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At least 55 records · Page 3Linked to original sources

Preliminary integrated geologic map databases for the United States. Digital data for the geology of the southern Brooks Range, Alaska

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. The files named __geol contain geologic polygons and line (contact) attributes; files named __fold contain fold axes; files named __lin contain lineaments; and files named __dike contain dikes as lines. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska↗

Maps showing geology, oil and gas fields and geologic provinces of the former Soviet Union

This digitally compiled map includes geology, geologic provinces, and oil and gas fields of the Former Soviet Union. The map is part of a worldwide series on CD-ROM by the World Energy Project released of the U.S. Geological Survey. The goal of the project is to assess the undiscovered, technically recoverable oil and gas resources of the world and report these results by the year 2000. For data management purposes the world was divided into eight energy regions corresponding approximately to the economic regions of the world as defined by the U.S. Department of State. The Former Soviet Union (Region 1) includes Armenia, Azerbaijan, Byelarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan. Each region was then further divided into geologic provinces on the basis of natural geologic entities and may include a dominant structural element or a number of contiguous elements. Some provinces contain multiple genetically related basins. Geologic province boundaries for the Former Soviet Union were delineated using data from a number of geologic maps and other tectonic and geographic data (see References). Offshore province boundaries were defined by the 2000 meter bathymetric contour from the map edited by Gabrielyants, 1990 (see References). Each province was assigned a unique number; the first digit is the region number; province numbers follow. An attempt was made to number the provinces in geographical groups; onshore, offshore, and combined on and offshore. The numbering starts in the west.

Open-File Report↗

Map showing geology, oil and gas fields, and geologic provinces of the Gulf of Mexico region

This map was created as part of a worldwide series of geologic maps for the U.S. Geological Survey’s World Energy Project, available on CD-ROM and through the Internet. The goal of the project is to assess the undiscovered, technically recoverable oil and gas resources of the world. Geologic provinces were created for ranking purposes in the World Petroleum Assessment 2000 (U.S. Geological Survey World Energy Assessment Team, 2000). A modified subset of these provinces are shown on the map, based on new bathymetric data and geologic knowledge. Geologic province boundaries are not intended to be taken for country boundaries or exclusive economic zone (EEZ) boundaries. The USGS World Petroleum Assessment 2000 - Description and Results can be found online at: http://pubs.usgs.gov/dds/dds-060 . Oil and gas fields are represented by a single geographic point in the center of the field and displays field type (oil or gas) only. The map includes three surface geology datasets, which were modified for display purposes.

Open-File Report↗

Guidance on geologic names usage for authors and peer reviewers of geologic maps and reports—A primer on stratigraphic nomenclature

Introduction Consistent and effective communication is essential for scientific publications. Scientific communication requires clear explanations and precise discussion of data and interpretations. “Authors must strive for clarity, consistency, and correct usage of both formal and informal terminology because of the complex interactions between time and space interpreted from the presently existing stratigraphic record” (Owen, 2009). The importance of consistent stratigraphic nomenclature as a means of effective geologic communication has been recognized since the U.S. Geological Survey (USGS) established the Geologic Names Committee (GNC) in 1899 to evaluate and address issues of stratigraphic nomenclature. The GNC currently consists of geologists from the USGS and the Association of American State Geologists. In an effort towards codifying stratigraphic nomenclature, the North American Commission on Stratigraphic Nomenclature developed the North American Stratigraphic Code (referred to hereafter as “the Code”; North American Commission on Stratigraphic Nomenclature [NACSN], 2021) in 1983 by revising and updating preexisting codes that were then in use, such as the International Stratigraphic Guide [ISG] (International Subcommission on Stratigraphic Classification [ISSC], 1976; see also, ISSC, 1994). Consistency in geologic names usage increases accuracy and quality of scientific publications. All formal USGS publications require a geologic names review (GNR) if any stratigraphic, lithodemic, geochronologic, or chronostratigraphic terminology is used. This review of, and guidance for, geologic names usage and stratigraphic principles should be referred to by authors and peer reviewers, not just those who conduct GNRs, and its guidance should be incorporated into their publications to improve geoscience communication. The notes and guidance in the sections that follow should be considered by USGS geologists and editors while writing or reviewing manuscripts that include geologic names and stratigraphic concepts. This primer may also be used by geologists and editors outside of the USGS for consistency with their publications.

Professional Paper↗

Geologic map of Mount Mazama and Crater Lake Caldera, Oregon, including the database for the geologic map of Mount Mazama and Crater Lake Caldera, Oregon

Crater Lake partly fills one of the most spectacular calderas of the world, an 8-by-10-km basin more than 1 km deep formed by collapse of the volcano known as Mount Mazama (fig. 1) during a rapid series of explosive eruptions about 7,700 years ago. Having a maximum depth of 594 m, Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 km2 of pristine forested and alpine terrain, including the lake itself, virtually all of Mount Mazama, and most of the area of the geologic map. The geology of the area was first described in detail by Diller and Patton (1902) and later by Williams (1942), whose vivid account led to international recognition of Crater Lake as the classic collapse caldera. Because of excellent preservation and access, Mount Mazama, Crater Lake caldera, and the deposits formed by the climactic eruption constitute a natural laboratory for study of volcanic and magmatic processes. For example, the climactic ejecta are renowned among volcanologists as evidence for systematic compositional zonation within a subterranean magma chamber. Mount Mazama's climactic eruption also is important as the source of the widespread Mazama ash, a useful Holocene stratigraphic marker throughout the Pacific Northwest, adjacent Canada, and offshore. A detailed bathymetric survey of the floor of Crater Lake in 2000 (Bacon and others, 2002) provides a unique record of postcaldera eruptions, the interplay between volcanism and filling of the lake, and sediment transport within this closed basin. Knowledge of the geology and eruptive history of the Mount Mazama edifice, greatly enhanced by the caldera wall exposures, gives exceptional insight into how large volcanoes of magmatic arcs grow and evolve. Lastly, the many smaller volcanoes of the High Cascades beyond the limits of Mount Mazama are a source of information on the flux of mantle-derived magma through the region. General principles of magmatic and eruptive processes revealed by the present study have been incorporated not only in scientific investigations elsewhere, but in the practical evaluation of hazards (Bacon and others, 1997b) and geothermal resources (Bacon and Nathenson, 1996) in the Crater Lake region. In addition to papers in scientific journals, field trip guides, and the hazard and geothermal reports, the major product of this long-term study of Mount Mazama is the geologic map. The map is unusual because it portrays bedrock (outcrop), surficial, and lake floor geology. Caldera wall geology is depicted in detail on the accompanying geologic panoramas.

Oregon↗

Health benefits of geologic materials and geologic processes

The reemerging field of Medical Geology is concerned with the impacts of geologic materials and geologic processes on animal and human health. Most medical geology research has been focused on health problems caused by excess or deficiency of trace elements, exposure to ambient dust, and on other geologically related health problems or health problems for which geoscience tools, techniques, or databases could be applied. Little, if any, attention has been focused on the beneficial health effects of rocks, minerals, and geologic processes. These beneficial effects may have been recognized as long as two million years ago and include emotional, mental, and physical health benefits. Some of the earliest known medicines were derived from rocks and minerals. For thousands of years various clays have been used as an antidote for poisons. “Terra sigillata,” still in use today, may have been the first patented medicine. Many trace elements, rocks, and minerals are used today in a wide variety of pharmaceuticals and health care products. There is also a segment of society that believes in the curative and preventative properties of crystals (talismans and amulets). Metals and trace elements are being used in some of today’s most sophisticated medical applications. Other recent examples of beneficial effects of geologic materials and processes include epidemiological studies in Japan that have identified a wide range of health problems (such as muscle and joint pain, hemorrhoids, burns, gout, etc.) that may be treated by one or more of nine chemically distinct types of hot springs, and a study in China indicating that residential coal combustion may be mobilizing sufficient iodine to prevent iodine deficiency disease.

International Journal of Environmental Research an↗

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance geologic map of the lower Yukon River region, Alaska

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska↗

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance geologic map of the western Aleutian Islands, Alaska

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO Exportfiles/ and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska↗

Preliminary integrated geologic map databases for the United States: Digital data for the reconnaissance bedrock geologic map for the northern Alaska peninsula area, southwest Alaska

he growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska↗

Reconnaissance geology north of the Hoholitna River, Taylor Mountains D-1 1:63,360-scale quadrangle, southwestern Alaska: A section in Geological studies in Alaska by the U.S. Geological Survey, 1999

The lower Paleozoic (Silurian and Ordovician) carbonate stratal succession is divided into six unnamed stratigraphic units in the northern part of the Taylor Mountains D-1 1:63,360-scale quadrangle of southwestern Alaska. Several of these units have previously been recognized in the McGrath and Medfra quadrangles to the northeast in strata of the Nixon Fork subterrane of the Farewell terrane (Decker and others, 1994 ). These rocks occur along the south side of a prominent east-west-trending anticlinoria! axis exposed slightly to the north in the Sleetmute A-2 1:63,360-scale quadrangle. Rocks of the Nixon Fork subterrane are now thought to represent a continental margin sequence rifted from Siberia. The low thermal alteration indices exhibited by the rocks of this area have elicited interest for petroleum exploration. However, low total organic carbon (TOC) values from potential source rocks within this lower Paleozoic succession indicate low petroleum potential.

Alaska↗