title: A sedimentological study of three saline lakes in the Dry Valleys of Victoria Land, Antarctica

authors: Gumbley, John Watson

subjects: Sediments

abstract: The Dry Valley region of Victoria Land is the largest ice-free area in Antarctica. Within the frigid arid environment of the Dry Valleys, where the mean annual air temperature is -20℃, there are several permanently ice-covered, amictic, saline lakes occupying undrained bedrock depressions. Three of these lakes, namely Lakes Vanda, Bonney and Joyce, have been studied with the aim of determining the nature of their bottom sediments and relating the stratigraphy of bottom sediment cores to Holocene climatic fluctuations. These lakes have an area of 0.8 to 5.2 km², are from 35 to 68m in maximum depth and have an ice-cover 3 to 4m thick. The lakes are chemically and thermally stratified and receive their water from meltwater streams draining the local glaciers.

The bottom sediments consist of detrital sands and silts, chemical precipitates and organic material. The detrital sediments consist of feldspar and quartz with smaller quantities of hornblende, augite, hypersthene and mica that are derived locally from the rocks exposed on the adjacent valley sides. These sediments are mainly wind-transported or, to a lesser extent, river-transported into the lakes. The wind derived sediments are either blown onto the lake-ice, where they eventually sink to the lake-floor, or they are blown into the moat developed about the shores of the lake in summer. The chemical precipitates consist mainly of gypsum, halite, aragonite and calcite whose constituent elements were derived from meltwater streams discharging into the lakes; however Lake Bonney also received dissolved solids of marine origin about 300,000 years B.P. and 1,200 years B.P.

From the sequence of chemical precipitate - rich bands and grain-size cycles in cores from Lakes Vanda and Joyce, together with the stratigraphy in the Lake Bonney cores, a sequence of climatic fluctuations is inferred. Colder climatic phases are most probably associated with periods of low lake-level during which chemical precipitates formed following the concentration of brines under frigid evaporitic conditions. At these times the sediment input from meltwater streams was low because of the locking-up of water in valley glaciers, and the main source of sediment would probably then be wind-derived. 

U/Th dating of the chemical precipitates has provided an absolute record of past climatic changes which indicate that the major glacier systems in the Dry Valley region were nonsynchronous. Low lake levels occurred in Lake Vanda some 2,000 and 5,500 years B.P. and on at least four earlier occasions. Sediment cores from Lake Joyce indicate a period of low lake-level about 3,000 years B.P. The Lake Bonney cores suggest periods of low lake-level occurred following each of the marine incursions into the valley (300,000 and 1,200 years B.P.) and that the advance of the Taylor Glacier into the Bonney Basin at least 10,000 years B.P. probably coincided with the Taylor I Glaciation. Frigid evaporitic conditions have continued to operate in Lake Bonney since 1,200 years B.P. with halite crystals forming on the lake-floor. However, the lake-level has been steadily rising over the last 500 years.

text: A sedimentological study of three saline lakes in the Dry Valleys of Victoria Land, Antarctica The Dry Valley region of Victoria Land is the largest ice-free area in Antarctica. Within the frigid arid environment of the Dry Valleys, where the mean annual air temperature is -20℃, there are several permanently ice-covered, amictic, saline lakes occupying undrained bedrock depressions. Three of these lakes, namely Lakes Vanda, Bonney and Joyce, have been studied with the aim of determining the nature of their bottom sediments and relating the stratigraphy of bottom sediment cores to Holocene climatic fluctuations. These lakes have an area of 0.8 to 5.2 km², are from 35 to 68m in maximum depth and have an ice-cover 3 to 4m thick. The lakes are chemically and thermally stratified and receive their water from meltwater streams draining the local glaciers.

The bottom sediments consist of detrital sands and silts, chemical precipitates and organic material. The detrital sediments consist of feldspar and quartz with smaller quantities of hornblende, augite, hypersthene and mica that are derived locally from the rocks exposed on the adjacent valley sides. These sediments are mainly wind-transported or, to a lesser extent, river-transported into the lakes. The wind derived sediments are either blown onto the lake-ice, where they eventually sink to the lake-floor, or they are blown into the moat developed about the shores of the lake in summer. The chemical precipitates consist mainly of gypsum, halite, aragonite and calcite whose constituent elements were derived from meltwater streams discharging into the lakes; however Lake Bonney also received dissolved solids of marine origin about 300,000 years B.P. and 1,200 years B.P.

From the sequence of chemical precipitate - rich bands and grain-size cycles in cores from Lakes Vanda and Joyce, together with the stratigraphy in the Lake Bonney cores, a sequence of climatic fluctuations is inferred. Colder climatic phases are most probably associated with periods of low lake-level during which chemical precipitates formed following the concentration of brines under frigid evaporitic conditions. At these times the sediment input from meltwater streams was low because of the locking-up of water in valley glaciers, and the main source of sediment would probably then be wind-derived. 

U/Th dating of the chemical precipitates has provided an absolute record of past climatic changes which indicate that the major glacier systems in the Dry Valley region were nonsynchronous. Low lake levels occurred in Lake Vanda some 2,000 and 5,500 years B.P. and on at least four earlier occasions. Sediment cores from Lake Joyce indicate a period of low lake-level about 3,000 years B.P. The Lake Bonney cores suggest periods of low lake-level occurred following each of the marine incursions into the valley (300,000 and 1,200 years B.P.) and that the advance of the Taylor Glacier into the Bonney Basin at least 10,000 years B.P. probably coincided with the Taylor I Glaciation. Frigid evaporitic conditions have continued to operate in Lake Bonney since 1,200 years B.P. with halite crystals forming on the lake-floor. However, the lake-level has been steadily rising over the last 500 years.

year: 1975

title: Reflections on a collaborative adult literacy and numeracy action enquiry

authors: McKim, Anne M.

subjects: action enquiry

abstract: This paper reports and reflects on a collaborative and multi-layered action enquiry project in the New Zealand polytechnic sector. In the context of widespread national professional development centred on adult literacy and numeracy teaching and learning in vocational educational institutions, an action enquiry methodology was piloted with vocational tutors in certificate and diploma programmes at nine polytechnics and institutes of technology. Most participating tutors had not previously carried out formal research, and few had worked with university researchers as external change agents before. A key aim of the overarching project was to investigate the effects and value of an action enquiry approach for embedding literacy and numeracy in vocational programmes. Reflection emerged as an important component in both the individual action enquiries undertaken by participating small teams and the meta-action enquiry project overlaying all of the projects. We conclude by considering the external agent role in building collaborative enquiry and relationships.

text: Reflections on a collaborative adult literacy and numeracy action enquiry This paper reports and reflects on a collaborative and multi-layered action enquiry project in the New Zealand polytechnic sector. In the context of widespread national professional development centred on adult literacy and numeracy teaching and learning in vocational educational institutions, an action enquiry methodology was piloted with vocational tutors in certificate and diploma programmes at nine polytechnics and institutes of technology. Most participating tutors had not previously carried out formal research, and few had worked with university researchers as external change agents before. A key aim of the overarching project was to investigate the effects and value of an action enquiry approach for embedding literacy and numeracy in vocational programmes. Reflection emerged as an important component in both the individual action enquiries undertaken by participating small teams and the meta-action enquiry project overlaying all of the projects. We conclude by considering the external agent role in building collaborative enquiry and relationships.

year: 2012

title: A critical analysis of Section 27 of the Sentencing Act (2002)

authors: Oakley, Tara Joan

subjects: Section 27

abstract: This thesis analyses the effectiveness of Section 27 of the Sentencing Act (2002) in achieving its primary objective of addressing the high rate of Māori incarceration. This problem largely stems from the destruction of Māori culture through colonisation and is held in place by systemic and institutional racism in the contemporary context. Theoretically, Section 27 provides a mechanism to off-set the societal dislocation and disadvantage Māori have experienced as a result of colonialism, crime control policies and urbanisation.

Analysis of the operational reality of Section 27 focused on the following questions:
•	Is Section 27 being utilised as intended by legislation?
•	What are the underlying rationale and reasons why the Section is utilised by Court officials?
•	What are the underlying rationale and reasons why the Section is not utilised by Court officials?
•	What changes to legislation, policy or institutional practice are required to enhance the use of Section 27?
The research involved qualitative interviews of eight lawyers from two different geographic locations in New Zealand, and four cultural consultants (those employed to write professional Section 27 reports). Their responses were analysed and grouped into three different themes: benefits, barriers, and improvement to legislation and practice.  

Major findings of the research include positive outcomes such as improved community re-engagement for offenders and improved sentencing outcomes. On the other hand, however, there is an inconsistency of use of Section 27, as well as a variable impact when it is used during the sentencing process. This inconsistency appears due to a lack of cultural knowledge and understanding within the court system. Thus, there is a need for cultural education of those working within the court system and for the development of a framework and guidelines.  For this to be imbedded as a consistent practice for use in sentencing decisions it needs to be backed up with adequate government funding and legislative and policy support.

text: A critical analysis of Section 27 of the Sentencing Act (2002) This thesis analyses the effectiveness of Section 27 of the Sentencing Act (2002) in achieving its primary objective of addressing the high rate of Māori incarceration. This problem largely stems from the destruction of Māori culture through colonisation and is held in place by systemic and institutional racism in the contemporary context. Theoretically, Section 27 provides a mechanism to off-set the societal dislocation and disadvantage Māori have experienced as a result of colonialism, crime control policies and urbanisation.

Analysis of the operational reality of Section 27 focused on the following questions:
•	Is Section 27 being utilised as intended by legislation?
•	What are the underlying rationale and reasons why the Section is utilised by Court officials?
•	What are the underlying rationale and reasons why the Section is not utilised by Court officials?
•	What changes to legislation, policy or institutional practice are required to enhance the use of Section 27?
The research involved qualitative interviews of eight lawyers from two different geographic locations in New Zealand, and four cultural consultants (those employed to write professional Section 27 reports). Their responses were analysed and grouped into three different themes: benefits, barriers, and improvement to legislation and practice.  

Major findings of the research include positive outcomes such as improved community re-engagement for offenders and improved sentencing outcomes. On the other hand, however, there is an inconsistency of use of Section 27, as well as a variable impact when it is used during the sentencing process. This inconsistency appears due to a lack of cultural knowledge and understanding within the court system. Thus, there is a need for cultural education of those working within the court system and for the development of a framework and guidelines.  For this to be imbedded as a consistent practice for use in sentencing decisions it needs to be backed up with adequate government funding and legislative and policy support.

year: 2020