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At least 793 records · Page 44Linked to original sources
USGS1979

Summary appraisals of the nation's ground-water resources – Lower Mississippi region

The Lower Mississippi Region comprises an area of 102,400 square miles (265,200 square kilometers). Almost all this area is in the physiographic province known as the Gulf Coastal Plain. Three small areas on the northwest boundary of the region are in the Interior Highlands. The Lower Mississippi Region has an abundance of ground water. The geologic structure in that part of the region within the Coastal Plain is an elongated trough which has been filled with permeable materials, resulting in vast subsurface reservoirs. Except in local areas where continued large withdrawals have caused significant water-level declines, these reservoirs are full. Recharge to the region's aquifers is primarily from rainfall. Annual rainfall in most of the region is well distributed throughout the year and is sufficient to satisfy evapotranspiration requirements and still provide recharge to the aquifers. An estimated 844 billion cubic feet (24 billion cubic meters) of fresh ground water is available for withdrawal annually in the region. Only about one-third of this quantity is being utilized. Therefore, on this basis alone, the region still has much potential for ground-water development. The Coastal Plain aquifers within the Lower Mississippi Region contain large reserves of saltwater in the downdip limits of the aquifers. The quantity of saltwater in the region is several times that of freshwater. As desalinization techniques are developed and as more uses are found for saltwater, this reserve could become an important source of water for the region. At present (1976), the most productive and potentially productive aquifers or aquifer systems in the region are the Mississippi River valley alluvial aquifer of Quaternary age and the Sparta Sand and the Memphis aquifer (Memphis Sand in Tennessee) of Tertiary age. The Sparta Sand and the Memphis aquifer are heavily utilized and have shown significant water-level declines. However, selected well hydrographs indicate that water levels may be stabilizing under present pumping conditions. The Mississippi River valley alluvial aquifer is the most extensive high-yielding aquifer in the region; yields of several thousand gallons per minute may be obtained at depths of less than 200 feet (61 meters). To obtain maximum benefit from the vast quantities of ground water in the region, adequate attention must be given to the effects of proposed development upon the ground-water regime. Knowledge of the geologic structure and hydraulic properties of the aquifer systems is essential to an evaluation of the effects of such development. Some studies have been made in sufficient detail to provide this knowledge, but additional studies are needed. Activities that could cause significant changes in the groundwater regime should be undertaken only after all available information has been considered. Failure to seek out and use such information may result in inefficient development of the groundwater resource and, in some instances, degradation of the quality of the resource. Some changes always result from ground-water development. The possible changes can be grouped into three categories: hydraulic, water quality, and those affecting the physical framework of the aquifers. Generally, they are small in magnitude and areal extent. Because these changes occur below the ground surface, they are unknown to the ground-water user unless they noticeably affect the quantity or quality of water produced or cause obvious physical effects, such as land subsidence. Great advances have been made in hydrologic technology in recent years. Predictive models have been developed that make it possible for the hydroiogist to simulate aquifer responses to proposed development or other stresses. These models would be invaluable tools in progressive water-resources planning and management.

Arkansas, Kentucky, Louisiana, Mississippi, Missou↗
USGS2015

Hydrologic response for a high-elevation storm in the South Dakota Black Hills

A group of thunderstorms produced >4 in of rain during four periods of progressively more intense rainfall across a small part of a relatively high-elevation area of the northern Black Hills on 5 August 2014. The resulting hydrologic response was noteworthy in two very small headwater drainage basins, where the measured peak flows are by far the largest—relative to drainage area—ever documented for the high-elevation Limestone Plateau area. However, peak flows attenuated quickly in a downstream direction owing to the storms tracking perpendicular to the drainage direction, moderately dry antecedent conditions, and progressive widening of the valley bottoms.

South Dakota↗
USGS1966

Geology of the Arabian Peninsula: Sedimentary geology of Saudi Arabia

Systematic mapping of the sedimentary geology of Saudi Arabia by Arabian-American Oil Co. (Aramco) began in 1933. By 1959, exploration parties of one type or another had surveyed more than 1,300,000 square kilometers (500,000 square miles) of sedimentary outcrop. The foundation for sedimentary deposition is the Arabian Shield a vast Precambrian complex of igneous and metamorphic rocks that occupies roughly one-third of the Arabian Peninsula in the west and crops out sporadically along the southern coast. Since the outset of the Paleozoic Era the shield has been amazingly stable, subject only to gentle, epeirogenic movement. On this rigid land mass was deposited an aggregate total of nearly 5,500 meters (18,000 feet) of sedimentary rocks ranging in age from presumed Cambrian to Pliocene(?). Paleozoic, Mesozoic, and lower Tertiary strata are magnificently exposed in central Arabia where they crop out in a great curved belt bordering the shield. Here the landscape is dominated by a series of essentially parallel west-facing escarpments, each supported by a resistant limestone cap. Exposures are unusually good, and many rock units can be traced without significant interruption for 500 to nearly 1,000 km. Beds reflecting buried basement configuration dip gently and uniformly away from the escarpment region into the Persian Gulf and Rub' al Khali basins. East of the escarpment belt is a broad expanse of relatively low-relief terrain in which Tertiary and younger deposits effectively mask older units. Clues to the character of pre-Tertiary rocks in this large area, which includes the Rub' al Khali desert and most of northeastern Arabia, are afforded only by widely scattered bore holes and oil wells. In extreme northwestern Arabia, largely lower Paleozoic sedimentary rocks are exposed, although a basinal area bordering the Paleozoic rocks on the north is characterized by thick Upper Cretaceous to Tertiary strata. Tertiary to Recent volcanic rocks cover substantial parts of the area. In general the older sedimentary rocks are exposed in north-central and northwestern Arabia near the Precambrian basement where as much as 2,000 m of lower Paleozoic rocks are present. Although unfossiliferous, the lower 600 m can be equated, at least in part, to rocks of certain Cambrian age in Jordan. Higher beds contain intervals confidently dated as Lower Ordovician, Silurian, and Lower Devonian. Lower Paleozoic rocks are chiefly coarse-grained sandstone of terrestrial origin, although marine shale occurs at several levels and the upper 300 m is mainly shale with thin beds of limestone. Lower Paleozoic strata are succeeded in the central escarpment region by a thick sequence (about 1,000 m) of Upper Permian and Triassic sedimentary rocks. The initial deposit, the Khuff Formation, is mostly shallow-water limestone; overlying beds are nonmarine elastics except for thick carbonate units in the middle part of the section. Above the Triassic System is some 200 to 500 m of Lower and Middle Jurassic rocks which, near the middle of the escarpment region, are interbedded marine shale and shelf limestone. These grade to sandstone, in part continental, in the northern and southern areas of outcrop. The Middle Jurassic is overlain by a great sequence-of nearly pure carbonate rocks, highly fossiliferous and accurately dated as Upper Jurassic and early Lower Cretaceous. The Jurassic System is spectacularly displayed in central Arabia where it forms the backbone of the escarpment region the Tuwayq Mountains. Carbonate sedimentation was interrupted several times in the closing stages of the Jurassic b^ the onset of evaporite conditions which gave rise to cyclic deposits of anhydrite and calcarenite. The resulting sequence the Arab Formation is of prime importance for its porous carbonate members contain billions of barrels of proved oil reserves The carbonate sequence is succeeded by a thick body of late Lower and Middle Cretaceous sandstone. (The Middle Cretaceous Series and Epoch, as defined by European geologist-, are used in this report.) Late Lower Cretaceous rocks are nonmarine and appear only in the middle and southern parts of the escarpment region. Middle Cretaceous rocks, nonmarine in the south, become progressively more marine in the north where they follow a transgressive path northwest across older beds as far as Jordan. Upper Cretaceous and Eocene rocks, almost exclusively in limestone and dolomite facies, are extensively exposed alorc the eastern edge of the escarpment belt and continue northwest into Iraq. The sequence, with an average thickness of about 5^0 m, includes rocks of Upper Cretaceous, Paleocene, lower Eocene, and middle Eocene ages. The stratigraphic sequence above the Eocene consists of 200 to 600 m of Miocene and Pliocene rocks, mostly of nonmarine origin. These deposits a heterogeneous assemblage of marly sandstone, sandy marl, and sandy limestone blanket the Rub' al Khali and northeastern Arabia. Above the Miocene and Pliocene rocks are unconsolidated Quaternary deposits which comprise great sand deserts and widespread gravel sheets. Sand of the Rub' al Khali Desert alone covers about 600,000 sq km (230,000 sq mi) or most of southern Arabia. Two major structural provinces are recognized within the Arabian Peninsula and adjacent areas. One is the comparatively stable interior region whose rigidity is controlled by the Precambrian basement. The other is the great mobile belt of Taurus, Zagros, and Oman Mountains, bordering the stable region on the north and east. Saudi Arabia falls entirely within the stable region. The interior stable region contains the Arabian shield as well as the Arabian Shelf an extension of the basement thinly veneered with little-disturbed sedimentary rocks. Widespread structural events, presumably related to epeirogenic movement within the basement, have divided the Arabian Shelf into several distinct and significant structural elements the Interior Homocline, the Interior Platform, and several basinal areas. Bordering the shield is a great belt of sedimentary rocks whose dip basinward is so slight and uniform as to be impreceptible to the eye. This Interior Homocline has an average width of about 400 km and a persistent dip varying from slightly more than 1°00' in older units to less than 0°30' in the youngest. One structural feature of the homocline the central Arabian arch has greatly influenced the present surface distribution of sedimentary rocks in the interior escarpment region. The arch, which affects all rocks from the basement up, marks the area of maximum curvature of the homocline in central Arabia. Although the arch has a varied history, it is apparently a residual high between the periodically sinking Persian Gulf and Rub' al Khali basins rather than a true independent positive feature. Support for this concept conies from the presence of a great arc of tensional structures the central Arabian graben and trough system near the crest of the arch and along the hinge line between the Persian Gulf basin and the stable western block. Bordering the homocline is the Interior Platform, a remarkably flat area of varying width in which systematic dip off the crystalline core no longer prevails. Superimposed on the platform are several major north-south anticlinal trends which include the great oil fields of Arabia Adjacent to the platform are several basinal areas that have from time to time received thick sedimentary deposits. Such basinal sags have developed on the shelf in the northeastern Rub' al Khali, northern Persian Gulf, Dibdibah and Sirhan-Turayf areas.

Professional Paper↗
USGS2012

The Novarupta-Katmai eruption of 1912 - largest eruption of the twentieth century; centennial perspectives

The explosive outburst at Novarupta (Alaska) in June 1912 was the 20th century's most voluminous volcanic eruption. Marking its centennial, we illustrate and document the complex eruptive sequence, which was long misattributed to nearby Mount Katmai, and how its deposits have provided key insights about volcanic and magmatic processes. It was one of the few historical eruptions to produce a collapsed caldera, voluminous high-silica rhyolite, wide compositional zonation (51-78 percent SiO 2 ), banded pumice, welded tuff, and an aerosol/dust veil that depressed global temperature measurably. It emplaced a series of ash flows that filled what became the Valley of Ten Thousand Smokes, sustaining high-temperature metal-transporting fumaroles for a decade. Three explosive episodes spanned ~60 hours, depositing ~17 km 3 of fallout and 11±2 km 3 of ignimbrite, together representing ~13.5 km 3 of zoned magma. No observers were nearby and no aircraft were in Alaska, and so the eruption narrative was assembled from scattered villages and ship reports. Because volcanology was in its infancy and the early investigations (1915-23) were conducted under arduous expeditionary conditions, many provocative misapprehensions attended reports based on those studies. Fieldwork at Katmai was not resumed until 1953, but, since then, global advances in physical volcanology and chemical petrology have gone hand in hand with studies of the 1912 deposits, clarifying the sequence of events and processes and turning the eruption into one of the best studied in the world. To provide perspective on this century-long evolution, we describe the geologic and geographic setting of the eruption - in a remote, sparsely inhabited wilderness; we review the cultural and scientific contexts at the time of the eruption and early expeditions; and we compile a chronology of the many Katmai investigations since 1912. Products of the eruption are described in detail, including eight layers of regionwide fallout, nine packages of ash flows, and three lava domes that followed the explosive pyroclastic episodes. Changes in the proportions of coerupting rhyolite, dacite, and andesite pumice documented for the fallout and ash-flow successions, which are locally interbedded, permit close correlation of those synchronously emplaced sequences and their varied facies. Petrological correlation of the sequence of deposits near Novarupta with ash layers at Kodiak village, 170 km downwind, where three episodes of ashfall were recorded (to the hour), provides key constraints on timing of the eruptive events. Syneruptive collapse of a kilometer-deep caldera took place atop Mount Katmai, a stratovolcano centered 10 km east of the eruption site at Novarupta, owing to drainage of magma from beneath the Katmai edifice. Correlation of ~50 earthquakes recorded at distant seismic stations (including 14 shocks of magnitude 6.0 to 7.0) to fitful caldera collapse provides further constraints on eruption timing, because layers of nonjuvenile breccia and mud ejected from Mount Katmai during collapse pulses are intercalated with the pumice-fall layers from Novarupta. Structure of the Novarupta vent, a 2-km-wide depression backfilled by welded tuff and inferred to be funnel-shaped at depth, is described in detail, as is the 4-km-wide caldera at Mount Katmai. Discussions are also provided concerning: (1) the impact on global climate of the great mass of sulfur-poor but halogen-rich aerosol ejected into the atmosphere by the rhyolite-dominated eruption; (2) chemical and mineralogical effects of the fumarolic acid gases; and (3) the timing of several syneruptive landslide deposits sandwiched within the pumice-fall sequence. Secondary posteruption phenomena characterized include impounded lakes, ash-rich debris flows, phreatic craters on the ignimbrite sheet, responses of glaciers to the fallout blanket and to beheading by caldera collapse, growth of new glaciers inside the caldera, and gradual filling of the caldera lake. Structure, composition, and ages of the several andesite-dacite stratovolcanoes, closely clustered near Novarupta, all of which remain fumarolically and seismically active, are summarized. But among them only Mount Katmai extends compositionally to include basalt and rhyolite. The petrological affinities of 1912 magmas erupted at Novarupta with pre-1912 Katmai lavas are outlined, and various chemical, mineralogical, isotopic, and experimental data are assembled to construct a model of preeruptive magma storage beneath Mount Katmai. The monograph concludes by comparing the 1912 eruption with several other well-studied large explosive eruptions, 14 of them historical and 9 prehistoric. Finally, we retrospectively review the historical difficulties in understanding what had actually taken place at Katmai in 1912 and the century of progress in volcano science that has allowed most of it to be figured out.

Alaska;British Columbia;Washington;Yukon↗
USGS2011

Proceedings of the Klamath Basin Science Conference, Medford, Oregon, February 1-5, 2010

This report presents the proceedings of the Klamath Basin Science Conference (February 2010). A primary purpose of the meeting was to inform and update Klamath Basin stakeholders about areas of scientific progress and accomplishment during the last 5 years. Secondary conference objectives focused on the identification of outstanding information needs and science priorities as they relate to whole watershed management, restoration ecology, and possible reintroduction of Pacific salmon associated with the Klamath Basin Restoration Agreement (KBRA). Information presented in plenary, technical, breakout, and poster sessions has been assembled into chapters that reflect the organization, major themes, and content of the conference. Chapter 1 reviews the major environmental issues and resource management and other stakeholder needs of the basin. Importantly, this assessment of information needs included the possibility of large-scale restoration projects in the future and lessons learned from a case study in South Florida. Other chapters (2-6) summarize information about key components of the Klamath Basin, support conceptual modeling of the aquatic ecosystem (Chapter 7), and synthesize our impressions of the most pressing science priorities for management and restoration. A wealth of information was presented at the conference and this has been captured in chapters addressing environmental setting and human development of the basin, hydrology, watershed processes, fishery resources, and potential effects from climate change. The final chapter (8) culminates in a discussion of many specific research priorities that relate to and bookend the broader management needs and restoration goals identified in Chapter 1. In many instances, the conferees emphasized long-term and process-oriented approaches to watershed science in the basin as planning moves forward.

California, Oregon↗
USGS1950

Stratigraphy and structure of the Aupuk anticline

In addition to conducting an examination of the surface geology in the Southern Foothills province between the Killik River and east fork of the Etivluk River, Navy Oil Unit Party No. 5 was requested to map the Aupuk anticline during the 1950 field season, for the purpose of evaluating the petroleum possibilities thereof from the standpoints of favorable statigraphy and possible structural closure. Field mapping of the Aupuk anticline began on August 1, and about 1 month was devoted to the study. Party personnel consisted of G. Donald Eberlein and Charles D. Reynolds, geologists, W. L. D'Olier and W. D. Carter, field assistants, Richard Olson, camp cook, and Max H. Davis, weasel mechanic. Robort M. Chapman, geologist, visited the party for 1 week early in August to help start the work and shared, with Eberlein, the responsibilities associated with the final compilation of this report. Three weasels were used for daily transportation to the field and for moving camp. A 10-foot Link boat equipped with 5 hp. outboard motor was used to cross the Colville River. As field work progressed from west to east it became apparent that the camp equipment and weasels would have to be gotten across the Colville River if field work was to be completed by early September. This crossing was effected without incident at a point approximately 10 miles below the confluence of the Kurupa and Colville Rivers on August 26. The party reached Umiat on September 5.

Alaska↗
USGS1973

Ground water in the Eugene-Springfield area, southern Willamette Valley, Oregon

The cities of Eugene and Springfield and their outlying suburban and rural districts constitute an area of rapid population growth where progressively greater volumes of ground water are being required for irrigation and industrial and public supplies. The area is also one of diverse geologic and hydrologic conditions. As used in this report, the Eugene-Springfield area covers about 450 square miles and includes a part of the lower foothills of the Coast and Cascade Ranges and a strip of the main valley plain of the southern Willamette Valley. Volcanic and sedimentary rock units exposed in the foothills range in age from Eocene to Miocene. In the main valley plain the older units are overlain by Pleistocene and Holocene alluvial deposits. Marine-deposited sandstone, siltstone, shale, and mudstone of the older sedimentary units are fine grained and poorly permeable and yield water slowly to wells. The volcanic rocks, primarily of dacitic and andesitic composition, yield small quantities of water that are generally adequate only for domestic use. The alluvial deposits (sand and gravel) of the valley plain (central lowland) contain the most productive aquifers in the area and are considered to be the only ground-water reservoir for which large-scale development of ground-water supplies is feasible. Aquifers in the area are recharged principally by direct infiltration of precipitation. Most of the precipitation, which averages about 4C inches per year, occurs during late autumn and winter. Minimum recharge by infiltration of precipitation to the alluvial aquifers beneath the valley plain is estimated to be about 100,000 acre-feet. Ground water is discharged naturally from the central lowland by seepage and spring flow to small streams, by subsurface outflow to adjacent areas, and by evapotranspiration. Storage capacity of the central lowland in the Eugene-Springfield area is estimated to be about 2.1 million acre-feet in the zone 10-150 feet below land surface. The quantity of ground water available annually from this area is far greater than the 23,000 acre-feet pumped for all uses in 1968. This pumpage was about 23 percent of the perennial yield (100,000 acre-ft), and about 77,000 acre-feet of water was left available for additional withdrawal. If annual withdrawals of water were increased to 100,000 acre-feet per year, the levels in the ground-water reservoir would be lowered. Once new equilibriums are established, increased withdrawals could be accommodated without progressive losses in aquifer storage or excessive losses in flow of the larger streams. Ground water from the alluvial deposits of the valley plain is chemically suitable for irrigation and other uses, as is most of the water obtained from perched-water bodies in the sedimentary and volcanic rocks. However, the mineral content of water from the older sedimentary rocks, particularly from deeper producing zones, is greater than the mineral content of water from the alluvial deposits. Locally, some of the water from the older rocks is too saline for most uses. Increased use of ground water may result in certain problems pertaining to waste-disposal practices, local overdraft of aquifers, well interference, and well construction. Present data are adequate to evaluate some of the factors relating to foreseeable problems but allow only tentative conclusions to be drawn about other factors, which include local direction of flow, rate of ground-water movement, and areas of possible ground-water contamination. Additional information obtained through systematic study will be needed to deal with these problems.

Oregon↗
USGS2006

Reassessing a troublesome fact of mountain life: Avalanches in Glacier National Park

For the past decade, our U.S. Geological Survey (USGS) research team has rummaged through Glacier National Park’s archives looking for records of snow avalanches. Our searches have paid off. We have found photographs that show snow avalanches blocking progress during the annual spring opening of the famed Going-to-the-Sun Road, ranger logs that describe cabins and telephone lines destroyed by avalanches, and superintendents’ reports that recount avalanche accidents that killed employees or visitors. Recently, we have combined these historical sources with field studies to investigate whether snow avalanches in the park may be more cyclical than random and as much an ecological process as a natural hazard. Our ongoing research in Montana has yielded relevant information for park managers elsewhere who deal with avalanche threats to park infrastructure and for ecologists seeking a better understanding of how mountain ecosystems function. Our research has focused on two transportation corridors: the Going-to-the-Sun Road that bisects the center of the park, and John F. Stevens Canyon, at the park’s southwest corner ( fig. 1 ). The Going-to-the-Sun Road is the park’s most visited attraction; deep snow and avalanches force the road’s closure each winter, and in spring, park crews dig it out using bulldozers and other heavy equipment ( fig. 2 ). Springtime avalanches can bury workers or push equipment off the road and over cliffs ( figs. 3a and 3b ), as happened in 1953, when two workers died. Our research started with a study of how interannual variations in snowfall and avalanches affect the road opening. The initial study helped park managers predict and plan for the road opening in spring and respond to the many topical questions from park visitors and locals. More recent studies have focused on determining the conditions that create springtime avalanches, which are a poorly understood aspect of the avalanche phenomenon.

Wyoming↗
USGS1982

Fluid-inclusion data on samples from Creede, Colorado, in relation to mineral paragenesis

Published and unpublished data on 2575 fluid inclusions in ore and gangue minerals from the Creede, Colorado, Ag-Pb-Zn-Cu vein deposit collected in our laboratories from 1959 to 1981 have shown that the average salinity (wt. % NaCl equivalent, hereinafter termed wt.% eq.) and homogenization temperature (Th), and the ranges of these two parameters for fluid inclusions in sphalerite, quartz, fluorite, and rhodochrosite, respectively, are 8.1 (4.6 - 13.4), 239?C (195-274?C); 6.1 (1.1-10.0), 260?C (190->400?C); 10.7 (6.1-11.1), 217?C (213-229?C) and 260?C (247-268?C) (bimodal distribution of Th); and 9.9 (9.3 - 10.6), 214?C (185-249?C). Inclusions have been measured in minerals from four of the five stages of mineralization previously recognized at Creede. The few inclusions of fluids depositing rhodochrosite (A-stage, earliest in the paragenesis) yield Th and salinity values more similar to those of the low-temperature (average Th 217?C) fluids forming some of the much later fluorite (C-stage) than to any of the other fluids. Th measurements on A-stage quartz range from 192?C to 263?C and average 237?C. The early, fine-grained, B-stage sphalerites yielded Th of 214 to 241?C and salinities of 6.1 to 10.2 wt. % eq. D-stage sphalerite (late in the paragenesis) has been studied in detail (growth-zone by growth-zone) for several localities along the OH vein and reveals a generally positive correlation among Th, salinity and iron content of the host sphalerite. The deposition of D-stage sphalerite was characterized by repeated cycling through different regions of salinity/Th space, as Th and salinity generally decreased with time. Seventeen salinity-Th measurements were made on D-stage sphalerite from one locality on the Bulldog Mountain vein system, which, like the OH vein, is one of four major ore-producing vein systems at Creede. These data suggest a lower Th for a given salinity fluid from sphalerite on the Bulldog Mountain vein than on the OH vein. The very high values of Th for some quartz samples (mostly D-stage) are believed to be a result of the trapping of both gas and liquid from a boiling fluid in the upper levels of the vein system. Boiling of fluids depositing D-stage quartz is indicated by the presence of steam inclusions in quartz and the extreme variability of Th values measured on quartz. The pressure was low (< 125 kg/cm 2) throughout ore deposition. Three major growth zones in D-stage sphalerite are recognized throughout the OH vein. Deposition of the first major zone began from fluids having intermediate salinities and temperatures (7.8-9.2 wt. % eq., 240?C) but the characteristics of the fluids oscillated after that, ranging from 7.2 to 10.1 wt. % eq. and from 225?C to 270?C. Deposition of the second major, most Fe-rich zone began with the hottest, most saline fluids present during D-stage mineralization (. 270?C, 10.5-12.5 wt. % eq., 3 mole % FeS in sphalerite). The fluid then oscillated with respect to Th and salinity (213-274?C, 5.2-12.5 wt. % eq.) but showed a general decrease in both with time. Deposition of the youngest major zone began with a very Fe-poor sphalerite (0.25-0.75 mole % FeS), from the least saline, coolest fluids (5-6.5 wt. % eq., 200-212?C) and ended with a trend of increasing temperature at approximately constant salinity. The fluid-inclusion data can best be explained by a mixing model involving at least two fluids--one hot and saline, the other cool and fresher. Sudden changes in the mixing ratio, presumably from changes in the plumbing, punctuated long periods of remarkably uniform conditions of ore fluid flow and deposition. The effects of other processes such as convection and heat exchange with wall rocks must have been superimposed on this simple mixing model, however. In contrast to an earlier interpretation, several aspects of the inclusion data may be interpreted to suggest exceedingly slow ore deposition. Work in progress may resolve some of these ambiguities and refine

Open-File Report↗
USGS1991

Cenozoic giant pectinids from California and the Tertiary Caribbean Province: Lyropecten, "Macrochlamis," Vertipecten, and Nodipecten species

Tertiary pectinids recognized for more than 125 years by field geologists can now be used to date and correlate 3-4 m.y. increments of the geologic record and to determine faunal distributions in relation to tectonic terranes. Fossil pectinids are commonly preserved in shallowmarine clastic deposits that mostly lack microfossils. The stratigraphic ranges of Lyropecten, "Macrochlamis," Vertipecten , and Nodipecten can be used to subdivide provincial megafaunal stages in California and to correlate chronostratigraphic units in the Pacific Northwest and Atlantic Coastal Plain. One New World taxon, "Macrochlamis" magnolia ojaiensis, n. subsp., supports a direct correlation between the middle "Vaqueros" Stage of California (interpolated as 27-23 m.y. B.P.) and an Upper Chattian-Lower Aquitanian Stage section in southwestern Switzerland. Two lithologic units widespread in California, the Vaqueros Formation (spanning 12 m.y., from the late Oligocene into the early Miocene) and Temblor Formation (deposited over a period of 26 m.y., from the late Eocene or early Oligocene to the middle Miocene), transgress much longer periods of time than have been generally recognized. Certain species pairs are identified as cognates, close relatives descended from a common ancestor. Close similarities are found between widely separated assemblages from the Salton Trough of California and the Caribbean, the Gulf Coastal Plain of eastern Mexico and the Sinu Valley of western Colombia, the Santa Rosalia area in Baja California Sur, Mexico, and the Paraguana Peninsula of Venezuela. Distribution patterns for relatively recently dispersed taxa have important implications for middle to late Cenozoic paleogeography and tectonic history, especially in west Mexico and the Caribbean. Speciation was concurrent with the closure of the Isthmus of Panama, the opening of the Gulf of California, and possibly with the northward translation of segments of the California Continental Borderland. Tertiary Caribbean and PacificPanamic Lyropectens and Nodipectens are plotted on a simplified tectonic map as an early step in considering Cenozoic molluscan distributions in relation to major plate boundaries. Taxa having unusual distributions are tabulated with the tectonic events that may have modified their observed geographic ranges. Southern California and the Baja California peninsula include tectonostratigraphic terranes and tectonic slivers that may have moved on the order of hundreds or thousands of kilometers in the Paleogene. Relations between recently dispersed faunas and tectonic terrane boundaries are further complicated by short-term variations in oceanographic phenomena such as currents, El Nino events, and shifts in areas of upwelling. Lyropecten evolved in the late Oligocene or early Miocene, Nodipecten by the late middle Miocene. According to the classification used here, Lyropecten still lives in the Galapagos. Holocene Nodipectens divide the Pacific-Panamic and Caribbean provinces into two subprovinces each. Habitat, life history, dispersal, and growth data are summarized for living Nodipectens, whose distinctive shell features include ledges and hollow nodes. Phylogenetic lineages are based on progressive trends in node formation and rib schemes, some of which have biostratigraphic significance.

Professional Paper↗
USGS1995

National Research Program of the U.S. Geological Survey, Water Resources Division fiscal year 1994

This report provides current information about the National Research Program (NRP) of the U.S. Geological Survey's Water Resources Division (WRD) during fiscal year 1994. Organized by NRP's six research disciplines ecology, geomorphology and sediment transport, ground-water chemistry, ground-water hydrology, surface-water chemistry, and surface-water hydrology the volume contains a summary of the problem, objective, approach, and progress for each project that was active during fiscal year 1994. It also contains bibliographic information that, because of the long-term nature of the program, covers a 5-year period.

Open-File Report↗
USGS1977

Development of water facilities in the Santa Ana River Basin, California, 1810-1968: a compilation of historical notes derived from many sources describing ditch and canal companies, diversions, and water rights

This report traces by text, maps, and photographs, the development of the water supply in the Santa Ana River basin from its beginning in 1810 or 1811 to 1968. The value of the report lies in the fact that interpretation of the hydrologic systems in the basin requires knowledge of the concurrent state of development of the water supply, because that development has progressively altered the local regimen of both surface water and ground water. Most of the information for the earlier years was extracted and condensed from an investigation made by W. H. Hall, California State Engineer during the years 1878-87. Hall's study described irrigation development in southern California from its beginning through 1888. Information for the years following 1888 was obtained from the archives of the numerous water companies and water agencies in the Santa Ana River basin and from the various depositories of courthouse, county, and municipal records. The history of water-resources development in the Santa Ana River basin begins with the introduction of irrigation in the area by the Spanish, who settled in southern California in the latter part, of the 18th century. The first irrigation diversion from the Santa Ana River was made in 1810 or 1811 by Jose Antonio Yorba and Juan Pablo Peralta. Irrigation remained a localized practice during the Mexican-Californian, or rancho, period following the separation of Mexico from Spain in 1821. Rancho grantees principally raised cattle, horses, and sheep and irrigated only small· plots of feed grain for their livestock and fruit crops for household use. The breakup of the ranchos through sales to Americans, who were migrating to California in ever-increasing numbers following the acquisition of California by the United States in 1848, marked the beginning of a rapid increase in water use and the beginning of widespread irrigation. Many water companies and water agencies were organized to divert the surface flow of the Santa Ana River and its tributaries for irrigation. The Santa Ana River had been a perennial stream, except in years of extreme drought, from its source in the mountains nearly to the Pacific Ocean. With the great increase in population and the accompanying use of water for irrigation, the river was no longer a perennial stream, and it was necessary to supplement the surface-water supply with ground water. Many wells were dug or drilled in the artesian areas of the upper basin; of those wells many originally flowed, but as ground-water pressures and levels declined, an increasing amount of pumping was required. Conservation measures were taken to store some of the surplus winter runoff for use during low runoff years and during summer periods of heavy demand. Conservation facilities included surface-storage reservoirs and water-spreading grounds or percolation basins for utilization of underground storage. The competition for water in the Santa Ana River basin has been accompanied by frequent litigation over water tights, and over the years these water rights have generally been established by court decree. Although the demand for water still increases, the water demand for agricultural use has declined since the mid-1940's in response to the rapid urbanization of agricultural areas. Since that date the continued expansion of communities has encroached significantly into the agricultural areas causing a decrease in water use for agriculture, a more than compensating increase in water use for municipal purposes, and a rapid change in the ownership of water rights. The urbanization of flood plains made floods potentially more damaging than they previously had been when the flood plains were used for agriculture. In recognition of this increased hazard, flood-control facilities such as reservoirs, debris basins, flood-conveyance channels, and levees have been constructed to reduce potential damage. Most of the construction has occurred since the devastating flood of March 1938. By the mid-1940's it was apparent that the local water supply--both surface and ground water--would be insufficient to meet the increasing demand in the basin. To augment the local supply, Colorado River water was purchased from the Metropolitan Water District of Southern California and released to the Santa Ana River beginning in August 1949. Additional supplemental water became available in the early 1970's from northern California through the conveyance facilities of the California Water Project.

California↗
USGS2018

Phase 1 studies summary of major findings of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

Executive Summary The South Bay Salt Pond Restoration Project (Project) is one of the largest restoration efforts in the United States. It is located in South San Francisco Bay of California. It is unique not only for its size—more than 15,000 acres—but also for its location adjacent to one of the nation’s largest urban areas, home to more than 4 million people (Alameda, Santa Clara, and San Mateo Counties). The Project is intended to restore and enhance wetlands in South San Francisco Bay while providing for flood management, wildlife-oriented public access, and recreation. Restoration goals of the project are to provide a mosaic of saltmarsh habitat to benefit marsh species and managed ponds to benefit waterbirds, throughout 3 complexes and 54 former salt ponds. Although much is known about the project area, significant uncertainties remain with a project of this geographic and temporal scale of an estimated 50 years to complete the restoration. For example, in order to convert anywhere from 50 to 90 percent of the existing managed ponds to saltmarsh habitat, conservation managers first enhance the habitat of managed ponds in order to increase use by waterbirds, and provide migratory, wintering, and nesting habitat for more than 90 species of waterbirds. Project managers have concluded that the best way to address these uncertainties is to carefully implement the project in phases and learn from the outcome of each phase. The Adaptive Management Plan (AMP) identifies specific restoration targets for multiple aspects of the Project and defines triggers that would necessitate some type of management action if a particular aspect is trending negatively. U.S. Geological Survey (USGS) biologist Laura Valoppi served as the project Lead Scientist and oversaw implementation of the AMP in coordination with other members of the Project Management Team (PMT), comprised of representatives from the California State Coastal Conservancy, California Department of Fish and Wildlife, the Santa Clara Valley Water District, the U.S. Army Corps of Engineers, and the U.S. Fish and Wildlife Service. To implement the AMP, the PMT have selected and funded applied studies and monitoring projects to address key uncertainties. This information is used by the PMT to make decisions about current management of the project area and future restoration actions in order to meet project. This document summarizes the major scientific findings from studies conducted from 2009 to 2016, as part of the science program that was conducted in conjunction with Phase 1 restoration and management actions. Additionally, this report summarizes the management response to the study results under the guidance of the AMP framework and provides a list of suggested studies to be conducted in “Phase 2–A scorecard summarizing the Project’s progress toward meeting the AMP goals for a range of Project objectives.” The scoring to date indicates that the Project is meeting or exceeding expectations for sediment accretion and western snowy plover ( Charadrius alexandrinus nivosus ) recovery. There is uncertainty with respect to objectives for California gulls ( Larus californicus ), California least tern ( Sternula antillarum ), steelhead trout ( Oncorhynchus mykiss ), and regulatory water quality objectives. Water quality and algal blooms, specifically of the managed ponds, is indicated as trending negative. However, the vast majority of objectives are trending positive, including increased abundance for a number of bird guilds, increasing marsh habitat, maintenance of mudflats, visitor experience, estuarine fish numbers, and special-status marsh species numbers.

California↗
USGS2009

Polybrominated diphenyl ether flame retardants in eggs may reduce reproductive success of ospreys in Oregon and Washington, USA

Spatial and temporal assessments and reports of polybrominated diphenyl ether (PBDE) flame retardants in birds remain sparse. In the present study, PBDEs were detected in all 120 osprey ( Pandion haliaetus ) eggs collected. The eggs were collected from nests along the Columbia, Willamette and Yakima rivers of Oregon (OR) and Washington (WA) and in Puget Sound (WA) between 2002 and 2007. PBDE congeners: 17, 28, 47, 49, 66, 85, 99, 100, 138, 153, 154 (possible coelution with brominated biphenyl 153 [BB153]), 183, 190 (detected in one egg), 209 (not detected), and BB101 (only detected in 2006 and 2007) and total-α-hexabromocyclododecane (only detected in five eggs) were analyzed for in the egg samples. Eggs from reservoirs in the forested headwaters of the Willamette River (2002) contained the lowest concentrations of ΣPBDEs (geometric mean [range], 98 [55.2–275] ng/g wet weight [ww]), while those from the middle Willamette River (2006) contained the highest (897 [507–1,880] ng/g ww). Concentrations in eggs from the Columbia River progressively increased downstream from Umatilla, OR (River Mile [RM] 286) to Skamokoa, WA (RM 29), which indicated additive PBDE sources along the river. In general, regardless of the year of egg collection, differences in PBDE concentrations reported in osprey eggs along the three major rivers studied (Columbia, Willamette and Yakima) seem to reflect differences in river flow (dilution effect) and the extent of human population and industry (source inputs) along the rivers. PBDE concentrations increased over time at two locations (Seattle, WA; Columbia River, RM 29-84) where temporal patterns could be evaluated. Only during 2006 (on the middle Willamette River, RM 61–157) and 2007 (on the lower Columbia River, RM 29–84) did ΣPBDE concentrations in osprey eggs exceed 1,000 ng/g ww with negative relationships indicated at both locations between productivity and ΣPBDE concentrations in eggs ( P = 0.008, P = 0.057). Osprey eggs from Everett, WA contained nearly twice the ΣPBDE concentration (geometric mean 239 vs. 141 ng/g ww, range 124–384 vs. 22.2–819 ng/g ww, P ≤ 0.05) as double-crested cormorant ( Phalacrocorax auritus ) eggs collected at the same location and time, which is likely due to dietary differences. No significant relationship (all P s > 0.147) was indicated between PBDE congeners (including ΣPBDEs) and eggshell thickness at the concentrations observed in this study.

Oregon, Washington↗
USGS1989

Water-resources investigations in Tennessee: Programs and activities of the U.S. Geological Survey, 1988-1989

he following report is the most current in a series of reports published by the Water Resources Division of the US. Geological Survey describing the ongoing water-resources programs and activities in the Tennessee District. These reports provide general information about the projects conducted by the Tennessee District in cooperation with state, local, and other federal agencies. In addition to describing the principal objectives of each program and project, information about the progress of each investigation is provided. The variety of projects conducted by the Tennessee District’s staff normally results in significant new findings. Each year the focus of the programs conducted by the U.S. Geological Survey in Tennessee varies in response to local, state, and federal interests. The local and state interests are addressed through our cooperative investigations program, in which the U.S. Geological Survey provides as much as 50 percent of the funds to conduct investigations. Almost two thirds of the projects in the District are in the cooperative program; the U.S. Geological Survey contributed almost 1.5 million dollars in matching funds to cooperative programs in Tennessee in fiscal year 1989. Federal funds from within the U.S. Geological Survey and other federal agencies financed additional programs at a cost of about 1 million dollars. Technical focus of local and federal programs has shifted during the last few years towards issues addressing hazardous-wastes and ground-water contamination. Many of the projects presented in this report address those issues. Emerging issues such as concerns about wetlands, scour of bridges, quality of storm-water runoff, and droughts, are well represented in the scope of the investigations described in this report. The results of these programs provide significant input to many other activities of the State of Tennessee and the Federal Government that have a direct impact on the quality of life. The information and conclusions obtained from these data-collection programs and investigations are crucial to meet many of the water-supply needs, regulatory, and other water-related issues that the local, state, and federal governments must address. The ability of the U.S. Geological Survey to provide the data to meet these needs resides with the support that the program receives by the State and Federal cooperators. I am pleased with the extent and degree of cooperation that the program receives across the State and from other federal agencies. This report is a testimony to this support. I wish to share these achievements with the dedicated employees of the Tennessee District as well as with the cooperating agencies and their representatives that make this program feasible.

Tennessee↗
USGS1980

Hydrologic data for urban studies in the Dallas, Texas, metropolitan area, 1978

This report contains rainfall and runoff data collected during the 1978 water year for drainage basins of Joes Creek, Bachman Branch, Turtle Creek, Coombs Creek, Cedar Creek, White Rock Creek, Elam Creek, Fivemile Creek, Newton Creek, Whites Branch, Prairie Creek, Tenmile Creek, Duck Creek, and South Mesquite Creek in the Dallas, Texas metropolitan area. The information will be useful in determining the extent to which progressive urbanization will affect the yield and mode of occurrence of storm runoff. Detailed rainfall-runoff computations are presented for ten storm periods during the 1978 water year. (USGS)

Texas↗
USGS2026

Trust-building as a keystone activity in beaver-related restoration practice

North American beavers ( Castor canadensis ) are increasingly being used to achieve restoration goals, prompting practitioners to engage with private landowners in efforts to promote beaver coexistence. Through 23 semi-structured interviews with restoration practitioners in Oregon, USA, we explored how practitioners from government agencies, non-governmental organizations (NGOs), service organizations, and private businesses communicate with private landowners about nonlethal beaver management and habitat creation. Using abductive analysis, we identified trust-building as an essential element of restoration practice. Practitioners described 60 tactics for building trust, which we organized using the Shared Foundations model of trust and distrust and the adaptive management cycle to bridge theory with field-based experience. Practitioners also reported navigating tensions between tactics and adapting their approaches to individual landowners and contexts. We argue that trust-building is a craft that can be mastered, propose a potential progression from novice to master trust-builder, and highlight the need for greater attention to trust, relationships, and trust repair in environmental management. Our findings offer a theoretically grounded yet practitioner-informed framework for understanding and improving trust-building efforts in restoration practice.

Oregon↗