Browsing by Author "Palmer A"

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    Basic Volcanic Elements of the Arxan-Chaihe Volcanic Field, Inner Mongolia, NE China
    (inTech Open: Rijeka, Croatia, 2020-10-30) Li B; Nemeth K; Palmer A; Wu J; Procter J; Liu J
    The Arxan-Chaihe Volcanic Field, Inner Mongolia, NE China is a Pleistocene to Recent volcanic field still considered to be active. In this chapter we provide an update of current volcanological research conducted in the last four years to describe the volcanic architecture of the identified vents, their eruptive history and potential volcanic hazards. Here we provide an evidence-based summary of the most common volcanic eruption styles and types the field experienced in its evolution. The volcanic field is strongly controlled by older structural elements of the region. Hence most of the volcanoes of the field are fissure-controlled, fissure-aligned and erupted in Hawaiian to Strombolian-style creating lava spatter and scoria cone cone chains. One of the largest and most complex volcano of the field (Tongxin) experienced a violent phreatomagmatic explosive phase creating a maar in an intra-mountain basin, while the youngest known eruptions formed a triple vent set (Yanshan) that reached violent Strombolian phases and created an extensive ash and lapilli plains in the surrounding areas. This complex vent system also emitted voluminous lava flows that change the landscape by damming fluival networks, providing a volcanological paradise for the recently established Arxan UNESCO GLobal Geopark.
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    Disentangling the effects of temperature and reactive minerals on soil carbon stocks across a thermal gradient in a temperate native forest ecosystem
    (Springer Nature, 2024-03) Siregar IH; Camps-Arbestain M; Kereszturi G; Palmer A; Kirschbaum MUF; Wang T; Weintraub-Lef SR
    Effects of global warming on soil organic carbon (C) can be investigated by comparing sites experiencing different temperatures. However, observations can be affected by covariance of temperature with other environmental properties. Here, we studied a thermal gradient in forest soils derived from volcanic materials on Mount Taranaki (New Zealand) to disentangle the effects of temperature and reactive minerals on soil organic C quantity and composition. We collected soils at four depths and four elevations with mean annual temperatures ranging from 7.3 to 10.5 °C. Soil C stocks were not significantly different across sites (average 162 MgC ha−1 to 85 cm depth, P >.05). Neither aluminium (Al)-complexed C, nor mineral-associated C changed significantly (P >.05) with temperature. The molecular characterisation of soil organic matter showed that plant-derived C declined with increasing temperature, while microbial-processed C increased. Accompanying these changes, soil short-range order (SRO) constituents (including allophane) generally increased with temperature. Results from structural equation modelling revealed that, although a warmer temperature tended to accelerate soil organic C decomposition as inferred from molecular fingerprints, it also exerted a positive effect on soil total C presumably by enhancing plant C input. Despite a close linkage between mineral-associated C and soil organic C, the increased abundance of reactive minerals at 30–85 cm depth with temperature did not increase soil organic C concentration at that depth. We therefore propose that fresh C inputs, rather than reactive minerals, mediate soil C responses to temperature across the thermal gradient of volcanic soils under humid-temperate climatic conditions
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    Geoheritage Values of the Wairarapa
    (12/10/2020) Palmer J; Nemeth K; Palmer A; Kosik S
    The Manawatu and Wairarapa regions, lower North Island, are an important geological archive for New Zealand but are not among the iconic geotourism attractions of New Zealand. Recently the geoheritage values of the region have been discussed by various groups including Massey University and Horizons Regional Council with an aim to promote the region to visitors seeking destinations with geological significance. The suggestion has been made the Manawatu River form the backbone of a geopark. While Manawatu River is regionally significant, we argue it lacks the unique attributes needed for globally significant geoheritage value. Here we demonstrate the wider region has at least two globally unique and geologically superb features that should be evaluated using global comparative studies. Exceptional turbidite successions representing accretionary prism successions are exposed in the Wairarapa region. These are comparable to the iconic “flysch” locations of the North American Cordillera, the Alps, the Pyrenees and the Carpathians. Furthermore, a succession of thrust faults and related mélange sequences are among the best exposed and most accessible in New Zealand. These undoubtedly carry high geoheritage value and we propose that these two geological features, with community support, regional council funding and the local university (Massey) facilitating the transfer of knowledge to the community, should be signposted and promoted to visitors. In the long term the stunning geological succession of the Wairarapa Mudstone Country should gain international recognition and form the basis of a UNESCO Global Geopark.
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    Integrating ecosystem services with geodesign to create multifunctional agricultural landscapes: A case study of a New Zealand hill country farm
    (Elsevier Ltd, 2023-02) Tran DX; Pearson D; Palmer A; Dominati EJ; Gray D; Lowry J
    An ecosystem-based management approach (EBM) is suggested as one solution to help to tackle environmental challenges facing worldwide farming systems whilst ensuring socio-economic demands are met. Despite its usefulness, the application of this approach at the farm-scale presents several implementation problems, including the difficulty of (a) incorporating the concept of ecosystem services (ES) into agricultural land use decision-making and (b) involving the farmer in the planning process. This study aims to propose a solution to overcome these challenges by utilising a geodesign framework and EBM approach to plan and design a sustainable multifunctional agricultural landscape at the farm scale. We demonstrate how the proposed approach can be applied to plan and design multifunctional agricultural landscapes that offer improved sustainability, using a New Zealand hill country farm as a case study. A geodesign framework is employed to generate future land use and management scenarios for the study area, visualize changes, and assess the impacts of future land use on landscape multifunctionality and the provision of associated ES and economic outcomes. In this framework, collaboration with the farmer was carried out to obtain farm information and co-design the farmed landscapes. The results from our study demonstrate that farmed landscapes where multiple land use/ land cover types co-exist can provide a wide range of ES and therefore, meet both economic and environmental demands. The assessment of impacts for different land use change scenarios demonstrates that land use change towards increasing landscape diversity and complexity is a key to achieving more sustainable multifunctional farmed landscapes. The integration of EBM and geodesign, is a transdisciplinary approach that can help farmers target land use and management decisions by considering the major ES that are, and could be, provided by the landscapes in which these farm systems are situated, therefore maximising the potential for beneficial outcomes.
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    Shallow magmatic processes revealed by cryptic microantecrysts: a case study from the Taupo Volcanic Zone
    (Springer Nature, 2021-11-05) Lormand C; Zellmer GF; Sakamoto N; Ubide T; Kilgour G; Yurimoto H; Palmer A; Németh K; Iizuka Y; Moebis A
    Arc magmas typically contain phenocrysts with complex zoning and diverse growth histories. Microlites highlight the same level of intracrystalline variations but require nanoscale resolution which is globally less available. The southern Taupo Volcanic Zone (TVZ), New Zealand, has produced a wide range of explosive eruptions yielding glassy microlite-bearing tephras. Major oxide analyses and textural information reveal that microlite rims are commonly out of equilibrium with the surrounding glass. We mapped microlites and microcrysts at submicron resolution for major and trace element distributions and observed three plagioclase textural patterns: (1) resorption and overgrowth, (2) oscillatory zoning, and (3) normal (sharp) zoning. Pyroxene textures are diverse: (1) resorption and overgrowth, (2) calcium-rich bands, (3) hollow textures, (4) oscillatory zoning, (5) sector zoning, (6) normal zoning and (7) reverse zoning. Microlite chemistry and textures inform processes operating during pre-eruptive magma ascent. They indicate a plumbing system periodically intruded by short-lived sub-aphyric dykes that entrain microantecrysts grown under diverse physico-chemical conditions and stored in rapidly cooled, previously intruded dykes. Changes in temperature gradients between the intrusion and the host rock throughout ascent and repeated magma injections lead to fluctuations in cooling rates and generate local heterogeneities illustrated by the microlite textures and rim compositions. Late-stage degassing occurs at water saturation, forming thin calcic microcryst rims through local partitioning effects. This detailed investigation of textures cryptic to conventional imaging shows that a significant proportion of the micrometre-sized crystal cargo of the TVZ is of antecrystic origin and may not be attributed to late-stage nucleation and growth at the onset of volcanic eruptions, as typically presumed.
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    USING PROXIMAL HYPERSPECTRAL SENSING TO MEASURE SOIL OLSEN P AND pH
    (12/04/2019) Grafton M; Kaul T; Palmer A; Bishop P; White M; Currie, L; Christensen, C
    This paper reports on work undertaken to use a large data set of hyperspectral data measured on dry soil samples to obtain regression analysis which allows predictions of pH and Olsen P to be obtained from an independent data set. The large data set was obtained from 3,190 soil samples taken from the Ravensdown Primary Growth Partnership to a depth of 7.5cm. The spectra were measured using an Analytical Spectral Device which recorded 2,150 wavebands of 1nm resolution between 350nm and 2,500nm. Values for Olsen P and pH were provided from chemical analysis by Analytical Research Laboratories. The spectra were regressed using “R” statistical software which has the power to handle the data and report the wavebands with the most significance for the model. The data set for the prediction came from a stratified nested, grid soil sampling exercise which was used to find Olsen P stability at varying depths. This set had 400 samples from each of two data sets from different areas on Patitapu Station using a grid sample protocol. The 100 most significant wavebands from the PGP data set were used to regress the Patitapu data which were combined. These were regressed using “R” (Version 3.41, The R Foundation) and Statdata (Palisade, New York), which produced the same result. The partial least square regression of pH was very significant and was predicted well. Olsen P had a very significant correlation which was quite noisy, correlating the log10 of Olsen P was also undertaken and it would appear something is being measured that is associated with Olsen P. This work shows that it is possible to measure soil nutrient by proximal hyperspectral analysis which is transferable to an independent data set.