Springfields Research Articles

Biogeochemistry of Recently Fossilized Siliceous Hot Spring Sinters from Yellowstone, USA.

Active hot springs are dynamic geobiologically active environments. Heat- and element-enriched fluids form hot spring sinter deposits that are inhabited by microbial and macroscopic eukaryotic communities, but it is unclear how variable heat, fluid circulation, and mineralization within hot spring systems affect the preservation of organic matter in sinters. We present geological, petrographic, and organic geochemical data from fossilized hot spring sinters (<13 Ka) from three distinct hot spring fields of Yellowstone National Park. The aims of this study were to examine the preservation of hydrocarbons and discern whether the hydrocarbons in these samples were derived from in situ communities or transported by hydrothermal fluids. Organic geochemistry reveals the presence of n-alkanes, methylalkanes, hopanes, and other terpanes, and the distribution of methylheptadecanes is compared to published observations of community composition in extant hot springs with similar geochemistry. Unexpectedly, hopanes have a thermally mature signal, and Raman spectroscopy confirms that the kerogen in some samples has nearly reached the oil window, despite never having been buried. Our results suggest that organic matter maturation occurred through below-surface processes in the hotter, deeper parts of the hydrothermal system and that this exogenous material was then transported and emplaced within the sinter.

Using Isotopic and Hydrochemical Indicators to Identify Sources of Sulfate in Karst Groundwater of the Niangziguan Spring Field, China

Karst groundwater in the Niangziguan spring fields is the main source to supply domestic and industrial water demands in Yangquan City, China. However, the safety of water supply in this region has recently suffered from deteriorating quality levels. Therefore, identifying pollution sources and causes is crucial for maintaining a reliable water supply. In this study, a systematic sample collection for the karst groundwater in the Niangziguan spring fields was implemented to identify hydrochemical characteristics of the karst groundwater through comprehensive analyses of hydrochemistry (piper diagram, and ion ratios,) and stable isotopes (S and H-O). The results show that the karst groundwater in the Niangziguan spring fields was categorized as SO4·HCO3-Ca·Mg, HCO3·SO4-Ca·Mg, and SO4-Ca types. K+, Cl-, and Na+ are mainly sourced from urban sewage and coal mine drainage. In addition, SO42− was mainly supplied by the dissolution of gypsum and the oxidation of FeS2 in coal-bearing strata. It is noteworthy that, based on H-O and S isotopes, 75% of the karst groundwater was contaminated by acidic water in coal mines at different degrees. In the groundwater of the Niangziguan spring field, the proportions of SO42− derived from FeS2 oxidation were 60.6% (N50, Chengxi spring), 30.3% (N51, Wulong spring), and 26.0% (N52, Four springs mixed with water). Acid mine drainage directly recharges and pollutes karst groundwater through faults or abandoned boreholes, or discharges to rivers, and indirectly pollutes karst groundwater through river infiltration in carbonate exposed areas. The main source of rapid increase of sulfate in karst groundwater is acid water from abandoned coal mines.

Neither Leaven nor Honey by Fire

Neither Leaven nor Honey by Fire G.C. Waldrep (bio) A distant mourning—my mother's argumentwith time dreams it slinks from tree to treein the orchard, gaffing, grafting, splinting scionsonto resistant stock, their hopeless patrolwounded with starlight's merciless talc.The porcelain bed cracks in its debt of spineas one might have expected, really—theftbeing, of course, a limited, advance engagementnot subject to Empire's spasms, its piacularrecrudescence, turtled hives adrifton the midnight floodwaters. Ruin makes usknow the names others call us, the nonhumanothers, e.g. stones, bacteria, ghosts.Someone lights a fire. I have spent the lastof my uncles' violence on this box of paints.That the door in my dreams always appearsas dark wood, bound in iron, is immaterialin the strictest sense. Oh vein, I cannot touchyou, you are so near. It's true, the sunis alarming when seen from space, orfrom inside music's chipped, acrylic mug.It won't hurt long is what I actually sayto her, my mother, to anyone, are you listening,froth of rye in the spring fields—my fatheris, after all, still living, poured out like wet ashonto some beaten ground, Elgar's panegyricto Nashville and every useful art. What we haveleft is our mutual love of flame rather than,say, mirrors, which we use to signalothers, my mother for instance, this, yes, thiswas the flesh, let it shudder and cauterize,hem and stoke. Such is the legible confession.We will be clothed with daughters elsewhere. [End Page 9] G.C. Waldrep G.C. Waldrep's most recent books are The Earliest Witnesses (Tupelo/Carcanet, 2021) and feast gently (Tupelo, 2018), winner of the William Carlos Williams Award from the Poetry Society of America. Recent work has appeared or is forthcoming in American Poetry Review, Poetry, Paris Review, New England Review, Yale Review, Colorado Review, The Nation, New American Writing, Conjunctions, and other journals. Waldrep lives in Lewisburg, Pa., where he teaches at Bucknell University. Copyright © 2021 Pleiades and Pleiades Press

Large-scale modes impact on Iraq climate variability

The impact of large-scale modes on Iraq climate is investigated here based on winter and spring fields of temperature and precipitation. The temperature data (1971–2010) was recorded at 8 stations whereas the precipitation fields (1981–2010) were recorded at 18 locations. Empirical orthogonal function analyses were performed in order to characterize the spatial variability of the Iraq climatological parameters. The relationships between the global sea surface temperature, sea level pressure, and geopotential height fields with the dominant modes of Iraq temperature and precipitation were also investigated. Correlation and regression maps emphasize links between Iraq climate and large-scale modes, like the Atlantic Multidecadal Oscillation and the El Nino Southern Oscillation phenomenon.

Reconstruction of the 236U input function for the Northeast Atlantic Ocean: Implications for 129I/236U and 236U/238U‐based tracer ages

AbstractA reconstruction of historical discharges of 236U into the Northeast Atlantic Ocean by nuclear installations is presented. The nuclear reprocessing facilities Sellafield (SF), Great Britain (GB) and La Hague (LH), France and potentially also the nuclear fuel processing installation Springfields (SP), GB represent the main contributors of 236U in the Northeast Atlantic Ocean. Because data on 236U releases is lacking, 236U discharges from SP and SF are estimated based on the U‐isotopic systematics found in the discharges from LH. The resulting reconstruction of 236U releases indicates that, until 2013, a total of (95 ± 32) kg of 236U was discharged from SF, SP, and LH. In a second step, the reconstructed 236U releases are combined with 129I data from literature and oceanic and atmospheric box models are used to derive the 129I/236U and 236U/238U input functions that, for example, can be used to calculate tracer ages of Atlantic Waters in the Arctic Ocean. Our conceptual results show that the combination of 129I/236U and 236U/238U generally allows the estimation of tracer ages over the past approximately 25 years if contributions of 236U from global fallout are considered. Finally, as a proof of concept, the new method is applied to calculate tracer ages of Arctic Ocean surface samples (collected in 2011/2012) and the results are in good agreement with literature data. We conclude that the combination of 129I/236U with 236U/238U in a dual tracer approach provides a sensitive tool for the calculation of tracer ages and ventilation rates in the North Atlantic region.

Travertine: Distinctive depositional fabrics of carbonates from thermal spring systems

AbstractThe terrestrial limestones forming at the emergence of thermal springs show a variety of unusual depositional facies. The specific lithological and petrological features of these deposits have few counterparts in the marine, and continental, karst‐related carbonates, but they are typical of the epigean limestone that has been quarried since antiquity in the surroundings of Tivoli (Rome) under the name of travertine, where it is still forming in hydro‐geothermal fields linked to extensional tectonics. The physicochemical, hydrodynamic and geological conditions specific to the Tivoli thermal spring system imply hypersaturated alkaline–sulphate, warm to hot waters, upwelling from springs fed through open fractures/faults in extensional and/or volcanic regimes. These features, together with the hydrodynamic behaviour of the water flows running from the vents, control the petrogenetic features of the travertine, a well‐bedded, mostly finely laminated, porous but quite compact limestone. The results of a detailed comparative petrological analysis carried out on the lithofacies of travertine limestones, and of those observed during formation within numerous active thermal spring fields, provide the elements required for an exhaustive textural classification of the travertine lithofacies, which has not yet been described systematically. According to the genetic processes and fabrics, the thermal deposits that originate from such hypersaturated alkaline–sulphate, warm to hot waters, can be subdivided into: abiotic crystalline crusts, microbially mediated crusts (microbialites) and granular deposits mostly represented by small accumulations of lime‐mudstone. Some of the granular deposits and the microbialites are only partially comparable with analogous sediments forming on tidal flats/sabkhas or other continental sites; however, the facies association of crystalline crusts and laminar curled microbialites has no counterpart in the marine realm. The widespread presence of thermophile bacteria and sulphobacteria, and the general absence of autochthonous eukaryote organisms, unable to live in poisonous sulphate waters, are also undeniable evidence of their thermal origin.

A time series of vent fluid compositions from 21°N, East Pacific Rise (1979, 1981, 1985), and the Guaymas Basin, Gulf of California (1982, 1985)

A time series study of four hot spring fields at 21°N on the East Pacific Rise demonstrates that the solution compositions of mid‐ocean ridge hydrothermal vents are stable on a decadal time scale. The Ocean Bottom Seismometer (OBS), National Geographic Smoker (NGS), and South West (SW) vents show no significant changes in the major element composition of their end‐member fluids since 1979. Two of the vents, OBS and SW, have maintained exit temperatures near 350°C since 1979. The NGS vent has remained close to 270°C since 1981 after cooling from 350°C in 1979. Only one vent, Hanging Gardens, shows important changes in solution chemistry from 1981 to 1985. In 1985 this vent appears to have cooled ∼10°C relative to the other vents. The depth of the reaction zone, as determined by quartz geobarometry, has increased by about 1 km at this vent. The large fluxes of compositionally stable fluids from these vents cannot be explained by transient conditions and unique circumstances. Rather, the constancy of small interfield variations in solution composition is more consistent with control by rock buffering. A 4‐year time series study of hydrothermal vents in the Guaymas Basin also shows no significant changes in the major element composition of the end‐member fluids. Interfield differences in solution chemistry have been maintained from 1982 to 1985. This phenomenon is best explained in terms of an equilibrium model.

Susceptibility of Adult Microplitis croceipes (Hymenoptera: Braconidae) to Insecticides Used for Heliothis spp. (Lepidoptera: Noctuidae) Control

Microplitis croceipes (Cresson) is a larval parasite of both Heliothis zea (Boddie) and H. virescens (F.) (the bollworm complex) (Lewis & Brazzel 1968). In Arkansas, M. croceipes is the predominant parasite of Heliothis spp. particularly in late spring and early summer cotton fields (Burleigh 1975). In Integrated Cotton Pest Management systems the process of insecticide selection often does not consider the impact to beneficial insects. This is partly due to the lack of information about the susceptibility of specific predators and parasites to various insecticides. This study was undertaken to provide information on the susceptibility of M. croceipes to insecticide formulations used in cotton pest management. The same testing procedure was used throughout the study. A 5.5 cm diam filter paper disk was dipped into varying concentrations of insecticide, air dried for ca. 2 h and taped to the side of a 0.27 1 waxed paper cup. A moist cotton ball and a raisin were placed in the cup for food and water. Adult M. croceipes were aspirated into a cup which was covered with a lid. Mortality was recorded at 1, 16, 24 and 48 h. The insecticide concentration was based on recommended rates for Heliothis control in cotton using an application volume of 18.9 1 of water per 0.4 ha (Table 1). Concentrations used were 5, 3, and 2 times field rate, field rate, and dilutions of 1 part field rate to 5, 10, 50, 500, and 5000 parts water. The adult M. croceipes used in testing had not been exposed to Heliothis larvae and were less than 3 days old. No attempt was made to equalize the number of males and females exposed to any particular concentration of insecticide. When mortality occurred, the tests were repeated at insecticide concentrations above and below the concentration that caused mortality. Insecticide susceptibility testing was conducted on adult M. croceipes reared from Heliothis spp. larvae collected from cotton fields during the fall of 1983 and using adults from a laboratory colony during 1984-5. This colony was obtained from the Department of Entomology, University of Arkansas, Fayetteville. A total of 10 insecticides were tested using 391 adults. Insecticide susceptibility was evaluated by determining percent mortality at concentrations more than field rate, field rate, and less than field rate. Data were analyzed using a two way ANOVA, the combined concentration levels and the different insecticides were used as treatments. Only insecticides which caused mortality were included in the analysis. The results of the insecticide susceptibility tests are shown in Fig. 1. No mortality occurred in the controls during testing. The biological control agents, B. thutringiensis

Petroleum Source Rock Potential and Crude Oil Correlation in Great Basin: ABSTRACT

Petroleum source beds in the Great Basin region include marine Paleozoic rocks and nonmarine upper Mesozoic and lower Cenozoic rocks. Potential source beds have been identified in continental-rise deposits of the Ordovician Vinini and Devonian Woodruff formations in the eastern part of the Roberts Mountains allochthon (Antler orogene), in central and north-central Nevada; in flysch-trough and prodelta-basin deposits of the Mississippian Chainman Shale and equivalent rocks of the Antler foreland basin, in Nevada and western Utah; and in lake-basin deposits of the Cretaceous Neward Canyon Formation and the Paleogene Sheep Pass and Elko formations and equivalent rocks, in central and eastern Nevada. Oil fields in the Great Basin are located within Neogene-Quaternary basins t at formed during Neogene basin-range block faulting. Most of the oil shows and crude oils analyzed can be correlated with Mississippian or Paleogene source rocks. The Mississippian Chainman Shale is confirmed as the major petroleum source rock, having generated the oil in the Trap Spring, Bacon Flat, and Grant Canyon fields in Railroad Valley and the Blackburn field in Pine Valley. The Paleogene Sheep Pass Formation is the source of the oil in the Eagle Springs field and probably the Current field in Railroad Valley. Oil occurrences in the northern Great Basin are believed to be derived from two or more other Tertiary lacustrine sequences. End_of_Article - Last_Page 861------------

A review of the U.K. collaborative programme to test the effects of mechanical and environmental variables on environmentally assisted crack growth of PWR pressure vessel steels

Knowledge of the rate of growth of possible defects in the wall of the PWR pressure vessel is necessary for in-service validation of vessel integrity. Large inter-laboratory variations between measured cyclic crack growth rates of pressure vessel steels in a simulated PWR environment have been reported. A collaborative programme is underway in the U.K. in order to resolve the reasons for these discrepancies. Corrosion fatigue testing under this programme is carried out at laboratories at UKAEA Harwell (AERE) and Springfields (SNL), the Central Electricity Generating Board Laboratories (CERL), Babcock Power Ltd (BPL) and Rolls Royce and Associates (RR &A). The current ASME XIA flaw evaluation code is based on data showing the greatest degree of sustained environmental cracking observed to date. The measured rate of crack extension is found to become less reproducible as the cyclic frequency is reduced towards values more representative of operating plant transients. Although instances of crack extension in excess of the ASME code have been recorded, these high cracking rates are not maintained, but decrease towards rates found in an inert environment after a few millimetres of growth. Several interacting parameters are found to influence the rate of crack extension. These include water flow rate, steel sulphur content and water chemistry, including oxygen and sulphate concentration. This paper reviews recent results obtained by the above laboratories under the U.K. collaborative environmentally assisted cracking programme. Current mechanistic interpretations of environmentally assisted cracking are discussed. Knowledge of the processes producing accelerated growth rates is necessary to allow the experimental data base to be extrapolated to plant transient conditions.

Ridge crest hydrothermal activity and the balances of the major and minor elements in the ocean: The Galapagos data

Samples collected by the deep submersible “Alvin” from four hot spring fields ( T = 3–13°C) on the crest of the Galapagos spreading ridge show pronounced and varied compositional anomalies. If it is assumed that these have a general significance, that they are associated with hydrothermal reactions between seawater and basalt wherever new oceanic crust is being produced then global fluxes can be computed. These are large. For Mg and SO 4 they balance the river input. For Li and Rb they exceed it by factors of between five and ten. Calcium is supplied at a rate equivalent to that of non-carbonate Ca from the continents. The additions of K, Ba and Si are between one third and two thirds of the river load. There are large positive and negative anomalies for Cl and Na indicating that substantial amounts of Cl may be taken up by the newly formed crust and transported deep into the subduction zones. Where there are data in common, the field measurements agree with the experimental findings at low (<5) water/rock ratios.