Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Geological 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 793 records · Page 44Linked to original sources

Geologic map of the Palisade quadrangle, Mesa County, Colorado

The Palisade 1:24,000 quadrangle is in Mesa County in western Colorado. Because the map area is dominated by various surficial deposits, the map depicts 22 different Quaternary units. Two prominent river terraces are present in the quadrangle containing gravels deposited by the Colorado River. The map area contains many mass movement deposits. Extensive landslide deposits are present along the eastern part of the quadrangle. These massive landslides originate on the flanks of Grand Mesa, in the Green River and Wasatch Formations, and flow west onto the Palisade quadrangle. In addition, large areas of the eastern and southern parts of the map are covered by extensive pediment surfaces. These pediment surfaces are underlain by debris flow deposits also originating from Grand Mesa. Material in these deposits consists of mainly subangular basalt cobbles and boulders and indicate that these debris flow deposits have traveled as much as 10 km from their source area. The pediment surfaces have been divided into 5 age classes based on their height above surrounding drainages. Two common bedrock units in the map area are the Mancos Shale and the Mesaverde Group both of Upper Cretaceous age. The Mancos shale is common in low lying areas near the western map border. The Mesaverde Group forms prominent sandstone cliffs in the north-central map area. The map is accompanied by a separate pamphlet containing unit descriptions, a section on geologic hazards (including landslides, piping, gullying, expansive soils, and flooding), and a section on economic geology (including sand and gravel, and coal). A table indicates what map units are susceptible to a given hazard. Approximately twenty references are cited at the end of the report.

Colorado↗

Geologic map of the east half of the Bellevue South 7.5' x 15' quadrangle, Issaquah area, King County, Washington

The Issaquah area includes several of the most outstanding geologic features of the eastern Puget Lowland region. Folds have warped thousands of meters of Tertiary sedimentary and volcanic rocks. Several hundred meters of both glacial and postglacial sediment have accumulated in a deep glacial trough, which is now partly occupied by Lake Sammamish but which was previously the conduit for massive volumes of meltwater during ice-sheet occupation and retreat. The eastern projection of an east-west-oriented crustal structure, which reflects Tertiary through Holocene fault displacement, extends across the eastern part of the map area. In addition to these geologic features, some of the most rapid human alteration of the landscape in the entire Puget Lowland has occurred here. Since the 19th century, coal was extensively mined and, since the early 1980s, the region has been overtaken by urbanization. In places, this alteration has dramatically accelerated the rate of geomorphic processes. For example, the hillsides have been regraded as a result of mining and quarries throughout the southern one-third of the quadrangle; stream channels have recently incised above the eastern shores of Lake Sammamish; and sediments have deposited on the lakeshore and into the lake itself.

Washington↗

Geologic map of the Arcadia Quadrangle of Mars

The Arcadia quadrangle of Mars contains three distinct geological provinces: (1) the 1000-km-diameter shield field volcano of Alba Patera, which occupies the southwestern quadrant ; (2) the complex T empe province, which comprises a number of younger volcanic and sedimentary blanket deposits over an ancient, highly cratered crust forming a plateau in the southwestern quadrant ; and (3) a plains province, consisting of northern wind-swept , c ratered plains and some younger subpolar deposits in the northeast corner of the quadrangle, plus less cratered plains surrounding much of the T empe and Alba regions. The plateau, informally named the Tempe Plateau and part of the proposed forma l term Tempe Terra, is separated from the main regions of cratered martian highlands to the south by Kasei Vallis , appearing at the extreme southeast corner of the map, which slopes northeastward onto Chryse Planitia.

IMAP↗

Preliminary geologic map of the Al Jawf Quadrangle, sheet 29D, Kingdom of Saudi Arabia

The Al Jawf quadrangle (Sheet 29 D) lies in the northwestern part of the Kingdom of Saudi Arabia about 900 km north of Jeddah. The quadrangle is located between lat 29°00'-30°00' N. and long 39°00'-40°30' E. It includes the southeastern rim of the Sirhan-Turayf basin, and is underlain by sedimentary rocks of Paleozoic to Cenozoic age. More than half of the quadrangle is covered by surficial deposits. The Phanerozoic sedimentary rocks of the map area were deposited under both marine and continental conditions. Marine deposits, produced by transgressions and regressions of the sea, are of outershelf to near-shore and coastal-lagoon origin, and the continental deposits are largely of fluvial and deltaic origin. Part of the Miocene-Pliocene rocks are believed to have been deposited in a lacustrine environment. Tensional structures, such as linear macro joints, grabens, block-faulting, and some folding are characteristic of the geology of the map area, and reflect a combination of Red Sea rifting and movement of the Hail Arch. This report introduces a new structural concept that extends the Wadi as Sirhan graben complex southeastward in the Al Jawf quadrangle into the An Nafud (Great Desert). This concept greatly increases the area of interest in the potentially oil-and-gas-bearing rocks of the Wadi as Sirhan region to include those of the An Nafud basin. Discovery of the largest specimen of Prototaxites sp. in the world, in the Al Jubah area of the northeastern part of the quadrangle, has helped solve a long-standing stratigraphic problem involving Devonian and Cretaceous rocks of the southeastern part of the Sirhan-Turayf basin. Phosphorite, a commodity of major economic interest in the Sirhan-Turayf basin, is exposed in the map area along escarpments that form the southeastern rim of the basin. The grade of the phosphorite is as much as 21 percent P 2 O 5 , but the beds are thin and lenticular.

Open-File Report↗

Geologic map of the Taruntius Quadrangle of the Moon

The distribution of major physiographic provinces and geologic units of the Tarant ius quadrangle is determined by the five intersecting circular multi-ringed mare basin s. Three basins, i n probable order of decreasing age, are Tran quill itatis , Fecun ditatis , Serenitatis, Nectaris , and Crisiu m . The uplifted ring structures of the basin form terra mountains, peninsulas , and islands, and the depressions between the uplifts are the major deposition sites of post -basin terra and mare material.

IMAP↗

Geologic map of the Oxia Palus Quadrangle of Mars

The Oxia Palus quadrangle contains three distinct geologic provinces: (1) an elevated cratered plateau that occupies three-fourths of the quadrangle and is similar to much of the southern hemisphere of Mars; (2) the low, relatively featureless Chryse Planitia in the northwest corner; and (3) a complex province of chaotic terrain and immense channels or valleys that divides the plateau and terminates in Chryse Planitia. Generally, the oldest geologic units occur in the plateau province and the youngest in Chryse Planitia. Discovery by Mariner 9 of the channels, the four largest of which are given names meaning “Mars” in Akkadian, Sumerian, Angelo-Saxon, and Greek (west to east), renews the possibility of water and therefore life on Mars. This possibility may be tested in July 196 by a landing of the unmanned Viking spacecraft in Chryse Planitia at the mouths of the channels (lat 19 1/2˚ N., long 34˚).

IMAP↗

Geologic map of the Silver Lake Quadrangle, Cowlitz County, Washington

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits of the Silver lake 7.5 minute quadrangle. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

Miscellaneous Field Studies Map↗

Integrating GIS-based geologic mapping, LiDAR-based lineament analysis and site specific rock slope data to delineate a zone of existing and potential rock slope instability located along the grandfather mountain window-Linville Falls shear zone contact, Southern Appalachian Mountains, Watauga County, North Carolina

Landslide hazard maps of Watauga County identify >2200 landslides, model debris flow susceptibility, and evaluate a 14km x 0.5km zone of existing and potential rock slope instability (ZEPRSI) near the Town of Boone. The ZEPRSI encompasses west-northwest trending (WNWT) topographic ridges where 14 active/past-active rock/weathered rock slides occur mainly in rocks of the Grandfather Mountain Window (GMW). The north side of this ridgeline is the GMW / Linville Falls Fault (LFF) contact. Sheared rocks of the Linville Falls Shear Zone (LFSZ) occur along the ridge and locally in the valley north of the contact. The valley is underlain principally by layered granitic gneiss comprising the Linville Falls/Beech Mountain/Stone Mountain Thrust Sheet. The integration of ArcGIS??? - format digital geologic and lineament mapping on a 6m LiDAR (Light Detecting and Ranging) digital elevation model (DEM) base, and kinematic analyses of site specific rock slope data (e.g., presence and degree of ductile and brittle deformation fabrics, rock type, rock weathering state) indicate: WNWT lineaments are expressions of a regionally extensive zone of fractures and faults; and ZEPRSI rock slope failures concentrate along excavated, north-facing LFF/LFSZ slopes where brittle fabrics overprint older metamorphic foliations, and other fractures create side and back release surfaces. Copyright 2009 ARMA, American Rock Mechanics Association.

Conference Paper↗

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↗