Earth Sciences Commons^™

Alunite And The Role Of Magmatic Fluids In The Tambo High-Sulfidation Deposit, El Indio–Pascua Belt, Chile, C.L. Deyell, R.O. Rye, G.P. Landis, T. Bissig

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

The Tambo high-sulfidation deposit, located within the El Indio–Pascua belt in Chile, produced almost 25 t (0.8 M oz) of gold from altered Tertiary rhyodacitic volcanic rocks. Episodic magmatic-hydrothermal activity in the district occurred over at least 4 my and is characterized by several stages of acid-sulfate alteration, including magmatic-hydrothermal, magmatic steam, steam-heated, and apparent supergene assemblages. Two stages of Au±Ag mineralization are recognized and are hosted in barite and alunite within hydrothermal breccias and veins. Isotopic compositions of fluid in alunite show a dominant magmatic signature, with only a variable ¹⁸O-enriched meteoric water component throughout the entire hydrothermal …

Secondary Sulfate Minerals Associated With Acid Drainage In The Eastern Us: Recycling Of Metals And Acidity In Surficial Environments, J. M. Hammarstrom, R. R. Seal Ii, A. L. Meier, J. M. Kornfeld

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

Weathering of metal-sulfide minerals produces suites of variably soluble efflorescent sulfate salts at a number of localities in the eastern United States. The salts, which are present on mine wastes, tailings piles, and outcrops, include minerals that incorporate heavy metals in solid solution, primarily the highly soluble members of the melanterite, rozenite, epsomite, halotrichite, and copiapite groups. The minerals were identified by a combination of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron-microprobe. Base-metal salts are rare at these localities, and Cu, Zn, and Co are commonly sequestered as solid solutions within Fe- and Fe–Al sulfate minerals. Salt …

Characterization Of Gas Chemistry And Noble-Gas Isotope Ratios Of Inclusion Fluids In Magmatic-Hydrothermal And Magmatic-Steam Alunite, Robert O. Rye, G.P. Landis

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

Chemical and isotope data were obtained for the active gas and noble gas of inclusion fluids in coarse-grained samples of magmatic-hydrothermal and magmatic-steam alunite from well-studied deposits (Marysvale, Utah; Tambo, Chile; Tapajo´s, Brazil; Cactus, California; Pierina, Peru), most of which are discussed in this Volume. Primary fluid inclusions in the alunite typically are less than 0.2 µm but range up to several micrometers. Analyses of the active-gas composition of these alunitehosted inclusion fluids released in vacuo by both crushing and heating indicate consistent differences in the compositions of magmatic-hydrothermal and magmatic-steam fluids. The compositions of fluids released by crushing were …

Evolution Of The Magmatic-Hydrothermal Acid-Sulfate System At Summitville, Colorado: Integration Of Geological, Stable-Isotope, And Fluid-Inclusion Evidence, Philip M. Bethke, Robert O. Rye, Roger E. Stoffregen, Peter G. Vikre

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

The Summitville Au–Ag–Cu deposit is a classic volcanic dome-hosted high-sulfidation deposit. It occurs in the Quartz Latite of South Mountain, a composite volcanic dome that was emplaced along the coincident margins of the Platoro and Summitville calderas at 22.5±0.5 Ma, penecontemporaneous with alteration and mineralization. A penecontemporaneous quartz monzonite porphyry intrusion underlies the district and is cut and overlain by pyrite–quartz stockwork veins with traces of chalcopyrite and molybdenite. Alteration and mineralization proceeded through three hypogene stages and a supergene stage, punctuated by at least three periods of hydrothermal brecciation. Intense acid leaching along fractures in the quartz latite produced …

Paleoproterozoic High-Sulfidation Mineralization In The Tapajo´S Gold Province, Amazonian Craton, Brazil: Geology, Mineralogy, Alunite Argon Age, And Stable-Isotope Constraints, Caetano Juliani, Robert O. Rye, Carmen M.D. Nunes, Lawrence W. Snee, Rafael H. Corrêa Silva, Lena V.S. Monteiro, Jorge S. Bettencourt, Rainer Neumann, Arnaldo Alcover Neto

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

The Brazilian Tapajós gold province contains the first evidence of high-sulfidation gold mineralization in the Amazonian Craton. The mineralization appears to be in large nested calderas. The Tapajós–Parima (or Ventuari–Tapajo´ s) geological province consists of a metamorphic, igneous, and sedimentary sequence formed during a 2.10 to 1.87 Ga ocean ̶ continent orogeny. The high-sulfidation mineralization with magmatic-hydrothermal alunite is related to hydrothermal breccias hosted in a rhyolitic volcanic ring complex that contains granitic stocks ranging in age from 1.89 to 1.87 Ga. Cone-shaped hydrothermal breccias, which flare upward, contain vuggy silica and have an overlying brecciated cap of massive silica; …

A Review Of The Stable-Isotope Geochemistry Of Sulfate Minerals In Selected Igneous Environments And Related Hydrothermal Systems, Robert O. Rye

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

The stable-isotope geochemistry of sulfate minerals that form principally in I-type igneous rocks and in the various related hydrothermal systems that develop from their magmas and evolved fluids is reviewed with respect to the degree of approach to isotope equilibrium between minerals and their parental aqueous species. Examples illustrate classical stable-isotope systematics and principles of interpretation in terms of fundamental processes that occur in these systems to produce (1) sulfate in igneous apatite, (2) igneous anhydrite, (3) anhydrite in porphyry-type deposits, (4) magmatic-hydrothermal alunite and closely related barites in high-sulfidation mineral deposits, (5) coarse-banded alunite in magmatic-steam systems, (6) …

"Sour Gas" Hydrothermal Jarosite: Ancient To Modern Acid-Sulfate Mineralization In The Southern Rio Grande Rift, Virgil W. Lueth, Robert O. Rye, Lisa Peters

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

As many as 29 mining districts along the Rio Grande Rift in southern New Mexico contain Rio Grande Rift-type (RGR) deposits consisting of fluorite–barite±sulfide–jarosite, and additional RGR deposits occur to the south in the Basin and Range province near Chihuahua, Mexico. Jarosite occurs in many of these deposits as a late-stage hydrothermal mineral coprecipitated with fluorite, or in veinlets that crosscut barite. In these deposits, many of which are limestone-hosted, jarosite is followed by natrojarosite and is nested within silicified or argillized wallrock and a sequence of fluorite–bariteFsulfide and late hematite– gypsum. These deposits range in age from ~10 to …

Stable-Isotope Geochemistry Of The Pierina High-Sulfidation Au–Ag Deposit, Peru: Influence Of Hydrodynamics On So42-–H2S Sulfur Isotopic Exchange In Magmatic-Steam And Steam-Heated Environments, Richard H. Fifarek, Robert O. Rye

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

The Pierina high-sulfidation Au–Ag deposit formed 14.5 my ago in rhyolite ash flow tuffs that overlie porphyritic andesite and dacite lavas and are adjacent to a crosscutting and interfingering dacite flow dome complex. The distribution of alteration zones indicates that fluid flow in the lavas was largely confined to structures but was dispersed laterally in the tuffs because of a high primary and alteration-induced permeability. The lithologically controlled hydrodynamics created unusual fluid, temperature, and pH conditions that led to complete SO₄ ^2‒–H₂S isotopic equilibration during the formation of some magmatic-steam and steam-heated alunite, a phenomenon not …

Supergene Destruction Of A Hydrothermal Replacement Alunite Deposit At Big Rock Candy Mountain, Utah: Mineralogy, Spectroscopic Remote Sensing, Stable-Isotope, And Argon-Age Evidences, Charles G. Cunningham, Robert O. Rye, Barnaby W. Rockwell, Michael J. Kunk, Terry B. Councell

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

Big Rock Candy Mountain is a prominent center of variegated altered volcanic rocks in west-central Utah. It consists of the eroded remnants of a hypogene alunite deposit that, at ~21 Ma, replaced intermediate-composition lava flows. The alunite formed in steam-heated conditions above the upwelling limb of a convection cell that was one of at least six spaced at 3- to 4- km intervals around the margin of a monzonite stock. Big Rock Candy Mountain is horizontally zoned outward from an alunite core to respective kaolinite, dickite, and propylite envelopes. The altered rocks are also vertically zoned from a lower pyrite– …

Chemical Openness And Potential For Misinterpretation Of The Solute Environment Of Coastal Sabkhat, Warren W. Wood, Ward E. Sanford, Shaun K. Frape

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

Sabkha deposits in the geologic record are commonly used to interpret the environmental conditions of deposition. Implicit in this use is the assumption that the solute system is chemically closed, that is, the authigenic minerals represent the composition of the fluids in their environment of origin. Thermodynamic and mass-balance calculations based on measurements of water and solute flux of contemporary Abu Dhabi coastal sabkha system, however, demonstrate that the system is open for sodium and chloride, where nearly half of the input is lost, but closed for sulfur, where nearly 100% is retained. Sulfur and chloride isotopes were consistent with …

Temporal Analysis Of The Frequency And Duration Of Low And High Streamflow: Years Of Record Needed To Characterize Streamflow Variability, Seungho Huh, David A. Dickey, M. R. Meador, K. E. Ruhl

United States Geological Survey: Staff Publications

A temporal analysis of the number and duration of exceedences of high- and low-flow thresholds was conducted to determine the number of years required to detect a level shift using data from Virginia, North Carolina, and South Carolina. Two methods were used—ordinary least squares assuming a known error variance and generalized least squares without a known error variance. Using ordinary least squares, the mean number of years required to detect a one standard deviation level shift in measures of low-flow variability was 57.2 (28.6 on either side of the break), compared to 40.0 years for measures of high-flow variability. These …

The Composition Of Coexisting Jarosite-Group Minerals And Water From The Richmond Mine, Iron Mountain, California, Heather E. Jamieson, Clare Robinson, Charles N. Alpers, D. Kirk Nordstrom, Alexei Poustovetov, Heather A. Lowers

United States Geological Survey: Staff Publications

Jarosite-group minerals accumulate in the form of stalactites and fine-grained mud on massive pyrite in the D drift of the Richmond mine, Iron Mountain, California. Water samples were collected by placing beakers under the dripping stalactites and by extracting pore water from the mud using a centrifuge. The water is rich in Fe³⁺ and SO₄^2–, with a pH of approximately 2.1, which is significantly higher than the extremely acidic waters found elsewhere in the mine. Electron-microprobe analysis and X-ray mapping indicate that the small crystals (<10 > μm in diameter) are compositionally zoned with respect to Na …

Taxonomic Relationships Among Phenacomys Voles As Inferred By Cytochrome B, M. Renee Bellinger, Susan M. Haig, Eric D. Forsman, Thomas D. Mullins

United States Geological Survey: Staff Publications

Taxonomic relationships among red tree voles (Phenacomys longicaudus longicaudus, P. l. silvicola), the Sonoma tree vole (P. pomo), the white-footed vole (P. albipes), and the heather vole (P. intermedius) were examined using 664 base pairs of the mitochondrial cytochrome b gene. Results indicate specific differences among red tree voles, Sonoma tree voles, white-footed voles, and heather voles, but no clear difference between the 2 Oregon subspecies of red tree voles (P. l. longicaudus and P. l. silvicola). Our data further indicated a close relationship between tree voles and albipes, …

Comparison Of Individual And Pooled Sampling Methods For Detecting Bacterial Pathogens Of Fish, Sonia Mumford, Chris Patterson, Joy Evered, Ray Brunson, Jay Levine, Jim Winton

United States Geological Survey: Staff Publications

Examination of finfish populations for viral and bacterial pathogens is an important component of fish disease control programs worldwide. Two methods are commonly used for collecting tissue samples for bacteriological culture, the currently accepted standards for detection of bacterial fish pathogens. The method specified in the Office International des Epizooties Manual of Diagnostic Tests for Aquatic Animals permits combining renal and splenic tissues from as many as 5 fish into pooled samples. The American Fisheries Society (AFS) Blue Book/US Fish and Wildlife Service (USFWS) Inspection Manual specifies the use of a bacteriological loop for collecting samples from the kidney of …

Characterization Of Waste Rock Associated With Acid Drainage At The Penn Mine, California, By Ground-Based Visible To Short-Wave Infrared Reflectance Spectroscopy Assisted By Digital Mapping, Irene C. Montero S., George H. Brimhalla, Charles N. Alpers, Gregg A. Swayze

United States Geological Survey: Staff Publications

Prior to remediation at the abandoned Cu–Zn Penn Mine in the Foothills massive sulfide belt of the Sierra Nevada, CA, acid mine drainage (AMD) was created, in part, by the subaerial oxidation of sulfides exposed on several waste piles. To support remediation efforts, a mineralogical study of the waste piles was undertaken by acquiring reflectance spectra (measured in the visible to short-wave infrared range of light (0.35–2.5 μm) using a portable, digitally integrated pen tablet PC mapping system with differential global positioning system and laser rangefinder support. Analysis of the spectral data made use of a continuum removal and band-shape …

Paleontology And Stratigraphy Of Upper Coniacianemiddle Santonian Ammonite Zones And Application To Erosion Surfaces And Marine Transgressive Strata In Montana And Alberta, W. A. Cobban, T. S. Dyman, K. W. Porter

United States Geological Survey: Staff Publications

Erosional surfaces are present in middle and upper Coniacian rocks in Montana and Alberta, and probably at the base of the middle Santonian in the Western Interior of Canada. These erosional surfaces are biostratigraphically constrained using inoceramid bivalves and ammonites, which are used to define lower, middle, and upper substages of both the Coniacian and Santonian stages of the Upper Cretaceous in this region. The most detailed biostratigraphy associated with these erosional surfaces concerns the MacGowan Concretionary Bed in the Kevin Member of the Marias River Shale in Montana, where the bed lies disconformably on middle or lowermost upper Coniacian …

Evidence For Marine Influence On A Low-Gradient Coastal Plain: Ichnology And Invertebrate Paleontology Of The Lower Tongue River Member (Fort Union Formation, Middle Paleocene), Western Williston Basin, U.S.A., Edward S. Belt, Neil E. Tibert, H. Allen Curran, John A. Diemer, Joseph H. Hartman, Timothy J. Kroeger, David M. Harwood

Department of Earth and Atmospheric Sciences: Faculty Publications

The Paleocene Tongue River Member of the Fort Union Formation contains trace-fossil associations indicative of marine influence in otherwise freshwater facies. The identified ichnogenera include: Arenicolites, Diplocraterion, Monocraterion, Ophiomorpha, Rhizocorallium, Skolithos linearis, Teichichnus, Thalassinoides, and one form of uncertain affinity. Two species of the marine diatom Coscinodiscus occur a few meters above the base of the member. The burrows occur in at least five discrete, thin, rippled, fine-grained sandstone beds within the lower 85 m of the member west of the Cedar Creek anticline (CCA) in the Signal Butte, Terry Badlands, and Pine Hills areas. T wo discrete burrowed …

Discovering Associations Between Climatic And Oceanic Parameters To Monitor Drought In Nebraska Using Data-Mining Techniques, Tsegaye Tadesse, Donald A. Wilhite, Michael J. Hayes, Steve Goddard

National Drought Mitigation Center: Faculty Publications

Drought is a complex natural hazard that is best characterized by multiple climatological and hydrological parameters. Improving our understanding of the relationships between these parameters is necessary to reduce the impacts of drought. Data mining is a recently developed technique that can be used to interact with large databases and assist in the discovery of associations between drought and oceanic data by extracting information from massive and multiple data archives. In this study, a new data-mining algorithm [i.e., Minimal Occurrences With Constraints and Time Lags (MOWCATL)] has been used to identify the relationships between oceanic parameters and drought indices. Rather …

Tapeworms Of Elasmobranchs (Part I) A Monograph On The Lecanicephalidea (Platyhelminthes, Cestoda), Kirsten Jensen

Bulletin of the University of Nebraska State Museum (1924–2023)

This represents the first monographic and phylogenetic treatment of the order Lecanicephalidea. The main objective was to treat the Lecanicephalidea at the generic level, while providing information on morphology, taxonomic history, phylogenetic relationships, geographic distribution, and host associations of the group. Following an introduction to the morphology of the Lecanicephalidea, the phylogenetic placement of the group is addressed. This is followed by a review of the taxonomic history of the group and relationships within, including summaries of 29 previously used classification schemes. Despite the generic focus of this study, the taxonomic status of 137 previously recognized lecanicephalidean species was evaluated, …

Reply To Comment By H. Lough, Department Of Civil Engineering, University Of Canterbury, Christchurch, New Zealand, On The Paper “Stream Depletion Predictions Using Pumping Test Data From A Heterogeneous Stream–Aquifer System (A Case Study From The Great Plains, Usa)”, S. J. Kollet, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

1. General remark

2. The study by Kollet and Zlotnik (2003)

3. Remark on the explanation of the drawdown behavior

4. Remark on the re-analysis of the data from piezometer C2d

5. Summary

Palaeogeography And Fluvial To Estuarine Architecture Of The Dakota Formation (Cretaceous, Alvian), Eastern Nebraska, Usa, Robert Matthew Joeckel, G. A. Ludvigson, B. J. Witzke, E. P. Kvale, P. L. Phillips, R. L. Brenner, S. G. Thomas, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Geologic Map And Topographic Profile Of The Newark Quadrangle, Nebraska, Steven M. Condon

United States Geological Survey: Publications

Newark Quadrangle, Nebraska

Geologic Map And Topographic Profile Of The Elm Creek West Quadrangle, Nebraska, Steven M. Condon

United States Geological Survey: Publications

Geologic Map and Topographic Profile of the Elm Creek West Quadrangle, Nebraska

Geologic Studies Of The Platte River, South-Central Nebraska And Adjacent Areas—Geologic Maps, Subsurface Study, And Geologic History, Steven M. Condon

United States Geological Survey: Publications

The Platte River of south-central Nebraska was studied at three scales to place the river in its geological context and to trace its evolution through geologic time. At the largest scale the Elm Creek West and the Newark 7.5 minute quadrangles were mapped. These quadrangles are located just west and just east of Kearney and serve to illustrate the main geomorphic elements of the present Platte River Valley. The central elements of the quadrangles are the Platte River channels, islands, and bottomlands, which are flanked by terraces that step up away from the river to the north and south. Significant …

Amphibian Research And Monitoring Initiative: Concepts And Implementation, Paul Stephen Corn, Michael J. Adams, William A. Battaglin, Alisa L. Gallant, Daniel L. James, Melinda Knutson, Catherine A. Langtimm, John R. Sauer

United States Geological Survey: Publications

This report provides the basis for discussion and subsequent articulation of a national plan for the Amphibian Research and Monitoring Initiative (ARMI). The authors were members of a task force formed from within the U.S. Geological Survey (USGS) that included scientists with expertise in biology, cartography, hydrology, and statistics. The assignment of the task force was to extend work begun by the National Amphibian Leadership Group. This group, composed of senior USGS scientists, managers, and external authorities, met in Gainesville, Florida, in February 20001. The product of this meeting was a document outlining the framework for a national program to …

Mercury Concentrations In Fishes From Select Water Bodies In Trinity County, California, 2000-2002, Jason T. May, Roger L. Hothem, Charles N. Alpers

United States Geological Survey: Publications

Sites of historical gold and mercury mining in the Trinity River watershed continue to release mercury to downstream water bodies. To evaluate the extent of mercury (Hg) contamination in the watershed, the U.S. Geological Survey collected samples of sediment, water, invertebrates, amphibians, and fishes from select water bodies and mine sites in Trinity County, California. This report presents total mercury data for 368 fishes collected during 2000–2002, from 4 locations within Trinity Lake, from 16 stream sites, and from 3 pond sites within the Trinity River watershed. The following species of fish were sampled (scientific name and number of samples …

Mercury Contamination From Historical Gold Mining In California, Charles N. Alpers, Michael P. Hunerlach, Jason T. May, Roger L. Hothem

United States Geological Survey: Publications

Mercury contamination from historical gold mines represents a potential risk to human health and the environment. This fact sheet provides background information on the use of mercury in historical gold mining and processing operations in California, with emphasis on historical hydraulic mining areas. It also describes results of recent USGS projects that address the potential risks associated with mercury contamination.

Miners used mercury (quicksilver) to recover gold throughout the western United States. Gold deposits were either hardrock (lode, gold-quartz veins) or placer (alluvial, unconsolidated gravels). Underground methods (adits and shafts) were used to mine hardrock gold deposits. Hydraulic, drift, or …

Questa Baseline And Pre-Mining Ground- Water Quality Investigation. 5. Well Installation, Water-Level Data, And Surface- And Ground-Water Geochemistry In The Straight Creek Drainage Basin, Red River Valley, New Mexico, 2001-03, Cheryl A. Naus, R. Blaine Mccleskey, D. Kirk Nordstrom, Lisa C. Donohoe, Andrew G. Hunt, Frederick L. Paillet, Roger H. Morin, Phillip L. Verplanck

United States Geological Survey: Publications

The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling groundwater chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and …

Origin Of Secondary Sulfate Minerals On Active Andesitic Stratovolcanoes, D.R. Zimbelman, Robert O. Rye, G.N. Breit

Geochemistry of Sulfate Minerals: A Tribute to Robert O. Rye

Sulfate minerals in altered rocks on the upper flanks and summits of active andesitic stratovolcanoes result from multiple processes. The origin of these sulfates at five active volcanoes, Citlalte´petl (Mexico), and Mount Adams, Hood, Rainier, and Shasta (Cascade Range, USA), was investigated using field observations, petrography, mineralogy, chemical modeling, and stable-isotope data. The four general groups of sulfate minerals identified are: (1) alunite group, (2) jarosite group, (3) readily soluble Fe- and Al-hydroxysulfates, and (4) simple alkaline-earth sulfates such as anhydrite, gypsum, and barite. Generalized assemblages of spatially associated secondary minerals were recognized: (1) alunite+silica±pyrite±kaolinite±gypsum±sulfur, (2) jarosite+alunite+silica; (3) jarosite+smectite+silica±pyrite, (4) …

Auditory Brainstem Responses In The Eastern Screech Owl: An Estimate Of Auditory Thresholds, Elizabeth F. Brittan-Powell, Bernard Lohr, D. Caldwell Hahn, Robert J. Dooling

United States Geological Survey: Staff Publications

The auditory brainstem response (ABR), a measure of neural synchrony, was used to estimate auditory sensitivity in the eastern screech owl (Megascops asio). The typical screech owl ABR waveform showed two to three prominent peaks occurring within 5 ms of stimulus onset. As sound pressure levels increased, the ABR peak amplitude increased and latency decreased. With an increasing stimulus presentation rate, ABR peak amplitude decreased and latency increased. Generally, changes in the ABR waveform to stimulus intensity and repetition rate are consistent with the pattern found in several avian families. The ABR audiogram shows that screech owls hear best between …