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Ecklonia radiata
Published in S.J. Hawkins, A.L. Allcock, A.E. Bates, L.B. Firth, I.P. Smith, S.E. Swearer, P.A. Todd, Oceanography and Marine Biology, 2019
Thomas Wernberg, Melinda A. Coleman, Russell C. Babcock, Sahira Y. Bell, John J. Bolton, Sean D. Connell, Catriona L. Hurd, Craig R. Johnson, Ezequiel M. Marzinelli, Nick T. Shears, Peter D. Steinberg, Mads S. Thomsen, Mathew A. Vanderklift, Adriana Vergés, Jeffrey T. Wright
Photosynthetic parameters, derived from photosynthesis (P) versus irradiance (E) curves, are a simple tool that has been used in conjunction with pigment content to examine how E. radiata acclimates (photoacclimation) to various irradiances. Pmax is the maximum photosynthetic rate when light availability does not limit photosynthesis and the initial slope of the P versus E curve (α) is a measure of the light-harvesting ability at subsaturating irradiances. The compensation irradiance (Ec) is the irradiance at which net photosynthesis balances respiration, and Ek is the light saturation point. A strong gradient of light is found along Doubtful Sound, a fjord in southwestern New Zealand and provides a natural laboratory for studying mechanisms of photoacclimation in E. radiata, which grows at sites with maximum irradiances ranging from 650 to 1250 μmols photons/m2/s2 (measured at a 1-m depth in November 2000, Miller et al. 2006). Pmax was similar at the five sites studied because the content of both chlorophyll a and accessory pigments was greater at low light compared to higher-light sites, which resulted in a greater ability to harvest light at low irradiances (i.e. increased α, Miller et al. 2006). Additionally, for the low-light sites, Ek was lower than at the high-light sites, as was Ec because of lower respiration rates. There was also a morphological acclimation, with blades being larger and thinner (i.e. greater surface area to volume ratio) at the low-light compared to high-light site, thought to reduce self-shading within the thallus.
Long water tunnel inspections by remotely operated vehicle
Published in Mark Knight, Neil Thomson, Underground Infrastructure Research, 2020
Robert (Bob) Clarke, P. Eng, Carmelo (Carmen) Sferrazza
From Lake Manapouri, water is drawn down through seven penstocks to underground turbines and then discharged through a 9.8km long tunnel into Deep Cove, Doubtful Sound and eventually into the Tasman Sea. This tunnel was constructed by conventional drill and blast techniques and is known as the first Manapouri tailrace tunnel (1MTT).
Emplacement and Paleozoic and Cretaceous recrystallisation of the Broughton Arm Peridotite in Western Fiordland, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2019
T. Dwight, J. M. Scott, J. J. Schwartz
The Broughton Arm Peridotite adds to the growing database of ultramafic rocks in New Zealand. Composed of several variably metamorphosed and recrystallised rocks outcropping over an area of 500 m (although it may extend several km to the north), it provides a record of the complex igneous and metamorphic history of central Fiordland from the mid-Paleozoic to the Cretaceous. The protolith to the Broughton Arm Peridotite is most likely to have been an ultramafic cumulate magma emplaced in the early to mid Paleozoic. A first metamorphic event, probably in the Carboniferous at c. 330 Ma, formed olivine–enstatite–Cr magnetite-dominated dunite and harzburgite assemblages. The margins of the peridotite have been subsequently converted to near mono-mineralic hornblendite and then amphibolite, and the harzburgitic-dunitic core has partially recrystallised to Mg-chlorite, tremolite, serpentinite-dominated assemblages. The growth of the hydrous phases was associated with grain size reduction, and in-situ titanite U-Pb dating of deformed host gneisses indicates that this amphibolite facies assemblage formed c. 106 Ma concurrent with deformation along the extensional Doubtful Sound Shear Zone.
Magmatism in Antarctica and its relation to Zealandia
Published in New Zealand Journal of Geology and Geophysics, 2020
John L. Smellie, Adam P. Martin, Kurt S. Panter, Philip R. Kyle, Adelina Geyer
The Ross Orogen plutonism is known collectively as the Granite Harbour Intrusive Complex (Cox et al. 2012; Figure 1) and rocks thought to be equivalent to this have been mapped in New Zealand (Gibson and Ireland 1996; Allibone et al. 2009a). At least four examples of Cambrian plutonism in New Zealand are thought to equate to Ross Orogen-related rocks. One example of granitoid orthogneiss at Kellard Point in Doubtful Sound (Figure 1) has been dated at 481 ± 8 Ma (Gibson and Ireland 1996), the Jaquiery granitoid gneiss (Figure 1) has been dated at 492 ± 9 Ma (Allibone et al. 2009a), the Pandora Orthogneiss (tonalite) is c. 500 Ma (Allibone et al. 2009b) and the Dead Goat Conglomerate contains a metagranitic clast with a radiometric date of 496 ± 9 Ma (Gutjahr et al. 2006). The Ross Orogen-related rocks in New Zealand are chronologically equivalent to the latest, post-tectonic phase of plutonism recognised in the Granite Harbour Intrusive Complex. The major element, whole rock chemistry of the New Zealand Jaquiery granitoid gneiss is described as distinctly different from Antarctic Ross Orogen lithologies, with relatively high Ca and exceptionally low K for such a siliceous rock (e.g. Allibone et al. 2009a). Comparison with more recently acquired geochemistry, however, shows a high degree of overlap of whole rock trace element concentrations (Martin et al. 2015 and references therein; Figure 3). In summary, Ross Orogen-related plutonism does form part of the New Zealand basement, with studied New Zealand examples overlapping chronologically and geochemically (trace elements) with rocks in Victoria Land, Antarctica.
Cretaceous molybdenite in metasomatic epidosite associated with the Pounamu ophiolite, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2020
Alan F. Cooper, Anthony Reay, Trevor R. Ireland, Marc D. Norman
Minor Mo mineralization occurs in a similar tectonic position in the Western Province at Lake Manapouri, Fiordland, where the Jurassic (c. 157 Ma) Pomona Island Granite, of weakly A-type affinity, contains disseminated crystals of molybdenite (Scott and Palin 2011). Although limited geochemistry indicates that there is no other heavy metal enrichment, Scott and Palin (2011) suggest that mineralisation is similar to the Climax-style processes described by Ludington and Plumlee (2009). Mo mineralisation was also described in gneisses and granites of the Fiordland Complex, intersected during the construction of the Lake Manapouri-Doubtful Sound tailrace tunnel (Wodzicki 1972).