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    Paleoenvironmental analysis of quaternary strata in the Levin area : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Quaternary Science at Massey University
    (Massey University, 1991) Sewell, Alan Henry
    Marine transgression during the Last Interglacial resulted in widespread inundation of the southern Manawatu area. The Otaki Formation constitutes the relatively thick blanket of predominantly marine sand deposited at the height of the transgression and is now exposed in a partially dissected marine terrace abutting the Tararua Range. Sedimentation was controlled by basement block faulting related to a regional strike-slip tectonic regime on the south­ eastern margin of the South Wanganui Basin. Wave-induced longshore currents from the north-west supplied abundant sediment to the coast. North-east of Levin the Kairanga Trough, occupying a north-east-trending structural depression between uplifted basement blocks, formed the centre of an embayment during the transgression. Tide-dominated depositional processes predominated around the margins of the embayment. In the Forest Lakes area, the absence of seaward barriers resulted in an open wave-dominated coastline. Between Ohau and Shannon mixed wave/tide processes predominated. Stabilisation of sea level resulted in shoreline progradation which was especially marked south of Levin where a dune belt formed, mantling the coastal cliff and later migrating inland. Retreat of the sea was followed by differential uplift and dissection of the newly exposed marine terrace. Two later marine transgressions cut treads in the earlier marine terrace, their strandlines being controlled by the previously established drainage pattern.·Ameliorating climate associated with the major sea level regression of the Last Glacial was accompanied by several phases of loess and minor dune sand accumulation on the exposed marine terraces. At the same time large areas of the terrace coverbeds were removed due to river aggradation. Final truncation of the Last Interglacial marine terraces occurred during the Holocene transgression. Tectonic warping of the marine terraces is continuing along pre-existing basement faults.
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    Late quaternary deposits of the eastern shore of Lake Wairarapa, North Island, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Soil Science at Massey University
    (Massey University, 1990) Mitchell, Alison Gislaine
    The lower Wairarapa Valley was an estuary as late as 6 500 years ago. Since then sediments from the Ruamahanga and Tauherenikau Rivers have deposited large loads of sediment into the area, prograding the eastern shore and changing the system from an estuary into lakes and rivers. The aims of this study were to investigate the late Quaternary deposits and soils of the eastern shore of Lake Wairarapa, using the information gained to look at the way in which infilling has taken place. The surface geology and soils of the study area were mapped. The mapping units were described and defined. Some chemical tests were carried out on selected soil samples. The order and method of infilling of the deposits are discussed.
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    Some aspects of the cenozoic geology of the Moawhango River region, in the Army training area in Waiouru, North Island, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Quaternary Geology at Massey University
    (Massey University, 1994) Williams, John Kim
    Late Tertiary marine strata of the Waiouru Formation were unconformably deposited on a dissected Late Cretaceous peneplain surface of unusually high relief formed on Torlesse Supergroup greywacke at Waiouru. Central North Island, New Zealand. Waiouru is uniquely located on the southern boundary of the Taupo Volcanic Zone and the northern margin of the Wanganui Basin, an infilled Pliocene basin now subject to Plio-Pleistocene uplift. Two transgressive episodes are identified. The first involved submergence of the peneplain in the Neogene, when Kapitean mudstone was deposited. Then a general marine shallowing occurred around the New Zealand landmass which saw uplift of Waiouru towards the end of the Kapitean Stage, followed by a period of sub-aerial erosion. The second transgressive episode was initiated by subsidence of the Wanganui Basin in the Pliocene, which led to onlap of coarse shallow-water sandstones during the Opoitian Stage. Basement subsidence tended to result in vertical rather than horizontal migration of the shoreline. No evidence has been found for previously recognised eustatic sealevel cycles, due possibly to masking by strong tidal conditions throughout the Opoitian sequence; Waiouru being located on the northern edge of the Pliocene Kuripapango Strait. Eventually, shallow seas supported a faunal population sufficient to produce widespread carbonate skeletal fragments that formed extensive shell limestone beds at the top of the Waiouru Formation. Rapid lateral and vertical changes in the facies are interpreted as due to rapidly changing local depositional conditions. These were caused by the submerging basement initially forming a steep coast with at least two offshore islands. Marine infilling occurred within former incised river valleys 3 km wide and over 300 m in depth. Erosion of local greywacke contributed to the Opoitian sedimentation, as did a granitic source, probably in North-west Nelson, with materials transported from this latter source by currents propagating through the Kuripapango Strait. The presence of abundant granite-derived micas in Opoitian strata, yet their absence in the Kapitean strata provide a limiting age for the arrival of micas in Wanganui Basin strata. As the Wanganui Basin depocentre moved southwards, offlap and emergence occurred with Plio-Pleistocene uplift. The paleo-Moawhango River established its course in the newly uplifted strata, forming superimposed gorges where it cut into exposed basement. Except for initially deposited basal strata, dips in the Neogene marine strata are almost all uniformly consistent with the regional dip. Mapping of the shell limestone beds has shown post-Opoitian development of a small scale (<2 km wide) anticline and a minor associated fault. To the south of the study area, the Waipipian age Taihape Mudstone overlies the Waiouru Formation. The contact between the two is interpreted to be the Opoitian-Waipipian boundary and thus the Waiouru Formation was deposited within the Opoitian Stage.
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    Late quaternary pollen stratigraphy, geology and soils of an area near Greytown : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Soil Science at Massey University
    (Massey University, 1987) Tompkins, Joanna Olive
    In the southern Wairarapa Valley there are extensive gravel fans, built by the Tauherenikau, Waiohine, and Waingawa Rivers. The fans form the Waiohine Surface which is lapped by a complex of Holocene fluvial, lacustrine and estuarine deposits. At the toe of the fans, peat deposits have accumulated over early Holocene sediments. This study involved; a) detailed mapping of the Quaternary deposits and soils and, b) analysis of pollen stratigraphy from continuous peat deposits in an area south of Greytown, in order to establish the Late Quaternary vegetative and environmental changes in the area. Detailed mapping showed that the c. 6,000 years B.P. Holocene high sea level did not encroach the area as was previously believed. After the formation of the Waiohine Surface c.10,000 years B.P., the Waiohine and possibly Tauherenikau Rivers infilled the area with aggradational gravels and sands. At c.8,500 years B.P. these river systems left the area and, peat deposits began accumulating soon after. The pollen spectrum, dated from c.8,500 years B.P. at the base, to c.5,500 years B.P. at the surface showed that the vegetation in the area suffered little change during the period of peat accumulation. Substantial areas of shrub, herbaceous and swamp communities existed in the valley, in addition to a Dacrydium cupressinum dominated podocarp-hardwood forest. Stands of Dacrycarpus dacrydioides were prominent on many wetter sites. A podocarp-hardwood complex, with areas of Nothofagus existed in the adjacent ranges. Climatic deterioration may have caused the rise in Nothofagus at the expense of the podocarps after 6,000 years B.P. The steady decline of D. dacrydioides with respect to D. cupressinum between 6,000 years B.P. and 5,000 years B.P. however, is a result of local drying around the bog. Fluctuations in vegetation are not of sufficient magnitude to justify the use of pollen zones.