title: Volcanic and sedimentary geology of the basaltic Karaka Volcano, South Auckland

authors: Hansen, Madison Keddie Ivy

subjects: volcano

abstract: Intraplate monogenetic volcanic fields are a common volcanic feature of the upper western North Island. There are four geographically related fields, approximately 38 km apart which young northwards from Raglan to Auckland. The South Auckland Volcanic Field (SAVF; 1.56–0.51 Ma) is older and more degraded than the Auckland Volcanic Field (AVF; active since 250 ka) to the north. Located between the two fields and overlying the Late Pliocene to Mid-Pleistocene pumiceous fluvial deposits of the Puketoka Formation, is the newly discovered Karaka Volcano. Although residents had referred to a volcanic landform in the area, it was in 2018 that evidence for a volcano based on geomorphology, a magnetic anomaly, weathered surficial deposits and water bore data was reported.

This thesis will present the recent findings of the volcano-sedimentary geology of the Karaka volcano. Evidence is based on stratigraphic analysis of two new drill cores, a complementary resistivity survey, petrography, scanning electron microscopy and geochemical investigations. One drill core intersected an upper 6 m blanket of Hamilton Ash Formation and a lower 7 m succession of interbedded, laminated dark brown organic-rich silts, and distal tephras. The lower succession is consistent with lake sediments associated with a crater lake within the geomorphic tuff ring. The second drill core, on the central high point of the volcanic landform, intersected an upper 6 m of brown and red clay. Beneath this, is a lower 9.5 m succession of volcanic ash, coarsening downwards, to a basaltic lapilli ash deposit with a lithic-rich matrix. This represents a phreatomagmatic phase in the upper part of the volcanic sequence. The resistivity survey connects the two drill holes giving an indication of extent and layering of the geology beneath the surface. No recognised volcanoes are within 5 km of this site, so it is unlikely that this pyroclastic deposit came from a distal vent, despite its isolated location outside of the predefined margins of the South Auckland and Auckland volcanic fields. 

Basalt lapilli within the pyroclastic succession are porphyritic with a trachytic to glassy groundmass with predominant phenocrysts of olivine, augite, opaque minerals and plagioclase. Geochemical analysis was conducted on whole rock samples of basalt lapilli by X-ray fluorescence spectroscopy (XRF) and on pyroxene, olivine, plagioclase and zeolites by electron probe microanalysis (EPMA). This data identified Karaka Basalt as a member of the Group B basalts of the SAVF. Lithics were fragments of the underlying sandstone and siltstone of the Waitemata Group.  The surrounding matrix comprised small basalt fragments, lithics, quartz and plagioclase.

Glass compositions of tephra by EPMA provide information that has been used to produce a tentative minimum age on the crater lake and by proxy the volcano itself. Tephra TW gives a possible correlation to the Kidnappers Ignimbrite which has been dated previously at ~0.99 Ma. The age of this tephra along with belonging to the SAVF, and a covering of Kauroa and Hamilton Ashes, gives the Karaka Volcano an approximate age range of 1.56 – 0.99 Ma.

text: Volcanic and sedimentary geology of the basaltic Karaka Volcano, South Auckland Intraplate monogenetic volcanic fields are a common volcanic feature of the upper western North Island. There are four geographically related fields, approximately 38 km apart which young northwards from Raglan to Auckland. The South Auckland Volcanic Field (SAVF; 1.56–0.51 Ma) is older and more degraded than the Auckland Volcanic Field (AVF; active since 250 ka) to the north. Located between the two fields and overlying the Late Pliocene to Mid-Pleistocene pumiceous fluvial deposits of the Puketoka Formation, is the newly discovered Karaka Volcano. Although residents had referred to a volcanic landform in the area, it was in 2018 that evidence for a volcano based on geomorphology, a magnetic anomaly, weathered surficial deposits and water bore data was reported.

This thesis will present the recent findings of the volcano-sedimentary geology of the Karaka volcano. Evidence is based on stratigraphic analysis of two new drill cores, a complementary resistivity survey, petrography, scanning electron microscopy and geochemical investigations. One drill core intersected an upper 6 m blanket of Hamilton Ash Formation and a lower 7 m succession of interbedded, laminated dark brown organic-rich silts, and distal tephras. The lower succession is consistent with lake sediments associated with a crater lake within the geomorphic tuff ring. The second drill core, on the central high point of the volcanic landform, intersected an upper 6 m of brown and red clay. Beneath this, is a lower 9.5 m succession of volcanic ash, coarsening downwards, to a basaltic lapilli ash deposit with a lithic-rich matrix. This represents a phreatomagmatic phase in the upper part of the volcanic sequence. The resistivity survey connects the two drill holes giving an indication of extent and layering of the geology beneath the surface. No recognised volcanoes are within 5 km of this site, so it is unlikely that this pyroclastic deposit came from a distal vent, despite its isolated location outside of the predefined margins of the South Auckland and Auckland volcanic fields. 

Basalt lapilli within the pyroclastic succession are porphyritic with a trachytic to glassy groundmass with predominant phenocrysts of olivine, augite, opaque minerals and plagioclase. Geochemical analysis was conducted on whole rock samples of basalt lapilli by X-ray fluorescence spectroscopy (XRF) and on pyroxene, olivine, plagioclase and zeolites by electron probe microanalysis (EPMA). This data identified Karaka Basalt as a member of the Group B basalts of the SAVF. Lithics were fragments of the underlying sandstone and siltstone of the Waitemata Group.  The surrounding matrix comprised small basalt fragments, lithics, quartz and plagioclase.

Glass compositions of tephra by EPMA provide information that has been used to produce a tentative minimum age on the crater lake and by proxy the volcano itself. Tephra TW gives a possible correlation to the Kidnappers Ignimbrite which has been dated previously at ~0.99 Ma. The age of this tephra along with belonging to the SAVF, and a covering of Kauroa and Hamilton Ashes, gives the Karaka Volcano an approximate age range of 1.56 – 0.99 Ma.

year: 2020

title: Intramolecular OH∙∙∙π interactions in alkenols and alkynols

authors: Miller, Benjamin J.

subjects: chemistry

abstract: The vibrational overtone spectra of propargyl alcohol (prop-2-yn-1-ol, PA), allyl alcohol (prop-2-en-1-ol, AA), propargyl carbinol (but-3-yn-1-ol, PC) and allyl carbinol (but-3-en-1-ol, AC) were recorded with intracavity laser photoacoustic spectroscopy (ICL-PAS) in the ΔvOH = 3, 4 and 5 regions for propargyl alcohol and allyl alcohol and in the ΔvOH = 4 and 5 regions for propargyl carbinol and allyl carbinol. Local mode anharmonic oscillator calculations were performed with explicitly correlated coupled cluster methods to guide spectral assignment. Atoms in molecules (AIM) and non-covalent interactions (NCI) calculations were carried out to analyze the interactions between the OH-group and the π-electrons of the carbon–carbon multiple bonds. We ascertain the effect of the carbon chain length and saturation on the conformation and spectroscopy of the four alcohols in relation to intramolecular hydrogen bonding interactions.

text: Intramolecular OH∙∙∙π interactions in alkenols and alkynols The vibrational overtone spectra of propargyl alcohol (prop-2-yn-1-ol, PA), allyl alcohol (prop-2-en-1-ol, AA), propargyl carbinol (but-3-yn-1-ol, PC) and allyl carbinol (but-3-en-1-ol, AC) were recorded with intracavity laser photoacoustic spectroscopy (ICL-PAS) in the ΔvOH = 3, 4 and 5 regions for propargyl alcohol and allyl alcohol and in the ΔvOH = 4 and 5 regions for propargyl carbinol and allyl carbinol. Local mode anharmonic oscillator calculations were performed with explicitly correlated coupled cluster methods to guide spectral assignment. Atoms in molecules (AIM) and non-covalent interactions (NCI) calculations were carried out to analyze the interactions between the OH-group and the π-electrons of the carbon–carbon multiple bonds. We ascertain the effect of the carbon chain length and saturation on the conformation and spectroscopy of the four alcohols in relation to intramolecular hydrogen bonding interactions.

year: 2011

title: An evaluation of the effectiveness of social equity strategies for Maori students in the School of Science and Technology

authors: Rua, Mohi

subjects: Maori students

abstract: In 1991 the School of Science and Technology (SOSAT) at the University of Waikato
had a very low participation rate of Maori and students from other non-dominant
ethnic groups. This situation was serious enough to concerned the then Dean of the
School and strategies were developed to change this situation. Four major strategies
are used to encourage, support and retain Maori students to successfully pursue and
complete a degree in Science. They are: the Te Putahi o te Manawa programme - a
mentoring programme; a scholarship and grant writing strategy (in particular
assistance with Tuapapa Putaiao Maori Fellowships(TPMFs) administered by FRST);
school visits; and field trips with secondary schools in the Waikato region that have a
high proportion of Maori students. The Maori & Psychology Research Unit (MPRU) was contracted by Gary Bramley of
the Equity Office of the SOSAT to conduct this evaluation. Evaluative information was gathered through administering questionnaires,
completing key informant interviews, and completing focus group interviews. In this evaluation we sought to determine the effectiveness of the social equity
strategies for Maori students in the SOSAT at the University of Waikato.

text: An evaluation of the effectiveness of social equity strategies for Maori students in the School of Science and Technology In 1991 the School of Science and Technology (SOSAT) at the University of Waikato
had a very low participation rate of Maori and students from other non-dominant
ethnic groups. This situation was serious enough to concerned the then Dean of the
School and strategies were developed to change this situation. Four major strategies
are used to encourage, support and retain Maori students to successfully pursue and
complete a degree in Science. They are: the Te Putahi o te Manawa programme - a
mentoring programme; a scholarship and grant writing strategy (in particular
assistance with Tuapapa Putaiao Maori Fellowships(TPMFs) administered by FRST);
school visits; and field trips with secondary schools in the Waikato region that have a
high proportion of Maori students. The Maori & Psychology Research Unit (MPRU) was contracted by Gary Bramley of
the Equity Office of the SOSAT to conduct this evaluation. Evaluative information was gathered through administering questionnaires,
completing key informant interviews, and completing focus group interviews. In this evaluation we sought to determine the effectiveness of the social equity
strategies for Maori students in the SOSAT at the University of Waikato.

year: 1999-11-11