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At least 721 records · Page 40Linked to original sources

Sketch of paleobotany

To understand the true force of the facts of paleobotany as arguments for geology it is essential that their full biologic significance be grasped. It has therefore been deemed proper, in this introduction to the several tabular and systematic statements which will make up the bulk of the volume and bear chiefly upon the geological aspect of the subject, to consider certain of the more important biologic questions, in addition to the specially geologic ones, and to discuss, from an historical and developmental standpoint, some of the leading problems of modern phytology.

Report↗

Water Resources Data, New Jersey, Water Year 2003; Volume 3. Water-Quality Data

Water-resources data for the 2003 water year for New Jersey are presented in three volumes, and consists of records of stage, discharge, and water-quality of streams; stage and contents of lakes and reservoirs; and water levels and water-quality of ground water. Volume 3 contains a summary of surface- and ground-water hydrologic conditions for the 2003 water year, a listing of current water-resources projects in New Jersey, a bibliography of water-related reports, articles, and fact sheets for New Jersey completed by the Geological Survey in recent years, water-quality records of chemical analyses from 123 continuing-record surface-water stations, 35 ground-water sites, records of daily statistics of temperature and other physical measurements from 20 continuous-recording stations, and 5 special-study sites consisting of 2 surface-water sites, 1 spring site, and 240 groundwater sites. Locations of water-quality stations are shown in figures 21-25. Locations of special-study sites are shown in figures 49-53. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating federal, state, and local agencies in New Jersey.

Water Data Report↗

Seismic, magnetic, and geotechnical properties of a landslide and clinker deposits, Powder River basin, Wyoming and Montana

Exploitation of vast coal and other resources in the Powder River Basin has caused recent, rapid increases in population and in commercial and residential development and has prompted land utilization studies. Two aspects of land utilization were studied for this report: (1) the seismic and geotechnical properties of a landslide and (2) the seismic, magnetic, and geotechnical properties of clinker deposits. (1) The landslide seismic survey revealed two layers in the slide area. The upper (low-velocity) layer is a relatively weak mantle of colluvium and unconsolidated and weathered bedrock that ranges in thickness from 3.0 to 7.5 m and has an average seismic velocity of about 390 m/s. It overlies high-velocity, relatively strong sedimentary bedrock that has velocities greater than about 1330 m/s. The low-velocity layer is also present at the other eight seismic refraction sites in the basin; a similar layer has also been reported in the Soviet Union in a landslide area over similar bedrock. The buried contact of the low- and high-velocity layers is relatively smooth and is nearly parallel with the restored topographic surface. There is no indication that any of the high-velocity layer (bedrock) has been displaced or removed. The seismic data also show that the shear modulus of the low-velocity layer is only about one-tenth that of the high-velocity layer and the shear strength (at failure) is only about one-thirtieth. Much of the slide failure is clearly in the shear mode, and failure is, therefore, concluded to be confined to the low-velocity layer. The major immediate factor contributing to landslide failure is apparently the addition of moisture to the low-velocity layer. The study implies that the low-velocity layer can be defined over some of the basin by seismic surveys and that they can help predict or delineate potential slides. Preventative actions that could then be taken include avoidance, dewatering, prevention of saturation, buttressing the toe, and unloading the head. The low-velocity layer is usually less than about 5 m thick and may be excavated by dozing, whereas the bedrock must be blasted. Thus, it would seem economically feasible to underpin a structure to nonweathered bedrock or, perhaps, to remove the low-velocity layer prior to construction. (2) Many coal beds in the Powder River Basin have burned along their outcrops, and the resulting intense heat has baked and fused the overlying clastic (sedimentary) rocks into clinkers. The clinkers are very magnetic and a buried edge of a single layer of burn can easily be located by magnetic prospecting methods. Location of the edge is very important in estimating unburned coal deposits, locating clinker quarries, and planning drilling of seismic reflection lines. The clinkers are very porous and highly fractured,-and seismic and geotechnical tests show that they have relatively low strength and competency. Many of the laboratory tests, however, are inherently biased because the clinkers are so highly fractured that only competent samples are selected. The laboratory tests, for example, show that clinkers must be loosened by heavy ripping tractors or blasting, whereas the field data and practical experience indicate that clinkers may be mined with light equipment. Heavy structures such as coal silos and bridge abutments may have to be sited on clinkers. However, differential settlement may occur, with failure in the shear mode, because chimneys of relatively greater strength occur among the weaker clinkers. Preliminary data indicate that the chimneys may be located by magnetic or possibly seismic surveys. Special foundation-preparation techniques could be used or, perhaps, the chimneys could be avoided altogether at a construction site.

Open-File Report↗

A preliminary report of the geohydrology of the Mississippi salt-dome basin

The U.S. Department of Energy is investigating the suitability of salt domes in the Mississippi salt-dome basin as repositories for storing radioactive wastes. The Department of Energy has requested that the U.S. Geological Survey describe the groundwater hydrology of the Mississippi salt-dome basin, giving special attention to direction and rate of movement of water. In this first part of a continuing investigation the data obtained from one year of extensive literature search and data compilation are summarized. The regional groundwater hydrology in the salt-dome basin is defined with respect to (1) groundwater flow, (2) facies changes, (3) geological structure, (4) recharge and discharge, (5) freshwater-saltwater relations, and (6) identification of localities where additional data are needed. From the 50 piercement-type salt domes in the Mississippi salt-dome basin three domes (Richton, Cypress Creek, and Lampton) were selected for more intensive study. To further evaluate the geohydrology of Richton, Lampton, and Cypress Creek domes as possible sites for storage of radioactive waste, an intensive geohydrologic study based on a comprehensive test drilling program near the domes is planned. (USGS)

Mississippi↗

Droughts, epic droughts and droughty centuries - lessons from a California paleoclimatic record: a PACLIM 2001 meeting report

During the early 1990s (but echoing studies by S.T. Harding at the University of California, from as early as the 1930s), several lines of paleoclimate evidence in and around the Sierra Nevada Range have provided the water community in California with some real horror stories. By studying ancient tree stumps submerged in Lake Tahoe and Tenaya Lake, stumps that were emerging from Mono Lake during its recent decline, and stumps that were exhumed in the Walker River bed during the floods of 1997, paleoclimatologists like Scott Stine of California State University, Hayward, assembled a picture of epic droughts in the central Sierra Nevada during the medieval period. These droughts had to be severe to drop water levels in the lakes and rivers low enough for the trees to grow in the first place, and then had to last for hundreds of years to explain tree-ring counts in these sizeable stumps. Worse yet, the evidence suggested at least two such epic droughts, one ending close to 1100 and the other close to 1350. These epic droughts challenged paleoclimatologists, as well as modern climatologists and hydrologists, to understand and, ultimately, to determine the likelihood that such droughts might recur in the foreseeable future. The first challenge, however, was to verify that such droughts were more than local events and as extreme as suggested. At this year’s Pacific Climate (PACLIM) Workshop, held March 18–21, 2001, at Asilomar (Pacific Grove, Calif.), special sessions brought together scientists to compare paleoclimatic reconstructions of ancient droughts and pluvial (wet) epidodes to try to determine the nature of decadal and centennial climate fluctuations in western North America, with emphasis on California. A companion session brought together modern climatologists to report on the latest explanations (and evidence) for decadal climate variations during the instrumental era of the 20th century.

Interagency Ecological Program Newsletter↗

Comparison of two approaches for determining ground-water discharge and pumpage in the lower Arkansas River Basin, Colorado, 1997-98

In March 1994, the Colorado Division of Water Resources (CDWR) adopted “Rules Governing the Measurement of Tributary Ground Water Diversions Located in the Arkansas River Basin” (Office of the State Engineer, 1994); these initial rules were amended in February 1996 (Office of the State Engineer, 1996). The amended rules require users of wells that divert tributary ground water to annually report the water pumped monthly by each well. The rules allow a well owner to report the pumpage measured by a totalizing flowmeter (TFM) or pumpage determined from electrical power data and a power conversion coefficient (PCC) (Hurr and Litke, 1989). Opinions by representatives of the State of Kansas, presented before the Special Master hearing a court case [State of Kansas v. State of Colorado, No. 105 Original (1996)] concerning post-Compact well pumping, stated that the PCC approach does not provide the same level of accuracy and reliability as a TFM when used to determine pumpage. In 1997, the U.S. Geological Survey (USGS), in cooperation with the CDWR, began a 2-year study to compare ground-water pumpage estimates made using the TFM and the PCC approaches. The study area was along the Arkansas River between Pueblo, Colorado, and the Colorado-Kansas State line (fig. 1). The two approaches for estimating ground-water discharge and pumpage were compared for more than 100 wells completed in the alluvial aquifer of the Arkansas River Basin. The TFM approach uses an inline flowmeter to directly measure instantaneous discharge and the total volume of water pumped at a well. The PCC approach uses electrical power consumption records and a power conversion coefficient to estimate the pumpage at ground-water wells. This executive summary describes the results of the comparison of the two approaches. Specifically, (1) the differences in instantaneous discharge measured with three portable flowmeters and measured with an inline TFM are evaluated, and the statistical differences in paired instantaneous discharge between the two approaches are determined; (2) short- and long-term variations in the PCC’s are presented; (3) differences in pumpage between the two approaches are evaluated, and the statistical differences in pumpage between the two approaches are determined; (4) potential sources of discrepancy between pumpage estimates are discussed; and (5) differences in total network pumpage using the two approaches are presented. During the irrigation seasons of 1997 and 1998, instantaneous discharge and electrical power demand were measured at randomly selected wells to determine PCC’s. At more than 100 wells, the PCC’s determined during the 1998 season were applied to total electrical power consumption data that was recorded between the initial and final readings at each network well site in 1998 to estimate total ground-water pumpage. At each site, an inline TFM was installed in a full-flowing, acceptable test section of pipe on the discharge side of the pump where the measurement of discharge was made. Measurements of instantaneous ground-water discharge also were made using three different types of portable flowmeters. The average velocity multiplied by the cross-sectional area of the discharge pipe was used to compute the discharge in gallons per minute. Whenever possible, discharge measurements were made at each network site using all three types of portable flowmeters.

Colorado↗

Accounting for site effects in probabilistic seismic hazard analyses of southern California: Overview of the SCEC Phase III Report

This article presents an overview of the Southern California Earthquake Center (SCEC) Phase-III effort to determine the extent to which probabilistic seismic hazard analysis (PSHA) can be improved by accounting for site effects. The contributions made in this endeavor are represented in the various articles that compose this special issue of BSSA. Given the somewhat arbitrary nature of the site-effect distinction, it must be carefully defined in any given context. With respect to PSHA, we define the site effect as the response, relative to an attenuation relationship, averaged over all damaging earthquakes in the region. A diligent effort has been made to identify any attributes that predispose a site to greater or lower levels of shaking. The most detailed maps of Quaternary geology are not found to be helpful; either they are overly detailed in terms of distinguishing different amplification factors or present southern California strong-motion observations are inadequate to reveal their superiority. A map based on the average shear-wave velocity in the upper 30 m, however, is found to delineate significantly different amplification factors. A correlation of amplification with basin depth is also found to be significant, implying up to a factor of two difference between the shallowest and deepest parts of the Los Angeles basin. In fact, for peak acceleration the basin-depth correction is more influential than the 30-m shear-wave velocity. Questions remain, however, as to whether basin depth is a proxy for some other site attribute. In spite of these significant and important site effects, the standard deviation of an attenuation relationship (the prediction error) is not significantly reduced by making such corrections. That is, given the influence of basin-edge-induced waves, subsurface focusing, and scattering in general, any model that attempts to predict ground motion with only a few parameters will have a substantial intrinsic variability. Our best hope for reducing such uncertainties is via waveform modeling based on first principals of physics. Finally, questions remain with respect to the overall reliability of attenuation relationships at large magnitudes and short distances. Current discrepancies between viable models produce up to a factor of 3 difference among predicted 10% in 50-yr exceedance levels, part of which results from the uncertain influence of sediment nonlinearity.

California↗

Baldcypress swamp management and climate change

In the future, climates may become warmer and drier in the southeastern United States; as a result, the range of baldcypress (Taxodium distichum) swamps may shrink. Managers of baldcypress swamps at the southern edge of the range may face special challenges in attempting to preserve these swamp habitats in the future if climates become warmer and drier.

Open-File Report↗

Geothermal gas sampling methods

The following method of geothermal gas collection meets our needs for chemical and isotopic gas analyses, requires a minimum of special equipment in the field, and provides field analytical data of assistance in a sampling program.

Open-File Report↗

A preliminary deposit model for lithium brines

This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. The global transition away from hydrocarbons toward energy alternatives increases demand for many scarce metals. Among these is lithium, a key component of lithium-ion batteries for electric and hybrid vehicles. Lithium brine deposits account for about three-fourths of the world’s lithium production. Updating an earlier deposit model, we emphasize geologic information that might directly or indirectly help in exploration for lithium brine deposits, or for assessing regions for mineral resource potential. Special attention is given to the best-known deposit in the world—Clayton Valley, Nevada, and to the giant Salar de Atacama, Chile.

California, Nevada↗

Historical and contemporary imagery to assess ecosystem change on the Arctic coastal plain of northern Alaska

The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low-relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades leading to thawing of on-shore permafrost and the disappearance of sea ice at unprecedented rates. The U.S. Geological Survey’s (USGS) Changing Arctic Ecosystems (CAE) research initiative was developed to investigate and forecast these rapid changes in the physical environment of the Arctic, and the associated changes to wildlife populations, in order to inform key management decisions by the U.S. Department of the Interior and other agencies. Forecasting future wildlife responses to changes in the Arctic can benefit greatly from historical records that inform what changes have already occurred. Several Arctic wildlife and plant species have already responded to climatic and physical changes to the Arctic Coastal Plain of northern Alaska. Thus, we located historical aerial imagery to improve our understanding of recent habitat changes and the associated response to such changes by wildlife populations. In this report, we describe and make available a set of 61 georectified aerial images of the Arctic Coastal Plain (taken from 1948 to 2010) that were obtained by the USGS to inform research objectives of the USGS CAE Initiative. Here, we describe the origins, metadata, and public availability of these images that were obtained within four main study areas on the Arctic Coastal Plain: Teshekpuk Lake Special Area, Chipp River, the Colville River Delta, and locations along the Dalton Highway Corridor between the Brooks Range and Deadhorse. We also provide general descriptions of observable changes to the geomorphology of landscapes that are apparent by comparing historical and contemporary images. These landscape changes include altered river corridors, lake drying, coastal erosion, and new vegetation communities. All original and georectified images and metadata are available through the USGS Alaska Science Center Portal (search under ‘Project Name’ using title of this report) or by contacting ascweb@usgs.gov .

Alaska↗

Integrated rangeland fire management strategy actionable science plan completion assessment: Invasives topic, 2015–20

Loss and degradation of sagebrush rangelands due to an accelerated invasive annual grass-wildfire cycle and other stressors are significant management, conservation, and economic issues in the western United States. These sagebrush rangelands comprise a unique biome spanning 11 states, support over 350 wildlife species, and provide important ecosystem services that include stabilizing the economies of western communities. Impacts to sagebrush ecosystem processes over large areas due to the annual grass-wildfire cycle necessitated the development of a coordinated, science-based strategy for improving efforts to achieve long-term protection, conservation, and restoration of sagebrush rangelands, which was framed in 2015 under the Integrated Rangeland Fire Management Strategy (IRFMS). Central to this effort was the development of an Actionable Science Plan (Plan) that identified 37 priority science needs (Needs) for informing the actions proposed under the 5 topics (Fire, Invasives, Restoration, Sagebrush and Sage-Grouse, Climate and Weather) that were part of the collective focus of the IRFMS. Notable keys to this effort were identification of the Needs co-produced by managers and researchers, and a focus on resulting science being “actionable.” Substantial investments aimed at fulfilling the Needs identified in the Plan have been made since its release in 2016. While the state of the science has advanced considerably, the extent to which knowledge gaps remain relative to identified Needs is relatively unknown. Moreover, new Needs have likely emerged since the original strategy as results from actionable science reveal new questions and possible (yet untested) solutions. A quantifiable assessment of the progress made on the original science Needs can identify unresolved gaps and new information that can help inform prioritization of future research efforts. This report details a systematic literature review that evaluated how well peer-reviewed journal articles and formal technical reports published between January 1, 2015, and December 31, 2020, addressed six needs (hereinafter “Needs”) identified under the Invasives topic in the Plan. The topic outlined research Needs related to the control of invasive plant species in sagebrush rangelands, with a special emphasis on invasive annual grasses. We established the level of progress towards addressing each Need following a standardized set of criteria, and developed summaries detailing how research objectives nested within Needs identified in the Plan (“Next Steps”) were either addressed well, partially addressed, or remain outstanding (that is, addressed poorly) in the literature through 2020. Our searches resulted in the inclusion of 198 science products that at least partially addressed a Need identified in the Invasives topic. The Needs that were well and partially addressed included: studies of natural and anthropogenic factors influencing the distribution and spread; methods of preventing, eradicating and controlling invasive plant species; development of mapping techniques that provide regularly updated annual grass and fine fuel projections; and assessment of the efficacy of potential cheatgrass biocontrol agents. Needs that were addressed poorly included (1) investigations of livestock grazing as a tool for managing invasive plants and (2) investigations of cheatgrass die-offs and identification and subsequent study of potential biocontrol agents associated with those die-offs. The information provided in this assessment will assist updating the Plan along with other science strategies.

western United States↗

Exploration for mineral deposits in White County, Georgia

White County is in the Northeast Georgia Highland. It comprises 243 square miles and has abouit 7,000 Inhabitants. The county seat is Cleveland. Although the scene of considerable mining activity in the past, White County now has few operating mines: a small production of clay 1 for the manufacture of miscellaneous potter near Cleveland, and three sand-gravel operations 2 at Helen. Minerals are one of White County's three basic resources, and the one whose development has been most neglected. This special study has been undertaken to expand mineral production, increase employment and create new economic opportunities in White County and adjacent areas.

Georgia↗

SPECtrum Processing Routines User's Manual Version 3 (program SPECPR)

Introduction The SPECtrum Processing Routines (SPECPR) is a large-scale interactive program for general one-dimensional array processing and optimized for reflectance spectroscopy data and analysis. The program processes one-dimensional arrays up to 4852 data points and the operations include addition, subtraction, multiplication, division, trigonometric functions, logarithmic and exponential functions, and many more specialized routines. The Specpr user interface is a menu driven, character command system with all user input entered as ascii characters to the program. User commands are thoroughly checked for the context in which they will be used. This provides for essentially all user input mistakes to be caught and appropriate error messages to be issued. The user interface also allows for command aliasing, variable substitutions, command history and batch command processing to occur at any point in the program. The user can also control his or her own variables, increment and decrement them, and monitor certain internal variables. This flexibility allows for sophisticated programming, e.g. from specific computations, to management of a database. All arrays are treated as one dimensional lists of numbers, each with an appropriate header for identification and history. Any array can be plotted versus another array, and each axis labeled appropriately. For example, you may plot a reflectance spectrum versus wavelength or wavelength versus reflectance. The array type is simply a label, so data like temperature versus time can be treated just as easily as a reflectance spectrum. Some routines are specific to certain purposes, however. For example, the Planck black body generator is specific to intensity versus wavelength, whereas a smoothing routine could operate equally on reflectance versus wavelength or temperature versus time. Each array element can have an error bar associated with it and errors are propagated through all appropriate routines. Data points can be marked deleted and deleted points are tracked appropriately. These features allow the program to be effectively used on real world data. This philosophy has resulted in a flexible system for which a user can manipulate data arrays efficiently. The program was designed for analysis of laboratory, field, telescopic, and spacecraft spectroscopic data, and although general in nature, there are biases built in. For example, horizontal axis labels default to wavelength in micrometers, but the defaults can be changed. Because of the orientation in Specpr to process planetary and terrestrial data, and the need to access such data, Specpr has been extended to have access to non-Specpr default file types. In particular, Specpr can "skewer" an 3-dimensional (3D) data file along any of the three axes. Further, block skewers can be done with the standard deviation of the mean computed for each channel in the block. Currently, Specpr can access any of the standard file types common in the terrestrial and planetary remote sensing communities. Details on 3D file I/O are given in Chapter 6. Specpr has multiple record types available within a single Specpr data file. Currently defined record types are data and text. In a data record, a standard one-dimensional array is held, along with its header information. The header information includes a title, history, dates and time of data acquisition and when the data were last processed, the user who processed the data, information typical of a spectrum like temperature and viewing geometry, as well as pointers to wavelengths, resolution, and text. If a spectrum is more than 256 channels in length, then the data gets put in succeeding records in the file, and the following records are continuation records. The second record type is the text, where a title and a block of text (up to 19 kbytes) can be stored. This record type is typically used for a description of samples, experiments, instruments, or data processing for a particular data set. It could also store the actual commands used to create a spectrum. The commands for a complicated plot for a publication might be stored in a text record. That way, you can easily regenerate the plot, or even write the commands to a non-Specpr file, modify them with any editor and re-execute them. The file types, text and command processing, combined with the math and special functions, provide for very powerful and general analysis tool. These facilities also provide the framework for database management.

Open-File Report↗

U.S. Geological Survey scientific activities in the exploration of Antarctica: 1946-2006 record of personnel in Antarctica and their postal cachets: U.S. Navy (1946-48, 1954-60), International Geophysical Year (1957-58), and USGS (1960-2006)

Antarctica, a vast region encompassing 13.2 million km2 (5.1 million mi2), is considered to be one of the most important scientific laboratories on Earth. During the past 60 years, the USGS, in collaboration and with logistical support from the National Science Foundation's Office of Polar Programs, has sent 325 USGS scientists to Antarctica to work on a wide range of projects: 169 personnel from the NMD (mostly aerial photography, surveying, and geodesy, primarily used for the modern mapping of Antarctica), 138 personnel from the GD (mostly geophysical and geological studies onshore and offshore), 15 personnel from the WRD (mostly hydrological/glaciological studies in the McMurdo Dry Valleys), 2 personnel from the BRD (microbiological studies in the McMurdo Dry Valleys), and 1 person from the Director's Office (P. Patrick Leahy, Acting Director, 2005–06 austral field season). Three GD scientists and three NMD scientists have carried out field work in Antarctica 9 or more times: John C. Behrendt (15), who started in 1956–57 and published two memoirs (Behrendt, 1998, 2005), Arthur B. Ford (10), who started in 1960–61, and Gary D. Clow (9), who started in 1985–86; Larry D. Hothem (12), who began as a winter-over geodesist at Mawson Station in 1968–69, and Jerry L. Mullins (12), who started in 1982–83 and followed in the legendary footsteps of his NMD predecessor, William R. MacDonald (9), who started in 1960–61 and supervised the acquisition of more than 1,000,000 square miles of aerial photography of Antarctica. This report provides a record as complete as possible, of USGS and non-USGS collaborating personnel in Antarctica from 1946–2006, the geographic locations of their work, and their scientific/engineering disciplines represented. Postal cachets for each year follow the table of personnel and scientific activities in the exploration of Antarctica during those 60 years. To commemorate special events and projects in Antarctica, it became an international practice to create postal cachets. A cachet is defined as a seal, emblem, or commemorative design printed or stamped on an envelope to mark a philatelic or special event. All stamp collectors are familiar with engraved cachets on envelopes of "First-Day-of-Issue" stamps. For Antarctica, a stamped (inked) impression informs the scientist, historian, stamp collector, and general public about the multidisciplinary science projects staffed by USGS scientists and other specialists during a specific austral summer field season. Because philatelic cachets were created by team members for each USGS field season, in most cases depicting the specific areas and scientific objectives, the cachets have become a convenient documentation of the people, projects, and geographic places for that year. Because the cachets are representative of USGS activities, each year's cachet is included in that year's Open-File Report (1960–61 to 2005–06). Starting with the 1983–84 season, however, two USGS cachets were prepared for the next seven years, one for the winter team at Amundsen-Scott South Pole Station, until 1992–93, and the other for all other field sites. Multiple cachets were created by USGS divisional programs during the 1962–63, 1963–64, 1970–71, 1972–73, 1975–76, 1978–79, 1979–80, 1983–84, 1984–85, 1986–87, 1995–96, 2003–04, and the 2005–06 years. This report includes facsimiles of each annual postal cachet (or postal cachets) designed by USGS graphic specialists and provides a record of USGS personnel (and non-USGS collaborating scientists) and their science division affiliation for each austral field season. In addition, cachets used by USGS personnel for U.S. Navy Operation Highjump (1946–47), U.S. Navy Operation Windmill (1947–48), U.S. Navy U.S.S. Atka reconnaissance cruise (1954–55), U.S. Navy Operation Deep Freeze (DF) (I, 1955–56; II, 1956–57; III, 1957–58; IV, 1958–59; and DF 60, 1959–60), and the International Geophysical Year (1957–58) are included, because USGS scientists made use of these cachets when involved in each of the field activities during these austral field seasons.

Open-File Report↗

Opportunities for businesses to use and support development of SEEA-aligned natural capital accounts

Global understanding of the interconnections between the environment and economy has increased, driving the development of frameworks and standards that support the measurement and valuation of natural capital and ecosystem services by both governments and businesses. This paper outlines how businesses can use natural capital accounts (NCA) aligned to the System of Environmental Economic Accounting (SEEA) standard described in this special issue to support identification, management, and valuation of natural capital not typically listed on corporate balance sheets. Such accounts have direct applications for business strategic planning, investment decisions, supply chain management , operations management, risk management, and corporate reporting. Businesses also have important roles to play in advancing SEEA-aligned NCA by providing information that would be useful to include in the accounts and by helping to shape accounts to provide decision-relevant information for both the private and the public sectors. Current pilot SEEA-aligned NCA data and analyses developed for the United States can help address some of the common challenges that businesses face in using natural capital data such as accessibility, quality, and credibility, important for business decision making. However, improvements are needed to fill data gaps and produce more frequent and timely estimates aligned to the temporal resolution needed by businesses.

Ecosystem Services↗

The timing of eclogite facies metamorphism and migmatization in the Orlica–Śnieżnik complex, Bohemian Massif: Constraints from a multimethod geochronological study

The Orlica–Śnieżnik complex (OSC) is a key geological element of the eastern Variscides and mainly consists of amphibolite facies orthogneisses and metasedimentary rocks. Sporadic occurrences of eclogites and granulites record high-pressure (HP) to ultrahigh-pressure (UHP) metamorphic conditions. A multimethod geochronological approach ( 40 Ar– 39 Ar, Rb–Sr, Sm–Nd, U–Pb) has been used to gain further insights into the polymetamorphic evolution of eclogites and associated country rocks. Special attention was given to the unresolved significance of a 370- to 360 Ma age group that was repeatedly described in previous studies. Efforts to verify the accuracy of c. 370 Ma K–Ar phengite and biotite dates reported for an eclogite and associated country-rock gneiss from the location Nowa Wieś suggest that these dates are meaningless, due to contamination with extraneous Ar. Extraneous Ar is also considered to be responsible for a significantly older 40 Ar– 39 Ar phengite date of c. 455 Ma for an eclogite from the location Wojtowka. Attempts to further substantiate the importance of 370–360 Ma zircon dates as an indicator for a melt-forming high-temperature (HT) episode did not provide evidence in support of anatectic processes at this time. Instead, SHRIMP U–Pb zircon dating of leucosomes and leucocratic veins within both orthogneisses and (U)HP granulites revealed two age populations (490–450 and 345–330 Ma respectively) that correspond to protolith ages of the magmatic precursors and late Variscan anatexis. The results of this study further underline the importance of Late Carboniferous metamorphic processes for the evolution of the OSC that comprise the waning stages of HP metamorphism and lower pressure HT overprinting with partial melting. Eclogites and their country rocks provided no chronometric evidence for an UHP and ultrahigh-temperature episode at 387–360 Ma, as recently suggested for granulites from the OSC, based on Lu–Hf garnet ages ( Anczkiewicz et al. , 2007 ).

Orlica-Snieznik complex↗