ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422463

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Several macrofossil collections have been made from mid-Tertiary beds in the Kaka District. In general, the preservation of the fossils is poor, and in only a few cases is it possible to determine them at the specific level with any confidence. Fossils from the Huia Formation are usually either badly decorticated or lack shell material entirely; those from the Burmeister and Sherry River Formations on the other hand, retain most of their shell but are badly crushed. The faunas are discussed below under formations. Corals were identified by Dr D. F. Squires, Smithsonian Institute, Washington, U.S.A., and Mr I. W. Keyes, New Zealand Geological Survey. The other macrofossils, with the exception of a small collection from near the Kaka lime quarry, were identified by the author.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422464

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

incorporates Gaussian smoothing of the observed anomalies with a frequency response of exp(-ν2/ω2) where ν is the frequency of the observed anomaly, and ω a frequency parameter which must be chosen with regard to the spacing of the observation points. The linear summation formula is modified to correct for irregularities in the distribution of observation points. The method has been developed for the interpolation of local variations in the deflcxtion components between astrogeodetic points.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422465

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Diversity, equitability, and classification of benthic foraminiferal assemblages in Tarakohe Mudstone (Golden Bay district, western Nelson, New Zealand) are investigated for paleoenvironmental data. A north-west trending basinal biotope, bordered to east and west by a marginal biotope, is recognized in the lower beds of the formation (Hutchinsonian-Altonian Stages). Upper beds (Clifdenian-Lillburnian Stages) appear to have been deposited in a shallow, near-shore environment. The formation represents a phase of marine retreat, probably northward.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422466

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Three years' observations of Tonga-Fiji-Kermadec earthquakes at stations in New Zealand have been analysed by the statistical techniques applied to Herrin's “1968 Seismological Tables forPPhases”, to yield smoothed regional travel times forPandS. The travel-time curve forPis later than Herrin's until it merges with it at about 30°, implying lower velocities than those of Herrin's model at shallow levels in the upper mantle, and higher velocities at deeper levels. The travel-time curve forScrosses the Jeffreys-Bullen curve at 21° and 27° and has a greater curvature in this range. A correlation between the isostatic gravity anomaly and the mean travel-time residual at the stations is tentatively explained in terms of higher velocities in the deep seismic zone.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422467

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The magnetic properties and petrological types of the larger samples from sixEltaninrock dredge hauls, taken from the Macquarie Ridge in 1965 to 1967, have been determined. Attempts have been made to relate the ice-rafted materials to their source areas. Five samples are considered to bein situ. These have been chemically analysed. Rocks close to harzburgite in composition are identified, up to 400 km north of the known Macquarie Island harzburgite occurrences. These dredged ultrabasic rocks contain common titanomagnetite and titanohematite fringes on silicates, and finely disseminated sulphides. The resulting high intensity of magnetisation and high ratio of remanent to induced magnetism would be sufficient to account for the large positive linear magnetic anomaly which Hatherton (1967) has defined over the northern 500 km of the Macquarie Ridge.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422468

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The lower Miocene Waitemata Group on Puketotara Peninsula has been formally divided into three formations: (a) the proposed Timber Bay Formation (?Waitakian-Otaian) composed mainly of thinly interbedded sandstones and mudstones, an intraformational conglomerate, and a channel-fill deposit; (b) the Pakaurangi Formation (Otaian-?Hutchinsonian) containing sandstones and pebble bands of the Hollands Member, richly fossiliferous silty sandstones locally intruded by basalts, all belonging to the Pakaurangi Member, and sulphurous, sandy siltstones of the Funnel Member; and (c) the proposed Motuouhi Formation (?Hutchinsonian) consisting of dark brown vitric tufts. Also included in the Waitemata Group is the informal Waipahihi formation which overlies the Motuouhi Formation.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422469

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Measurements of magnetic remanence and susceptibility were made on 176 samples of volcanic rocks from 22 late Cenozoic formations from the North Island. Intensities of remanence, susceptibilities, and Q ratios are highly variable in both the ignimbrites and andesites and their ranges overlap, indicating that the magnetic anomalies produced by ignimbrite bodies would be difficult to distinguish from those produced by andesite flows. An analysis of the directions of magnetization of the ignimbrites indicates that groups of petrologically distinct ignimbrites probably formed during the same volcanic episode.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422470

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Reflectance is a good indicator of rank in many New Zealand coals, particularlY those of moderate volatile content. For equivalent reflectance values New Zealand coals have a lower volatile matter content and a higher calorific value than some North American coals.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422471

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Cross sections through the South Fork Mountain Schist of north-western California and the Colebrooke Formation schist of south-western Oregon are described and the regional relationships of the rocks outlined. The schists are of the so-called blueschist facies, and have undergone intense synmetamorphic and less intense post-metamorphic folding and cataclasis. High pressure-low temperature conditions of metamorphism apparently preceded and then overlapped dynamic metamorphism. Three textural subzones result from progressive increase in deformation; mineral zonation related to increase in P-T conditions is less distinct. Axial planes of folds dip easterly and most of the structures probably “face” westerly towards the Pacific Ocean. Relations between mineral and textural isogradic surfaces are obscure, but they are almost certainly non-parallel. Textural zones in the South Fork Mountain Schist are apparently inverted and mineral isograds steepened by thrust-faulting, but neither is directly related to the faults as now exposed. K/Ar dates reveal a dose relationship between metamorphic grade and age of schists in an apparently progressive sequence. The inferred macroscopic structures, the textural and mineral isograd relationships, and the age-grade relation are attributed to regional metamorphism deep in the crust, accompanied by localised deformation on deep shear zones.

ISSN:0028-8306    

DOI:10.1080/00288306.1971.10422472

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor