title: Emplacement age and thermal footprint of the diamondiferous Ellendale E9 lamproite pipe, Western Australia

authors: Evans, Noreen J.

subjects: (U-Th)/He

abstract: The diamondiferous Ellendale 9 (E9) pipe is a funnel-shaped maar-diatreme volcano consisting of inward-dipping tuff sequences intruded by lamproite plugs and dykes. The host rocks for the E9 pipe are Permian sandstones. The multiple lithological contacts exposed within the mined maar volcano provide a natural laboratory in which to study the effect of volcanic processes on U-Th-Pb-He systematics. Zircon from the regional sandstone and E9 lamproite display a bimodal distribution of ages on (U-Th)/He-U/Pb plots. The zircon U/Pb ages for the E9 pipe (n = 52) range from 440 to 2,725 Ma, while the cluster of (U-Th)/He ages for the lamproite dyke zircon indicate that dyke emplacement occurred at 20.6 ± 2.8 Ma, concordant with a maximum emplacement age of about ≤22 Ma from phlogopite ⁴⁰Ar/ ³⁹Ar. These ages indicate a xenocrystic origin for the zircon entrained in the E9 dyke. The U/Pb ages of detrital zircon from the regional sandstone host (373-3,248 Ma; n = 41) are indistinguishable from those of the lamproite zircon xenocrysts, whereas the detrital zircon in the host sandstone yield (U-Th)/He ages from 260 to 1,500 Ma. A thermochronology traverse across the E9 lamproite dyke reveals that the zircon (U-Th)/He ages in the host sandstone have not been significantly thermally reset during dyke emplacement, even at the contact. The capability of the zircon (U-Th)/He method to distinguish deep, mantle source lithologies from upper crustal source lithologies could be used in geochemical exploration for diamonds. Pre-screening of detrital samples using etching and helium assay methods will improve the efficiency and decrease the cost of greenfields exploration.

text: Emplacement age and thermal footprint of the diamondiferous Ellendale E9 lamproite pipe, Western Australia The diamondiferous Ellendale 9 (E9) pipe is a funnel-shaped maar-diatreme volcano consisting of inward-dipping tuff sequences intruded by lamproite plugs and dykes. The host rocks for the E9 pipe are Permian sandstones. The multiple lithological contacts exposed within the mined maar volcano provide a natural laboratory in which to study the effect of volcanic processes on U-Th-Pb-He systematics. Zircon from the regional sandstone and E9 lamproite display a bimodal distribution of ages on (U-Th)/He-U/Pb plots. The zircon U/Pb ages for the E9 pipe (n = 52) range from 440 to 2,725 Ma, while the cluster of (U-Th)/He ages for the lamproite dyke zircon indicate that dyke emplacement occurred at 20.6 ± 2.8 Ma, concordant with a maximum emplacement age of about ≤22 Ma from phlogopite ⁴⁰Ar/ ³⁹Ar. These ages indicate a xenocrystic origin for the zircon entrained in the E9 dyke. The U/Pb ages of detrital zircon from the regional sandstone host (373-3,248 Ma; n = 41) are indistinguishable from those of the lamproite zircon xenocrysts, whereas the detrital zircon in the host sandstone yield (U-Th)/He ages from 260 to 1,500 Ma. A thermochronology traverse across the E9 lamproite dyke reveals that the zircon (U-Th)/He ages in the host sandstone have not been significantly thermally reset during dyke emplacement, even at the contact. The capability of the zircon (U-Th)/He method to distinguish deep, mantle source lithologies from upper crustal source lithologies could be used in geochemical exploration for diamonds. Pre-screening of detrital samples using etching and helium assay methods will improve the efficiency and decrease the cost of greenfields exploration.

year: 2013

title: Browsing around a Digital Library: Today and Tomorrow

authors: Witten, Ian H.

subjects: computer science

abstract: What will it be like to work in tomorrow’s digital library? We begin by browsing around an experimental digital library of the present, glancing at some collections and showing how they are organized. Then we look to the future. Although present digital libraries are quite like conventional libraries, we argue that future ones will feel qualitatively different. Readers- and writers- will work in the library using a kind of context-directed browsing. This will be supported by structures derived from automatic analysis of the contents of the library- not just the catalogue, or abstracts, but the full text of the books and journals- using new techniques of text mining.

text: Browsing around a Digital Library: Today and Tomorrow What will it be like to work in tomorrow’s digital library? We begin by browsing around an experimental digital library of the present, glancing at some collections and showing how they are organized. Then we look to the future. Although present digital libraries are quite like conventional libraries, we argue that future ones will feel qualitatively different. Readers- and writers- will work in the library using a kind of context-directed browsing. This will be supported by structures derived from automatic analysis of the contents of the library- not just the catalogue, or abstracts, but the full text of the books and journals- using new techniques of text mining.

year: 2000

title: New Zealand history is Maori history: Tikanga as the ethical foundation of historical scholarship In Aotearoa New Zealand

authors: Mahuika, Nepia

subjects: Arts & Humanities

abstract: IT SHOULD COME AS NO SURPRISE TO FIND that New Zealand history is Māori history. In 1987 when Tipene O’Regan stated that the ‘the past belongs to all New Zealanders, but first it is ours’, he was drawing attention to New Zealand history’s foundation in Māori history.1 Thinking about New Zealand history as Māori history does not mean denying the histories of European, Asian and Pasifika immigrants, but draws attention to the notion that ‘settler’ aspirations to claim ‘Aotearoa’ as home occur within a much broader narrative of indigenous occupation and struggle.2 Indeed, how can New Zealand history be the story of ‘here’ when it has ‘othered’ indigenous narratives that speak to the heart of what it is to belong in the land of the long white cloud? Yes, New Zealand history is Māori history – and that presents a problem for tangata whenua self-determination. Likewise, for Pākehā, it is an issue because until New Zealand history recognizes and enables the centrality of Māori history it will always fail to articulate the collective ‘us’ that is so often assumed in the discourse of ‘full and final settlement’.3 In its current form it will never be able to ethically or adequately account for the shaping of a New Zealand identity that finds ‘composure’ in the story of how Pākehā became ‘native’ New Zealanders.4 For Māori, these issues are keenly felt, because while New Zealand history has always been about us, it has predominantly been articulated on the colonizers’ terms. In the ‘discursive constructions’ that are New Zealand histories, the indigenous have regularly been culturally appropriated, dislocated and misrepresented.5 Even when Māori have turned their back on the writing of New Zealand history it has been, and will still be, a history of being or becoming ‘native’. Yes, New Zealand history is Māori history – so why does it feel like the story of Pākehā settlers?

text: New Zealand history is Maori history: Tikanga as the ethical foundation of historical scholarship In Aotearoa New Zealand IT SHOULD COME AS NO SURPRISE TO FIND that New Zealand history is Māori history. In 1987 when Tipene O’Regan stated that the ‘the past belongs to all New Zealanders, but first it is ours’, he was drawing attention to New Zealand history’s foundation in Māori history.1 Thinking about New Zealand history as Māori history does not mean denying the histories of European, Asian and Pasifika immigrants, but draws attention to the notion that ‘settler’ aspirations to claim ‘Aotearoa’ as home occur within a much broader narrative of indigenous occupation and struggle.2 Indeed, how can New Zealand history be the story of ‘here’ when it has ‘othered’ indigenous narratives that speak to the heart of what it is to belong in the land of the long white cloud? Yes, New Zealand history is Māori history – and that presents a problem for tangata whenua self-determination. Likewise, for Pākehā, it is an issue because until New Zealand history recognizes and enables the centrality of Māori history it will always fail to articulate the collective ‘us’ that is so often assumed in the discourse of ‘full and final settlement’.3 In its current form it will never be able to ethically or adequately account for the shaping of a New Zealand identity that finds ‘composure’ in the story of how Pākehā became ‘native’ New Zealanders.4 For Māori, these issues are keenly felt, because while New Zealand history has always been about us, it has predominantly been articulated on the colonizers’ terms. In the ‘discursive constructions’ that are New Zealand histories, the indigenous have regularly been culturally appropriated, dislocated and misrepresented.5 Even when Māori have turned their back on the writing of New Zealand history it has been, and will still be, a history of being or becoming ‘native’. Yes, New Zealand history is Māori history – so why does it feel like the story of Pākehā settlers?

year: 2015