ISSN:0016-786X    

DOI:10.1080/11035895709449108

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0016-786X    

DOI:10.1080/11035895709449109

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The Upper Ordovician Saunja (Fia), Vormsi (Fib), Pirgu (Fic), and Porkuni (F2; in this paper included in the Ordovician) stages and the Lower Silurian Juuru (G1) stage are briefly characterized lithologically and faunistically according to the writer's field observations in the Tapa district. A stratigraphic column of the Lower Silurian in central Estonia up to the Adavere (H) stage is republished, somewhat modified, after Elsa Rosenstein (1943). A correlation of the lowermost Silurian between Estonia and Norway is suggested, whereby the supposedly considerable hiatus between the Porkuni and Juuru stages is much diminished.

ISSN:0016-786X    

DOI:10.1080/11035895709449110

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The granite, a coarse massive type, contains the following minerals: quarz, microcline, oligoclase, biotite, sphene, apatite, zircon, and magnetite with some secondary sericite, chlorite, and calcite. The minerals were isolated according to the method shown diagrammatically in Fig. 1. The relation between chemical composition and optical properties of the microcline and the biotite is elucidated. In the system of P. Niggli the granite represents a normal-granitic to yosemite-granitic magma type.

ISSN:0016-786X    

DOI:10.1080/11035895709449111

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

In the present paper an account is given of the extent a determination of only the unit cell dimension and the refractive index may be used to predicte the composition of a garnet. For this purpose 17 analysed garnets were investigated, the unit cell dimensions and the refractive indices are shown in Table 1. By using fig. 1 and 2, in which the unit cell size and the refractive index of 60 analysed garnets have been combined, it is possible to obtain a characterization accurate enough to be used in petrogenetical problems. To distinguish accurately between an almandite and a spessartite partial chemical analysis for manganese is necessary. From fig. 2 it seems clear, however, that a garnet with n > 1.80 and < 1.82 is not especially rich in spessartite.

ISSN:0016-786X    

DOI:10.1080/11035895709449112

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

A preliminary investigation has been made of the bentonite beds in Billingen, Vestergötland, Sweden. The clay consists of a complex mixed layer mineral; the layers are mostly illitic and are mixed with probably chloritic and partly dehydrated montmorillonite layers. This clay mineral differs from the types found in the corresponding beds at Kinnekulle, 30 km, NW of Billingen, but is similar to the clay mineral found in the K-bentonites of Pennsylvania. Chlorite is present in varying amounts.

ISSN:0016-786X    

DOI:10.1080/11035895709449113

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0016-786X    

DOI:10.1080/11035895709449114

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

ISSN:0016-786X    

DOI:10.1080/11035895709449115

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

The mineralogical composition of Finnish Pleistocene sediments is discussed and the rôle of geological factors is denoted.

ISSN:0016-786X    

DOI:10.1080/11035895709449116

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor

摘要:

For measurement and statistical investigation of such properties as the parameters, surface and shape of the projection of fine particles and pores respectively in the section of a solid, automatic instrument is required which can be further developed. On proposal of the author design work for such an instrument limited to measurements of the length and width of sediment particles has been carried out for several years at the Royal Institute of Technology, Division of Electrical measurements. The system of an electronic investigator including a television tube for analysing and a computing machine is recommended. Provided that it will be possible to apply the instrument to a great many fields the development and completion thereof should interest not only researchers but various industries as well.

ISSN:0016-786X    

DOI:10.1080/11035895709449117

出版商:Taylor & Francis Group    

年代:1957

数据来源: Taylor