摘要:

Petrography of the acid igneous rock of the Shag Valley in North-east Otago, previously classified as a quartz porphyry, indicates that this rock is an ignimbrite. Formerly described as a dyke, the Shag Valley rock is now considered to be a surface rock interbedded with coal measures of Upper Senonian age, and is the first occurrence of ignimbrite described from the South Tsland of New Zealand.

ISSN:0028-8306    

DOI:10.1080/00288306.1959.10417656

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Several radioactive hornfels and granite boulders have been found scattered through the Hawks Crag Breccia in the Big River and Lower Buller Gorge areas., Uraninite has been identified in the radioactive biotite hornfels from the Lower Buller Gorge. An unidentified, iron-rich, uranium-bearing mineral occurs in the radioactive biotite hornfels from the Big River area. The radioactivity in the biotite granite from the Big River area is concentrated in the zircon and apatite inclusions and to a lesser extent in the biotite.

ISSN:0028-8306    

DOI:10.1080/00288306.1959.10417657

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

In a study of some New Zealand and American ignimbrites (welded tuffs or ash-flow deposits), close similarities were found in the lithology and topographic relations of the deposits.

ISSN:0028-8306    

DOI:10.1080/00288306.1959.10417658

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor

摘要:

Petrological study of the andesite lavas exposed in Whakapapanui Gorge on the northern slopes of Mt. Ruapehu reveals constant mineralogical composition of flows. All are porphyritic andesites with phenocrysts of plagioclase, hypersthene, and augite set in a hyalopilitic groundmass. Slight variations in texture sometimes occur between and within flows of lava.

ISSN:0028-8306    

DOI:10.1080/00288306.1959.10417659

出版商:Taylor & Francis Group    

年代:1959

数据来源: Taylor