摘要:

In eastern Wairarapa indurated sedimentary “basement” forms an almost continuous belt some 140 km long and 3–15 km wide, generally overlain unconformably by late Cenozoic strata or faulted against Late Cretaceous-Early Tertiary rocks. These “basement” rocks, previously considered to be Late Jurassic-Early Cretaceous (Torlesse Supergroup) or Early Cretaceous (Taitai-Clarence Series) are mostly Motuan (Albian; Clarence Series), but locally probably as old as Urutawan (Albian). No base to the sequence is known.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424150

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Two examples of low-angle thrusts which lead to repetition of succession have been located, one in the Cenozoic rocks of the Esk Valley outlier in Canterbury Alps and the other in Cass Anticline of coastal Canterbury. Both the thrusts predate local folding attributed to the Kaikoura Orogeny, and in the Cass Anticline example, the displacement may be a Pleistocene syntaphral slide towards the contemporaneous Motunau submarine canyon.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424151

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Four parallel belts of rocks west of North Mavora Lake, northern Southland, New Zealand, are mapped and described.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424152

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Potassium-argon total rock, sanidine, and plagioclase ages are presented for 24 rhyolite, dacite, andesite, and basalt rocks of the Upper Cretaceous, Mt Somers Volcanics of mid Canterbury. Ages are grouped as follows: (1) total-rock ages of andesites and dacites: 45–94 Ma, but with a significant concentration at 82–91 Ma; (2) plagioclase ages of andesites and dacites: 87–93 Ma; (3) sanidine ages of pitchstone flows and rhyolitic intrusives: 88–99 Ma. The wide range of andesite total-rock ages, which do not correlate with co-existing plagioclase ages, indicate that substantial argon loss (up to 50%) may, in a few cases, have occurred from a second potassic phase, most probably volcanic glass. The majority of total-rock/plagioclase pairs show concordant ages, which in turn are similar to sanidine ages of closely associated rhyolitic rocks. Detailed stratigraphic evidence and potassium variations in the feldspars show that argon loss (about 5%) has occurred in most plagioclases (K < 0·8%) and some sanidines (K < 7%), causing younger ages than anticipated. In addition, despite favourable potassium concentrations (7% < K < 0·9%) of their feldspars, andesites known to predate rhyolites none the less yield younger ages. To some extent this pattern is explained by slight differences in the andesite-rhyolite sequences at the three main eruptive centres at Mt Somers, Malvern Hills, and Rangitata Gorge. Both andesite and rhyolite volcanism at Mt Somers (94–98 Ma) may predate rhyolites in the Malvern Hills area, 91–94 Ma. Mt Somers Volcanics extend from about 98 Ma (upper Albian) to at least 92 Ma (Turonian). Owing to the slight argon loss problem, the younger age limit for volcanism cannot be assessed.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424153

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Five beaches (Oakura, Werekino, Harriet, Oaonui, and Okaweu) in western Taranaki were monitored for 15 months and were found to display seasonal variation in beach volume and morphology. This variation may be related to cyclicity in the wave climate and is more pronounced on beaches facing directly into the prevalent swell direction.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424154

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The distribution of micro-earthquakes observed in a 17 day survey of the Rangitikei-Manawatu region in February 1977, was similar to the long-term earthquake distribution.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424155

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Regional components of the central North Island Bouguer and isostatic gravity anomaly fields are presented as third-degree, two-way polynomials. The Bouguer regional contours strike northeast, except in the Bay of Plenty region, where contours parallel the coast. The isostatic regional contours strike uniformly north-east and go through a maximum which coincides with the axis of epicentres of intermediate depth earthquakes.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424156

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The presence of an ice core or ice cement has arrested soil formation on hummocky drift behind Trilogy, Loop, and C end moraines in eastern Wright Valley. Soils on the Trilogy and Loop hummocks contain fewer salts and are coarser in texture than soils on the associated end moraines. Lack of soil development on hummocks is due to frost heaving and sorting, and while soils on hummocks behind the Loop end moraine may be as old asc. 135 000 y. b.p., they have properties more closely resembling the 18 000-year-old Trilogy soils. Data suggest that soil chronosequences may be invalid where component soils have been disturbed by frost action, and that soils on comparable sites must be used for comparative weathering studies.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424157

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A magnesian halotrichite [(Fe0.63Mg0.37).Al2(SO4)4.22H2O] from a fumarole deposit on the active andesitic volcano of White Island, New Zealand, occurs as the major component in the mixture halotrichite—H2S04-H20—alunogen, with accessory gypsum, alunite, anhydrite, quartz, cristo-balite, and tridymite. Optical, physical, and chemical data are given for the halotrichite. K :Na ratios in the alunite (85K:15Na) and in the solution (28K:72Na) show equilibrium between the salt and solutions.

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424158

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Two new genera—SparsipollisandHarrisipollenites—are erected to accommodate spinulose, annulate, porate pollen, and finely reticulate, monoporate, pollen tetrads, respectively. Three new species are described—Sparsipollis papillatus, Harrisipollenites annulatus, andParsonsidites multi-porus. Pseudowinterapollis couperiKrutzsch 1970 is described for the first time.Aglaoreidia qualumisPartridge andLiliacidites sphericusCouper are transferred to the genusSparganiaceae-pollenitesThiergart ex Potonié 1960, restrictingAglaoreidiato species with flattened distal or proximal sides and distinctive graduated reticulation.Triporopollenites bellusPartridge, an Australian Miocene-Pliocene species, is recorded from New Zealand, andParsonsidites psilatusCouper is redescribed.P. psilatusandP. multiporushave a botanical affinity with the family Balanophoraceae, not Apocynaceae (Parsonsia).

ISSN:0028-8306    

DOI:10.1080/00288306.1979.10424159

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor