1,094 research outputs found
A Geochemical Study of Hydrothermal Signals in Marine Sediments: The Rainbow Hydro thermal Area, 36 degrees on the Mid-Atlantic Ridge
No full textThe geochemistry of a suite of cores accumulating at increasing distance down-stream of a major hydrothermal vent site has been characterized for the first time, in order to examine the changing chemistry of particles being deposited from the plume with distance from the vent, to try to establish the different processes operating in the plume, particularly with regard to scavenging of elements from seawater, and to quantify the fluxes from seawater to the sediments as a result of venting, for a wide range of major and trace elements (Mg, Fe, V, Mn, Co, Cu, Zn, REE, PGE, Os isotopes).Sediment cores were collected at 2-25km downplume of the Rainbow hydrothermal vent site at 36o14'N on the Mid-Atlantic Ridge, a known site of vigorous high-temperature venting. Samples from long-term sediment traps located 0.5-2 km from this vent were also studied. All samples showed similar bulk chemistry, with an overprint of hydrothermally derived material. Sedimentation rates of 40-60 mg.m2d-1 for the cores were established using bulk radiocarbon dating of the carbonate material, and were found to be of the same order as the sediment traps 11-25 mg.m2.d-1. The maximum age of the core samples ranged from 8-26 x 103 radiocarbon years.For many elements, particularly the PGEs, the element to iron ratios in plume derived material were found to be up to an order of magnitude higher than those found globally in metalliferous sediments of hydrogenous origin. Burial fluxes to the Rainbow sediments have been calculated for hydrothermally derived elements - Mn (16-37 μmol.cm-2.kyr-1), Fe (368-718μmol.cm-2.kyr-1), Co(0.3-0.5μmol.cm-2.kyr-1), Cu(3.5-12μmol.cm-2.kyr-1), Zn(0.2-0.6μmol.cm-2.kyr-1), - and elements scavenged from seawater by hydrothermal Fe-oxyhydroxides - P (36-64μmol.cm-2.kyr-1), V (3-5μmol.cm-2.kyr-1), As (0.6-1.4μmol.cm-2.kyr-1), Pd(20-53pmol.cm-2.kyr-1), Os (0.1-2.3pmol.cm-2.kyr-1), Ir(0.2-0.6pmol.cm-2.kyr-1), Pt(6.5 - 18.5pmol.cm-2.kyr-1). Magnesium from seawater appears to co-precipitate with Fe in the vent plume at this site, and Mg burial fluxes are calculated to be 73-146μmol.cm-2.kyr-1 . Burial fluxes of the hydrothermally derived elements represent only a fraction of the estimated vent output, implying that vent products are dispersed over long distances. Element/Fe ratios for scavenged elements are high compared to other metalliferous sediments, indicating enhanced scavenging efficiency at this site.</p
The inorganic carbon chemistry in coastal and shelf waters around Ireland
No full textThe wintertime spatial distribution of carbonate parameters in outer estuarine and coastal waters around Ireland is described from total alkalinity (TA) and dissolved inorganic carbon (DIC) data collected between 2010 and 2013. Due to predominantly limestone bedrock of their river catchments, the River Shannon and Barrow, Nore and Suir River system export high concentrations (>3800 ?mol kg?1) of TA to their estuarine and inshore coastal waters where estuarine alkalinity decreases with increasing salinity. TA is lower in rivers with a non-calcareous bedrock, with positively correlated alkalinity-salinity relationships in both the Lee and Foyle outer estuaries. Winter pCO2 in the Shannon, Barrow/Nore/Suir and Lee estuaries is supersaturated relative to atmospheric CO2, while pCO2 in the outer Liffey estuary is slightly lower than atmospheric CO2 in three consecutive winters, indicative of a CO2 sink. Winter pCO2 is close to atmospheric equilibrium along the western shelf and through the centre of the Irish Sea, while it is a CO2 sink across the North Channel. While aragonite was supersaturated in most Irish waters, it was close to undersaturation in both the Lee estuary, attributed to its low alkalinity freshwater source, and Barrow/Nore/Suir estuary related to the flux of high concentrations of DIC from this river system. The seasonal impacts on inorganic carbon chemistry was also investigated by comparing winter and summer data collected between 2009 and 2013 along two transects in western coastal waters and along the western shelf edge. DIC was ~60 ?mol kg?1 lower in summer relative to winter in the coastal transects and 39 ?mol kg?1 lower along the shelf edge, accompanied by depleted nutrients and supersaturation of dissolved oxygen during summer, indicative of primary production. TA was generally higher in summer relative to winter corresponding with a decrease in nitrate, indicating that primary production dominated the TA distribution over calcification. An exception to this was at two stations along the shelf edge where TA was lower in summer relative to winter (51 ?mol kg?1) and coincides with high reflectance in satellite images from a coccolithophore bloom at the time of sampling. While pCO2 was close to atmospheric equilibrium along the shelf edge during winter, this area was a CO2 sink during summer, apart from the stations where calcification was likely occurring resulting in elevated CO2 relative to atmospheric concentrations
The reinvestigation of Hoffman's/Robberg cave - the artefactual and shellfish assemblages, 2007
No full textIncludes abstract.Includes bibliographical references (leaves 150-159).This thesis documents the re-investigation of Hoffman's/Robberg Cave, a little known site located on the Robberg Peninsula near Plettenberg Bay on the southern Cape coast of South Africa. Previous excavations carried out at the site early in the twentieth century and again in the late 1950s are scantily documented. Furthermore, a large collection derived from Hoffman' s excavations, which I examined and catalogued in 2006, is only a selective sample of the archaeological remains from the site
Larch Hills School class, 1935/36
No full textFront row, l-r: Robin Hart, Geof Holmes, Earl McKay, Ralph Cave, John Baker, Gordon Askew, Phill Cave, Tony Eppler, Ronny McKay. 2nd row, l-r: Charlie Mould, Bob Haney, Reg Cranfield, George Cave, Jasper Armitage. 3rd row, l-r: Anne Baker, Marion Askew, Irene Cave, Laurie Hart, Doreen Eppler, Anne Craven. Back row, l-r: Doreen Rattery, Ursula Kelighy, Yvonne Kelighy, Teacher - Miss Gillpin, Nancy Cave, Phyllis Holmes, Rachel Hart, Carol Hooper
Larch Hills School class, 1936/37
No full textFront row, l-r: Phyllis Holmes, Donna Moore, Irene Cave, Jean MacKay, Betty Twentyman, Ronny McKay, Ursula Kelighy, David Hart, Robin Hart, Geof Holmes, Anne Craven, Anne Baker. Middle row, l-r: Reg Cranfield, Doreen Eppler, John Baker, Earl McKay, Nancy Cave, Phill Cave, Tony Eppler, Bob Haney, George Cave. Back row, l-r: Carol Hooper, Ralph Cave, Rachel Hart, Charlie Mould, Yvonne Kelighy, Sidney Jordon, Doreen Rattery. Teacher - Mary Hughes
The cave: A search for the mother’s story in narrative literature
No full textThe mother’s voice is underrepresented in literature. The mother has been a silent figure, always present, often near, featuring in the story of another, but rarely the focus of the story. She has been spoken for, about and around, but rarely empowered to speak for herself.
In this thesis I argue that the mother’s story, in narrative fiction and memoir, should be available, and culturally valued. Since the diversity of women’s experiences of mothering cannot be explained by any single theory or ideology, narrative may articulate the complexities and ambiguities experienced in motherhood in ways that scholarly discourses do not always allow.
This thesis includes a creative component—a collection of related fictional stories narrated by one mother, and entitled “The Cave”. Adopting the concept of the cave, as a metaphor for the transformative potential of mothering, the fiction draws on the mundane, everyday experiences of a life that is centred on caring for children. The exegesis that follows is based on three approaches to mothering narratives: their research, reading and writing. It explores the emergence of the mother’s story within theoretical discourses around motherhood, and its more recent appearances in fiction and non-fiction narratives. It suggests reasons for the absence of the mother’s subjective voice, argues that women have been disadvantaged by this silence, and seeks new possibilities for representing the complexity of mothering experiences
Minnesota Loggers and Invasive Forest Plants: Attitudes, Behaviors and Concerns
No full textThis research was supported by the Minnesota SFI State Implementation Committee, the Minnesota Logger Education Program, Minnesota Forest Industries, the USDA Forest Service Northern Research Station, the University of Minnesota’s Department of Forest Resources, and the Minnesota Agricultural Experiment Station under Projects MN 42-057and MN 42-072. The findings and conclusions in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.Snyder, Stephanie A.; Blinn, Charles R.; Peterson, Rachel R.. (2019). Minnesota Loggers and Invasive Forest Plants: Attitudes, Behaviors and Concerns. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/216431
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
Geomorphological context and formation history of Cloggs Cave: what was the cave like when people inhabited it?
No full textNew research undertaken at Cloggs Cave, in the foothills of the Australian Alps, employed an integrated geological-geomorphological-archaeological approach with manifold dating methods and fine resolution LiDAR 3D mapping. Long-standing questions about the site’s chronostratigraphy (e.g. the exact relationship between basal megafaunal deposits and archaeological layers), sedimentation processes and geomorphic changes were resolved. The cave’s formation history was reconstructed to understand its changing morphology and morphogenic processes, and to clarify how these processes shaped the cave’s deposits. Key findings include the identification of: 1) the geomorphological processes that caused the lateral juxtaposition of 52,000 year-old megafaunal and later occupational layers; 2) the existence of one and possibly two (now-buried) palaeo-entrance(s) that enabled now-extinct megafauna and extant large fauna to enter the cave, most likely via a free-roaming passage rather than a pit drop; 3) morphological changes to the cave during the time of the Old People, including the timing of changes to the inclination of palaeo-surfaces; and 4) modifications to stalactites, crushing of calcite formations for the manufacture of powder, construction of a stone arrangement, and movement of large limestone blocks by the Old People. Ultimately, these findings demonstrate that to properly understand what Cloggs Cave was like when the Old People visited the site requires the construction of a narrative that spans some 400 million years and the development of an approach capable of integrating the many scales and processes (e.g. geological, geomorphological, archaeological) that configured to shape the site.Jean-Jacques Delannoy, Bruno David Joanna Fresløv, Russell Mullett, Gunai Kurnai Land and Waters Aboriginal Corporation, Helen Green, Johan Berthet, Fiona Petchey, Lee J. Arnold, Rachel Wood, Matthew McDowell, Joe Crouch, Jerome Mialanes, Jeremy Ash, Vanessa N.L. Won
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