Bibliography of North American geology, 1919-1928
Explore the source record for details and available documents.
Bulletin↗
SEARCH · Geology Reports
Results for “Geological Bulletin”
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.
Record of North American geology for 1890
Explore the source record for details and available documents.
Bulletin↗
Bibliography of North American geology, 1929-1939
Explore the source record for details and available documents.
Bulletin↗
Record of North American geology for 1891
Explore the source record for details and available documents.
Bulletin↗
Chapter K: Progress in the Evaluation of Alkali-Aggregate Reaction in Concrete Construction in the Pacific Northwest, United States and Canada
The supply of aggregates suitable for use in construction and maintenance of infrastructure in western North America is a continuing concern to the engineering and resources-management community. Steady population growth throughout the region has fueled demand for high-quality aggregates, in the face of rapid depletion of existing aggregate resources and slow and difficult permitting of new sources of traditional aggregate types. In addition to these challenges, the requirement for aggregates to meet various engineering standards continues to increase. In addition to their physical-mechanical properties, other performance characteristics of construction aggregates specifically depend on their mineralogy and texture. These properties can result in deleterious chemical reactions when aggregate is used in concrete mixes. When this chemical reaction-termed 'alkali-aggregate reaction' (AAR)-occurs, it can pose a major problem for concrete structures, reducing their service life and requiring expensive repair or even replacement of the concrete. AAR is thus to be avoided in order to promote the longevity of concrete structures and to ensure that public moneys invested in infrastructure are well spent. Because the AAR phenomenon is directly related to the mineral composition, texture, and petrogenesis of the rock particles that make up aggregates, an understanding of the relation between the geology and the performance of aggregates in concrete is important. In the Pacific Northwest, some aggregates have a moderate to high AAR potential, but many others have no or only a low AAR potential. Overall, AAR is not as widespread or serious a problem in the Pacific Northwest as in other regions of North America. The identification of reactive aggregates in the Pacific Northwest and the accurate prediction of their behavior in concrete continue to present challenges for the assessment and management of geologic resources to the owners and operators of pits and quarries and to the users of the concrete aggregates mined from these deposits. This situation is complicated by the length of time typically required for AAR to become noticeable in concrete construction in the Pacific Northwest, commonly on such a scale that other deterioration mechanisms may have masked the effects of AAR. Distinguishing between the effects of AAR and those related to other problems in concrete is important for understanding the nature and severity of AAR throughout the Pacific Northwest. Furthermore, developing an understanding of the extent of the problem will assist efforts to maximize the intelligent and stewardly use of aggregate resources in the Pacific Northwest. This chapter illustrates the current 'state of the art' of AAR studies in the Pacific Northwest, a region with a common geologic heritage as well as many distinct geologic elements. The optimal use of aggregates in the construction of concrete structures that will achieve their design life is possible through an understanding of the engineering and geologic properties of these aggregates and of their geologic setting.
Bulletin↗
Peak streamflow trends in South Dakota and their relation to changes in climate, water years 1921–2020
Peak-flow (flood) frequency analysis is essential to water-resources management applications, including the design of critical infrastructure such as bridges and culverts, and floodplain mapping. Federal guidelines for performing peak-flow flood frequency analyses are presented in a U.S. Geological Survey Techniques and Methods Report known as Bulletin 17C. A basic assumption within Bulletin 17C, which documents the guidelines for determining annual peak streamflow frequency, is that, for basins without major hydrologic alterations (for example, regulation, diversion, and urbanization), statistical properties of the distribution of annual peak streamflows are stationary; that is, the mean, variance, and skew are constant through time. Nonstationarity is a statistical property of a peak-flow series such that the long-term (on the order of decades) distributional properties change one or more times either gradually or abruptly through time. Individual nonstationarities may be attributed to one source such as flow regulation, land-use change, or climate but are often the result of a combination of sources, making detection and attribution of nonstationarities challenging. In response to a growing concern regarding nonstationarity in peak streamflows in the region, the U.S. Geological Survey, in cooperation with the Departments of Transportation of Illinois, Iowa, Michigan, Minnesota, Missouri, South Dakota, and Wisconsin; the Montana Department of Natural Resources and Conservation; and the North Dakota Department of Water Resources, assessed the potential nonstationarity in peak streamflows in the north-central United States. This chapter characterizes the effects of natural hydroclimatic shifts and potential climate change on annual peak streamflows in the State of South Dakota. Annual peak and daily streamflow as well as model-simulated gridded climatic data were examined for temporal monotonic trends, change points, and other statistical properties indicative of changing climatic and environmental conditions. Changes in annual peak and daily flows were evaluated among 13, 35, and 81 qualifying U.S. Geological Survey streamgages for the 75-, 50-, and 30-year trend periods through water year 2020 (the period from October 1, 2019, to September 30, 2020) in South Dakota, respectively. No qualifying streamgages were in the 100-year trend period in the State. Statistical tests for autocorrelation (independent and identically distributed assumption), monotonic trends, and change points in the median and scale are analyzed to evaluate potential stationarity violations (nonstationarity) for performing at-site peak-flow flood-frequency analysis. The trends are reported using a likelihood approach as an alternative to simply reporting significant trends with an arbitrary p -value cutoff point. A distinct east-west spatial pattern of likely upward and downward monotonic trends and change points, respectively, was detected in 75- and 50-year trend periods, but an inconsistent spatial pattern was detected in the 30-year trend period. Additionally, change points in the median annual peak streamflows were detected in the late 1970s and early 1980s in the western part of the State, but in the east, the change point was more commonly detected in 1992–93. A similar east-west spatial pattern of likely upward and downward trends was detected in the annual peak-flow timing, the day of the year of the annal peak streamflow. In the western part of the State, the annual peak streamflows are arriving earlier, but in the east, the annual peak streamflows are arriving later. A peaks-over-threshold (POT) analysis where, on average, there are two events per year (POT2) and four events per year (POT4) was also used to evaluate changes in the frequency (count) of daily streamflows exceeding the threshold. Similar to detected changes in the annual peak streamflow, an east-west likely upward or downward change corresponding to an increase or decrease, respectively, in the frequency of daily streamflow greater than a POT2 and POT4 threshold was detected. A monthly water-balance model was used to evaluate hydroclimatic variation in annual and seasonal precipitation, snowfall, potential evapotranspiration, and soil moisture storage for all qualifying streamgages in the 75-, 50-, and 30-year trend periods. Detected trends in the annual hydroclimatic metrics for the 75- and 50-year trend periods indicate a spatially consistent statewide increase in precipitation, decrease in snowfall, increase in potential evapotranspiration, and increase in soil moisture storage. Furthermore, detected trends in seasonal precipitation in the 75- and 50-year trend periods highlight a pronounced change in precipitation in winter and later into the summer season, especially in the 50-year trend period in the eastern part of the State. Statewide increases in seasonal soil moisture storage were also detected, highlighting year-round increasing flood magnitudes, particularly in the eastern part of the State. Based on the results of these stationarity tests for the qualifying streamgages in South Dakota among the 75-, 50-, and 30-year trend periods, consistent temporal and spatial patterns of nonstationarity were detected among the 75- and 50-year trend periods. Furthermore, when nonstationarity is detected in daily streamflow, increased streamflow and volume (increasing frequency in POT), as well as potentially bridge scour, may have implications on culvert and highway design in the eastern part of South Dakota. Thus, when performing at-site peak-flow flood-frequency analyses in South Dakota, potential nonstationarities and alternative approaches are important considerations.
South Dakota↗
Gas hydrate resources of northern Alaska
Large amounts of natural gas, composed mainly of methane, can occur in arctic sedimentary basins in the form of gas hydrates under appropriate temperature and pressure conditions. Gas hydrates are solids, composed of rigid cages of water molecules that trap molecules of gas. These substances are regarded as a potential unconventional source of natural gas because of their enormous gas-storage capacity. Most published gas hydrate resource estimates are highly simplified and based on limited geological data. The gas hydrate resource assessment for northern Alaska presented in this paper is based on a "play analysis" scheme, in which geological factors controlling the accumulation and preservation of gas hydrates are individually evaluated and risked for each hydrate play. This resource assessment identified two gas hydrate plays; the in-place gas resources within the gas hydrates of northern Alaska are estimated to range from 6.7 to 66.8 trillion cubic metres of gas (236 to 2,357 trillion cubic feet of gas), at the 0.50 and 0.05 probability levels respectively. The mean in-place hydrate resource estimate for northern Alaska is calculated to be 16.7 trillion cubic metres of gas (590 trillion cubic feet of gas). If this assessment is valid, the amount of natural gas stored as gas hydrates in northern Alaska could be almost seven times larger then the estimated total remaining recoverable conventional natural gas resources in the entire United States.
Alaska↗
Effect of height and orientation (microclimate) on geomorphic degradation rates and processes, late-glacial terrace scarps in central Idaho
Skip Nav Destination RESEARCH ARTICLE | JULY 01, 1986 Effect of height and orientation (microclimate) on geomorphic degradation rates and processes, late-glacial terrace scarps in central Idaho KENNETH L. PIERCE ; STEVEN M. COLMAN Author and Article Information GSA Bulletin (1986) 97 (7): 869–885. https://doi.org/10.1130/0016-7606(1986)97<869:EOHAOM>2.0.CO;2 Article history Standard View 2.0.CO;2" data-doctype="contentPdf" data-article-id="188507" data-mce-href="https://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/97/7/869/3434736/i0016-7606-97-7-869.pdf"> Open the PDF for in another window Cite Share Icon Share Permissions Abstract Terrace scarps can serve as a nearly ideal natural laboratory for the study of the evolution of slopes. This paper examines the effects of scarp size (height) and orientation (microclimate) by keeping constant variables such as age, lithology, and regional climate. If a scarp degrades as a closed system, and downslope movement is directly proportional to surface gradient , the evolution of the scarp is modeled by the diffusion equation. For a group of scarps of same age and known starting angle, the diffusion-equation model predicts the relation between maximum scarp angle (𝛉) and scarp height ( h ). Late Pleistocene terrace scarps now as steep as 33.25°, as well as measured angles of repose for sand and gravel, require a starting angle as steep as 33.5°. For latest Pleistocene Idaho and Utah scarps, as h increases, 𝛉 is gentler (more degraded) than modeled by the diffusion equation with a constant rate coefficient. The degradation-rate coefficient ( c ) increases tenfold with scarp height; it should not change with scarp height if downslope movement is solely determined by surface gradient (to the first power). Soil wash appears to be responsible for this departure from the diffusion-equation model, for transport rate by soil wash is a function of scarp size (height). South-facing scarps are less vegetated and more degraded than north-facing scarps. For scarps 2 m high, the degradation rate ( c *) on S-facing scarps is 2 times that on N-facing scarps; for 10-m scarps, it is 5 times. The observed dependence of the rate coefficient c * on scarp height can be removed by normalizing c * to values for west-facing scarps of the same height. The residual c * values calculated by this method correlate well with differences in incident solar radiation resulting from the different scarp orientations and maximum gradients. This correlation demonstrates the importance of orientation on slope processes and their rates through the differences in freeze-thaw cycles, soil moisture, and vegetative cover. Scarp morphology may be used to estimate age, if one accounts for the effects of climate and for scarp height, orientation, and lithology. For example, using the dated Bonneville shoreline scarps for calibration and comparing only scarps of equal height, we estimate the Drum Mountains fault scarps to be 9,000 yr old. This age is about twice that produced by previous diffusion-equation calculations that have not accounted for the height as we have here, but it is the same as independent geologic estimates of their age.
Idaho↗
Water Resources Division training bulletin, October 1981 through September 1982
This bulletin is designed to inform interested personnel about training available through the Water Resources Division of the U.S. Geological Survey during the period October 1981 through September 1982. The information in this bulletin also can assist supervisors and training officers in developing a coordinated, efficient training program for the personnel for whom they are responsible. The objective of the Water Resources Division training program is to provide specialized training in many phases of hydrology and other subjects related to water-resources investigations. The courses featured in this bulletin are on specialized subjects that are not generally available elsewhere, including the latest developments in applications of ground-water, surface-water, and water-quality hydrologic methods in the field and in the laboratory. The training described herein provides: (1) rapid application of new research results to increase the skills of personnel, and (2) provides newly recruited personnel with special training skills and methods required in water-resources investigations. These courses will assist personnel in learning, reviewing, and expanding their knowledge of technical operations involved in various phases of hydrology and related subjects, and also will develop an overall insight into the broad field of water-resources work.
Open-File Report↗
Solution effects on elevated limestone terraces
Limestone terraces on a number of islands in the southwest Pacific show a well-developed wall or rampart along their seaward edges that apparently is formed by solution. Such rimmed terraces resemble, on a much enlarged scale, the solution facets developed on flat-lying joint blocks of limestone, recently described by Smith and Albritton (1941). In an attempt to check the interpretation of field observations, a rimmed facet was produced experimentally in the laboratory. The artificial structure appears to be very similar to the natural facets on joint blocks and in many ways closely resembles the much larger rimmed terraces of the Pacific islands. It is believed that rimmed terraces with a profile similar to that of the island of Eua, Tonga, indicate island uplift accompanied by tilting. © 1945, The Geological Society of America, Inc.
Geological Society of America Bulletin↗
Lower Middle Ordovician stratigraphy of the Shenandoah Valley, Virginia
In classifying the lower Middle Ordovician of the Shenandoah Valley, the formation names Stones River, Mosheim, Lenoir, Holston, Whitesburg, and Athens have been used without adequate evidence. Detailed study shows that the so-called Athens and Whitesburg, as developed near Harrisonburg, are laterally continuous with the greater part of the Chambersburg limestone, which is supposed to be younger than the Athens. The newly discovered relations of these formations affect the classification of the Middle Ordovician in much of the northern Appalachian region. The present study has been high-lighted by the discovery that Cryptophragmus antiquatus , widely regarded as a valid guide to the lower Black River, ranges through several hundred feet of beds, possibly as high as lower Trenton. In the Shenandoah Valley, this fossil is most abundant near the top of the Chambersburg, which is supposed to be late Black River or early Trenton. In the proposed reclassification, the lower Middle Ordovician is divided into six time-stratigraphic units, in ascending order: the New Market limestone, Whistle Creek limestone, Lincolnshire limestone, Edinburg formation, Oranda formation, and Collierstown limestone. The Edinburg embraces two equivalent facies: one of cobbly limestone (Lantz Mills facies) which is mainly developed in the northern and western parts of the Shenandoah Valley; and a relatively thicker body of black limestone and shale (Liberty Hall facies) which is typically developed in the Harrison-burg-Staunton area. In the western part of Shenandoah County, the topmost division of the Edinburg formation is composed of light-gray calcilutite and calcarenite, named the St. Luke limestone member. The rusty-brown granular limestones just below Butts' Athens in the Harrisonburg-Staunton-Lexington area are here named the Botetourt limestone member of the Edinburg formation. At least part of the New Market limestone is linked with a part of the New York Chazy and type Lenoir, but the Lincolnshire seems to be post-Chazy. All the succeeding beds, comprising the greater part of the lower Middle Ordovician succession, are Black River or Trenton.
Virginia↗
Appalachian drainage and the highland border sediments of the Newark series
The highland border fanglomerates of the Newark basin in New York, New Jersey, and eastern Pennsylvania show no extraordinary correlation with present drainage either in distribution or lithologic character and degree of rounding of their gravels. The writer found no evidence of deposition of any of the fanglomerates by major streams and no evidence that any of the present streams enter the basin through Triassic-filled remnants of Triassic valleys. Available evidence indicates that streams which deposited the Newark fanglomerates were relatively short and steep, consequent on the northwest border fault scarp or flexure. Variations in lithologic character of the fanglomerates were due largely to the rock types exposed along the margin of the northwest highland block. The lithologic character of the Newark sediments and particularly of the basal Stockton supports this hypothesis.
New York, New Jersey, Pennsylvania↗
Delineation of parallel folds and measurement of stratigraphic dimensions
The delineation of parallel folds in structural sections, and the extraction therefrom of stratigraphic information, has generally been done with considerable personal interpretation. If profiles must be drawn, or sections measured, from structural observations used in pairs, this is unavoidable; but superior results may be obtained if more than two observations are simultaneously utilized. The first section of this paper is an exposition of the method of evolute and involutes, which is applicable if three or more observations are available, lying in or close to a profile plane that is normal to the strike of a series of folded rocks. Parallel curves, which in certain sections represent the traces of parallel stratigraphic surfaces, are necessarily involutes that may be generated from one or more evolutes. It is more practical to derive an evolute, and to construct from it a set of parallel curves, than it is to draw such curves directly. Simple graphical methods are given for the construction of evolutes from different sets of structural data, and for the subsequent derivation of parallel curves. An examination of the resulting evolutes and involutes shows that most of them may be represented by the equation y = ax n , if suitable values are assigned to the parameters a and n. The second section of the paper is an exposition of methods that apply to the measurement of stratigraphic thickness, or other stratigraphic dimensions, if structural observations must be used in pairs. Four methods are discussed, which are known as the method of mean strikes and dips, the method of integrated trigonometric functions, the method of skew-line normals, and the method of integrated strikes and dips. The last named of these is a new method, which yields a mean value for the strike or dip, utilizing indirectly the concept of concentric arcs. A formula for mean dip (or mean strike) is derived, which has been computed for all values from 0° to 90°, at intervals of 5°. The results of this computation are given in a chart, which is used for the graphical computation of these values and for interpolation to less than 5°. The mean values of strike and dip that are thus obtained are substituted in any formula for stratigraphic dimensions that applies to a homoclinal sequence of rocks. Under the topic of Errors and Differences, it is shown that the error resulting from the application of the method of evolute and involutes is small and is dependent mainly upon original errors in the determination of strike and dip. When observations are used in pairs, however, the resulting error may be much larger. If certain enumerated conditions are favorable, this error may be 10 per cent or less; but under unfavorable conditions, it may be 100 per cent or more. © 1947, The Geological Society of America, Inc.
Geological Society of America Bulletin↗
Application of Brianchon's theorem to construction of geologic profiles
Brianchon's theorem states that the three diagonals joining opposite vertices of a hexagon circumscribed about a conic are concurrent. A corollary of this theorem applies to a pentagon so that the points of tangency of an inscribed conic may be located. Any five non-concurrent straight lines in a plane, no three of which are parallel, will ordinarily form some kind of a pentagon; and if considered as tangents to a conic, they will define its shape and position. If these five lines are also normals to the traces of parallel stratigraphic surfaces having a constant strike, the derived conic may be regarded as an evolute, from which a set of involutes can be drawn that will constitute a structural profile. A method is thus afforded for constructing a profile normal to the strike of the rocks, and for measuring stratigraphic thickness, by the utilization of five observations of dip along a suitable linear traverse. Graphical methods are also given for constructing a parabolic evolute from four observations and a circular evolute from three observations. Additional points on the conic evolutes are obtained by the application of Pascal's theorem. A mathematical analysis is presented of the relationship between a conic and five of its tangents; and the conic evolute, rather than its involutes, is recommended as a satisfactory record of the structure of a parallel fold. To obtain the equation of this evolute, the equations of the five tangents are first derived, using trilinear coordinates. Thereafter the tangential and trilinear equations of the general conic are deduced. Criteria are given for classifying the conic as a hyperbola, ellipse, parabola, or circle. These graphical and analytical methods are adaptations of the general method of evolute and involutes. They are offered, not as substitutes for the general method, but as quicker, though somewhat less accurate, means of obtaining similar results, where structural conditions justify their use. © 1948, The Geological Society of America, Inc.
Geological Society of America Bulletin↗
Ocoee series of the southern Appalachians
The Ocoee series is divided into four major units present from northern North Carolina to western Georgia and a fifth, younger, formation present only in southern North Carolina and Georgia. The units recognize dare as follows: The Ocoee series is a broad synclinal belt of resistant Great Smoky quartzite, which forms most of the Great Smoky Mountains and the Bald Mountains, with Nantahala slate and in places the Big Butt quartzite enclosed in synclines; the Hurricane graywacke is on the flanks of the main syncline. In the deeper Murphy syncline the Big Butt quartzite is overlain by the Valleytown formation. The Ocoee series is thrust northwestward on the Great Smoky overthrust over Paleozoic rocks of the Great Valley, and in Tennessee overrides unmetamorphosed sandstone, shale, limestone, and limestone conglomerate which previously were mapped as Wilhite slate and were included in the Ocoee series. These rocks in a few places contain Middle Ordovician fossils and are a newly recognized part of a clastic shore facies equivalent to an expanded Tellico sandstone of undetermined stratigraphic range. This part of the Ordovician shore facies is in the Pulaski block in Tennessee and is exposed also in windows in the Great Smoky overthrust block in Tennessee, North Carolina, and Georgia. The Ocoee series does not resemble the Lower Cambrian Chilhowee group, which it overrides, nor any other Lower Cambrian facies. Lower Cambrian quartzites overlie with erosional unconformity the Catoctin basalt, Swift Run tuff, and Mt. Rogers volcanic series, proving that these volcanic rocks are late pre-Cambrian. The Ocoee series resembles the Lynchburg gneiss, which is equivalent to the late pre-Cambrian Swift Run tuff. The Ocoee series is stratigraphically overlain by the Lower Cambrian Unicoi formation and is late pre-Cambrian. © 1949, The Geological Society of America, Inc.
North Carolina, Georgia↗
Pleistocene history of coastal Alabama
Following its deposition, the late Pliocene or early Pleistocene Citronelle formation was entrenched by consequent streams and then tilted toward the Gulf. Submergence in waters 190 to 210 feet above present sea level then resulted in a compound shore line and marine erosion of the Coharie terrace. Four other marine terraces occur below the Coharie level: the Sunderland at 150 to 160 feet, the Wicomico at 90 to 110 feet, the Penholoway at 60-70 feet, and the Pamlico at 20 to 30 feet. The Coharie, Penholoway, and Pamlico marine terraces are associated with fluvial or estuarine terraces in the Mobile River Valley. After Pamlico submergence, a Mobile River floodplain and delta was formed at 10 to 11 feet below present sea level. © 1950, The Geological Society of America, Inc.
Louisiana↗