Schweizerische Mineralogische Und Petrographische Mitteilungen最新文献

{"title":"A new silicate dissolution procedure for isotope studies on garnet and other rock forming minerals","authors":"T. Nägler, B. Kamber","doi":"10.5169/SEALS-57688","DOIUrl":"https://doi.org/10.5169/SEALS-57688","url":null,"abstract":"A new silicate digestion technique, based on sequential acid treatment (HBr → HF-HNO3 → HNO3), is presented. The main features are: (i) only \"off the shelf\" equipment is needed, (ii) it avoids HClO4 and H2SO4, (in) precipitates which may coat residual grains and inhibit total dissolution are removed by ultrasonic agitation, (iv) cations which are likely to form fluorides in the course of dissolution are largely extracted from the silicates before HF is applied, thus minimising the danger of laboratory fractionation (of e.g. Sm/Nd or U/Pb) and incomplete spike-sample equilibration, (v) the procedure can be optimised for specific silicates (or mineral chemistries), (vi) thanks to the use of transparent beakers the state of dissolution can be traced without interrupting the process and residual fluorides are easily detected and (vii) blank contribution is easily traced. This technique is an alternative to steel jacketed Teflon® bomb digestion and an improvement over traditional closed vial approaches.","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128130917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inverse metamorphic zonation in very low-grade Tibetan zone series of SE Zanskar and its tectonic consequences (NW India, Himalaya)","authors":"L. Spring, H. Masson, E. Stutz, P. Thélin, R. Marchant, A. Steck","doi":"10.5169/SEALS-55563","DOIUrl":"https://doi.org/10.5169/SEALS-55563","url":null,"abstract":"The metamorphism of the carbonate rocks of the SE Zanskar Tibetan zone\u0000has been studied by `'illite crystallinity'' and calcite-dolomite\u0000thermometry. The epizonal Zangla unit overlies the anchizonal Chumik\u0000unit. This discontinuous inverse zonation demonstrates a late to\u0000post-metamorphic thrust of the first unit over the second.\u0000The studied area underwent a complex tectonic history: - The tectonic\u0000units were stacked from the NE to the SW, generating recumbent folds, NE\u0000dipping thrusts and the regional metamorphism. The compressive movements\u0000were active under lower temperature conditions, resulting in late\u0000thrusts that disturbed the metamorphic zonation. The discontinuous\u0000inverse metamorphic zonation dates from this phase. - A NE vergent\u0000backfolding phase occurred at lower temperature conditions. It caused\u0000the uplift of more metamorphic levels. - A late extensional phase is\u0000revealed by the presence of NE dipping low angle normal faults, and a\u0000major high angle fault, the Sarchu fault.\u0000The low angle normal faults locally run along earlier thrusts (composite\u0000tectonic contacts). Their throw has been sufficient to reset a normal\u0000stratigraphic superposition (young layers overlying old ones), but\u0000insufficient to erase the inverse metamorphic relationship. However, the\u0000combined action of backfolding and normal faulting can locally lessen,\u0000or even cancel, the inverse metamorphic superposition. After deduction\u0000of the normal fault translation, the vertical component of the original\u0000thrust displacement through stratigraphy is 400 m, which is a value far\u0000too low to explain the temperature difference between the two units. The\u0000horizontal component of displacement is therefore far more important\u0000than the vertical one. The regional distribution of metamorphism within\u0000the Zangla unit points out to an anchizonal front and an epizonal inner\u0000part. This fact is in agreement with nappe tectonics.","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127527536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remarks on depleted mantle evolution models used for Nd model age calculation","authors":"T. Nägler, P. Stille","doi":"10.5169/SEALS-55581","DOIUrl":"https://doi.org/10.5169/SEALS-55581","url":null,"abstract":"This paper reviews published models on Nd isotopic evolution of the upper mantle, and focusses in particular on the problems of models currently in use for Nd model age (T Nd ) calculation and should help to prevent misleading T Nd interpretation. Presently, T Nd calculations are generally based on depleted mantle (DM) evolutionary models (T DM ), implying that continental crust is generated from suboceanic, convecting mantle. However, the properties of the secular evolution curve of the DM, are rather controversial. Depending on the models used, differences between calculated T DM ages for a given sample may be as much as a few hundred millions years","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129011681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sur la composition et les propriétés optiques de quelques plagioclases","authors":"L. Duparc, M. Gysin","doi":"10.5169/SEALS-8213","DOIUrl":"https://doi.org/10.5169/SEALS-8213","url":null,"abstract":"","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129452890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Les gites platinifères de l'Oural en relation avec ceux du Transvaal","authors":"L. Duparc","doi":"10.5169/SEALS-7343","DOIUrl":"https://doi.org/10.5169/SEALS-7343","url":null,"abstract":"","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129676120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The age of the Mont-Blanc granite (Western Alps): a heterogeneous isotopic systeme dated by Rb-Sr whole rock determinations on its microgranular enclaves","authors":"F. Bussy, U. Schaltegger, Christian Marro","doi":"10.5169/SEALS-52773","DOIUrl":"https://doi.org/10.5169/SEALS-52773","url":null,"abstract":"New Rb-Sr whole rock age data have been obtained for the Mont-Blanc calc-alkaline Hercynian granite. Different facies of the granite have been sampled, as well as locally abundant microgranular enclaves of magmatic origin. The analytical data for the granite and for some of the enclaves are scattered within the Sr evolution diagram, which points to isotopic disequilibrium. Other enclaves form a homogeneous system which gives an age of 316.1 ± 19.5 Ma and an initial 87Sr/86Sr ratio of 0.7058 ± 0.0005. The following evolution is plausible: - individualization of microgranular enclaves due to the dismembering of mafic synplutonic dikes within the granitic magma; - complete isotopic equilibrium between granite and enclaves during a late-magmatic stage; - remobilization ofthe granite and certain enclaves in a post-magmatic stage and during Alpine orogenesis. Certain enclaves are not affected and retain the original characteristics of the system. The 316 Ma age of these \"relics\" and their initial ratio of 0.7058 are therefore thought to be valid for the granite as well. These results are similar to those obtained for other calc-alkaline Hercynian plutons in Western Europe. They indicate an origin for the granitic magma in the deep crust with involvement of mantle-derived material in unknown proportions, represented by the microgranular enclaves.","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114626461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rosickyite (monoclinic gamma-sulphur) from La Presta Asphalt Mine, Neuchatel, Switzerland: new X-ray powder diffraction data","authors":"N. Meisser, K. Schenk, J. Spangenberg","doi":"10.5169/SEALS-60969","DOIUrl":"https://doi.org/10.5169/SEALS-60969","url":null,"abstract":"Rosickyite, the natural monoclinic gamma -form of sulphur, exists in\u0000only a few localities around the globe. In the old asphalt mine at La\u0000Presta, Neuchatel. Switzerland, rosickyite occurs locally as small, but\u0000very well formed crystals suitable for crystallographic studies. It\u0000grows as an alteration product of pyrite-rich asphalt. Rosickyite from\u0000La Presta mine is pure molecular sulphur, as revealed by gas\u0000chromatography-mass spectrometry. The X-ray powder diffraction data of\u0000La Presta rosickyite does not match the one previously published for\u0000this species. Therefore, a single crystal study was undertaken and a new\u0000indexed X-ray powder diffraction diagram for natural rosickyite is\u0000proposed.","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133022828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Les Schistes lustrés à ophiolites de la nappe du Tsaté: un ancien prisme d'accrétion issu de la marge active apulienne?","authors":"M. Marthaler, G. Stampfli","doi":"10.5169/SEALS-52789","DOIUrl":"https://doi.org/10.5169/SEALS-52789","url":null,"abstract":"","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123426510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrographie des kristallinen Grundgebirges der Nordschweiz und Systematik der herzynischen Granite","authors":"Martin Mazurek, Tjerk Peters","doi":"10.5169/SEALS-54893","DOIUrl":"https://doi.org/10.5169/SEALS-54893","url":null,"abstract":"The North Swiss crystalline basement is hidden beneath a sedimentary cover of variable thickness. It has been penetrated by several exploration drillholes aimed at coal, oil, gas, salt or thermal water. In recent years, 6 deep drillholes supplying long basement profiles were conducted by NAGRA. Similar to the outcrops in the Southern Black Forest, the North Swiss crystalline basement consists of Pre-Hercynian high-grade gneisses which were intruded by Hercynian plutons. The gneiss series is dominated by paragneisses (6 boreholes; mainly metapelites and meta-graywackes), and minor orthogneisses (1) and banded, amphibolite-rich series (2) were encountered. The Hercynian plutons comprise mainly granites (15) whereas K-rich basic intrusives were recovered from one single site","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124684779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ferrogabbroic and basaltic meta-eclogites from the Antrona mafic-ultramafic complex and the Centovalli-Locarno region (Italy and southern Switzerland)-first results","authors":"A. Colombi, H. Pfeifer","doi":"10.5169/SEALS-50883","DOIUrl":"https://doi.org/10.5169/SEALS-50883","url":null,"abstract":"","PeriodicalId":407711,"journal":{"name":"Schweizerische Mineralogische Und Petrographische Mitteilungen","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134105585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}