title: Contrasting carbonate depositional systems for Pliocene cool-water limestones cropping out in central Hawke's Bay, New Zealand

authors: Caron, Vincent

subjects: cool-water limestones

abstract: Pliocene limestone formations in central Hawke's Bay (eastern North Island, New Zealand) accumulated on and near the margins of a narrow forearc basin seaway within the convergent Australia/Pacific plate boundary zone. The active tectonic setting and varied paleogeographic features of the limestone units investigated, in association with probable glacioeustatic sea-level fluctuations, resulted in complex stratigraphic architectures and contrasting types of carbonate accumulation on either side of the seaway. Here, we recognise recurring patterns of sedimentary facies, and sequences and systems tracts bounded by key physical surfaces within the limestone sheets. The facies types range from Bioclastic (B) to Siliciclastic (S) end-members via Mixed (M) carbonate-siliciclastic deposits. Skeletal components are typical cool-water associations dominated by epifaunal calcitic bivalves, bryozoans, and especially barnacles. Siliciclastic contents vary from one formation to another, and highlight siliciclastic-rich limestone units in the western ranges versus siliciclastic-poor limestone units in the eastern coastal hills. Heterogeneities in facies types, stratal patterns, and also in diagenetic pathways between eastern and western limestone units are considered to originate in the coeval occurrence in different parts of the forearc basin of two main morphodynamic carbonate systems over time.

text: Contrasting carbonate depositional systems for Pliocene cool-water limestones cropping out in central Hawke's Bay, New Zealand Pliocene limestone formations in central Hawke's Bay (eastern North Island, New Zealand) accumulated on and near the margins of a narrow forearc basin seaway within the convergent Australia/Pacific plate boundary zone. The active tectonic setting and varied paleogeographic features of the limestone units investigated, in association with probable glacioeustatic sea-level fluctuations, resulted in complex stratigraphic architectures and contrasting types of carbonate accumulation on either side of the seaway. Here, we recognise recurring patterns of sedimentary facies, and sequences and systems tracts bounded by key physical surfaces within the limestone sheets. The facies types range from Bioclastic (B) to Siliciclastic (S) end-members via Mixed (M) carbonate-siliciclastic deposits. Skeletal components are typical cool-water associations dominated by epifaunal calcitic bivalves, bryozoans, and especially barnacles. Siliciclastic contents vary from one formation to another, and highlight siliciclastic-rich limestone units in the western ranges versus siliciclastic-poor limestone units in the eastern coastal hills. Heterogeneities in facies types, stratal patterns, and also in diagenetic pathways between eastern and western limestone units are considered to originate in the coeval occurrence in different parts of the forearc basin of two main morphodynamic carbonate systems over time.

year: 2004-12-01

title: A K-fold averaging cross-validation procedure

authors: Jung, Yoonsuh

abstract: Cross-validation (CV) type of methods have been widely used to facilitate model estimation and variable selection. In this work, we suggest a new K-fold CV procedure to select a candidate ‘optimal’ model from each hold-out fold and average the K candidate ‘optimal’ models to obtain the ultimate model. Due to the averaging effect, the variance of the proposed estimates can be significantly reduced. This new procedure results in more stable and efficient parameter estimation than the classical K-fold CV procedure. In addition, we show the asymptotic equivalence between the proposed and classical CV procedures in the linear regression setting. We also demonstrate the broad applicability of the proposed procedure via two examples of parameter sparsity regularisation and quantile smoothing splines modelling. We illustrate the promise of the proposed method through simulations and a real data example.

text: A K-fold averaging cross-validation procedure Cross-validation (CV) type of methods have been widely used to facilitate model estimation and variable selection. In this work, we suggest a new K-fold CV procedure to select a candidate ‘optimal’ model from each hold-out fold and average the K candidate ‘optimal’ models to obtain the ultimate model. Due to the averaging effect, the variance of the proposed estimates can be significantly reduced. This new procedure results in more stable and efficient parameter estimation than the classical K-fold CV procedure. In addition, we show the asymptotic equivalence between the proposed and classical CV procedures in the linear regression setting. We also demonstrate the broad applicability of the proposed procedure via two examples of parameter sparsity regularisation and quantile smoothing splines modelling. We illustrate the promise of the proposed method through simulations and a real data example.

year: 2015-02-26

title: Te Awa Atua, Te Awa Tapu, Te Awa Wahine: An examination of stories, ceremonies and practices regarding menstruation in the pre-colonial Māori world.

authors: Murphy, Ngahuia Aroha Grace

subjects: mana wahine

abstract: This thesis examines Māori cosmological stories, ceremonies, and traditional practices regarding menstruation in pre-colonial Māori society. I use kaupapa Māori and mana wahine as a theoretical and methodological framework, contextualising these stories within Māori cultural paradigms.This is important because menstruation has been framed within deeply misogynist, colonial ideologies in some ethnographic accounts, distorting menstrual rites and practices beyond recognition. These interpretations have been used to inform colonialist narratives of female inferiority in traditional Māori society, attempting to change Native constructs of womanhood. Such narratives have been perpetuated in contemporary literature, reinforcing powerful discourses of menstrual pollution and female inferiority. This thesis is a challenge to such representations. By examining menstrual stories located in Māori cosmologies, and investigating tribal histories, oral literatures, ceremonies and rites, I argue that menstruation was seen as a medium of whakapapa (genealogy) that connected Māori women to our pantheon of atua (supernatural beings). A study of ancient menstrual rites, recorded in tribal songs and chants, reveal that menstrual blood was used for psychic and spiritual protection. These examples unveil striking Indigenous constructs of womanhood that transform colonialist interpretations and radically challenge notions of female inferiority and menstrual pollution. I maintain in this thesis that presenting menstruation and menstrual blood as putrid is a politically motivated act of colonial violence that specifically targets the source of our continuity as Indigenous People, the whare tangata (house of humanity – womb of women). I pose the question ‘if menstrual blood symbolises whakapapa, what does it mean to present it as ‘unclean’ and how do such representations cut across the politics of tino rangatiratanga (autonomy)?’ Through in-depth semi-structured interviews, kōrero (dialogue), and wānanga (series of conversations) with Māori women, including cultural experts, scholars, artists, and mana wahine exponents, I gather a collection of ceremonies, stories, and wisdoms that reclaim Māori spiritualities which celebrate menstruation as divine. Within the context of a colonial history of marginalisation, this work is an activist site of political resistance which takes a step towards re-threading the feminine strands in the spiritual fabric of our world, torn asunder by the ideological imposition of a colonial, Christian male god. I argue, that menstruation is a potent site of decolonisation, cultural reclamation, and resistance toward the perpetuation of colonial hegemony.

text: Te Awa Atua, Te Awa Tapu, Te Awa Wahine: An examination of stories, ceremonies and practices regarding menstruation in the pre-colonial Māori world. This thesis examines Māori cosmological stories, ceremonies, and traditional practices regarding menstruation in pre-colonial Māori society. I use kaupapa Māori and mana wahine as a theoretical and methodological framework, contextualising these stories within Māori cultural paradigms.This is important because menstruation has been framed within deeply misogynist, colonial ideologies in some ethnographic accounts, distorting menstrual rites and practices beyond recognition. These interpretations have been used to inform colonialist narratives of female inferiority in traditional Māori society, attempting to change Native constructs of womanhood. Such narratives have been perpetuated in contemporary literature, reinforcing powerful discourses of menstrual pollution and female inferiority. This thesis is a challenge to such representations. By examining menstrual stories located in Māori cosmologies, and investigating tribal histories, oral literatures, ceremonies and rites, I argue that menstruation was seen as a medium of whakapapa (genealogy) that connected Māori women to our pantheon of atua (supernatural beings). A study of ancient menstrual rites, recorded in tribal songs and chants, reveal that menstrual blood was used for psychic and spiritual protection. These examples unveil striking Indigenous constructs of womanhood that transform colonialist interpretations and radically challenge notions of female inferiority and menstrual pollution. I maintain in this thesis that presenting menstruation and menstrual blood as putrid is a politically motivated act of colonial violence that specifically targets the source of our continuity as Indigenous People, the whare tangata (house of humanity – womb of women). I pose the question ‘if menstrual blood symbolises whakapapa, what does it mean to present it as ‘unclean’ and how do such representations cut across the politics of tino rangatiratanga (autonomy)?’ Through in-depth semi-structured interviews, kōrero (dialogue), and wānanga (series of conversations) with Māori women, including cultural experts, scholars, artists, and mana wahine exponents, I gather a collection of ceremonies, stories, and wisdoms that reclaim Māori spiritualities which celebrate menstruation as divine. Within the context of a colonial history of marginalisation, this work is an activist site of political resistance which takes a step towards re-threading the feminine strands in the spiritual fabric of our world, torn asunder by the ideological imposition of a colonial, Christian male god. I argue, that menstruation is a potent site of decolonisation, cultural reclamation, and resistance toward the perpetuation of colonial hegemony.

year: 2011