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931.
Gabriel C. Rau Martin S. Andersen Andrew M. McCallum Richard Ian Acworth 《Hydrogeology Journal》2010,18(5):1093-1110
Two methods applying natural heat as a tracer to quantify surface water–groundwater exchange were evaluated using field data. Arrays capable of monitoring and recording the streambed response to diurnal temperature variations in the surface water were deployed for a 2-month period in three locations in perennial pools at Maules Creek, New South Wales, Australia. Multi-level array design, field deployment and parameter estimation are discussed. The applicability of analytical solutions derived from the heat transport equation to the streambed environments was analysed using the recorded temperature time series. The stream was found to lose water to the aquifer, which was supported by simultaneously recorded hydraulic gradients. However, the one-dimensional (1D) analytical solutions did not adequately describe the observed streambed thermal response at two locations. The resulting artefacts in the estimated flow velocities are discussed. It was hypothesised that the artefacts originate from model limitation due to streambed heterogeneity and application of 1D solutions to multi-dimensional and dynamic streambed flow. This consequently imposes limitations on the field applicability of the methods. Nevertheless, in combination with time series of surface water and streambed water levels, the use of heat as a tracer provided a powerful tool for better understanding the shallow hydrogeological system. 相似文献
932.
Ian Smalley Slobodan Markovic Ken O’Hara-Dhand 《Central European Journal of Geosciences》2010,2(1):15-18
Charles Lyell, on his way to becoming a famous geologist, married Mary Horner in Bonn in July 1832; volume 3 of his ‘Principles of Geology’ was published by John Murray in London in May 1833. Between these two dates Lyell encountered the loess of the Rhine valley. The loess impressed Lyell and he included mentions of it in the Principles, first in 1833 and then, with some revised ideas, in volume 4 of the 4th edition published in 1835. Twelve editions of the Principles were published between 1830 and 1875 and it became one of the most important works in the development of geology, and made a major contribution to the worldwide spread of loess awareness. It is possible that Lyell was drawn to the loess because of its high molluscan content, he was particularly attracted to the study of shells. 相似文献
933.
Ian J. Smalley Slobodan B. Markovic Ken O’Hara-Dhand 《Central European Journal of Geosciences》2010,2(1):3-8
The International Union of Quaternary Research (INQUA) organized the study and consideration of the Quaternary Period (the last 2.6 million years in Earth’s history) via a set of commissions, sub-commissions, working groups, projects and programmes. One of the most successful and best records was the Loess Commission (LC) which functioned assub-commission and then commission from 1961 to 2003, resulting in 40 years of useful activity. The history of the LC can be divided into three phases: 1, from 1961–1977 when the President was Julius Fink; 2, from 1977–1991, with President Marton Pecsi; 3, from 1991–2003 with Presidents An Zhi-Sheng and Ian Smalley. Fink, from Vienna, and Pecsi, from Budapest, gave the LC a distinctly Central European aspect. The nature of loess in Central Europe influenced the nature of the LC but the settings for phases 1 and 2 were quite distinct. Phase 1 was a small scale academic operation, carried out in German. As phase 2 began in 1977 the scope expanded and Central Europe became a base for worldwide loess studies. where the LC language changed to English. Phase 2 was run from a National Geographical Institute and demonstrated a different approach to loess research, although the basic programmes of continent-wide mapping and stratigraphy remained the same. The Commission benefited from this change of style and emphasis. In phase 3 the administration moved away from Central Europe but the Finkian ethos remained solid. 相似文献
934.
935.
Ken O’Hara-Dhand Richard L. S. Taylor Ian James Smalley David H. Krinsley Claudio Vita-Finzi 《Central European Journal of Geosciences》2010,2(1):45-51
Impact between windblown quartz grains as a source of desert dust is consistent with laboratory abrasion experiments and has received some field confirmation in the Negev. The suggestion is that an important process on Mars now gains support from laboratory studies; even though their geochemical interpretation is controversial, they show that dust generation by impact is tenable even for quartz. A simple mechanism for small dust production from sand seas is proposed; internal stresses can be mobilized by impact energy. A speculative mechanism (the andesite scenario) is proposed for fine particle production by particle impact on Mars. The internal stress range in terrestrial sand grains may vary, depending on the nature of the source rock, and this may influence particle production by impact processes. 相似文献
936.
937.
Ian C. LYON 《Meteoritics & planetary science》2005,40(7):981-987
Abstract— This paper describes the use of matrix‐assisted laser desorption and ionization (MALDI) to measure the mass distribution of nanodiamonds extracted from meteorites. The techniques used to prepare and mass analyze nanodiamond samples from the Murchison (CM2) and Allende (CV3) meteorites are described. The mass spectra of nanodiamonds (peaking at between 1 times 104‐1.5 times 104 Daltons) are compared with size distributions obtained by point‐counting transmission electron microscopy (TEM) images obtained elsewhere and reasonable agreement is found. The implications of the ability to produce and mass analyze a beam of nanodiamonds are explored. 相似文献
938.
Matt Hilton Chris Collins Roberto De Propris Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Warrick J. Couch Gavin B. Dalton Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole A. Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve J. Maddox Darren Madgwick Peder Norberg John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,363(2):661-674
939.
940.