125,344 research outputs found
Swinburn Volcanic Complex, Central Otago, New Zealand
No full textSwinburn Volcanic Complex is the remnant of a Miocene volcano, forming part of the Dunedin Volcanic Group (~ 24 - 9Ma), on the South Island of New Zealand. It is part of the Waipiata Volcanic Field, and its basalts are distinct from most others in that field. New analyses of Swinburn rocks, which have only very few mantle nodules, are compared with other new data from peridotite-bearing basanites collected from different volcanic rocks of Dunedin Volcanic Group. Swinburn basaltic rocks are geochemically and isotopically different than any other rock so far described from the intraplate Waipiata Volcanic Field or the Dunedin Volcanic Complex. I have identified geochemical and isotopic affinities (e.g. high 207Pb/204Pb trend together with lower trace element concentrations) of Swinburn rocks with those formed from Cretaceous basaltic magmas elsewhere in Zealandia and the Hikurangi Plateau. Percolation processes have: a) metasomatized the lithosphere, leaving strong geochemical imprints (e.g. carbonatite, OIB and HIMU-like), b) locally modified the thermal gradient c) produced metasomatic cumulates (amphibole-bearing veins and/or pyroxenites) which have major and trace-element compositions suitable for the mantle source that fed the Dunedin Volcanic Group. Within the footprint of this Group, Swinburn Volcanic Complex is an anomaly. Under the Swinburn Complex, percolating fluids interacted with one part of the lithospheric mantle that had been already metasomatized by Cretaceous melts. The combination of Cretaceous and Miocene percolation through the same mantle domain formed the distinctive geochemistry of Miocene Swinburn magmas.
Petrographic and geochemical differences among samples from Swinburn also reveal that more than one batch of magma was involved in the formation of the complex. By combining field evidence with new geochemical data, two effusive eruptions or eruptive periods are inferred, separated an episode of magma intrusion.
Reversed polarity of the magnetic field at the time of Swinburn effusion and intrusion activity was identified by paleomagnetic analysis. A magnetometer survey suggests the presence of several buried features.
There are pegmatitic domains in the Swinburn basaltic rocks. Compaction of a crystal mush, together with the buoyant separation of residual melt rich in dissolved volatiles, is interpreted as the main mechanism driving the upward movement of Swinburn segregation domains and the formation of those segregation veins and domains.
Results of this multidisciplinary analysis of the Swinburn Volcanic Complex, based on petrographic, mineralogical, geochemical and geophysical investigations are summarised below.
1) Older pyroclastic rocks, and the majority of the exposed vesicular lavas, represent the first activity of
the complex, whereas younger pyroclastic products and a lava exposed in the western part of the complex (G7) formed during the last event.
2) The Swinburn body was emplaced during two effusive events by the intrusion of two batches of magma with similar composition. The higher amount of magnetic minerals forming the rocks of the Main body explains the inhomogeneous magnetic signal showed by my newly produced 3D magnetic map of the area. The association of magnetic profiles with cross sections unveiled several buried features such as a fault, possible thickness variations in the body, and places where Quarry and Main rocks overlap.
3) Compaction together with the buoyant rise of volatile-rich residual melt are interpreted to have been the main mechanisms driving upward movement of segregated residual liquids to form pegmatitic domains and veins. Compaction of the lower and central parts of the emplaced magma body caused dilatation and tearing in the upper crystallising front, which were filled by residual liquid to form segregation veins.
4) The concentration of major and trace elements is similar for plagioclases and clinopyroxenes crystallised near the top and bottom of the body but different for mineral crystallised near the mid-level of it. These differences reflect slower cooling of the interior of the body, furthest from basal and top cooling surfaces.
The comparison of Swinburn features with those of volcanoes elsewhere worldwide sheds light on processes that regulate the origin of melts, and formation of segregation products during cooling of emplaced magmas. Following the main aim to determine the volcanic evolution and processes of the Swinburn Volcanic Complex and how it impacts on the wider volcanological perspective, this study demonstrates that even inside a broadly monogenetic volcanic field, individual volcanic complexes may be products of multiple eruptions. They can preserve significant local heterogeneities and magma source regions distinct from those of most volcanoes in the field
Swinburn Volcanic Complex, Central Otago, New Zealand
No full textSwinburn Volcanic Complex is the remnant of a Miocene volcano, forming part of the Dunedin Volcanic Group (~ 24 - 9Ma), on the South Island of New Zealand. It is part of the Waipiata Volcanic Field, and its basalts are distinct from most others in that field. New analyses of Swinburn rocks, which have only very few mantle nodules, are compared with other new data from peridotite-bearing basanites collected from different volcanic rocks of Dunedin Volcanic Group. Swinburn basaltic rocks are geochemically and isotopically different than any other rock so far described from the intraplate Waipiata Volcanic Field or the Dunedin Volcanic Complex. I have identified geochemical and isotopic affinities (e.g. high 207Pb/204Pb trend together with lower trace element concentrations) of Swinburn rocks with those formed from Cretaceous basaltic magmas elsewhere in Zealandia and the Hikurangi Plateau. Percolation processes have: a) metasomatized the lithosphere, leaving strong geochemical imprints (e.g. carbonatite, OIB and HIMU-like), b) locally modified the thermal gradient c) produced metasomatic cumulates (amphibole-bearing veins and/or pyroxenites) which have major and trace-element compositions suitable for the mantle source that fed the Dunedin Volcanic Group. Within the footprint of this Group, Swinburn Volcanic Complex is an anomaly. Under the Swinburn Complex, percolating fluids interacted with one part of the lithospheric mantle that had been already metasomatized by Cretaceous melts. The combination of Cretaceous and Miocene percolation through the same mantle domain formed the distinctive geochemistry of Miocene Swinburn magmas.
Petrographic and geochemical differences among samples from Swinburn also reveal that more than one batch of magma was involved in the formation of the complex. By combining field evidence with new geochemical data, two effusive eruptions or eruptive periods are inferred, separated an episode of magma intrusion.
Reversed polarity of the magnetic field at the time of Swinburn effusion and intrusion activity was identified by paleomagnetic analysis. A magnetometer survey suggests the presence of several buried features.
There are pegmatitic domains in the Swinburn basaltic rocks. Compaction of a crystal mush, together with the buoyant separation of residual melt rich in dissolved volatiles, is interpreted as the main mechanism driving the upward movement of Swinburn segregation domains and the formation of those segregation veins and domains.
Results of this multidisciplinary analysis of the Swinburn Volcanic Complex, based on petrographic, mineralogical, geochemical and geophysical investigations are summarised below.
1) Older pyroclastic rocks, and the majority of the exposed vesicular lavas, represent the first activity of
the complex, whereas younger pyroclastic products and a lava exposed in the western part of the complex (G7) formed during the last event.
2) The Swinburn body was emplaced during two effusive events by the intrusion of two batches of magma with similar composition. The higher amount of magnetic minerals forming the rocks of the Main body explains the inhomogeneous magnetic signal showed by my newly produced 3D magnetic map of the area. The association of magnetic profiles with cross sections unveiled several buried features such as a fault, possible thickness variations in the body, and places where Quarry and Main rocks overlap.
3) Compaction together with the buoyant rise of volatile-rich residual melt are interpreted to have been the main mechanisms driving upward movement of segregated residual liquids to form pegmatitic domains and veins. Compaction of the lower and central parts of the emplaced magma body caused dilatation and tearing in the upper crystallising front, which were filled by residual liquid to form segregation veins.
4) The concentration of major and trace elements is similar for plagioclases and clinopyroxenes crystallised near the top and bottom of the body but different for mineral crystallised near the mid-level of it. These differences reflect slower cooling of the interior of the body, furthest from basal and top cooling surfaces.
The comparison of Swinburn features with those of volcanoes elsewhere worldwide sheds light on processes that regulate the origin of melts, and formation of segregation products during cooling of emplaced magmas. Following the main aim to determine the volcanic evolution and processes of the Swinburn Volcanic Complex and how it impacts on the wider volcanological perspective, this study demonstrates that even inside a broadly monogenetic volcanic field, individual volcanic complexes may be products of multiple eruptions. They can preserve significant local heterogeneities and magma source regions distinct from those of most volcanoes in the field
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Aterations in very low density lipoprotein subfractions in normotriglyceridemic non-insulin-dependent diabetics.
No full textPragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Dr. Edwin Wright Collection: Author Unknown
No full textNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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