摘要:

The density values published by Saxov & Abrahamsen (1964) on the granites of Bornholm have indicated the fact that by using density classes some of these “granites” should be designated as “granodiorites”. The determination of their mineral content and density done by the author has proved that the Ronne Grano-diorite, the Paradisbakke Migmatite, the Vang Granite, and the Svaneke Granite must be classified as granodiorites (or biotite-amphibole-granodiorites, resp.), and the Hammer Granite, the Almindingen Granite, and the Hasle Granite as normal granites (or biotite-normal-granites, respectively). The Granitic Gneiss (Gudhjem Granite) lies between granites and granodiorites.

ISSN:0016-786X    

DOI:10.1080/11035896709449230

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

In the Glas Eilean vent occur agglomerates, acid veins, and an acid dyke. Petrographic studies lead to the conclusion that the matrix of the agglomerates, acid material from the veins, and the acid rock from the dyke all represent intruded tuffaceous material, which is called “tuffisite”. The acid-veining is of non-dilational type, where fragments of different rocks, shapes and sizes are cemented together by intruded tuffaceous material. The occurrence of acid-veins in the Glas Eilean vent containing agglomerate demonstrates that net-veining is essentially a volcanic phenomenon originating at shallow depth. The peculiar shape of the acid-dyke and the inclusions of the large number of vent-breccia fragments suggest that the dyke was formed as an intrusive tuff by hot gases charged with magma. The intimate association in the tuff of two contrasting glasses, viz. acid and basic, provides evidence of liquid immiscibility. The Glas Eilean vent was initiated by a violent explosion which was followed by gas-streaming as envisaged by Reynolds. This brought about the emplacement of the tuffisite. The rounded nature of some fragments suggests the role of sandblast in a fluidized system.

ISSN:0016-786X    

DOI:10.1080/11035896709449231

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Superglacial till in a real lowland (Uppland) and in a lowland with distal low plateaus (Närke) is lithologically analysed (grain counting and determination of Ca). As in a previous study of basal till (Gillberg 1964), distribution maps (Figs. 3—6, 9, 10) and distribution diagrams (Figs. 2, 7, 8, II) have been constructed, being the basis for a discussion of the ice movements and the till homogeneity.

ISSN:0016-786X    

DOI:10.1080/11035896709449232

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Västra Gräddmanhällan, an island in the archipelago of Kalix, the Bothnian Gulf, Northern Sweden, has good outcrops of dolomite and dolomitic limestone in which occur calcareous algae. Other sedimentary deposits here are calcareous quartzitic rocks and a gray slate. The rocks are cut by late dikes of altered ultrabasic rocks of kimberlite type. Local boulders of a brown conglomerate, a brown, altered kimberlite and of a green kimberlite breccia are met with in the Pleistocene beach deposits of the same island.

ISSN:0016-786X    

DOI:10.1080/11035896709449233

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

A tunnel profile through the rocks in the upper part of Svartöberget in the vicinity of the harbour of Luleå, Northern Sweden, is described. The predominant rock is an amphibolite richly penetrated by dikes of red granite and accompanying pegmatite. These dikes also cut sparsely occurring dikes of an older, greyish granite variety. The roof and the walls of the tunnel are now dressed by cement plaster and are no longer accessible to examination.

ISSN:0016-786X    

DOI:10.1080/11035896709449234

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The material here dealt with includes: — I. Seven vertebral centra ofScanisauruscf.nazarowi(Bogolubov 1911), from the L. Campanian of the island of Ivö. The centra seem to belong to the same skeleton as a previously described series of centra (“series II”; cf. Persson 1959, p. 452; Pl. 9). — II. A vertebral centrum referred toScanisaurussp., from the clay of Åsen in the parish of Näsum (? U. Cretaceous). The locality is famous for its richness in fossil drift-wood, but with the exception of plesiosaurian remains (Persson 1962, p. 149) no animal fossils have been found there. — III. Some plesiosaurian bone fragments from a 51 m deep borehole in Ivetofta near Bromölla (L. Campanian).

ISSN:0016-786X    

DOI:10.1080/11035896709449235

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The Precambrian meta-sedimentary rocks of the Västervik area, along Sweden's southeast coast, exhibit many well-preserved primary sedimentary structures. Cross-bedding, measuring from one cm to three m in amplitude, is the most common depositional feature preserved, other than the bedding sequences as such. Tabular and trough cross-beds occur in many variations.

ISSN:0016-786X    

DOI:10.1080/11035896709449236

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Metaquartzites and gneisses from the Västervik area contain abundant well-preserved cross-bedding which, together with other structures such as mud cracks and load casts (Gavelin & Russell 1967), clearly indicate that the rocks were originally deposited in a deltaic-tidal flat environment. A total of 985 cross-beds from the more clearly deltaic part of the area, around Gamlebyviken, were systematically measured to determine the direction of sediment transport, the results being plotted on a base map.

ISSN:0016-786X    

DOI:10.1080/11035896709449237

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0016-786X    

DOI:10.1080/11035896709449238

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

R. W. G. Wyckoff: Crystal Structures, 2nd edition, Vol. 3. Interscience Publishers (John Wiley & Sons), New York · London · Sydney 1966. 981 sidor. Pris 210 s. Reviewed by Olof Gabrielson

ISSN:0016-786X    

DOI:10.1080/11035896709449239

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor