopawamsic terrane include Ordovician metavolcanic and metasedimentary rocks of the Chopawamsic Formation, Ordovician to Silurian granodiorite sheet intrusions, and Paleozoic mafic intrusions. Silurian to Devonian rocks of the Quantico Formation, mostly garnet-mica schist, crop out in the northwesternmost part of the map area, and are in unconformable contact with rocks of the Chopawamsic Formation on the southeastern limb of the Quantico synclinorium. The main map unit in the Elk Hill Complex is Neoproterozoic mica gneiss, which is in pre-metamorphic fault contact with rocks of the Chopawamsic Formation to the west. The main map unit of the Goochland terrane is the Maidens Gneiss. Except for Jurassic diabase dikes, all rocks on the Buckner 7.5-minute quadrangle were metamorphosed to amphibolite facies during the Alleghanian orogeny and preserve multiple compositional and phyllosilicate penetrative foliations. Evidence of amphibolite-facies metamorphism during the Taconic orogeny is preserved in rocks of the Elk Hill Complex. The entire width of the Maidens Gneiss on the Buckner 7.5-minute quadrangle is within the Spotsylvania high-strain zone and amphibolite-facies mylonitic textures are pervasive. Quartz veins and Jurassic diabase dikes crosscut all older rocks of the quadrangle. Multiple levels of terrace deposits are present along and near the major streams of the quadrangle. The lower terrace deposits are likely remnants of former positions of the Little River on the landscape, whereas higher deposits may be remnants of former deposits of the Atlantic Coastal Plain that covered this portion of the Piedmont Province. A linear cluster of aftershocks from the magnitude 5.8 earthquake that occurred near Mineral, Virginia, in 2011 defines the Fredericks Hall fault, which is at depth on the Buckner quadrangle. Most of the aftershocks occurred in the core of the Elk Creek antiform and have no relation to faults mapped at the surface. Several abandoned crushed stone and building stone quarries, as well as a mica prospect, exist in the quadrangle.

Virginia↗
USGS2025

Bedrock geologic map of the Bellows Falls 7.5- x 15-minute quadrangle, Windham and Windsor Counties, Vermont, and Sullivan and Cheshire Counties, New Hampshire

Introduction The bedrock geology of the Bellows Falls 7.5- x 15-minute quadrangle, Vermont and New Hampshire, consists of polydeformed Ordovician to Devonian metasedimentary, metavolcanic, and metaplutonic rocks of the Connecticut Valley trough, Bronson Hill anticlinorium (or Bronson Hill terrane), and the Central Maine terrane. Previous work in this area includes a 1:62,500-scale published map and text (1946), State geologic maps of New Hampshire (1997) and Vermont (2011), and various maps and reports presented largely as parts of field trip guidebooks. A provisional open-file map of the geology of the Vermont part of the Bellows Falls 7.5- x 15-minute quadrangle, completed in 1997, is incorporated and revised on this map based on additional fieldwork. This study recognizes three major structural levels from west to east and from lowest to highest: (1) autochthonous rocks of the Connecticut Valley trough; (2) allochthonous rocks of the New Hampshire sequence and Bronson Hill arc in the Monroe thrust sheet (or nappe), including the Skitchewaug nappe; and (3) allochthonous rocks of the Fall Mountain thrust sheet or nappe.

New Hampshire, Vermont↗
USGS2020

Geologic map of the Patrick quadrangle, Chesterfield County, South Carolina

The Patrick 7.5 minute quadrangle, located in Chesterfield County, South Carolina, lies entirely within the upper Atlantic Coastal Plain province. Directly to the southeast in the Dovesville quadrangle, the Pliocene Orangeburg Scarp marks the western edge of marine terraces that characterize the upper limit of the middle Atlantic Coastal Plain. The geologic mapping for this quadrangle was done from 2013-2015 by Bradley A. Fitzwater at Old Dominion University as part of a Master’s thesis supervised by G. Richard Whittecar. Christopher S. Swezey (U.S. Geological Survey) and Fitzwater collaborated in the geologic mapping of both the Patrick quadrangle and the adjacent Middendorf quadrangle (Swezey et al., 2021). The geologic mapping was conducted using a lidar base from 2013, whereas this published product shows the geologic data on a USGS topographic map base from 1968. As a result of differences in resolution, the published map may display a few minor discrepancies with respect to alignment of geologic data with topographic and hydrologic features.

South Carolina↗
USGS2012

Spot-mapping underestimates song-territory size and use of mature forest by breeding golden-winged warblers in Minnesota, USA

Studies of songbird breeding habitat often compare habitat characteristics of used and unused areas. Although there is usually meticulous effort to precisely and consistently measure habitat characteristics, accuracy of methods for estimating which areas are used versus which are unused by birds remains generally untested. To examine accuracy of spot-mapping to identify singing territories of golden-winged warblers ( Vermivora chrysoptera ), which are considered an early successional forest specialists, we used spot-mapping and radiotelemetry to record song perches and delineate song territories for breeding male golden-winged warblers in northwestern Minnesota, USA. We also used radiotelemetry to record locations (song and nonsong perches) of a subsample ( n  = 12) of males throughout the day to delineate home ranges. We found that telemetry-based estimates of song territories were 3 times larger and included more mature forest than those estimated from spot-mapping. In addition, home ranges estimated using radiotelemetry included more mature forest than spot-mapping- and telemetry-based song territories, with 75% of afternoon perches located in mature forest. Our results suggest that mature forest comprises a larger component of golden-winged warbler song territories and home ranges than is indicated based on spot-mapping in Minnesota. Because it appears that standard observational methods can underestimate territory size and misidentify cover-type associations for golden-winged warblers, we caution that management and conservation plans may be misinformed, and that similar studies are needed for golden-winged warblers across their range and for other songbird species.

Minnesota↗
USGS2000

High-Resolution Thermal Inertia Mapping from the Mars Global Surveyor Thermal Emission Spectrometer

High-resolution thermal inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission. Thermal inertia is the key property controlling the diurnal surface temperature variations, and is dependent on the physical character of the top few centimeters of the surface. It represents a complex combination of particle size, rock abundance, exposures of bedrock, and degree of induration. In this work we describe the derivation of thermal inertia from TES data, present global scale analysis, and place these results into context with earlier work. A global map of nighttime thermal-bolometer-based thermal inertia is presented at 14?? per pixel resolution, with approximately 63% coverage between 50??S and 70??N latitude. Global analysis shows a similar pattern of high and low thermal inertia as seen in previous Viking low-resolution mapping. Significantly more detail is present in the high-resolution TES thermal inertia. This detail represents horizontal small-scale variability in the nature of the surface. Correlation with albedo indicates the presence of a previously undiscovered surface unit of moderate-to-high thermal inertia and intermediate albedo. This new unit has a modal peak thermal inertia of 180-250 J m-2 K-1 s-12 and a narrow range of albedo near 0.24. The unit, covering a significant fraction of the surface, typically surrounds the low thermal inertia regions and may comprise a deposit of indurated fine material. Local 3-km-resolution maps are also presented as examples of eolian, fluvial, and volcanic geology. Some impact crater rims and intracrater dunes show higher thermal inertias than the surrounding terrain; thermal inertia of aeolian deposits such as intracrater dunes may be related to average particle size. Outflow channels and valleys consistently show higher thermal inertias than the surrounding terrain. Generally, correlations between spatial variations in thermal inertia and geologic features suggest a relationship between the hundred-meter-scale morphology and the centimeter-scale surface layer. ?? 2000 Academic Press.

Icarus↗