USGS Science⌕ Search

SEARCH · USGS Science

Results for “Search and Discovery”

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 37 records · Page 2Linked to original sources
USGS1975

Mineral resource management of the Outer Continental Shelf : leasing procedures, evaluation of resources, and supervision of production operations on leased lands of the Outer Continental Shelf

An important function of the Geological Survey is the evaluation and management of the mineral resources of the Outer Continental Shelf, particularly with respect to oil and gas, salt, and sulfur. Production of oil and gas from the Outer Continental Shelf of the United States has increased substantially over the past 20 years and represents an increasing percentage of total United States production. As discovery of major onshore production of oil and gas has become more difficult, the search has moved into the surrounding waters where submerged sedimentary formations are conducive to the accumulation of oil and gas. Increased energy demands of recent years have accelerated the pace of offshore operations with a corresponding improvement in technology as exploration and development have proceeded farther from shore and into deeper water. While improved technology and enforcement of more stringent regulations have made offshore operations safer, it is unrealistic to believe that completely accident-free operations can ever be achieved. Only slightly more than six percent of the world's continental terrace is adjacent to the United States, but less than one percent has been explored for oil and gas. Since the lead time for the development of offshore oil and gas resources can be as much as a decade, they do not provide an immediate energy supply but should be viewed in the light of a near-term source with a potential of becoming a medium-range source of supply pending the development of alternative energy sources. Revenues from the Outer Continental Shelf are deposited to the general fund of the United States Treasury. A major portion of these funds is allocated to the Land and Water Conservation Fund, the largest Federal grant-in-aid program of assistance to States, counties, and cities for the acquisition and development of public parks, open space, and recreation lands and water.

Circular↗
USGS1968

A preliminary report of a recently discovered aquifer at Sioux Falls, South Dakota

A hydrologic study of the Big Sioux aquifer system was begun July 1, 1966, by the U.S. Geological Survey, in cooperation with the City of Sioux Falls and the East Dakota Conservancy Sub-District. Test drilling being done in the search for a southern outlet to the Big Sioux aquifer has led to the discovery of the outlet and of a deeper aquifer than was previously know to exist in this area. This aquifer, herein called the Sioux Falls aquifer, was first recognized as a very clean gravel in test hole USGS #1 between the depths of 60 to 83 feet. Subsequent test drilling and aquifer testing has shown the Sioux Falls aquifer to be capable of producing several hundred gallons of water per minute. THe chemical quality of this water surpasses that currently being used for the city supply. Further investigation of the aquifer is planned as a part of the continuing expansion of the water-supply facilities for Sioux Falls. This publication has been authorized by the Director of the U.S. Geological Survey and Earl McCart, Commissioner, City of Sioux Falls, South Dakota.

South Dakota↗
USGS1975

A spring aerial census of red foxes in North Dakota

Systematic aerial searches were flown on transects to locate adult red foxes ( Vulpes vulpes ), pups, and rearing dens on 559.4 km2 (six townships) in eastern North Dakota during mid-May and mid-June each year from 1969 through 1973 and during mid-April 1969 and early May 1970. The combined sightings of foxes and fox dens from the mid-May and mid-June searches were used to identify individual fox families. The number of fox families was used as the measurement of density. Dens, highly visible during the mid-May searches, were the most reliable family indicator; 84 percent of 270 families identified during the study were represented by dens. Adult foxes second in importance, were most observable during the mid-May searches when 20 to 35 percent of those estimated to be available were sighted. Adult sightings during other search periods ranged from 4 to 17 percent of those available. Pup sightings were the most variable family indicator, but they led to the discovery of some dens. Sources of error for which adjustment factors were determined are: den moves exceeding criterion established for the spacing of dens in a single family, overestimation of the number of fox families living near township boundaries, and the percentage of fox families overlooked during the aerial searches. These adjustment factors appeared to be largely compensatory.

North Dakota↗
USGS1943

Report on the bauxite possibilities of Cuba

The recent discovery of extensive bauxite deposits in the red and buff clays of Jamaica suggested the desirability of a search for similar occurrences in Cuba, especially as lateritic iron ore was known to occur in Cuba. The writer spent the period from May 9 to July 16, 1943, in this examination, two weeks of which were spent in Jamaica. The investigation was under the auspices of the State Department and the Interdepartmental Committee for Cooperation with the American Republics. Mr. Charles Ducoté, Commercial Attaché, and Mr. C. A. Botsford, Minerals Attaché of the American Embassy in Havana, were of much assistance in arranging facilities for transportation and in other ways. Mr. Robert Donald of the Metals Reserve Company Agency at Santiago de Cuba kindly arranged for some analyses of samples in the Agency laboratory.

Open-File Report↗
USGS2012

Characterization of previously unidentified lunar pyroclastic deposits using Lunar Reconnaissance Orbiter Camera (LROC) data

We used a Lunar Reconnaissance Orbiter Camera (LROC) global monochrome Wide-angle Camera (WAC) mosaic to conduct a survey of the Moon to search for previously unidentified pyroclastic deposits. Promising locations were examined in detail using LROC multispectral WAC mosaics, high-resolution LROC Narrow Angle Camera (NAC) images, and Clementine multispectral (ultraviolet-visible or UVVIS) data. Out of 47 potential deposits chosen for closer examination, 12 were selected as probable newly identified pyroclastic deposits. Potential pyroclastic deposits were generally found in settings similar to previously identified deposits, including areas within or near mare deposits adjacent to highlands, within floor-fractured craters, and along fissures in mare deposits. However, a significant new finding is the discovery of localized pyroclastic deposits within floor-fractured craters Anderson E and F on the lunar farside, isolated from other known similar deposits. Our search confirms that most major regional and localized low-albedo pyroclastic deposits have been identified on the Moon down to ~100 m/pix resolution, and that additional newly identified deposits are likely to be either isolated small deposits or additional portions of discontinuous, patchy deposits.

Journal of Geophysical Research E: Planets↗
USGS1979

Martian channels and the search for extraterrestrial life

The origin of the channels on Mars has been a subject of intense interest since they were first recognized on early Mariner 9 images (Driscoll, 1972; Masursky, 1973). Their presence on the planet, and their striking resemblance to terrestrial flood channels related to glacial outbursts or to dendritic river systems has suggested to most investigators (Baker, 1974, 1977; Nummedal, 1978; Carr, 1979; Masursky et al., 1977) that they were formed by running water. Because life as we know it is dependent on water, the discovery by the 'Mariner cameras', of watercut channels and volcanoes as a source for water, and water ice in the residual north polar cap by Viking, has reaffirmed the choice of Mars as the best target for the search for extraterrestrial life. ?? 1979 Springer-Verlag.

Journal of Molecular Evolution↗
USGS1985

Undiscovered phosphate resources in the Caribbean region and their potential value for agricultural development

The countries of the world's humid tropical regions lack the soil fertility necessary for high agricultural productivity. A recently developed agricultural technology that increases soil fertility can make tropical agriculture highly productive, but the technique requires large inputs into the soil of phosphorus and other fertilizers and soil amendments. Use of fertilizers derived from phosphate rock is increasing greatly throughout the world, and fertilizer raw materials are being produced more and more frequently from phosphate rock deposits close to the areas of use. An increased understanding of the origin of phosphate rock in ancient oceans has enabled exploration geologists to target areas of potential mineral resource value and to search directly for deposits. However, because of the difficulty of prospecting for mineral deposits in forested tropical regions, phosphate rock deposits are not being explored for in the countries of the humid tropics, including most countries of the Caribbean region. As a result, the countries of the Caribbean must import phosphate rock or phosphorus fertilizer products. In the present trade market, imports of phosphate are too low for the initiation of new agricultural technology in the Caribbean and Central American region. A newly proposed program of discovery and development of undiscovered phosphate rock deposits revolves around reconnaissance studies, prospecting by core drilling, and analysis of bulk samples. The program should increase the chance of discovering economic phosphate rock deposits. The search for and evaluation of phosphate rock resources in the countries of the Caribbean region would take about 5 years and cost an average of $15 million per country. The program is designed to begin with high risk-low cost steps and end with low risk-high cost steps. A successful program could improve the foreign exchange positions of countries in the Caribbean region by adding earnings from agricultural product exports and by substituting domestically produced phosphate rock and fertilizer products for imported phosphate fertilizers. A successful program also could provide enough domestically produced phosphorus fertilizer products to allow initiation of new agricultural technology in the region and thus increase domestic food production. Finally, a new phosphorus fertilizer industry would create new jobs in the mining, chemical, and transportation industries of the Caribbean region.

Circular↗
USGS1893

Insect fauna of the Rhode Island coal field

Some years ago Rev. Edgar F. Clark, then of Providence, Rhode Island, discovered in the Coal-measures of the neighborhood of that city the wing of a cockroach. This stimulated further search by others as well as himself, with the result of finding a fair number and variety of insect types, some of special interest. Most of the discoveries have been made by Mr. Clark (part of them while in the service of the U. S. Geological Survey) and by two young inen of Providence, Messrs. Frederick P. Gorham and Herbert Scholfield, who have been particularly encouraged in their work by Prof. A. S. Packard, of Brown University. All of the specimens have passed under my eye and are herewith described and figured. They consist of Anthracomartus, the first discovered Arachnid in the Carboniferous deposits of the eastern United States; a new genus of Neuropteroidea and one of Protophasmida, each very different from any forms hitherto found in this country, but rather allied to some from the rich Carboniferous beds of Commentry, in France, presenting new features of alliance between the Carboniferous faunas of Europe and America; and a number of cockroaches, all represented by their wings alone. These last show considerable variety of form, both known subfamilies of Paloblattarioe being present, including three genera and nearly a dozen species, the genus Etoblattina, which is the prevalent Carboniferous type the world over, being represented by at least eight species, which again show unusual diversity in size, form, and distribution of the nervules that form the framework of the wing. All the species without exception are new to science and unknown elsewhere. A few additional stones have been submitted to me containing what are apparently parts of the wings of cockroaches, but they are too fragmentary to be of the least value. Nothing more can be said than that they are or may be portions of such wings. It is hoped that the publication of this bulletin will excite further exploration and result in more extended discoveries.

Rhode Island↗
USGS2013

Stable isotopes in mid-ocean ridge hydrothermal systems: Interactions between fluids, minerals, and organisms

Studies of abundance variations of light stable isotopes in nature have had a tremendous impact on all aspects of geochemistry since the development, in 1947, of a gas source isotope ratio mass spectrometer capable of measuring small variations in stable isotope ratios (Nice, 1947]. Stable isotope geochemistry is now a mature field, as witnessed by the proliferation of commercially available mass spectrometers installed at virtually every major academic, government, and private-sector research geochemistry laboratory. A recent search of a literature database revealed over 3,000 articles that utilized stable isotope geochemistry over the last 20 years. Nonetheless, many exciting new technical developments are leading to exciting new discoveries and applications. In particular, micro-analytical techniques involving new generations of laser- and ion-microprobes are revolutionizing the types of analyses that can be done on spot sizes as small as a few tens of micrometers [Shanks and Criss, 1989]. New generations of conventional gas source and thermal ionization mass spectrometers, with high levels of automation and increased sensitivity and precision, are allowing analyses of large numbers of samples, like those needed for stable isotope stratigraphy in marine sediments, and are enabling the development and application of new isotopic systems.

Book chapter↗
USGS2015

Now hiring! Empirically testing a three-step intervention to increase faculty gender diversity in STEM

Workforce homogeneity limits creativity, discovery, and job satisfaction; nonetheless, the vast majority of university faculty in science, technology, engineering, and mathematics (STEM) fields are men. We conducted a randomized and controlled three-step faculty search intervention based in self-determination theory aimed at increasing the number of women faculty in STEM at one US university where increasing diversity had historically proved elusive. Results show that the numbers of women candidates considered for and offered tenure-track positions were significantly higher in the intervention groups compared with those in controls. Searches in the intervention were 6.3 times more likely to make an offer to a woman candidate, and women who were made an offer were 5.8 times more likely to accept the offer from an intervention search. Although the focus was on increasing women faculty within STEM, the intervention can be adapted to other scientific and academic communities to advance diversity along any dimension.

BioScience↗
USGS1975

Mineral deposits in western Saudi Arabia; a preliminary report

Mineral deposits in Saudi Arabia include a variety of deposits which were formed in many geologic environments. These include magmatic and late magmatic deposits in igneous masses, contact metamorphic deposits along the margins of igneous bodies, and stratiform sulfide deposits and veins. Notable deposits of sedimentary origin include deposits of iron oxides and phosphate. Strata-bound massive sulfide deposits containing copper, zinc, and nickel sulfides associated with pyrite and pyrrhotite in complexly deformed volcanic rocks in Saudi Arabia have been the subject of controversy. They are considered by some geologists to be of syngenetic or volcanogenic origin, and by others to be epigenetic. The principal mineral deposits in western Saudi Arabia are localized in mineral belts within tectonic zones that trend northerly, northeasterly, and northwesterly. These belts contain the exploration target areas most promising for future exploration. Noteworthy among these are: 1) the northerly-trending Bidah copper-zinc belt; 2) the Sayid copper-zinc zone; 3) the northwest-trending Nuqrah copper zinc-silver belt; and 4) the north-northwesterly-trending Al Amar belt. Gold and silver deposits are mainly localized in north-trending structural features of the Hijaz geotectonic cycle and northwest Najd trends. Saudi Arabian metal deposits known thus far contain reserves in the 2 billion dollar range. Further exploration should result in discoveries that could significantly increase this amount; Saudi Arabia may well have workable metallic and nonmetallic mineral resources for industrial developments in many parts of the Kingdom. In order to effectively carry on a search for new mineral deposits, the belts should be mapped in detail, with emphasis on the delineation of stratigraphic and structural features that control metallization. In addition, geochemical and geophysical studies should be made of promising areas to outline exploration targets. These targets could then be systematically explored.

Open-File Report↗
USGS1959

Geology of uranium and associated ore deposits, central part of the Front Range mineral belt, Colorado

The Central City district and adjoining mining areas in the central part of the Front Range mineral belt have supplied small quantities of uranium ore intermittently since the discovery of pitchblende at Central City in 1871. During the early years of development the uranium production form the region was of national importance, and until 1951 the region was this country's principal domestic source of pitchblende. In recent years, however, the production has been insignificant although the search for uranium has been greater than at any previous time. The pitchblende occurs as a local minor constituent of gold- and silver-bearing base-metal sulfide veins, chiefly valuable for their gold content, which have yielded ores valued at about $200 million.

Colorado↗
USGS1975

In search of a statistical probability model for petroleum-resource assessment : a critique of the probabilistic significance of certain concepts and methods used in petroleum-resource assessment : to that end, a probabilistic model is sketched

Exploratory drilling is still in incipient or youthful stages in those areas of the world where the bulk of the potential petroleum resources is yet to be discovered. Methods of assessing resources from projections based on historical production and reserve data are limited to mature areas. For most of the world's petroleum-prospective areas, a more speculative situation calls for a critical review of resource-assessment methodology. The language of mathematical statistics is required to define more rigorously the appraisal of petroleum resources. Basically, two approaches have been used to appraise the amounts of undiscovered mineral resources in a geologic province: (1) projection models, which use statistical data on the past outcome of exploration and development in the province; and (2) estimation models of the overall resources of the province, which use certain known parameters of the province together with the outcome of exploration and development in analogous provinces. These two approaches often lead to widely different estimates. Some of the controversy that arises results from a confusion of the probabilistic significance of the quantities yielded by each of the two approaches. Also, inherent limitations of analytic projection models-such as those using the logistic and Gomperts functions --have often been ignored. The resource-assessment problem should be recast in terms that provide for consideration of the probability of existence of the resource and of the probability of discovery of a deposit. Then the two above-mentioned models occupy the two ends of the probability range. The new approach accounts for (1) what can be expected with reasonably high certainty by mere projections of what has been accomplished in the past; (2) the inherent biases of decision-makers and resource estimators; (3) upper bounds that can be set up as goals for exploration; and (4) the uncertainties in geologic conditions in a search for minerals. Actual outcomes can then be viewed as phenomena subject to statistical uncertainty and responsive to changes in economic and technologic factors.

Circular↗
USGS2012

Structural equation modeling and the analysis of long-term monitoring data

The analysis of long-term monitoring data is increasingly important; not only for the discovery and documentation of changes in environmental systems, but also as an enterprise whose fruits validate the allocation of effort and scarce funds to monitoring. In simple terms, we may distinguish between the detection of change in some ecosystem attribute versus the investigation of causes and consequences associated with that change. The statistical framework known as structural equation modeling (SEM) can contribute to both detection of changes and the search for causes. This chapter summarizes some of the capabilities of SEM and shows a few ways it can be used to model temporal change. Because of its ability to test hypotheses about whether rates of change are zero or nonzero, it can be used for change detection with repeated-measures data. As more of the capabilities of SEM are presented, its capacity for evaluating causal networks is highlighted. Here is where its potential for making a unique contribution to the analysis of long-term monitoring data is revealed. Thus, one?s primary motivation for using SEM with monitoring data will be to investigate hypotheses about what factors may be driving change. In this chapter, it will be necessary to first introduce notation to describe the elements of structural equation models (SE models) so as to permit an unambiguous presentation of their various forms. The first part of the chapter works through the fundamental features of models of increasing complexity, while the second part of the chapter illustrates several of these possibilities using a real example.

Book chapter↗
USGS1977

Preliminary data on some Precambrian deposits of zinc-copper-lead sulfides and zinc spinel (granite) in Colorado

Precambrian sulfide deposits in the Southern Rocky Mountains in Colorado are being studied and re-evaluated according to geologic concepts which were developed in recent years in other parts of the world during successful research regarding economic massive sulfide deposits. These studies, initiated in 1974 in Colorado by the U.S. Geological Survey, have indicated that a new look at areas containing long dormant mines and prospects may well lead to the discovery of minable Precambrian sulfide deposits. The zinc, copper, and lead contents of ores investigated to date, supplemented by silver and gold contents, indicate that many long-forgotten deposits are minable in terms of grade. The deposits occur in Precambrian rocks metamorphosed to the lower amphibolite facies in one major region and to the upper amphibolite facies in other regions. Field studies have provided ample evidence indicating that the search for commercial tonnages can he facilitated by using newer concepts of economic geology regarding ore-host rock associations as prospecting guides and by using structural considerations aimed toward learning how metamorphism and folding have modified the shapes and distribution of the ore bodies. A newly recognized concept, originating from the current studies by the U.S. Geological Survey in Colorado, concerns the potential economic significance of gahnite, a zinc spinel. The field and laboratory data indicate that gahnite can be used by geologists as a prospector's guide to ore and can be considerd by mining engineers as a potential major ore mineral, contributing significant amounts of zinc to the sulfide ores in many of the deposits. Studies to date indicate that the Gunnison area, the Salida area, and the Guffey area are particularly favorable to the search for minable deposits, and the potential is equally present in many other areas.

Colorado↗
USGS1958

The next decade in geochemistry

The purpose, associations, functions; and activities of the Geochmical Society are reviewed briefly. Work on the Colorado Plateau uranium deposits is described as an example of what geochemical research, in conjunction with detailed field work, mineralogical studies, and related techniques can contribute to the understanding of a type of deposit. It is pointed out that not only have these studies given a great deal of information about the origin of the ores, but they have brought about directly a manifold increase in production and reserves of uranium in the United States. Indirectly, they aided the discovery of the tremendous deposits of the Blind River area in Ontario. It is suggested that similar broad cooperative attacks could not only yield comparable results with other types of mineral deposits, such as laterites and Mississippi Valley type lead-zinc deposits, but could also advance our knowledge and understanding of such diverse problems of geology and cosmology as the origin of granites, origin and geologic implications of meteorites (including tektites), origin and search for petroleum, and geochemical relations and interpretations of natural waters. For each of these problems methods of approach are outlined and for some of them, specific projects and correlative problems are mentioned. It is further suggested that the broad cooperative attack needed for most of these problems might be fostered most effectively by a programme comparable to that of the I.G.Y., even though for most types of geochemical research synoptic sampling and observations are not as important as they are for many projects in geophysics.

Geochimica et Cosmochimica Acta↗
USGS1979

The corrosive well waters of Egypt's western desert

The discovery that ground waters of Egypt's Western Desert are highly corrosive is lost in antiquity. Inhabitants of the oases have been aware of the troublesome property for many decades and early investigators mention it in their reports concerning the area. Introduction of modern well-drilling techniques and replacements of native wood casing with steel during the 20th century increased corrosion problems and, in what is called the New Valley Project, led to an intense search for causes and corrective treatments. This revealed that extreme corrosiveness results from combined effects of relatively acidic waters with significant concentrations of destructive sulfide ion; unfavorable ratios of sulfate and chloride to less aggressive ions; mineral equilibria and electrode potential which hinder formation of protective films; relative high chemical reaction rates because of abnormal temperatures, and high surface velocities related to well design. There is general agreement among investigators that conventional corrosion control methods such as coating metal surfaces, chemical treatment of the water, and electrolytic protection with impressed current and sacrificial electrodes are ineffective or impracticable for wells in the Western Desert's New Valley. Thus, control must be sought through the use of materials more resistant to corrosion than plain carbon steel wherever well screens and casings are necessary. Of the alternatives considered, stainless steel appears to. be the most promising where high strength and long-term services are required and the alloy's relatively high cost is acceptable. Epoxy resin-bonded fiberglass and wood appear to be practicable, relatively inexpensive alternatives for installations which do. not exceed their strength limitations. Other materials such as high strength aluminum and Monel Metal have shown sufficient promise to. merit their consideration in particular locations and uses. The limited experience with pumping in these desert wells leaves uncertainties concerning the durability of conventional pump designs. Egypt's New Valley Project provides an excellent opportunity for continuing study of the corrosion problems that concern ground-water developers in many parts of the world.

Water Supply Paper↗
USGS2020

Some approaches to accounting for incidental carcass discoveries in non-monitored years using the Evidence of Absence model

Executive Summary We evaluate three approaches to accounting for incidental carcasses when estimating an upper bound on total mortality (𝑀) as 𝑀 ∗ using the Evidence of Absence model (EoA; Dalthorp and others, 2017) to assess compliance with an Incidental Take Permit (ITP) (Dalthorp & Huso, 2015) under a monitoring protocol that includes formal, dedicated carcass surveys that achieve an overall detection probability of 𝑔 𝑠 =0.15 in the first year, followed by 4 years with no formal monitoring but with carcasses potentially discovered incidentally by operations and maintenance crews in their normal course of activity or otherwise discovered outside the formal searches. We refer to carcasses discovered incidentally as “incidentals” and define 𝑥 𝑖 as the count of incidentals. Similarly, we define 𝑥 𝑠 as the number of carcasses found during the formal searches conducted the first year.

Open-File Report↗