229 research outputs found
Hydrothermal mobilisation of Au and other metals in supra-subduction oceanic crust: Insights from the Troodos ophiolite
No full textThe Troodos ophiolite is an ideal location to investigate the relationships between the mobilisation of metals by hydrothermal fluids from the lower oceanic crust and the formation of volcanogenic massive sulphide (VMS) deposits. The ophiolite hosts the classic “Cyprus-type” Cu-rich VMS deposits as well as abundant zones of epidosite alteration in the lower sheeted dyke section that are significantly depleted in base metals including Cu and Zn, and are considered to be the source of the metals enriched in the overlying deposits. Previous research indicates that the Troodos VMS deposits are irregularly enriched in Au and related elements As, Sb, and Se, but the behaviour of these elements during the hydrothermal alteration of the Troodos ophiolite hitherto has been poorly investigated. Low detection limit whole rock analyses of fresh glass samples reveal that the Troodos primitive crust has a similar metal content and distribution to modern-day arc-related environments such as the Manus Basin. Compared to mid-oceanic ridge basalt (MORB), the Troodos primitive crust is enriched in As, Sb and Pb most likely due to addition from a subducting slab during crustal formation. During early stages of magmatic differentiation (9–3.5 wt% MgO) Au, As, Sb, Se, Cu, Zn and Pb behave as incompatible elements due to the sulphide-undersaturated nature of the melt. The onset of magnetite crystallisation, however, at ∼3.5 wt% MgO leads to sulphide segregation and depletion of strongly chalcophile elements (Au, Cu and Se) during continued differentiation (<3.5 wt% MgO) whereas poorly chalcophile elements (As, Sb, Zn and Pb) remain incompatible. These differences in metal behaviour can account for the Cu-rich, Zn-Pb-poor of the Cyprus-type VMS deposits as the source area rocks show high Cu fertility compared to Zn and Pb. Mobilisation of metals during hydrothermal alteration of the Troodos ophiolite is more extensive than observed in hydrothermally altered MORB. Mass balance calculations show that the epidosite zones are significantly depleted in Au (−88 ± 16%), As (−89 ± 23%), Sb (−60 ± 12%), Se (−91 ± 20%), Cu (−84 ± 18%), Zn (−63 ± 9%) and Pb (−60 ± 8%). Background altered diabase from outside epidosite zones shows similar metal depletions which suggests that the source areas of VMS are not restricted to epidosite zones but are extended to the lower sheeted dyke section. The masses of metals mobilised from a source area of 10.9 km3, (composed of a 5 km3 epidosite zone and 5.9 km3 of background altered diabase) in the Solea graben are 47 t Au, 21 kt As, 1200 t Sb, 3100 t Se, 2.4 Mt Cu, 1.8 Mt Zn and 27 kt Pb. Comparison of metal quantities mobilised from lower sheeted dike section in the Solea graben with those hosted in VMS deposits shows trapping efficiencies ranging from 4 to 37% indicating that most of the metals is lost by other processes
Sulphide mineral evolution and metal mobility during alteration of the oceanic crust: Insights from ODP Hole 1256D
Get PDFFluxes of metals during the hydrothermal alteration of the oceanic crust have far reaching effects including buffering of the compositions of the ocean and lithosphere, supporting microbial life and the formation of sulphide ore deposits. The mechanisms responsible for metal mobilisation during the evolution of the oceanic crust are complex and are neither fully constrained nor quantified. Investigations into the mineral reactions that release metals, such as sulphide leaching, would generate better understanding of the controls on metal mobility in the oceanic crust. We investigate the sulphide and oxide mineral paragenesis and the extent to which these minerals control the metal budget in samples from Ocean Drilling Program (ODP) Hole 1256D. The ODP Hole 1256D drill core provides a unique sample suite representative of a complete section of a fast-spreading oceanic crust from the volcanic section down to the plutonic complex. The sulphide population at Hole 1256D is divided into five groups based on mineralogical assemblage, lithological location and texture: the magmatic, metasomatised, high temperature hydrothermal, low temperature and patchy sulphides. The initiation of hydrothermal alteration by downward flow of moderate temperature (250–350 °C) hydrothermal fluids under oxidising conditions leads to metasomatism of the magmatic sulphides in the sheeted dyke and plutonic complexes. Subsequent increase in the degree of hydrothermal alteration at temperatures >350 °C under reducing conditions then leads to the leaching of the metasomatised sulphides by rising hydrothermal fluids. Mass balance calculations show that the mobility of Cu, Se and Au occurs through sulphide leaching during high temperature hydrothermal alteration and that the mobility of Zn, As, Sb and Pb is controlled by silicate rather than sulphide alteration. Sulphide leaching is not complete at Hole 1256D and more advanced alteration would mobilise greater masses of metals. Alteration of oxide minerals does not release significant quantities of metal into the hydrothermal fluid at Hole 1256D. Mixing of rising high temperature fluids with low temperature fluids, either in the upper sheeted dyke section or in the transitional zone, triggers local high temperature hydrothermal sulphide precipitation and trapping of Co, Ni, Cu, Zn, As, Ag, Sb, Se, Te, Au, Hg and Pb. In the volcanic section, low temperature fluid circulation (<150 °C) leads to low temperature sulphide precipitation in the form of pyrite fronts that have high As concentrations due to uptake from the circulating fluids. Deep late low temperature circulation in the sheeted dyke and the plutonic complexes results in local precipitation of patchy sulphides and local metal remobilisation. Control of sulphides over Au, Se and Cu throughout fast-spreading mid-oceanic crust history implies that the generation of hydrothermal fluids enriched in these metals, which can eventually form VMS deposits, is strongly controlled by sulphide leaching
Letter to Warren Patten dated July 23, 1884
No full textUteAfter a confrontation between Indians and soldiers near the Colorado River, the author of this letter asks Agent Patten to which tribe the Indians belon
Kim Moodie : Recent Work
No full textCatalogue to accompany an exhibition of Moodie’s recent paintings, prints and drawings (1996-1999). Curator J. Patten exposes “the ambivalent nature and rhizomatous structure” of the artist’s production, discussing the themes of knowledge and written language, colonialism, conquest domination, carnival, human folly, the grotesque, the spritual/material and low /high culture. The author also examines Moodie’s vision, his personal universe and working methods, while describing the skin-like surfaces accentuated through the repetition of imagery and inclusion of objects such as rose petals. List of works. Biographical notes. 4 bibl. ref
George Towar Correspondence
Get PDFEntries include typed introductory correspondence to Patten from state librarian Hall and a typed letter from Hilda Jacob of the Maine State Library on finding Patten\u27s address a few years later, a typed letter of reply from Patten on plain paper from Frank Merriwell\u27s Rancho in California with a pledge to present a gift of his book to the Maine State Library on publication, several newspaper clipping obituaries including a photographic image of Patten in a wicker chair reading, a typed letter to Patten\u27s son concerning the feasibility of a gift of a collection of his father\u27s books to the Maine Author Collection, Harvan Barr Patten\u27s typed reply on H.B. Patten, Signal Oil Products, Vista, California, stationery concerning the prospect of a biography, a typed reply of receipt from the Maine State Library with appreciation to H.B. Patten for fulfilling his father\u27s claim with a book gift of his additional copy of Mr. Frank Merriwell, and copies of the typed transcripts of correspondence with the Maine State Library from Patten\u27s daughter-in-law after Harvan Barr Patten passed away, concerning the possibility of sending some of Gilbert Patten\u27s books to the Maine Author Collection
The jolly book of funcraft / by Patten Beard ... with sixty-two illustrations arranged by the author and photographed under her drection by G. S. North.
No full textxiv, 257 p.
Insight into Emerging Opportunities for Sustainable-Led Strategies in Textiles
Get PDFSustainability is an important, but ever-changing area of development. The potential benefits to society and the planet are limitless. However, many profit seeking companies struggle with sustainability and how to incorporate sustainable-led strategies without compromising the bottom- line. It is particularly true in textiles, where it can be a significant challenge to deliver impactful products, while utilizing sustainable-led strategies. This paper provides insight into the opportunities for sustainable-led strategies in textiles. After a brief review of sustainable-led strategies, the paper explores the impact of technology on sustainability and how this interaction has led to market opportunities in a variety of industries, including textiles. The discussion indicates that sustainable-led strategies can be an effective approach in textiles. As sustainability becomes more important to the planet and consumer demand for sustainable products grow, companies in textiles can utilize technology to implement effective sustainable-led strategies to maximize the growing demand for sustainable products and drive the bottom-line
H. P. Davis Correspondence
Get PDFEntries include a handwritten letter from Davis suggesting that the Maine Author Collection could include works by the Davis family and the author Patten and typed letters of correspondence from the Maine State Library
Field and woodland plants
No full text"With eight plates in colour, and numerous illustrations by Patten Wilson, and photographs from nature by the author."Mode of access: Internet
Cora Estelle Waldron Correspondence
Get PDFEntries include brief biographical information, a handwritten letter of presentation from Waldron on blue-edged notepaper stationery sent with a copy of the anthology Maine and Vermont Poets (missing?) featuring two of her poems, a typed letter from the Maine State Library introducing Waldron to the Maine Author Collection and returning her book gift for inscription, a handwritten biographical letter on plain paper from Waldron in which she describes her relationship to the lawyer Gilbert Patten Brown, a possible anthologist and longtime acquaintance, and the arrangement of poems in her head before composition on paper, a handwritten letter on silver-edged notepaper stationery sent with a photographic portrait and two poems The Old, Old House by the Sea written about Spruce Head Village, Maine, and appearing as a newspaper clipping from the Rockland Courier Gazette and the handwritten A Sound Pine Tree, a typed letter on receipt of Waldron\u27s inscribed book gift with some correspondence concerning a correction to the poem Spruce Head Island, and a handwritten copy of this poem
- …
