Massey Documents by Type
Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294
Browse
4 results
Search Results
Item 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 HenryMarine 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.Item A high resolution record of late quaternary climatic and environmental change in Taranaki, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand(Massey University, 2013) Tinkler, Robert JohnA high-resolution characterisation of climatic and environmental change in Taranaki, New Zealand over the last 80,000 years using biotic and abiotic proxies is presented. This research contributes to the small set of sediment cores that extend from the present back through the Last Glacial Maximum (LGM) in the southern North Island, and adds to the small number of near-continuous cores in New Zealand. Fossil pollen data presented here provides a record of vegetation changes in response to climate change (temperature, wind and rainfall). In addition, the project applies a recently developed pollen temperature transfer function (Wilmshurst et al. 2007) to quantify, for the first time, temperature change across the entire LGM in this region, and elucidates the timing of Late Quaternary New Zealand climatic events and phases. Climate change timing and magnitude is tested against the climate event stratigraphy (CES) developed by the NZ-INTIMATE (INTegration of Icecore, Marine and Terrestrial archives) group (Alloway et al. 2007), including: Last Glacial Coldest Period (LGCP); the mid-eLGM Interstadial; the Last Glacial-Interglacial Transition (LGIT); Termination I; the Antarctic Cold Reversal (ACR); the Late-Glacial Warm Period (LGWP), the Late-Glacial Reversal (LGR); and Early Holocene Warming (EHW). During the Moerangi Interstadial between 40,000 and 30,000 cal yrs BP, both the Eltham and coastal Taranaki pollen records show that cold-climate taxa such as Nothofagus menziesii, Nothofagus subg. Fuscospora, Hoheria, Plagianthus, Phyllocladus and Poaceae dominated the pollen assemblage. In addition to being cold, low numbers of fern and tree fern spores imply that conditions were drier than present. The LGCP at Eltham (29,000 – 18,000 cal yrs BP) began around 1,200 years earlier than similar records from elsewhere in New Zealand. Transfer functions suggest that mean annual temperatures at the LGCP/ LGM at Eltham were 5.7°C cooler than present. Within the LGCP, the mid-eLGM Interstadial described in similar records from New Zealand seems to be evident in the W-MAT-derived temperature curve at Eltham, where warming of around 0.8°C occurs between 27,000 and 24,500 cal yrs BP. The LGIT appears to have begun around 18,000 cal yrs BP and concluded around 14,600 cal yrs BP at Eltham, which agrees well with speleothem data from Northwest Nelson, but is more short-lived than at Otamangakau Bog where the LGIT is thought to have persisted for another 1,500 years. A period of sharp cooling inferred from the Eltham pollen record between 16,600 and 15,000 cal yrs BP, when mean annual temperature fell between 1°C and 4°C from the previous period, is matched in time, but not in intensity at some other western and central North Island, and some South island sites, and may be a sampling artefact. The LGWP duration at Eltham (14,600 – 13,500 cal yrs BP) broadly corresponds with NZ-INTIMATE and Northwest Nelson estimates of 14,800 – 13,500 cal yrs BP; mean annual temperatures at Eltham came within 0.6°C of modern-day mean annual temperatures at this time. The timing of the LGR at Eltham shows good agreement with NZ-INTIMATE estimates (Alloway et al. 2007; Lowe et al. 2008), that is, from around 13,500 to 12,500 cal yrs BP. The LGR onset at Eltham preceded onset at the Auckland maars by 600 years and concluded 1,500 years earlier than at Auckland; mean annual temperature at Eltham at this time was approximately 2°C cooler than the present day MAT of 11.2°C. The EHW event commenced at Eltham around 12,500 cal yrs BP, around 1,000 years earlier than at Kaipo Bog, Otamangakau Bog; and largely synchronous with the Auckland maars and Okarito. Pollen records from coastal Taranaki sites span d18O Stage 5a (Otamangakau Interstadial, c. 80,000 yrs BP) through to d18O Stage 2 (Last Glacial-Interglacial Transition, c. 18,500 cal yrs BP), and encompass the stadial complex between these two interstadials (d18O Stage 4, c. 70,000 – 60,000 yrs BP). These records contribute to the small number of pollen-based paleoenvironmental and paleoclimatic narratives for New Zealand extending from the LGIT to the Otamangakau Stadial (d18O stage 5a) time periods. A major contribution of the current A High Resolution Record of Late Quaternary Climatic and Environmental Change in Taranaki, New Zealand study is to reconstruct and characterise d18O stage 5a and d18O stage 4 temperatures based on two pollen transfer functions developed by Wilmshurst et al. (2007). During d18O Stage 5a around 80,000 cal yrs BP, conditions were warmer and wetter than the succeeding glacial. d18O Stage 4 and the early part of d18O Stage 3 were cool with relatively low precipitation and were likely to have been windy at coastal Taranaki sites. Although d18O Stage 4 was cool, it was not as cold as the LGM: pollen transfer functions showed decreases in estimated mean annual temperature from d18O stage 5a, with mean annual temperatures falling around 2°C to reach 7°C. Precipitation likely decreased during d18O stage 4, as indicated by low levels of drought-intolerant taxa Dacrydium cupressinum, Cyathea smithii, and monolete spores, whilst low shrub diversity implies that disturbance was likely to have been low. During early d18O stage 3, the climate warmed and became wetter in coastal Taranaki, as indicated by increasing conifer abundance; in particular Dacrydium cupressinum, high abundance of Cyathea smithii, and a decline in cold-tolerant Nothofagus, Halocarpus, Asteraceae, and Poaceae after 60,000 yrs BP. These conditions persisted for < 5,000 years before temperatures decreased again, then between 50,000 and 40,000 yrs BP the decline in Poaceae and cold-tolerant shrubs Phyllocladus, Halocarpus and Asteraceae, as well as the sharp rise in tall tree conifers, all point to climate amelioration. Conditions were still relatively cool; although pollen transfer functions imply that that mean annual temperatures increased slightly, with mean annual temperature estimates fluctuating between 7°C and 8°C, this was approximately 3 to 4°C cooler than present. For the first time in New Zealand, aerosolic quartz dust was extracted from organic sediments; this peat-derived data informs a paleowind narrative for Taranaki. The technique used in the current study to extract quartz from peats can be considered successful, insofar as relatively pure samples of quartz could be isolated in sufficient mass to be able to measure them, and relate the data to the age model and the coeval pollen influx. The paleowind reconstructions from Eltham can be summarised as follows: strong winds dominated between 36,200 and 35,100 cal yrs BP, 30,746 and 32,101 cal yrs BP, 28,364 to 17,477 cal yrs BP, and 16,118 to 15,806 cal yrs BP. Intermediate winds occurred between 30,746 and 28,364 cal yrs BP, 17,477 and 16,118 cal yrs BP, and 15,619 to 14,916 cal yrs BP; winds of light intensity dominated between 34,777 and 32,101 cal yrs BP and 14,916 and 9,900 cal yrs BP. Major dust peaks at 31,358 cal yrs BP; 21,300 cal yrs BP and 15,955 cal yrs BP all correlated well with the Vostok ice core as well as marine core P69 (Stewart & Neall 1984), and Onaero and Waitui in northern Taranaki. Similarly, dust minima after about 15,000 cal yrs BP at Eltham, Vostok, marine core P69, Onaero, and Waitui suggests that the quartz dust signature at Eltham is consistent with both global and regional estimates of dust influx as the atmospheric dust load responded to changes in wind direction and strength, in particular the intensity of westerly winds, and changes to sediment source area characteristics such as vegetation cover. Combining fossil pollen data and aerosolic quartz dust results is a new technique to investigate the relationship between wind intensity, temperature and plant assemblages. The Eltham fossil pollen and aerosolic quartz data was analysed to determine how the relative proportions of competitive, stress tolerant and ruderal taxa respond to winds of differing intensities over time, as well as quantifying the impact of wind of different intensities on plant diversity over the period 36,200 to 9,900 cal yrs BP. In essence, competitor, C-selected taxa increased in relative abundance, and stress-tolerant, S-selected and ruderal, r-selected taxa decreased over the last 15,000 years at Eltham, as both temperature and wind intensity ameliorated. Wind data was examined against pollen diversity data to test the Intermediate Disturbance Hypothesis (IDH) in the vegetation of the Taranaki region. A moderate relationship between floral diversity and dust flux was found, with periods of high and low dust flux corresponding to lower diversity, and periods of intermediate dust flux corresponding to higher diversity, as predicted by the IDH.Item Are the Northland rivers of New Zealand in synchrony with global Holocene climate change? : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Geography at Massey University, Palmerston North, New Zealand(Massey University, 2013) Richardson, JaneClimate during the Holocene has not been stable, and with predictions of human induced climate change it has become increasingly important to understand the underlying ‘natural’ dynamics of the global climate system. Fluvial systems are sensitive respondents to and recorders of environmental change (including climate). This research integrates meta-data analysis of a New Zealand fluvial radiocarbon (14C) database with targeted research in catchments across the Northland region to determine the influence of Holocene climate change on river behaviour in New Zealand, and to assess whether or not Northland rivers are in synchrony with global climate change. The research incorporates 14C dating and meta-analysis techniques, sedimentology, geophysics, ground survey (RTK-dGPS) and Geographic Information Systems analysis to investigate the response of New Zealand and Northland rivers to Holocene climate and anthropogenic change. The emerging pattern of Holocene river behaviour in New Zealand is one of increased river activity in southern regions (South Island) in response to enhanced westerly atmospheric circulation (promoted by negative Southern Annular Mode [SAM]-like circulation), while in northern regions (North Island) river activity is enhanced by meridional atmospheric circulation (promoted by La Niña-like and positive SAM-like circulation). In Northland, Holocene floodplain development reflects the interplay between valley configuration and accommodation space, sediment supply, fluctuation in climate and anthropogenic factors in the last several hundred years. Evidence from Northland rivers suggests that a globally extensive abrupt climate change signal can promote a synchronous fluvial response, overprinting complex regional patterns of Holocene river behaviour. The research demonstrates that at the centennial-scale, regional atmospheric circulation change is a key driver of river behaviour, with anthropogenic catchment disturbance responsible for enhanced river activity and floodplain aggradation in the last ~ 500 years. It is therefore likely that any future climate change involving a shift in the atmospheric circulation regime will have an impact on river behaviour in New Zealand. However, at the catchment- or reach-scale, river response will be largely determined by local controls such as sediment supply and accommodation space, with these factors largely moderated by the post-settlement fluvial history.Item Late Holocene environmental record and geological history of the Lake Colenso area, north-western Ruahine Range, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Quaternary Science, Soil and Earth Sciences, Institute of Natural Resources, Massey University, Palmerston North, New Zealand(Massey University, 2011) MacDonald-Creevey, Amanda Mallory; MacDonald-Creevey, Amanda MallorySediment cores from a landslide-dammed lake, Lake Colenso (North Island, New Zealand), contain a decadal- to centennial-scale record of changing climate spanning the past 1800 years. A multi-proxy approach has been used to obtain a high-resolution record of variability from the Lake Colenso catchment, and tephra horizons combined with radiocarbon ages provide chronological constraints. Since the lake is located within a mountainous forested catchment of the northern Ruahine Range, it has remained pristine and isolated from human disturbance. Additionally, pollen analysis indicates minimal human influence in the lake catchment; hence the site offers a rare opportunity to investigate natural environmental change during a period in which anthropogenic impact has tended to obscure natural variability in many records from elsewhere in New Zealand (Wilmshurst et al., 1997). Sedimentology and elemental geochemistry reflect periods of rapid sediment influx into the lake, here interpreted as storm events which are preserved at an average of 1 every 150 years. This record, supported by stable isotope records from ostracods, shows distinct periods of increased storminess, and is related to the interaction between regional atmospheric circulation systems, El Niño-Southern Oscillation, Southern Annular Mode and the Pacific Decadal Oscillation. Furthermore, the association with other regional records of climate over the late Holocene highlights the effect of regional climatic forcing. A combination of findings is characterised by broad changes that correlate to the regionally distinctive Medieval Warm Period and Little Ice Age periods, providing further evidence for a climatically variable Holocene (Mayewski et al., 2004). The multi-proxy record presented here is a valuable contribution to existing paleoenvironmental knowledge of the late Holocene in New Zealand. The geology of the study area is characterised by alternating periods of subsidence and uplift throughout the Plio-Pleistocene which resulted in the deposition of Wanganui Basin sediments in the region. Historic earthquake records from nearby major faults are commensurate with ages obtained for landslides at Lake Colenso, which allow a further understanding into landscape evolution and the development of present-day Lake Colenso.