title: Petrogenesis of the Rifted Southern Victoria Land Lithospheric Mantle, Antarctica, Inferred from Petrography, Geochemistry, Thermobarometry and Oxybarometry of Peridotite and Pyroxenite Xenoliths from the Mount Morning Eruptive Centre

authors: Martin, Adam P.

subjects: Science & Technology

abstract: The lithospheric mantle beneath West Antarctica has been characterized using petrology, whole-rock and mineral major element geochemistry, whole-rock trace element chemistry and Mössbauer spectroscopy data obtained on a suite of peridotite (lherzolite and harzburgite) and pyroxenite xenoliths from the Mount Morning eruptive centre, Southern Victoria Land. The timing of pyroxenite formation in Victoria Land overlaps with subduction of the Palaeo-Pacific plate beneath the Gondwana margin and pyroxenite is likely to have formed when fluids derived from, or modified by, melting of the subducting, eclogitic, oceanic crustal plate percolated through peridotite of the lithospheric mantle. Subsequent melting of lithospheric pyroxenite veins similar to those represented in the Mount Morning xenolith suite has contributed to the enriched trace element (and isotope) signatures seen in Cenozoic volcanic rocks from Mount Morning, elsewhere in Victoria Land and Zealandia. In general, the harzburgite xenoliths reflect between 20 and 30% melt depletion. Their depleted element budgets are consistent with Archaean cratonization ages and they have mantle-normalized trace element patterns comparable with typical subcontinental lithospheric mantle. The spinel lherzolite mineral data suggest a similar amount of depletion to that recorded in the harzburgites (20–30%), whereas plagioclase lherzolite mineral data suggest <15% melt depletion. The lherzolite (spinel and plagioclase) xenolith whole-rocks have compositions indicating <20% melt depletion, consistent with Proterozoic to Phanerozoic cratonization ages, and have mantle-normalized trace element patterns comparable with typical depleted mid-ocean ridge mantle. All peridotite xenoliths have undergone a number of melt–rock reaction events. Melting took place mainly in the spinel peridotite stability field, but one plagioclase peridotite group containing high-sodium clinopyroxenes is best modelled by melting in the garnet field. Median oxygen fugacity estimates based on Mössbauer spectroscopy measurements of spinel and pyroxene for spinel-facies conditions in the rifted Antarctic lithosphere are –0·6 Δlog fO₂ at Mount Morning and –1·0 ± 0·1 (1σ) Δlog fO₂ for all of Victoria Land, relative to the fayalite–magnetite–quartz buffer. These values are in good agreement with a calculated global median value of –0·9 ± 0·1 (1σ) Δlog fO₂ for mantle spinel-facies rocks from continental rift systems.

text: Petrogenesis of the Rifted Southern Victoria Land Lithospheric Mantle, Antarctica, Inferred from Petrography, Geochemistry, Thermobarometry and Oxybarometry of Peridotite and Pyroxenite Xenoliths from the Mount Morning Eruptive Centre The lithospheric mantle beneath West Antarctica has been characterized using petrology, whole-rock and mineral major element geochemistry, whole-rock trace element chemistry and Mössbauer spectroscopy data obtained on a suite of peridotite (lherzolite and harzburgite) and pyroxenite xenoliths from the Mount Morning eruptive centre, Southern Victoria Land. The timing of pyroxenite formation in Victoria Land overlaps with subduction of the Palaeo-Pacific plate beneath the Gondwana margin and pyroxenite is likely to have formed when fluids derived from, or modified by, melting of the subducting, eclogitic, oceanic crustal plate percolated through peridotite of the lithospheric mantle. Subsequent melting of lithospheric pyroxenite veins similar to those represented in the Mount Morning xenolith suite has contributed to the enriched trace element (and isotope) signatures seen in Cenozoic volcanic rocks from Mount Morning, elsewhere in Victoria Land and Zealandia. In general, the harzburgite xenoliths reflect between 20 and 30% melt depletion. Their depleted element budgets are consistent with Archaean cratonization ages and they have mantle-normalized trace element patterns comparable with typical subcontinental lithospheric mantle. The spinel lherzolite mineral data suggest a similar amount of depletion to that recorded in the harzburgites (20–30%), whereas plagioclase lherzolite mineral data suggest <15% melt depletion. The lherzolite (spinel and plagioclase) xenolith whole-rocks have compositions indicating <20% melt depletion, consistent with Proterozoic to Phanerozoic cratonization ages, and have mantle-normalized trace element patterns comparable with typical depleted mid-ocean ridge mantle. All peridotite xenoliths have undergone a number of melt–rock reaction events. Melting took place mainly in the spinel peridotite stability field, but one plagioclase peridotite group containing high-sodium clinopyroxenes is best modelled by melting in the garnet field. Median oxygen fugacity estimates based on Mössbauer spectroscopy measurements of spinel and pyroxene for spinel-facies conditions in the rifted Antarctic lithosphere are –0·6 Δlog fO₂ at Mount Morning and –1·0 ± 0·1 (1σ) Δlog fO₂ for all of Victoria Land, relative to the fayalite–magnetite–quartz buffer. These values are in good agreement with a calculated global median value of –0·9 ± 0·1 (1σ) Δlog fO₂ for mantle spinel-facies rocks from continental rift systems.

year: 2015

title: Exploring usability evaluation of localised software in Malaysia

authors: Yeo, Alvin

abstract: This thesis postulates the theory that software usability evaluation should be adapted to the culture in which it is carried out. An experiment has been conducted to explore the effectiveness of usability assessment tools (UATs). These UATs are studied in the context of usability evaluation phase of the global software development life-cycle. In particular, the study investigates whether imported UATs were appropriate in the usability evaluation of a localised spreadsheet in Malaysia. The experiment reveals that there is some support for the thesis and recommends a further large-scale formal study.

text: Exploring usability evaluation of localised software in Malaysia This thesis postulates the theory that software usability evaluation should be adapted to the culture in which it is carried out. An experiment has been conducted to explore the effectiveness of usability assessment tools (UATs). These UATs are studied in the context of usability evaluation phase of the global software development life-cycle. In particular, the study investigates whether imported UATs were appropriate in the usability evaluation of a localised spreadsheet in Malaysia. The experiment reveals that there is some support for the thesis and recommends a further large-scale formal study.

year: 2002

title: Nga Taumata o te Moana - A return to rangatiratanga over the takutai moana

authors: Downs, Season-Mary

subjects: takutai moana

abstract: The Foreshore and Seabed Act 2004 extinguished Māori customary rights to the foreshore and seabed at law by vesting ownership of the foreshore and seabed in the Crown.   The Act prohibited Māori from having their customary rights recognised at common law by removing the jurisdiction of the courts to investigate customary rights in the takutai moana.  The 2004 Act provided for the recognition of new lesser rights, should Māori be able to meet the tests specified in the legislation.  The legislation was heavily criticised and deemed inconsistent with the treaty,  the rule of law, and international human rights law, where it extinguished the rights of Māori, but not the rights of other right holders.   The legislation was so controversial the 2004 Act was repealed by the Marine and Coastal Area (Takutai Moana) Act 2011.   In the Crown’s mind, the 2011 Act is final, and the longstanding foreshore and seabed dispute related to Māori customary claims to the takutai moana is resolved by the legislation. 

The purpose of the Marine and Coastal Area (Takutai Moana) Act 2011 is to “establish a durable scheme to ensure the protection of the legitimate interests of all New Zealanders” in the takutai moana.    Under the new Act, the takutai moana is now given the special status of “common marine and coastal area”; an area that is “incapable of ownership” by the Crown, Māori or anyone else.   The Act states that it “acknowledges” the “Treaty of Waitangi (Te Tiriti o Waitangi)” and “recognises” the “mana tuku iho” exercised in the common marine and coastal area by iwi, hapū, and whānau as tangata whenua.    Like the 2004 Act, the 2011 Act still bars Māori from obtaining common law customary rights in the takutai moana, and instead puts in place a regime for the recognition of new legal rights that are created by the Act itself.

The primary research question is:  Is the Marine and Coastal Area (Takutai Moana) Act 2011 consistent with te Tiriti o Waitangi, the Māori version of the treaty?

The primary research question is answered by examining the colonial experience of Te Kapotai, a coastal hapū (tribe) in the Southern Bay of Islands from pre-te Tiriti times through to the present day.  It provides an account of how, over time, Crown law, policy and practice have eroded the ability of Te Kapotai to exercise their rangatiratanga (authority) over their takutai moana.  This thesis concludes that the 2011 Act is inconsistent with te Tiriti for four key reasons:
1.	The Act was developed and implemented without negotiation and consent from Māori;
2.	The Act continues to remove the customary rights and procedure for recognition of those rights that were previously available at common law; 
3.	The Act fails to provide for the exercise of rangatiratanga by Māori over the takutai moana as guaranteed under Article 2 of te Tiriti o Waitangi; and 
4.	The Act is in breach of the principle of equity and equal treatment under Article 3 of te Tiriti o Waitangi where it treats Māori and their rights to the takutai moana differently to how all other right/interest holders in the foreshore and seabed are treated.

This research recommends a multifaceted approach to resolving the takutai moana issue, which includes pausing the implementation of the 2011 Act, and the development of interim options to increase Māori participation in the management of the takutai moana.  It promotes that a transformational approach to the takutai moana issue can be achieved when te Tiriti is implemented, and when Māori can exercise rangatiratanga over the takutai moana in a manner that was intended under te Tiriti o Waitangi.

text: Nga Taumata o te Moana - A return to rangatiratanga over the takutai moana The Foreshore and Seabed Act 2004 extinguished Māori customary rights to the foreshore and seabed at law by vesting ownership of the foreshore and seabed in the Crown.   The Act prohibited Māori from having their customary rights recognised at common law by removing the jurisdiction of the courts to investigate customary rights in the takutai moana.  The 2004 Act provided for the recognition of new lesser rights, should Māori be able to meet the tests specified in the legislation.  The legislation was heavily criticised and deemed inconsistent with the treaty,  the rule of law, and international human rights law, where it extinguished the rights of Māori, but not the rights of other right holders.   The legislation was so controversial the 2004 Act was repealed by the Marine and Coastal Area (Takutai Moana) Act 2011.   In the Crown’s mind, the 2011 Act is final, and the longstanding foreshore and seabed dispute related to Māori customary claims to the takutai moana is resolved by the legislation. 

The purpose of the Marine and Coastal Area (Takutai Moana) Act 2011 is to “establish a durable scheme to ensure the protection of the legitimate interests of all New Zealanders” in the takutai moana.    Under the new Act, the takutai moana is now given the special status of “common marine and coastal area”; an area that is “incapable of ownership” by the Crown, Māori or anyone else.   The Act states that it “acknowledges” the “Treaty of Waitangi (Te Tiriti o Waitangi)” and “recognises” the “mana tuku iho” exercised in the common marine and coastal area by iwi, hapū, and whānau as tangata whenua.    Like the 2004 Act, the 2011 Act still bars Māori from obtaining common law customary rights in the takutai moana, and instead puts in place a regime for the recognition of new legal rights that are created by the Act itself.

The primary research question is:  Is the Marine and Coastal Area (Takutai Moana) Act 2011 consistent with te Tiriti o Waitangi, the Māori version of the treaty?

The primary research question is answered by examining the colonial experience of Te Kapotai, a coastal hapū (tribe) in the Southern Bay of Islands from pre-te Tiriti times through to the present day.  It provides an account of how, over time, Crown law, policy and practice have eroded the ability of Te Kapotai to exercise their rangatiratanga (authority) over their takutai moana.  This thesis concludes that the 2011 Act is inconsistent with te Tiriti for four key reasons:
1.	The Act was developed and implemented without negotiation and consent from Māori;
2.	The Act continues to remove the customary rights and procedure for recognition of those rights that were previously available at common law; 
3.	The Act fails to provide for the exercise of rangatiratanga by Māori over the takutai moana as guaranteed under Article 2 of te Tiriti o Waitangi; and 
4.	The Act is in breach of the principle of equity and equal treatment under Article 3 of te Tiriti o Waitangi where it treats Māori and their rights to the takutai moana differently to how all other right/interest holders in the foreshore and seabed are treated.

This research recommends a multifaceted approach to resolving the takutai moana issue, which includes pausing the implementation of the 2011 Act, and the development of interim options to increase Māori participation in the management of the takutai moana.  It promotes that a transformational approach to the takutai moana issue can be achieved when te Tiriti is implemented, and when Māori can exercise rangatiratanga over the takutai moana in a manner that was intended under te Tiriti o Waitangi.

year: 2020