86 results for Journal article, 1970

  • Notice from the Editor

    Selby, Michael J. (1971)

    Journal article
    University of Waikato

    Notice from the Editor from Volume 5, Number 2, 1971 of Earth Science Journal.

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  • Coverpage and Contents

    Waikato Geological Society (1971)

    Journal article
    University of Waikato

    Coverpage and Contents from Volume 5, Number 2, 1971 of Earth Science Journal.

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  • Dynamic equilibrium in applied geomorphology: Two case studies

    Douglas, Ian (1971)

    Journal article
    University of Waikato

    Engineering works and agricultural activity which change the relationship between rainfall and river flow lead to modifications of river channels with attendant erosion and deposition problems. In the Swiss Jura Lakes area, the natural flooding of the River Aare became such an acute problem by the mid-nineteenth century that extensive engineering works were carried out to alleviate flooding. The land thus reclaimed became a valuable agricultural asset, but the fall of the water table following removal of the annual flood risk, led to a fall in the level of the land as peat was changed into humus. Renewed flooding occurred. The natural readjustment following the first series of flood alleviation works reproduced the original problem and a second series of engineering works has had to be undertaken to remedy the situation. On the Belgian coast, harbour construction and the spread of buildings over the sand dunes have resulted in severe beach erosion in the eastern seaside resorts. Extensive engineering works have had to be undertaken to restore the beach. These examples illustrate how man's challenges to nature are often recurrent phenomena, and how the alteration of one aspect of the physical environment may lead to a succession of readjustments. Each phase of engineering activity may be considered a break in natural equilibrium, and each period of natural erosion or deposition a trend towards a new equilibrium.

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  • Dust from Australia- A reappraisal

    Healy, T.R. (1970)

    Journal article
    University of Waikato

    This paper reviews the meteorological events of October 1928 associated with severe duststorms in Australia and subsequent transport of dust to New Zealand. In the light of contemporary knowledge of the jet streams, and from reappraisal of the original synoptic charts, reported meteorological conditions and press reports pertaining to these duststorms, it is postulated that for dust to be deposited upon New Zealand within 24 hours, of duststorms in Australia it presumably travelled via the jet stream region of the' middle and upper troposphere.

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  • Measurement of tide induced changes to water table profiles in coarse and fine sand beaches along Pegasus Bay, Canterbury

    Ericksen, Neil (1970)

    Journal article
    University of Waikato

    Measurements of changing water table profiles in beaches along Pegasus Bay, Canterbury, show an interchange of water between the sea and beach sand pores throughout a single semi-diurnal tidal cycle. The velocity of water escaping from the water table in response to an ebbing tide does not appear sufficient to elutriate material of silt size or larger from the beach. The low computed velocity is thought to be due to hydrostatic control, by sand dunes at the back of the beach, on water table amplitude. Fresh water and wave wash are considered important supplementary sources to that of tidal water in influencing water table profiles.

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  • A flume for studying the relative erodibility of soils and sediments

    Selby, Michael J. (1970)

    Journal article
    University of Waikato

    A flume has been built for studying the erodibility of soils and sediments by gullying. It consists of two boxes containing undisturbed soil samples. One box is set above the other and water from a stilling tank passes over the soil of the upper box and falls onto the soil of the lower box causing lip and channel scour and plunge-pool erosion. The sediment is collected and measured, and a measure of erodibility related to discharge, length of test and sediment yield is thus available.

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  • Contorted stratification with clay lobes in volcanic ash beds, Raglan-Hamilton region, New Zealand

    Tonkin, Philip J. (1970)

    Journal article
    University of Waikato

    Contorted stratification in basal volcanic ash beds of the Pleistocene Hamilton Ash Formation incorporates halloysitic clay lobes which project upward into a bed of predominantly allophanic material. The forms produced are similar to convolute laminations described in other marine and non-marine sedimentary sequences. The halloysitic clay lobes have been described previously as concretions and as the products of differential weathering processes. A third hypothesis is proposed to explain the formation of the clay lobes and associated contorted stratification of these basal ash beds, namely, that the beds were deformed by plastic flowage of halloysitic clay into a sensitive allophanic bed. This deformation was possibly a result of water-saturated beds rapidly losing strength as a result of cyclic reversals of stress and strain produced by earthquake shock waves.

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  • Complex belemnites of the Puaroan (lower-? middle Tithonian) stage in the Port Waikato Region of New Zealand

    Challinor, A.B. (1970)

    Journal article
    University of Waikato

    Belemnite guards range through 2700 feet of Puaroan strata in the Port Waikato region. All are Belemnopsis of the uhligi-complex. Belemnopsis aucklandica aucklandica (Hochstetter) in its most typical form may be restricted to the lower 700 feet of the sequence. Three species are described, together with what may be transitional forms. The morphology of juvenile guards is in marked contrast with that of mature specimens, and development of the adult guard is revealed by examination of internal sections. Some aspects of belemnite paleoecology are discussed. Belemnite biostratigraphy of the area is outlined and the more important fossil localities are described.

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  • An appraisal of nutrient supplies available for tree growth in a pumice soil

    Knight, P.J.; Will, G.M. (1970)

    Journal article
    University of Waikato

    Chemical analyses have confirmed and explained the results of an earlier pot trial in which the availability of major nutrients in six pumice ash layers of Kaingaroa silty sand was assessed by the growth of radiata pine seedlings. Almost all of the tree-available P is found in the present topsoil: the quantities-of P that occur in two buried soils (Waimihia and Rotoma ashes) are almost entirely in the form of organic P which is apparently very resistant to breakdown due to complexing with allophane. The N in these layers is similarly unavailable. The mineral layers, about 4 ft in thickness (Taupo pumice and lapilli), which lie between the present topsoil and the uppermost buried soil, are very low in total N and P and exchangeable Mg, but relatively high in exchangeable K. Only the lower buried soil contains a reasonable quantity of exchangeable Mg and has a Mg : K ratio in favour of Mg.

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  • Coverpage and Contents

    Waikato Geological Society (1970)

    Journal article
    University of Waikato

    Coverpage and Contents from Volume 4, Number 1, 1970 of Earth Science Journal.

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  • The movement of sediment in a channel in relation to magnitude and frequency concepts- a New Zealand example

    Pain, C.F.; Hosking, Peter L. (1970)

    Journal article
    University of Waikato

    In areas where surface wash contributes most of the debris to a channel network, the effect of events of moderate magnitude and frequency appear to be more important than catastrophic events for land form development. In previous studies this idea has been emphasised, largely as a result of the fact that the contribution of bedload to sediment yield has rarely been considered. Examination of these ideas under certain New Zealand conditions would seem to present a somewhat different picture. Where rapid mass movement is the main contributor of sediment to the channel, both the development of hill-slope form and the movement of sediment in channels must be related to the frequency of occurrence of mass movements. The evidence seems to suggest that most major mass movements are triggered during high-intensity, low-frequency storms. The Orere River catchment in the Hunua greywacke block of South Auckland, New Zealand, is examined to test these ideas. Although historical data are limited, the character of the sediments in the lower catchment would suggest a succession of major periods of deposition. High-intensity storms of 1966 and 1967 resulted in the deposition of large amounts of material in the channels throughout the catchment, with a gradual removal of material mainly from the upper catchment since that time. From the limited evidence that is available, a simple model of sediment movement through the catchment is presented.

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  • Coverpage and Contents

    Waikato Geological Society (1970)

    Journal article
    University of Waikato

    Coverpage and Contents from Volume 4, Number 2, 1970 of Earth Science Journal.

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  • Book reviews and Book notices

    Waikato Geological Society (1970)

    Journal article
    University of Waikato

    Book reviews and Book notices from Volume 4, Number 2, 1970 of Earth Science Journal.

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  • Quaternary warping at Gorge Saddle, western Southland

    Force, Eric R.; Force, Lucy M.; Thyne, Martin L. (1970)

    Journal article
    University of Waikato

    Gorge Saddle is one low point on a drainage divide between Fiordland and the Southland Plain. Eastward sloping Quaternary terraces east of the divide and westward sloping terraces to the west contain granitic pebbles which could have been derived only from the west. This suggests doming at the present divide concurrent with transport from the west.

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  • The Sydney duricrusts: their terminology and nomenclature

    Faniran, Adetoye (1970)

    Journal article
    University of Waikato

    Two main duricrust types - laterites and ferricretes - and their underlying materials are mapped and described for the northern parts of the Sydney district, New South Wales. Laterites are by far the more widespread, being found both in the Wainamatta-Shales and in the Hawkesbury-Sandstone areas, particularly on the broad hilltops and interfiuves of the major divide between the three drainage systems - the north-flowing Hawkesbury-Broken Bay, the south-flowing Parramatta-Port Jackson and the east-flowing Pacific Ocean systems. The ferricretes occur mainly in the drier parts of the northwest, especially in the conglomeratic river gravels of the Maroota area. The two materials have similar profile characteristics but they are different in hand specimen, in textural and structural characteristics, and also in mineralogical composition. The duricrusts and their profiles have been widely destroyed and differentially truncated, so that their various zones and subzones are presently exposed at different places. These materials, especially in respect of laterites, are classified from field and laboratory evidence, according to their recognised, or assigned, position in the typical deep weathering profile. Names are assigned, depending on the area where the best examples were found.

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  • The soils of the southeastern sector of Egmont National Park

    Tonkin, Philip J. (1970)

    Journal article
    University of Waikato

    The soils of the southeastern slopes of Egmont National Park, Taranaki, are youthful in absolute age and also in soil development. They are classed as recent soils on a parent material basis: andesitic tephras, alluvium, and peat with interbedded tephra. Of these groups the former covers the greatest part of the surveyed area and was studied in the most detail. The recent soils from andesitic tephra have a profile form dominated by buried soil horizons and little weathered tephra layers, the youngest of which was erupted 210 years ago. Characteristic features are the very weak weathering of minerals in the upper soil layers, the variable depth of melanisation, the extremely leached state of the soil profile and lastly the marked similarity of the soil chemical parameters despite appreciably different biotic regimes and a range in slope and altitude. It is concluded that the extremely high rainfall, in excess of 150 inches per annum, so controls soil processes that the variables of site and vegetation are not expressed in the measured soil parameters.

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  • Input and output considerations in estimating rates of chemical denudation

    Goudie, Andrew (1970)

    Journal article
    University of Waikato

    Estimation of rates of solutional denudation in river basins necessitates some consideration of salt inputs as well as consideration of salt outputs. Recent work in nutrient cycling has stressed the complexity and importance of the input factor, particularly when throughfall chemistry is taken into account. Frequently the differences between rates of input and output of salt in a river basin are small, suggesting that many published rates of solutional denudation, which consider outputs alone, or inputs only in part, are excessive. The input of salts, which may take place in rain, snow, fog and throughfall are most important in coastal areas. Analysis of data, for both the semi-arid United States and the Cotswold Hills in England, illustrate the need for long-term sampling, and for a detailed spatial network of sampling points.

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  • Soil crusting in Western Samoa. Part I - Some examples of crusting and methods of control

    Reynolds, S.G. (1971)

    Journal article
    University of Waikato

    The problems and effects of soil crusting in Western Samoa are discussed. Illustrations of typical crust features include the glazed or 'frosted' surface of certain crusts, and dispersion mosaics. Surface mulches and fine wire mesh frames were investigated as control measures to dissipate the considerable kinetic energy of falling raindrops before they reach the soil surface. Soil crusting was much reduced by these control methods. Mulching increased the germination percentage of dwarf beans, and frames the germinating percentage of lettuce and cabbage over untreated plots; the yield of dwarf beans was increased by 80 per cent using a mulch of coconut fronds.

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  • The age of quaternary surfaces at Waihi Beach

    Selby, Michael J.; Pullar, W.A.; McCraw, J.D. (1971)

    Journal article
    University of Waikato

    The Waihi Beach surfaces were originally mapped and correlated with European surfaces of similar altitude by Kear and Waterhouse (1961). Exposures along the edges of the surfaces indicate that they are covered with volcanic ashes, the younger of which are of known age. It is the sub-ash surface which should be used for height correlations, and it is the most seaward ash-covered part of the surface which is preferred as the reference point for altitude studies. The heights of the surfaces may not correlate with positions of sea-level at the ages indicated by the ash beds.

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  • Mass movement in Tangoio conservation reserve northern Hawkes Bay

    Eyles, R.J. (1971)

    Journal article
    University of Waikato

    In a random sample of 52 valley-side profiles at Tangoio, mass movements are shown to occur preferentially on profiles with a northerly aspect, which are long, or steeply sloping. Detailed measurements of 27 debris slide and two slump scars dating from a storm in May 1971 enable an estimate of the rate of erosion of loess and volcanic ash from valley-sides to be made. Valley-side slopes are changing from a convexo-concave equilibrium form under the original forest towards a new, more rectilinear equilibrium form under grass.

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