title: Aroha

authors: Maxwell, Te Kahautu

abstract: Waita Tira. Lyrics composed by Te Kahautu Maxwell, muscial score composed by Raharuha Mitai, Thomas Mitai, Renee Mitai. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group) (3mins)

Waiata ā Tira: Aroha
Whakaeke: Pinepine Te Kura
Mōteatea: Tērā te haeata
Waiata ā Ringa: Tiaho Mai
Poi: E ia, e ia
Haka: Ranginui
Whakawātea: Te Tiriti o Waitangi

text: Aroha Waita Tira. Lyrics composed by Te Kahautu Maxwell, muscial score composed by Raharuha Mitai, Thomas Mitai, Renee Mitai. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group) (3mins)

Waiata ā Tira: Aroha
Whakaeke: Pinepine Te Kura
Mōteatea: Tērā te haeata
Waiata ā Ringa: Tiaho Mai
Poi: E ia, e ia
Haka: Ranginui
Whakawātea: Te Tiriti o Waitangi

year: 2020-02-06

title: Marine inequality, borderization, and the radical potential of kinship

authors: McCormack, Fiona

subjects: Aquaculture

abstract: This article utilizes scholarship on borders to interpret the persistence of inequality in Indigenous seascapes, irrespective of moves to redress colonial wrongs or the growing anthropocenic recognition of human-nature interconnectedness. I examine border politics in the context of Māori claims for marine title and rights and the post-settlement development of aquaculture. Drawing on Harsha Walia’s concept of “border imperialism” and Achille Mbembe’s thesis on “borderization,” the article highlights the endurance of colonial forms alongside their neoliberal transformation into the enclosures and entrapments arising in the context of accelerated marine industrialization. By holding in tension the interconnection between marine environments and kinship, on one hand, and scholarship on borders, on the other, the article suggests that Indigenous Māori kinship, expanding through multiple layers of difference, constitutes a site of resistance that has the potential to refute the logic of borderization.

text: Marine inequality, borderization, and the radical potential of kinship This article utilizes scholarship on borders to interpret the persistence of inequality in Indigenous seascapes, irrespective of moves to redress colonial wrongs or the growing anthropocenic recognition of human-nature interconnectedness. I examine border politics in the context of Māori claims for marine title and rights and the post-settlement development of aquaculture. Drawing on Harsha Walia’s concept of “border imperialism” and Achille Mbembe’s thesis on “borderization,” the article highlights the endurance of colonial forms alongside their neoliberal transformation into the enclosures and entrapments arising in the context of accelerated marine industrialization. By holding in tension the interconnection between marine environments and kinship, on one hand, and scholarship on borders, on the other, the article suggests that Indigenous Māori kinship, expanding through multiple layers of difference, constitutes a site of resistance that has the potential to refute the logic of borderization.

year: 2025

title: Characteristics and origin of hydrothermal pebble dykes and associated host rock alteration on the Thames coast, Coromandel Volcanic Zone

authors: Harvey-Wishart, Holly

abstract: During the Miocene to early Pliocene (c. 18 Ma to 2 Ma), subduction-related  volcanism migrated down the Coromandel Peninsula forming the Coromandel  Volcanic Zone. This period resulted in the development of extensive  hydrothermal systems which interacted with the associated volcanic sequences, the Coromandel Group andesites and dacites. As well as introducing extensive alteration and epithermal Au-Ag deposits, the active environment resulted in the emplacement of co-hydrothermal pebble dyke units. Examples of these features have been identified on the Coromandel west coast, exposed as bodies of fractured rock material, hosting well-rounded clasts due to milling during transport forming “pebbles”. This material has been incorporated from a variety of lithologies from different stratigraphic depths, providing a ground surface expression of the subsurface. As the formation of these dykes is not well defined, whether they are a result of volcanic or hydrothermal activity, this study aims to investigate their origin and the influence they may have had on the character of proximal hydrothermal alteration.  

A combination of field descriptions, optical petrology, SEM, XRD, XRF and ICP-MS geochemistry was all involved in investigating the study site along the Thames coastline, where two clusters of dykes are exposed within a ~ 600 m span of beach. The local hydrothermal character was determined from the mineralogy, reflective of the fluids and physical conditions involved in the mineralization of altered products. The extent of the site hosts multiple alteration zones, recognised as propylitic and phyllic alteration associated with periods of mineralisation, and supergene argillic overprinting.  The gangue mineralogy also mirrors the character of the broader system, reflecting near-neutral fluids associated with the low-sulfidation epithermal environment at temperatures of  ~ 240 – 260 °C. 

To understand the role of the pebble dykes within this setting and the origin of their deposits, identifying the mechanisms involved in their formation is crucial. Characteristics of dyke morphologies, clast lithologies and morphologies, and  alteration character suggest fluidisation played a large role, particularly so in the 
transport of fragmented rock material from depth. The extent of their ascent is best reflected by the occurrences of greywacke argillite and sandstone components found in each of the exposures. These lithologies are sourced from the Manaia Hill group of the Waipapa Terrane, a deep basement unit recognised  as the basement rock of New Zealand. Therefore, the presence of greywacke and argillite clasts suggest possible significant depths of material transport and the interaction with high volumes of hydrothermal solutions. However, due to the alteration style and morphologies of the clasts, it is also possible they were instead fragmented at similar depths to the shallower local volcanic stratigraphy.  If pebble dykes were to act as permeable pathways for ore-bearing solutions within a hydrothermal system, it is possible they could play a significant role in the concentration of metals in economically viable quantities. Therefore, under the right circumstances; emplacement during or pre-mineralisation, orientated preferential to fluid flow direction and hosted within otherwise impermeable host rock, they could yet act as a vector towards potential mineralisation.

text: Characteristics and origin of hydrothermal pebble dykes and associated host rock alteration on the Thames coast, Coromandel Volcanic Zone During the Miocene to early Pliocene (c. 18 Ma to 2 Ma), subduction-related  volcanism migrated down the Coromandel Peninsula forming the Coromandel  Volcanic Zone. This period resulted in the development of extensive  hydrothermal systems which interacted with the associated volcanic sequences, the Coromandel Group andesites and dacites. As well as introducing extensive alteration and epithermal Au-Ag deposits, the active environment resulted in the emplacement of co-hydrothermal pebble dyke units. Examples of these features have been identified on the Coromandel west coast, exposed as bodies of fractured rock material, hosting well-rounded clasts due to milling during transport forming “pebbles”. This material has been incorporated from a variety of lithologies from different stratigraphic depths, providing a ground surface expression of the subsurface. As the formation of these dykes is not well defined, whether they are a result of volcanic or hydrothermal activity, this study aims to investigate their origin and the influence they may have had on the character of proximal hydrothermal alteration.  

A combination of field descriptions, optical petrology, SEM, XRD, XRF and ICP-MS geochemistry was all involved in investigating the study site along the Thames coastline, where two clusters of dykes are exposed within a ~ 600 m span of beach. The local hydrothermal character was determined from the mineralogy, reflective of the fluids and physical conditions involved in the mineralization of altered products. The extent of the site hosts multiple alteration zones, recognised as propylitic and phyllic alteration associated with periods of mineralisation, and supergene argillic overprinting.  The gangue mineralogy also mirrors the character of the broader system, reflecting near-neutral fluids associated with the low-sulfidation epithermal environment at temperatures of  ~ 240 – 260 °C. 

To understand the role of the pebble dykes within this setting and the origin of their deposits, identifying the mechanisms involved in their formation is crucial. Characteristics of dyke morphologies, clast lithologies and morphologies, and  alteration character suggest fluidisation played a large role, particularly so in the 
transport of fragmented rock material from depth. The extent of their ascent is best reflected by the occurrences of greywacke argillite and sandstone components found in each of the exposures. These lithologies are sourced from the Manaia Hill group of the Waipapa Terrane, a deep basement unit recognised  as the basement rock of New Zealand. Therefore, the presence of greywacke and argillite clasts suggest possible significant depths of material transport and the interaction with high volumes of hydrothermal solutions. However, due to the alteration style and morphologies of the clasts, it is also possible they were instead fragmented at similar depths to the shallower local volcanic stratigraphy.  If pebble dykes were to act as permeable pathways for ore-bearing solutions within a hydrothermal system, it is possible they could play a significant role in the concentration of metals in economically viable quantities. Therefore, under the right circumstances; emplacement during or pre-mineralisation, orientated preferential to fluid flow direction and hosted within otherwise impermeable host rock, they could yet act as a vector towards potential mineralisation.

year: 2020