Cro‐Magnon: How the Ice Age Gave Birth to the First Modern Humans. Brian Fagan (Ed.). 2011. Bloomsbury Press,New York. 320 pp., ISBN 978‐1‐608‐19405‐6, $18 (paper).     

Fiona Coward 《Geoarchaeology》2012,27(6):540-542

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The Aspen–Amsterdam void finder comparison project     

Jörg M. Colberg  Frazer Pearce  Caroline Foster  Erwin Platen  Riccardo Brunino  Mark Neyrinck  Spyros Basilakos  Anthony Fairall  Hume Feldman  Stefan Gottlöber  Oliver Hahn  Fiona Hoyle  Volker Müller  Lorne Nelson  Manolis Plionis  Cristiano Porciani  Sergei Shandarin  Michael S. Vogeley  Rien van de Weygaert 《Monthly notices of the Royal Astronomical Society》2008,387(2):933-944

Despite a history that dates back at least a quarter of a century, studies of voids in the large-scale structure of the Universe are bedevilled by a major problem: there exist a large number of quite different void-finding algorithms, a fact that has so far got in the way of groups comparing their results without worrying about whether such a comparison in fact makes sense. Because of the recent increased interest in voids, both in very large galaxy surveys and in detailed simulations of cosmic structure formation, this situation is very unfortunate. We here present the first systematic comparison study of 13 different void finders constructed using particles, haloes, and semi-analytical model galaxies extracted from a subvolume of the Millennium simulation. This study includes many groups that have studied voids over the past decade. We show their results and discuss their differences and agreements. As it turns out, the basic results of the various methods agree very well with each other in that they all locate a major void near the centre of our volume. Voids have very underdense centres, reaching below 10 per cent of the mean cosmic density. In addition, those void finders that allow for void galaxies show that those galaxies follow similar trends. For example, the overdensity of void galaxies brighter than   m _B =−20  is found to be smaller than about −0.8 by all our void finding algorithms.  相似文献   

Climate change policy and practice in regional New Zealand: How are actors negotiating science and policy?     

Alison Greenaway  Fiona Carswell 《New Zealand geographer》2009,65(2):107-117

Regional governance to address climate change is being constituted in New Zealand through domestic policy measures and international discourses. We examine climate change responses in two regions: Marlborough and Waikato. Informants expressed a desire for more transparent government policy; that planning for climate change makes good business sense for farmers and other businesses; that technology is sought to increase productivity and decrease environmental impact; and research networks build capacity for local action, linking sectors and organisations. Often conflicting, these responses to climate change were informed by a mix of discourses shaping New Zealand, including participatory democracy, the knowledge economy and sustainable development.  相似文献   

Constraints on the average magnetic field strength of relic radio sources 0917+75 and 1401−33 from XMM–Newton observations     

C. M. Hubert Chen  D. E. Harris  Fiona A. Harrison  Peter H. Mao † 《Monthly notices of the Royal Astronomical Society》2008,383(3):1259-1268

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A large population of metal-rich, compact, intergalactic C iv absorbers – evidence for poor small-scale metal mixing     

Joop Schaye  Robert F. Carswell  Tae-Sun Kim 《Monthly notices of the Royal Astronomical Society》2007,379(3):1169-1194

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Crustal structure above the Iceland mantle plume imaged by the ICEMELT refraction profile   总被引：2，自引：0，他引：2  

Fiona A. Darbyshire  Ingi Th. Bjarnason  Robert S. White  & Ólafur G. Flóvenz 《Geophysical Journal International》1998,135(3):1131-1149

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Nannofossils: the smoking gun for the Canarian hotspot          下载免费PDF全文

Valentin R. Troll  Frances M. Deegan  Steffi Burchardt  Kirsten Zaczek  Juan‐Carlos Carracedo  Fiona C. Meade  Vicente Soler  Mario Cachao  Jorge Ferreira  Abigail K. Barker 《Geology Today》2015,31(4):137-145

The origin of volcanism in the Canary Islands has been a matter of controversy for several decades. Discussions have hinged on whether the Canaries owe their origin to seafloor fractures associated with the Atlas Mountain range or to an underlying plume or hotspot of superheated mantle material. However, the debate has recently come to a conclusion following the discovery of nannofossils preserved in the products of the 2011–2012 submarine eruption at El Hierro, which tell us about the age and growth history of the western‐most island of the archipelago. Light coloured, pumice‐like ‘floating rocks’ were found on the sea surface during the first days of the eruption and have been shown to contain fragments of pre‐island sedimentary strata. These sedimentary rock fragments were picked up by ascending magma and transported to the surface during the eruption, and remarkably retained specimens of pre‐island Upper Cretaceous to Pliocene calcareous nannofossils (e.g. coccolithophores). These marine microorganisms are well known biostratigraphical markers and now provide crucial evidence that the westernmost and youngest island in the Canaries is underlain by the youngest sediment relative to the other islands in the archipelago. This finding supports an age progression for the onset of volcanism at the individual islands of the archipeligo. Importantly, as fracture‐related volcanism is known to produce non‐systematic age‐distributions within volcanic alignments, the now‐confirmed age progression corroberates to the relative motion of the African plate over an underlying mantle plume or hotspot as the cause for the present‐day Canary volcanism.  相似文献   

Chronology,stratigraphy and palaeoenvironmental interpretation of a Late Pleistocene to mid‐Holocene cave accumulation on Kangaroo Island,South Australia     

Matthew C. McDowell  Erick A. Bestland  Fiona Bertuch  Linda K. Ayliffe  John C. Hellstrom  Geraldine E. Jacobsen  Gavin J. Prideaux 《Boreas: An International Journal of Quaternary Research》2013,42(4):974-994

Chronological, sedimentological and geochemical analyses of a clastic infill from Kelly Hill Cave (5K1), Kangaroo Island, document a palaeoenvironmental record that spans from the Late Pleistocene to the middle Holocene. We AMS radiocarbon‐dated bone collagen and U–Th‐dated speleothem to determine that fossiliferous sediments were deposited between >20 ka and 7 ka ago. Most of the 15 sedimentary layers are dominated by sand‐ and silt‐sized quartz that is physically and geochemically comparable with surface soils in the Kelly Hill area. Late Pleistocene and Last Glacial Maximum strata are represented primarily by homogeneous, poorly sorted quartz‐rich sediments that contain little organic matter, but include a thin layer composed largely of silt‐sized clay pellets that resemble sediments deflated from playa lakes. Microstructures observed in petrographic slides indicate that, with the exception of one layer, all sediments experienced little reworking once deposited in the cave. Some layers display pedogenic microstructures such as redeposited clays and opaline silica infilling that indicate postdepositional modification; that is, cave‐floor soil development. Overlying Holocene‐aged sediments also consist mainly of quartz but have much greater organic matter content. Some of these sediments have been strongly influenced by re‐precipitated organic matter that appears to have been transported into the cave via vadose drip water. The presence of dissolved organic matter in soil/vadose waters suggests a high vegetation density and acidic soils, which are congruent with the more equitable climatic conditions characteristic of the Holocene. The sediments described here provide a valuable palaeoenvironmental record that will facilitate future interpretation of associated vertebrate fossils.  相似文献   

New quantitative approaches for classifying and predicting local-scale habitats in estuaries     

Fiona J. Valesini  Mathew Hourston  Michelle D. Wildsmith  Natasha J. Coen  Ian C. Potter 《Estuarine, Coastal and Shelf Science》2010

This study has developed quantitative approaches for firstly classifying local-scale nearshore habitats in an estuary and then predicting the habitat of any nearshore site in that system. Both approaches employ measurements for a suite of enduring environmental criteria that are biologically relevant and can be easily derived from readily available maps. While the approaches were developed for south-western Australian estuaries, with a focus here on the Swan and Peel-Harvey, they can easily be tailored to any system.  相似文献   

Geochemistry of meteoric diagenesis in carbonate islands of the northern Bahamas: 1. Evidence from field studies     

Fiona F. Whitaker  Peter L. Smart 《水文研究》2007,21(7):949-966

Processes driving carbonate diagenesis in islands of the northern Bahamas are investigated using major ion, dissolved oxygen and dissolved organic carbon analyses of water samples from surface and ground waters, and measurements of soil gas P. Meteoric waters equilibrate with aragonite, but reactions are water controlled rather than mineral‐controlled and drive dissolution rather than concurrent precipitation of calcite. Surface runoff waters equilibrate with atmospheric P and rapidly recharge the vadose zone, limiting subaerial bedrock dissolution to only 6·6–15 mg l^?1 Ca. P of soil gas measured in the summer wet season ((7·4 ± 3·7) × 10^?3 atm) is elevated compared with that of the atmosphere, despite the thin skeletal organic nature of the soil and the discontinuous soil cover. Soil waters retained in surface pockets are equilibrated with respect to aragonite and have dissolved 51 ± 19 mg l^?1 Ca. This is substantially less than the 93 ± 18 mg l^?1 Ca in samples from pumping boreholes that sample meteoric waters from the freshwater lens. The high P of the freshwater lens ((16 ± 8·3) × 10^?3 atm for pumping boreholes) suggests that significant additional CO₂ may be derived by oxidation of soil‐ and surface‐derived organic carbon within the lens. The suboxic nature of the majority of the freshwater lens and the observed depletion in sulphate support this suggestion, and indicate that both aerobic and anaerobic oxidation may take place. Shallow lens samples from observation boreholes are calcite supersaturated and have a lower P than deeper lens waters, indicating that CO₂ degasses from the water table, driving precipitation of calcite cements. We suggest that the geochemical evolution of waters in the vadose zone and upper part of the freshwater lens may be determined by the presence of a body of ground air with P controlled by production in the freshwater lens and soil and by degassing to the atmosphere. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献