title: Geology of the Hamilton region

authors: Schofield, J.C.

subjects: Hamilton

abstract: This account takes the form of a synopsis which closely follows that prepared for a bulletin entitled "Geology of the Ngaruawahia Subdivision" (Kear and Schofield, in press). Normally such repetition should be avoided but an exception is made in view of delays in publishing the bulletin and of the parochial nature of this first number of the Earth Science Journal.

text: Geology of the Hamilton region This account takes the form of a synopsis which closely follows that prepared for a bulletin entitled "Geology of the Ngaruawahia Subdivision" (Kear and Schofield, in press). Normally such repetition should be avoided but an exception is made in view of delays in publishing the bulletin and of the parochial nature of this first number of the Earth Science Journal.

year: 1967

title: Discriminating cool-water from warm-water carbonates and their diagenetic environments using element geochemistry: the Oligocene Tikorangi Formation (Taranaki Basin) and the dolomite effect

authors: Hood, Steven D.

subjects: carbonate geochemistry

abstract: Fields portrayed within bivariate element plots have been used to distinguish between carbonates formed in warm- (tropical) water and cool- (temperate) water depositional settings. Here, element concentrations (Ca, Mg, Sr, Na, Fe, and Mn) have been determined for the carbonate fraction of bulk samples from the late Oligocene Tikorangi Formation, a subsurface, mixed dolomite-calcite, cool-water limestone sequence in Taranaki Basin, New Zealand. While the occurrence of dolomite is rare in New Zealand Cenozoic carbonates, and in cool-water carbonates more generally, the dolomite in the Tikorangi carbonates is shown to have a dramatic effect on the "traditional" positioning of cool-water limestone fields within bivariate element plots. Rare undolomitised, wholly calcitic carbonate samples in the Tikorangi Formation have the following average composition: Mg 2800 ppm; Ca 319 100 ppm; Na 800 ppm; Fe 6300 ppm; Sr 2400 ppm; and Mn 300 ppm. Tikorangi Formation dolomite-rich samples (>15% dolomite) have average values of: Mg 53 400 ppm; Ca 290 400 ppm; Na 4700 ppm; Fe 28 100 ppm; Sr 5400 ppm; and Mn 500 ppm. Element-element plots for dolomite-bearing samples show elevated Mg, Na, and Sr values compared with most other low-Mg calcite New Zealand Cenozoic limestones. The increased trace element contents are directly attributable to the trace element-enriched nature of the burial-derived dolomites, termed here the "dolomite effect". Fe levels in the Tikorangi Formation carbonates far exceed both modern and ancient cool-water and warm-water analogues, while Sr values are also higher than those in modern Tasmanian cool-water carbonates, and approach modern Bahaman warm-water carbonate values. Trace element data used in conjunction with more traditional petrographic data have aided in the diagenetic interpretation of the carbonate-dominated Tikorangi sequence. The geochemical results have been particularly useful for providing more definitive evidence for deep burial dolomitisation of the deposits under the influence of marine-modified pore fluids.

text: Discriminating cool-water from warm-water carbonates and their diagenetic environments using element geochemistry: the Oligocene Tikorangi Formation (Taranaki Basin) and the dolomite effect Fields portrayed within bivariate element plots have been used to distinguish between carbonates formed in warm- (tropical) water and cool- (temperate) water depositional settings. Here, element concentrations (Ca, Mg, Sr, Na, Fe, and Mn) have been determined for the carbonate fraction of bulk samples from the late Oligocene Tikorangi Formation, a subsurface, mixed dolomite-calcite, cool-water limestone sequence in Taranaki Basin, New Zealand. While the occurrence of dolomite is rare in New Zealand Cenozoic carbonates, and in cool-water carbonates more generally, the dolomite in the Tikorangi carbonates is shown to have a dramatic effect on the "traditional" positioning of cool-water limestone fields within bivariate element plots. Rare undolomitised, wholly calcitic carbonate samples in the Tikorangi Formation have the following average composition: Mg 2800 ppm; Ca 319 100 ppm; Na 800 ppm; Fe 6300 ppm; Sr 2400 ppm; and Mn 300 ppm. Tikorangi Formation dolomite-rich samples (>15% dolomite) have average values of: Mg 53 400 ppm; Ca 290 400 ppm; Na 4700 ppm; Fe 28 100 ppm; Sr 5400 ppm; and Mn 500 ppm. Element-element plots for dolomite-bearing samples show elevated Mg, Na, and Sr values compared with most other low-Mg calcite New Zealand Cenozoic limestones. The increased trace element contents are directly attributable to the trace element-enriched nature of the burial-derived dolomites, termed here the "dolomite effect". Fe levels in the Tikorangi Formation carbonates far exceed both modern and ancient cool-water and warm-water analogues, while Sr values are also higher than those in modern Tasmanian cool-water carbonates, and approach modern Bahaman warm-water carbonate values. Trace element data used in conjunction with more traditional petrographic data have aided in the diagenetic interpretation of the carbonate-dominated Tikorangi sequence. The geochemical results have been particularly useful for providing more definitive evidence for deep burial dolomitisation of the deposits under the influence of marine-modified pore fluids.

year: 2004-12-01

title: Listening and Learning from Rangatahi Māori: the Voices of Māori Youth

authors: Berryman, Mere

subjects: student self-determination

abstract: This paper presents three stories-over-time of the secondary schooling experiences of New Zealand’s rangatahi Māori–or Māori youth. The stories span fifteen years of New Zealand schooling and are told from three perspectives: the experiences of the students as told in their own words; the voices of youth within the prevailing political contexts of government policy; and, the reframing and repositioning of researchers listening to the experiences of rangatahi Māori who believe they have succeeded as Māori. In reality, the stories are interwoven, however, in an effort to make sense of the various methodological dilemmas, risks, and entanglements across the three points of learning, we have endeavored to disentangle these different threads from the whole and follow these independent of each other. We then weave these threads together again, as we sense-make across this complexity to identify implications for other educators, policy makers and researchers.

text: Listening and Learning from Rangatahi Māori: the Voices of Māori Youth This paper presents three stories-over-time of the secondary schooling experiences of New Zealand’s rangatahi Māori–or Māori youth. The stories span fifteen years of New Zealand schooling and are told from three perspectives: the experiences of the students as told in their own words; the voices of youth within the prevailing political contexts of government policy; and, the reframing and repositioning of researchers listening to the experiences of rangatahi Māori who believe they have succeeded as Māori. In reality, the stories are interwoven, however, in an effort to make sense of the various methodological dilemmas, risks, and entanglements across the three points of learning, we have endeavored to disentangle these different threads from the whole and follow these independent of each other. We then weave these threads together again, as we sense-make across this complexity to identify implications for other educators, policy makers and researchers.

year: 2017