摘要:

All the igneous rocks and breccia bodies described belong to the Manukau Breccia of the Waitemata Group (Otaian), and they form small bosses, dikes, and sills intruded along north-north-west and east-north-east trends; no surface flows were found. The rocks have been divided into the following eight types: olivine nephelinite, olivine basalt, pyroxene basalt, bronzite andesite, augite andesite, augite-hypersthene andesite, hornblende andesite, and dacite. The mineralogy and petrography of each rock type is described, illustrating a mineralogical gradation from olivine basalt to dacite through part of a differentiation series; an unusual feature of the series is the high calcium content of the plagioclase and pyroxene mineral groups.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428182

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Granitic boulders have been found at four localities in the central North Island: Mt Tarawera, Huka, Atiamuri, and Hinuera. They occur closely associated with the acid volcanic suite, in pumice breccias and associated water-laid deposits. Two distinct types of boulders are recognised, the true granodiorites of Tarawera and Huka, and those characteristically containing extensive graphic intergrowths, found at Atiamuri and Hinuera. Both types are characterised by a “high temperature” mineralogy, and are regarded as co-magmatic with the acid volcanic rocks of the region, and not part of the basement. The granodiorites are characterised by subhedral to euhedral zoned plagioclase, subhedral to euhedral embayed quartz, subhedral to interstitial sanidine, and the presence of biotite, hornblende, hypersthene, and magnetite. The granodiorites are considered to be representative of the magma from which they crystallised, but the second type show evidence of progressive potassium enrichment and are considered to be late-stage differentiates of their parent magma. Modal and chemical data are given.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428183

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Globigerinidae with multiple apertures found in Miocene samples from Oamaru and Clifden, Southland, are described in terms of the degree to with thenth chamber envelops earlier chambers, the height of the primary and one of the supplementary apertures, the number of chambers and apertures per specimen, and direction of chamber coiling. Measured characters show patterns of continuous variation within the class studied. This emphasises the arbitrary character of the “central types” used by Blow to describe the morphological changes in the lineage leading toOrbulinaand suggests that simple statistical measures may better express these trends.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428184

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Fifteen species of Brachiopoda are described from limestones of the Stephens Formation (lower Tatarian) and from the Wairaki Breccia (upper Tatarian) of New Zealand. The Stephens fauna represents the youngest known cold-water fauna of the Permian Gondwana realm. The fauna from the Wairaki Breccia, though definitely of Permian age, has a Mesozoic aspect in that it lacks members of the Productoidea and other suborders and families that elsewhere survived until the close of the Paleozoic era. Newly named taxa arePlekonella iniquitasn. sp.,Wairakiella rostratan. gen., n. sp. (family Wellerellidae),Martiniopsis patellan. sp.,Ambikella furcan. sp.,A. antesulcatan. sp., andAmygdalocosta raran. gen., n. sp. (family Dielasmatidae).

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428185

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Neritic deposits of Eocene and Oligocene age, partly underlain by coal measures, occur over large areas of south-west Auckland, west Nelson and north Westland, and north-east Otago (Waitaki). The well described deposits of south-west Auckland and Waitaki consist of sedimentary units bounded by unconformities and each containing distinctive fossils. Each sedimentary unit reflects an increase, each unconformity a decrease, in depth of sea, and the successions represent cycles of deposition and non-deposition or erosion. The succession of cycles in Waitaki matches that in south-west Auckland. The early Tertiary of Nelson and Westland has not been fully described but seems to contain comparable sedimentary cycles.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428186

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Glaciological theory indicates that, as a first approximation, surface slope of a valley glacier is inversely proportional to depth for a given cross-sectional shape. Data are available on surface slope, depth, cross-sectional shape, and elevation of the floor for the lower parts of the Late Pleistocene (Otiran) glaciers of the Tasman and Godley Valleys, permitting an assessment of the “constant” of proportionality.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428187

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The Early Pleistocene is represented on the West Coast of the South Island by theOld Man Group, which between the Grey Valley in the north and Ross in the south is composed of three formations. TheDonnelly Conglomerate(up to 400 ft) (oldest) composed mainly of tectonic gravels, with finer beds and lignite at the base and thin valley or piedmont glaciation deposits at the top. TheJones Formation(up to ?400 ft) consists of till and glacial siltstone with minor sandstone and lignite. There may have been two ice advances, but there is no evidence of an interglacial period. TheHumphreys Conglomerate(up to 5,000 ft) (youngest) consists of tectonic gravels. Contemporaneous movements occurring when the Kaikoura Orogeny approached its climax, folded all these deposits. Late weathering has decomposed many of the components of the conglomerates.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428188

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The rhyolites of the Taupo-Rotorua region contain phenocrysts of plagioclase and magnetite, normally accompanied by hypersthene and quartz, and less commonly by hornblende and biotite. Three ferromagnesian assemblages are distinguished, namely, hypersthene rhyolites, hypersthene-hornblende rhyolites, and biotite-bearing rhyolites, which normally also contain hypersthene and hornblende. The occurrence of these three assemblages is statistically correlated with both total phenocryst contents and modal plagioclase/modal quartz ratios of the rhyolites in which they occur. The correlations are based on modal analyses of 246 rhyolites.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428189

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Low amounts of selenium occur in granites, rhyolites, rhyolitic pumices, limestones, and schists. High amounts occur in andesites (particularly ashes), Upper Cretaceous argillites, and basalts. The selenium content of soil-forming rocks averages 0-42 p.p.m. Se; this value is strongly influenced by the large areas covered by sedimentary rocks having a clay component and it is higher than an average based upon igneous rocks. Weathering processes at the soil surface result in a retention of selenium and prevent a recycling of the element via the marine environment.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428190

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The Pongaroa Fault is a strongly curved, but overall north-east-trending structure. Considerable Miocene movement on the fault is indicated to the south of Pongaroa township, where it juxtaposes dissimilar pre-Taranaki successions. At its southern end the fault dies out on the surface in beds of Taranaki age; however, construction of a paleogeological map shows that it continues southwards, concealed beneath Lillburnian-Waiauan and Taranaki rocks, to join the Tinui Fault. Comparison of the paleogeology on the north-west side of the Pongaroa Fault, 3 miles south of Pongaroa township, with the paleogeology in the south-east of the mapped area, reveals that the successions were originally contiguous and that they were displaced during the Miocene by about 8 miles of dextral transcurrent movement on the Pongaroa Fault. After deposition of the Lillburnian-Waiauan and Taranaki, minor transcurrent movement on a north-east-trending cross fault offset the Pongaroa Fault.

ISSN:0028-8306    

DOI:10.1080/00288306.1967.10428191

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor