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1.
David J. A. Williams Beda A. Hofmann Ian G. Glasspool 《Swiss Journal of Geoscience》2008,101(3):651-658
Vitrinite reflectance (Rr), proximate analysis and carbon isotope composition (δ13C) have been used to characterise coal samples from two zones of Late Carboniferous sediments (Gastern and Ferden) in the Aar massif where they are penetrated by the Lötschberg base tunnel (constructed between 1999 and 2005). Samples are characterised by variable ash yields (21.7–93.9%; dry basis); those with ash yields of less than ~50% and with volatile matter content (V;dry ash-free basis) within the limits 2 < V% ≤ 8 are anthracite. Values of Rr range from 3.89% to 5.17% and indicate coalification to the rank of anthracite and meta-anthracite in both Gastern and Ferden Carboniferous zones. Samples of anthracite and shale from the Gastern Carboniferous exhibit a relatively small range in δ13C values (–24.52‰ to –23.38‰; mean: –23.86‰) and are lighter than anthracite samples from the Ferden Carboniferous (mean: –22.20‰). The degree of coalification in the Gastern and Ferden Carboniferous zones primarily depends on the maximum rock temperature (T) attained as a result of burial heating. Vitrinite reflectance based estimates of T range from ~290° –360 °C. For a proposed palaeogeothemal gradient of 25 ° C/km at the time of maximum coalification the required overburden is attributable to relatively thin autochtonous Mesozoic/Cenozoic sedimentary cover of the Aar massif and Gastern granite and deep tectonic burial beneath advancing Helvetic, Ultrahelvetic and Prealpine (Penninic) nappes in Early Oligocene to Miocene. 相似文献
2.
Albrecht Steck 《Swiss Journal of Geoscience》2008,101(2):515-546
This study presents a review of published geological data, combined with original observations on the tectonics of the Simplon
massif and the Lepontine gneiss dome in the Western Alps. New observations concern the geometry of the Oligocene Vanzone back
fold, formed under amphibolite facies conditions, and of its root between Domodossola and Locarno, which is cut at an acute
angle by the Miocene, epi- to anchizonal, dextral Centovalli strike-slip fault. The structures of the Simplon massif result
from collision over 50 Ma between two plate boundaries with a different geometry: the underthrusted European plate and the
Adriatic indenter. Detailed mapping and analysis of a complex structural interference pattern, combined with observations
on the metamorphic grade of the superimposed structures and radiometric data, allow a kinematic model to be developed for
this zone of oblique continental collision. The following main Alpine tectonic phases and structures may be distinguished:
It is suggested that movements of shortening in fan shaped NW, W and SW directions accompanied the more regular NW- to WNW-directed
displacement of the Adriatic indenter during continental collision.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Editorial Handling: Stefan Bucher 相似文献
1. | NW-directed nappe emplacement, starting in the Early Eocene (~50 Ma); |
2. | W, SW and S-verging transverse folds; |
3. | transpressional movements on the dextral Simplon ductile shear zone since ~32 Ma; |
4. | formation of the Bergell – Vanzone backfolds and of the southern steep belt during the Oligocene, emplacement of the mantle derived 31–29 Ma Bergell and Biella granodiorites and porphyritic andesites as well as intrusions of 29–25 Ma crustal aplites and pegmatites; |
5. | formation of the dextral discrete Rhone-Simplon line and the Centovalli line during the Miocene, accompanied by the pull-apart development of the Lepontine gneiss dome – Dent Blanche (Valpelline) depression. |
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Editorial Handling: Stefan Bucher 相似文献
3.
Marco Herwegh Jean-Pierre Hürzeler O. Adrian Pfiffner Stefan M. Schmid Rainer Abart Andreas Ebert 《Swiss Journal of Geoscience》2008,101(2):323-340
This excursion guide results form a field trip to the Glarus nappe complex organized by the Swiss Tectonic Studies Group in 2006. The aim of the excursion was to discuss old and recent concepts related to the evolution of the Glarus thrust. The major aspects were (i) the interplay between deformation, fluid flow and geochemical alteration, (ii) episodic versus continuous deformation and fluid flow, and (iii) the link between large-scale structures, microstructures, and geochemical aspects. Despite 150 years of research in the Glarus nappe complex and the new results discussed during the excursion, there exist controversies that still are unsolved. 相似文献
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针对数据备份服务器备份性能优化问题,分别对实时数据存储与历史数据备份之间的关系、数据备份服务器所备份的数据类型非唯一性、客户数量对备份服务器备份效率的影响三方面进行初步的测试与分析,提出了通过优化数据块的选取、优化数据采集方式、优化备份策略提高备份服务器备份效率的基本方法。 相似文献
9.
山西运城市森林火险等级预报系统 总被引:1,自引:0,他引:1
利用有关气象及森林火灾资料,分析了林林火灾的发生与气象条件、火条件及森林含水率的关系,计算了森林火险综合预报指标,建立了以预报方程,经试用效果良好。 相似文献
10.
数列预测一直是评价决策中最常见而又信于把握的问题之一。本文在总结现有预测方法的基础上,结合前铛预报思想和灰色预测理论,依据数据求同原则,提出了运用二次灰关联分析,建立组合模型的预测方法,该方法易于计算机实现,并已实际应用于油气储量预测研究中。 相似文献