共查询到20条相似文献，搜索用时 593 毫秒
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B. K. Bhadra A. K. Gupta J. R. Sharma 《Journal of the Geological Society of India》2009,73(6):875-877
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Discussion on “A rapid loess flowslide triggered by irrigation in China” by D. Zhang,G. Wang,C. Luo,J. Chen,and Y. Zhou 总被引：1，自引：0，他引：1
Luciano Picarelli 《Landslides》2010,7(2):203-205
Catastrophic debris flows hit many areas in the world. Surprisingly, the features of the materials which are involved are
often very similar as well as the causes of rupture and the mechanics of resulting movement. A continuous exchange of ideas
among people involved in studies and investigations could be highly beneficial in the setting up of reliable criteria for
risk mitigation. 相似文献
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Colin J. N. Wilson Terry M. Seward Aidan S. R. Allan Bruce L. A. Charlier Léa Bello 《Contributions to Mineralogy and Petrology》2012,164(2):359-368
Trace concentrations of Ti in quartz are used to indicate the pressure and temperature conditions of crystallization in the ‘TitaniQ’ geothermobarometer of Thomas et al. (Contrib Miner Petrol 160:743–759, 2010). It utilises the partitioning of Ti into quartz as an indicator of the pressures and/or temperatures of crystal growth. For a given value of TiO2 activity in the system, if temperatures are inferred to ±20 °C, pressure is constrained to ±1 kbar and vice versa. There are significant contrasts, however, between the conclusions from TitaniQ and those for natural quartz (as well as other mineral phases) in volcanic rocks. Application of the TitaniQ model to quartz from the 27 ka Oruanui and 760 ka Bishop high-silica rhyolites, where the values of T, P and TiO2 activity are constrained by other means (Fe–Ti oxide equilibria, melt inclusion entrapment pressures in gas-saturated melts, melt and amphibole compositions), yields inconsistent results. If realistic values are given to any two of these three parameters, then the value of the third is wholly unrealistic. The model yields growth temperatures at or below the granite solidus, pressures in the lower crust or upper mantle, or TiO2 activities inconsistent with the mineralogical and chemical compositions of the magmas. CL imagery and measurements of Ti (and other elements) in quartz are of great value in showing the growth histories and changes in conditions experienced by crystals, but direct linkages to P, T conditions during crystal growth cannot be achieved. 相似文献
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The paper ‘Guidelines on the use of inverse velocity method as a tool for setting alarm thresholds and forecasting landslides and structure collapses’ by T. Carlà, E. Intrieri, F. Di Traglia, T. Nolesini, G. Gigli and N. Casagli deals with a sensitive topic for landslide risk management. Exploring the pre-failure behaviour of four different case histories, the authors proposed standard procedures for the application of the inverse velocity method (INV, Fukuzono 1985). Specifically, they suggested guidelines for the filtering of velocity data and an original and simple approach to automatically set the first and the second alarm thresholds using the inverse velocity method. The present discussion addresses three different topics: (1) data filter selection according to the features of monitoring instrument; (2) the importance of data sampling frequency for the forecasting analysis and (3) the influence of the starting point (SP in this discussion) for the application of INV analysis. Moreover, based on this matter, a new method is proposed to update the INV analysis on an ongoing basis. 相似文献
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《Gondwana Research》2013,24(4):1656-1658
The abundant and diverse assemblage of filamentous microbial fossils permineralized in the ~ 3465 Ma Apex chert of northwestern Australia — among the oldest records of life — are arguably the “best studied,” by the most workers using the most advanced techniques, in the history of science. Despite the extensive body of data establishing the biogenicity of the demonstrably cellular carbonaceous Apex fossils, Pinti et al. (2013) and Marshall and Marshall (2013) have raised issues regarding the interpretation of their studies of the Apex chert presented in our recent review article (Schopf and Kudryavtsev, 2012). We agree with the assessment of both of the relevant papers by Pinti et al. (2009, 2013): the observations they report do not apply to the bona fide microscopic fossils of the Apex chert. Similarly, like the minute objects reported by Pinti et al. (2009, 2013), the “quartz and haematite-filled fractures” discussed by Marshall and Marshall (2013) are mineralic pseudofossils that are not relevant to interpretation of the Apex fossil microbes and their suggestion that “multiple populations of carbonaceous material may be a wide-spread issue through out the Precambrian” is without merit. 相似文献
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Thea Vogt 《Comptes Rendus Geoscience》2012,344(10):535-537
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