title: Silicic volcanism of the Tauranga Volcanic Centre and the climactic Waiteariki supereruption at the dawn of the Taupō Volcanic Zone

authors: Prentice, Marlena Lee

subjects: Volcanism

abstract: The Tauranga Volcanic Centre (TgaVC), located in the western Bay of Plenty, Aotearoa New Zealand was active between 2.9–1.9 Ma.  Silicic volcanism of this period occurred spatially and temporally between the defined locations of the Taupō Volcanic Zone (TVZ) and its predecessor, the Coromandel Volcanic Zone (CVZ), but despite their prominence, the volcanic origin, eruption dynamics and petrogenetic relationships of the volcanic deposits of this period have not previously been studied in detail.  This study combines a comprehensive field study with whole-rock, glass and mineral geochemistry and isotopic (Sr, Nd and O) analysis to interpret the origin, evolution and petrogenetic relations of the volcanic deposits of the TgaVC, with particular emphasis on the deposits of the Waiteariki Ignimbrite.   
This thesis provides an enhanced chronology for explosive volcanism of the TgaVC with four locally widespread units named and defined as follows: Welcome Bay and Wharo ignimbrites (together formerly known as Lower Pāpāmoa Ignimbrite); Otawera Ignimbrite; and Arateka Ignimbrite (formerly known as Upper Pāpāmoa Ignimbrite).  These eruptives were followed by the eruption of the voluminous (870 ± 87 km³ DRE) Waiteariki Ignimbrite at 2.1 Ma which has been correlated with the distal Hikuroa Pumice Member in northern Hawke’s Bay (150-170 km southeast of TgaVC).  The integrated proximal and distal records show that at least eight eruptions occurred in the TgaVC between 2.4 and 1.9 Ma and provide a maximum repose period between explosive eruptions of ca. 50 kyrs. 
The magnitude 8 (M8) Waiteariki super-eruption consisted of the eruption of crystal-rich rhyodacite magma from the newly defined Omanawa Caldera, identified here on the basis of ignimbrite thickness variations, textural features and the presence of numerous silicic lava domes in association with a prominent negative gravity anomaly situated at the southern end of an asymmetrical rifted graben underlying the northern Mamaku Plateau.  The Waiteariki Ignimbrite is a monotonous intermediate deposit, characterised by crystal-rich (37 %), rhyodacite (ave. 70.7 wt. % SiO₂) magma with a consistent mineralogical assemblage of plagioclase, hornblende, pyroxene, quartz ± biotite; restricted ranges in whole-rock geochemistry and matrix glass compositions; and the complete absence of compositional gradients and a precursory Plinian phase.  Phenocrysts, however, record a complex evolutionary history, providing evidence for a highly heterogeneous mush-source zone.
Individual lavas of the Minden Rhyolite Subgroup of the TgaVC can be grouped into either low- and high-⁸⁷Sr/⁸⁶Sr magmas exclusively erupted in the west and east, respectively.  Juvenile products within the Waiteariki and Welcome Bay ignimbrites are mineralogically, geochemically, and isotopically consistent with the high-⁸⁷Sr/⁸⁶Sr Minden Rhyolites, which connects these domes to the magmatic system underlying the Omanawa Caldera.  Nd and Sr isotopic values across the TgaVC are comparable to those of the broader TVZ.  Calculated δ¹⁸Oₘₑₗₜ values for the TgaVC magmas indicate a temporal trend of decreasing δ¹⁸Ovalues in the TVZ through time.  Upper crustal differentiation was dominated by fractional crystallisation (i.e western domes) or assimilation-fractional crystallisation followed by mixing of magmas (Omanawa magma body and eastern domes) while segregated melts (e.g. Bowentown, Mt Maunganui, Maungatūtū/Mt Misery) have unique late-stage differentiation histories.  
As volcanism associated with the Omanawa Caldera and the broader TgaVC occurred within the defined structural boundaries of the Taupō Rift, volcanism of the TgaVC is regarded here to represent the first silicic system of the TVZ.  Geothermobarometry indicate crystallisation and storage occurred within the mid- to shallow crust (c. 3.5 to 6 km depth) between 50-160 MPa and 740-900 °C indicating that magmas have broadly resided under near-identical, shallow conditions over the lifespan of the TVZ (~2.5 Ma).  Dominated by high-silica, crystal-poor rhyolitic magmas, the continued eruption of homogenous, crystal-rich magmas throughout the TgaVC is unique within the context of the TVZ and it is inferred that active crustal rifting enabled continual tapping of the crystal-mush reservoir which culminated in a deep-seated failure of the magma reservoir, followed by rapid decompression and large-scale evacuation of the Omanawa magmatic system.

text: Silicic volcanism of the Tauranga Volcanic Centre and the climactic Waiteariki supereruption at the dawn of the Taupō Volcanic Zone The Tauranga Volcanic Centre (TgaVC), located in the western Bay of Plenty, Aotearoa New Zealand was active between 2.9–1.9 Ma.  Silicic volcanism of this period occurred spatially and temporally between the defined locations of the Taupō Volcanic Zone (TVZ) and its predecessor, the Coromandel Volcanic Zone (CVZ), but despite their prominence, the volcanic origin, eruption dynamics and petrogenetic relationships of the volcanic deposits of this period have not previously been studied in detail.  This study combines a comprehensive field study with whole-rock, glass and mineral geochemistry and isotopic (Sr, Nd and O) analysis to interpret the origin, evolution and petrogenetic relations of the volcanic deposits of the TgaVC, with particular emphasis on the deposits of the Waiteariki Ignimbrite.   
This thesis provides an enhanced chronology for explosive volcanism of the TgaVC with four locally widespread units named and defined as follows: Welcome Bay and Wharo ignimbrites (together formerly known as Lower Pāpāmoa Ignimbrite); Otawera Ignimbrite; and Arateka Ignimbrite (formerly known as Upper Pāpāmoa Ignimbrite).  These eruptives were followed by the eruption of the voluminous (870 ± 87 km³ DRE) Waiteariki Ignimbrite at 2.1 Ma which has been correlated with the distal Hikuroa Pumice Member in northern Hawke’s Bay (150-170 km southeast of TgaVC).  The integrated proximal and distal records show that at least eight eruptions occurred in the TgaVC between 2.4 and 1.9 Ma and provide a maximum repose period between explosive eruptions of ca. 50 kyrs. 
The magnitude 8 (M8) Waiteariki super-eruption consisted of the eruption of crystal-rich rhyodacite magma from the newly defined Omanawa Caldera, identified here on the basis of ignimbrite thickness variations, textural features and the presence of numerous silicic lava domes in association with a prominent negative gravity anomaly situated at the southern end of an asymmetrical rifted graben underlying the northern Mamaku Plateau.  The Waiteariki Ignimbrite is a monotonous intermediate deposit, characterised by crystal-rich (37 %), rhyodacite (ave. 70.7 wt. % SiO₂) magma with a consistent mineralogical assemblage of plagioclase, hornblende, pyroxene, quartz ± biotite; restricted ranges in whole-rock geochemistry and matrix glass compositions; and the complete absence of compositional gradients and a precursory Plinian phase.  Phenocrysts, however, record a complex evolutionary history, providing evidence for a highly heterogeneous mush-source zone.
Individual lavas of the Minden Rhyolite Subgroup of the TgaVC can be grouped into either low- and high-⁸⁷Sr/⁸⁶Sr magmas exclusively erupted in the west and east, respectively.  Juvenile products within the Waiteariki and Welcome Bay ignimbrites are mineralogically, geochemically, and isotopically consistent with the high-⁸⁷Sr/⁸⁶Sr Minden Rhyolites, which connects these domes to the magmatic system underlying the Omanawa Caldera.  Nd and Sr isotopic values across the TgaVC are comparable to those of the broader TVZ.  Calculated δ¹⁸Oₘₑₗₜ values for the TgaVC magmas indicate a temporal trend of decreasing δ¹⁸Ovalues in the TVZ through time.  Upper crustal differentiation was dominated by fractional crystallisation (i.e western domes) or assimilation-fractional crystallisation followed by mixing of magmas (Omanawa magma body and eastern domes) while segregated melts (e.g. Bowentown, Mt Maunganui, Maungatūtū/Mt Misery) have unique late-stage differentiation histories.  
As volcanism associated with the Omanawa Caldera and the broader TgaVC occurred within the defined structural boundaries of the Taupō Rift, volcanism of the TgaVC is regarded here to represent the first silicic system of the TVZ.  Geothermobarometry indicate crystallisation and storage occurred within the mid- to shallow crust (c. 3.5 to 6 km depth) between 50-160 MPa and 740-900 °C indicating that magmas have broadly resided under near-identical, shallow conditions over the lifespan of the TVZ (~2.5 Ma).  Dominated by high-silica, crystal-poor rhyolitic magmas, the continued eruption of homogenous, crystal-rich magmas throughout the TgaVC is unique within the context of the TVZ and it is inferred that active crustal rifting enabled continual tapping of the crystal-mush reservoir which culminated in a deep-seated failure of the magma reservoir, followed by rapid decompression and large-scale evacuation of the Omanawa magmatic system.

year: 2023

title: Corporate Governance and Performance of Microfinance Institutions (MFIs): A Comparative Study in Sri Lanka and India

authors: Thrikawala, Sujani Sudhara

subjects: Corporate Governance

abstract: This thesis investigates the impact of corporate governance practices on financial performance and outreach of microfinance institutions (MFIs) in Sri Lanka and India. Guidance and principles developed from prior research which has predominantly focussed on corporate governance relating to corporations in mature financial markets may not be efficacious. There is a need for a more specific approach to identify better governance structures for the microfinance sector which will support MFIs to attain long-term sustainability of the industry. In order to contribute to this debate, this research examines (i) the relationship between corporate governance practices, financial performance and outreach of Sri Lankan MFIs (ii) the relationship between corporate governance practices, financial performance and outreach of Indian MFIs (iii) MFIs’ corporate governance and performance differences between Sri Lanka and India and (iv) the relationship between corporate governance and performance of MFIs based on a combined sample and considering the influence of national governance quality.
A study of corporate governance in the microfinance sector is timely and important as unfair practice accusations against MFIs raise questions around what is an appropriate framework for monitoring and control of MFI activities. A well-structured corporate governance practice may reduce the impact of corruption and undue bureaucracy by increasing transparency and accountability of funds utilised in microfinance activities. Even though studies of corporate governance and firm performance in mature markets are largely and rapidly evolving, their impact on MFI performance is little researched and reported. It is argued that MFIs which maintain good corporate governance practices will be financially and socially sustainable.
This thesis makes a number of contributions to the existing knowledge of corporate governance and MFI performance in several ways. First, it provides evidence from Sri Lanka and India of what aspects of corporate governance need to be strengthened and how much impact each individual component has on MFI financial performance and outreach. Second, the study identifies the importance of considering differences in institutional values, culture, and the environment of each country and points to the risk of applying normative assertions of corporate governance practices in the microfinance sector. Third, this study, through careful diagnostic testing, uses microeconometric techniques to control endogeneity which may have negated some findings reported in the literature. In particular, unobserved heterogeneity, simultaneity and dynamic endogeneity inherent in the corporate governance–performance relationship studies are eliminated. Finally, in contrast to extant studies in the microfinance sector, this is the first direct study to accommodate corporate governance, financial performance and outreach of MFIs in both Sri Lanka and India. The impact of cross-country differences in government effectiveness, regulatory quality and rule of law on MFI performance is also considered.
Data needed to test various hypotheses are sourced from the Microfinance Information Exchange (MIX) database, Lanka Microfinance Practitioners' Association (LMFPA) in Sri Lanka and Sa-Dhan, the microfinance network in India. Furthermore, firm-level corporate governance data are collected from the individual institutions by going through their annual reports, individual firm websites and through personally contacting the individual firms. The sample period for the Sri Lankan and Indian MFIs is 2007 to 2012. Fixed-effect, random-effect and system generalised method of moment (GMM) estimator approaches are used to answer the research questions.
In Sri Lanka, female CEO, female chair, larger boards, client representatives on board and internal audit function improve the financial performance of MFIs. When there are more female directors and more international/donor representatives on a board, financial performance declines. The outreach of Sri Lankan MFIs improves when there are more international/donor representatives and fewer client representatives on boards.
In the Indian context, the results indicate that international/donor representatives, client representatives and outside directors on board, and an internal audit function statistically significantly positively correlate with financial performance of MFIs. For female chair and number of female directors on the board there is a negative correlation. However, in India, better outreach can be achieved when there is a female chair and when there are more female directors and more international/donor agencies representatives on the board. Female CEOs and larger boards appear to have negative effect on MFI outreach.
The findings from Sri Lankan MFIs support the prediction of agency theory regarding the effective monitoring impact the performance of MFIs. But it is contrary to the number of board members as larger boards positively associate with MFI financial performance. This is consistent with resource dependency theory as larger boards provide a wide range of expertise and resources for the institution. In a voluntary organisation costs are reduced when board members are involved in a range of activities or functions that might otherwise have been covered by paid staff. This is also a way of aligning board members with senior management. The issue that arises is the extent to which this goal congruence is tilted toward management aspirations and produces a shadow agency cost. Even though agency theory emphasises the negative impact of duality, from the findings of this study it is difficult to make inferences about the separation of CEO and chair is better for MFI financial performance as well as there is no impact for MFI outreach. Findings of Indian analysis are also consistent with the perspectives of agency theory to a large extent, as diversified boards improve MFI financial performance. Similar to Sri Lanka, CEO/chair duality has no effect on MFI financial performance or outreach, which is not consistent with the predictions of agency theory.
Importantly, the results of this study suggest that the impact of corporate governance on MFI performance persists in both countries even after the dynamic nature of the corporate governance and performance relationship is taken into consideration. Financial performance of both countries is improved with larger boards with more client representation. For both countries, more female representatives and outside directors on the board and internal audit function negatively affect MFI financial performance. Outreach in both countries is enhanced with more international/donor representative and fewer outside directors.
Notably, the findings of this study indicate that the relationship between current MFI performance and past (one-year lagged) performance is statistically significantly positive for financial performance and outreach variables in both countries, suggesting that the corporate governance – performance relationship of MFIs should be examined in a dynamic framework. This highlights the importance of considering the past performance as an independent variable for current corporate governance and performance studies in the microfinance sector. Furthermore, this study shows the quality of national governance has a statistically significantly positive effect on financial performance and outreach of MFIs in both countries.
This research demonstrates that corporate governance practices in for-profit companies have some synergies with the microfinance industry. The results reported in this study reflect a deeper commitment to robustness and micro econometric issues than previous studies and this robustness provides a platform for industry and political policy developments that can significantly enhance the quality of life for the poorest and low income people in Sri Lanka and India. The opportunities for microfinance to make a significant difference to the poorest of the poor in low income countries and emerging economies are not waning. Further research in other countries is required to establish if this is a generalisable trend or unique to Sri Lanka and India.
Finally, this research recommends that it is possible to improve corporate governance practices of MFIs in Sri Lanka and India by promulgating a regulatory and supervisory system. The sector needs a strong regulatory framework to strengthen its governance and institutional structures, and to enhance opportunities for the sustainability and development of the microfinance industry.

text: Corporate Governance and Performance of Microfinance Institutions (MFIs): A Comparative Study in Sri Lanka and India This thesis investigates the impact of corporate governance practices on financial performance and outreach of microfinance institutions (MFIs) in Sri Lanka and India. Guidance and principles developed from prior research which has predominantly focussed on corporate governance relating to corporations in mature financial markets may not be efficacious. There is a need for a more specific approach to identify better governance structures for the microfinance sector which will support MFIs to attain long-term sustainability of the industry. In order to contribute to this debate, this research examines (i) the relationship between corporate governance practices, financial performance and outreach of Sri Lankan MFIs (ii) the relationship between corporate governance practices, financial performance and outreach of Indian MFIs (iii) MFIs’ corporate governance and performance differences between Sri Lanka and India and (iv) the relationship between corporate governance and performance of MFIs based on a combined sample and considering the influence of national governance quality.
A study of corporate governance in the microfinance sector is timely and important as unfair practice accusations against MFIs raise questions around what is an appropriate framework for monitoring and control of MFI activities. A well-structured corporate governance practice may reduce the impact of corruption and undue bureaucracy by increasing transparency and accountability of funds utilised in microfinance activities. Even though studies of corporate governance and firm performance in mature markets are largely and rapidly evolving, their impact on MFI performance is little researched and reported. It is argued that MFIs which maintain good corporate governance practices will be financially and socially sustainable.
This thesis makes a number of contributions to the existing knowledge of corporate governance and MFI performance in several ways. First, it provides evidence from Sri Lanka and India of what aspects of corporate governance need to be strengthened and how much impact each individual component has on MFI financial performance and outreach. Second, the study identifies the importance of considering differences in institutional values, culture, and the environment of each country and points to the risk of applying normative assertions of corporate governance practices in the microfinance sector. Third, this study, through careful diagnostic testing, uses microeconometric techniques to control endogeneity which may have negated some findings reported in the literature. In particular, unobserved heterogeneity, simultaneity and dynamic endogeneity inherent in the corporate governance–performance relationship studies are eliminated. Finally, in contrast to extant studies in the microfinance sector, this is the first direct study to accommodate corporate governance, financial performance and outreach of MFIs in both Sri Lanka and India. The impact of cross-country differences in government effectiveness, regulatory quality and rule of law on MFI performance is also considered.
Data needed to test various hypotheses are sourced from the Microfinance Information Exchange (MIX) database, Lanka Microfinance Practitioners' Association (LMFPA) in Sri Lanka and Sa-Dhan, the microfinance network in India. Furthermore, firm-level corporate governance data are collected from the individual institutions by going through their annual reports, individual firm websites and through personally contacting the individual firms. The sample period for the Sri Lankan and Indian MFIs is 2007 to 2012. Fixed-effect, random-effect and system generalised method of moment (GMM) estimator approaches are used to answer the research questions.
In Sri Lanka, female CEO, female chair, larger boards, client representatives on board and internal audit function improve the financial performance of MFIs. When there are more female directors and more international/donor representatives on a board, financial performance declines. The outreach of Sri Lankan MFIs improves when there are more international/donor representatives and fewer client representatives on boards.
In the Indian context, the results indicate that international/donor representatives, client representatives and outside directors on board, and an internal audit function statistically significantly positively correlate with financial performance of MFIs. For female chair and number of female directors on the board there is a negative correlation. However, in India, better outreach can be achieved when there is a female chair and when there are more female directors and more international/donor agencies representatives on the board. Female CEOs and larger boards appear to have negative effect on MFI outreach.
The findings from Sri Lankan MFIs support the prediction of agency theory regarding the effective monitoring impact the performance of MFIs. But it is contrary to the number of board members as larger boards positively associate with MFI financial performance. This is consistent with resource dependency theory as larger boards provide a wide range of expertise and resources for the institution. In a voluntary organisation costs are reduced when board members are involved in a range of activities or functions that might otherwise have been covered by paid staff. This is also a way of aligning board members with senior management. The issue that arises is the extent to which this goal congruence is tilted toward management aspirations and produces a shadow agency cost. Even though agency theory emphasises the negative impact of duality, from the findings of this study it is difficult to make inferences about the separation of CEO and chair is better for MFI financial performance as well as there is no impact for MFI outreach. Findings of Indian analysis are also consistent with the perspectives of agency theory to a large extent, as diversified boards improve MFI financial performance. Similar to Sri Lanka, CEO/chair duality has no effect on MFI financial performance or outreach, which is not consistent with the predictions of agency theory.
Importantly, the results of this study suggest that the impact of corporate governance on MFI performance persists in both countries even after the dynamic nature of the corporate governance and performance relationship is taken into consideration. Financial performance of both countries is improved with larger boards with more client representation. For both countries, more female representatives and outside directors on the board and internal audit function negatively affect MFI financial performance. Outreach in both countries is enhanced with more international/donor representative and fewer outside directors.
Notably, the findings of this study indicate that the relationship between current MFI performance and past (one-year lagged) performance is statistically significantly positive for financial performance and outreach variables in both countries, suggesting that the corporate governance – performance relationship of MFIs should be examined in a dynamic framework. This highlights the importance of considering the past performance as an independent variable for current corporate governance and performance studies in the microfinance sector. Furthermore, this study shows the quality of national governance has a statistically significantly positive effect on financial performance and outreach of MFIs in both countries.
This research demonstrates that corporate governance practices in for-profit companies have some synergies with the microfinance industry. The results reported in this study reflect a deeper commitment to robustness and micro econometric issues than previous studies and this robustness provides a platform for industry and political policy developments that can significantly enhance the quality of life for the poorest and low income people in Sri Lanka and India. The opportunities for microfinance to make a significant difference to the poorest of the poor in low income countries and emerging economies are not waning. Further research in other countries is required to establish if this is a generalisable trend or unique to Sri Lanka and India.
Finally, this research recommends that it is possible to improve corporate governance practices of MFIs in Sri Lanka and India by promulgating a regulatory and supervisory system. The sector needs a strong regulatory framework to strengthen its governance and institutional structures, and to enhance opportunities for the sustainability and development of the microfinance industry.

year: 2016

title: Culture and collaborative conservation? Inter-cultural difference and the Maungatautari Project

authors: Harms, Matthew

subjects: Inter-cultural navigation

abstract: This thesis situates and examines the role of sociocultural difference and biculturalism in the Maungatautari Sanctuary Mountain project, a multi-stakeholder community-based biodiversity conservation project in the Waikato region of New Zealand’s North Island. In the project, Mana Whenua (local indigenous Māori groups) and Pākehā (New Zealanders of British and European descent) from the area endeavour to interact and partner in the non-profit Maungatautari Ecological Island Trust (MEIT) as its primary stakeholder groups. Utilizing sociocultural anthropology, three years of participant observation, participant interviews, fieldwork data and contextualizing history, the role of culture and issues of biculturalism and partnership are examined in relation to the respective sociocultural backgrounds and identity of project participants. Findings indicate that sociocultural difference in the form of varying beliefs, values, attitudes, practices and protocol, and identity/cultural politics have led to dissonance and strained stakeholder interrelations that negatively affected the project. In some instances, a post-colonial ‘neo-paternalism’ marginalised local Māori cultural input and needs in the project. At other times project participants successfully bridged inter-cultural differences. In these occurrences they created a collaborative, complementary, bicultural partnership which valued, sought to understand, and incorporated differing sociocultural aspects, advancing project goals. Further analysis identified an ongoing risk of future multi-stakeholder dissonance relative to culturally-derived disparate views on such issues as cultural harvesting, species reintroductions and care, ecotourism, development on the mountain, and biodiversity research. Normative solutions are identified which can aid Maungatautari stakeholders and other culturally-heterogeneous multi-stakeholder conservation groups work toward and produce inclusive, inter-cultural partnership.

text: Culture and collaborative conservation? Inter-cultural difference and the Maungatautari Project This thesis situates and examines the role of sociocultural difference and biculturalism in the Maungatautari Sanctuary Mountain project, a multi-stakeholder community-based biodiversity conservation project in the Waikato region of New Zealand’s North Island. In the project, Mana Whenua (local indigenous Māori groups) and Pākehā (New Zealanders of British and European descent) from the area endeavour to interact and partner in the non-profit Maungatautari Ecological Island Trust (MEIT) as its primary stakeholder groups. Utilizing sociocultural anthropology, three years of participant observation, participant interviews, fieldwork data and contextualizing history, the role of culture and issues of biculturalism and partnership are examined in relation to the respective sociocultural backgrounds and identity of project participants. Findings indicate that sociocultural difference in the form of varying beliefs, values, attitudes, practices and protocol, and identity/cultural politics have led to dissonance and strained stakeholder interrelations that negatively affected the project. In some instances, a post-colonial ‘neo-paternalism’ marginalised local Māori cultural input and needs in the project. At other times project participants successfully bridged inter-cultural differences. In these occurrences they created a collaborative, complementary, bicultural partnership which valued, sought to understand, and incorporated differing sociocultural aspects, advancing project goals. Further analysis identified an ongoing risk of future multi-stakeholder dissonance relative to culturally-derived disparate views on such issues as cultural harvesting, species reintroductions and care, ecotourism, development on the mountain, and biodiversity research. Normative solutions are identified which can aid Maungatautari stakeholders and other culturally-heterogeneous multi-stakeholder conservation groups work toward and produce inclusive, inter-cultural partnership.

year: 2018