title: The Chronology of the Ross Sea II glaciation, an Antarctic glaciation of Illinoian Age

authors: Judd, Fiona Mary

abstract: A meltwater stream in the Marshall Valley, southern Victoria Land, Antarctica has revealed a stratigraphy of glacial drift and lacustrine lake beds. 
The sequence has been differentiated by U/Th dating into the Ross Sea I Glaciation (15-30,000 years B.P.), represented by a gypsum bed and the Ross Sea II(?) Glaciation (130-180,000 years B.P.), represented by three calcium carbonate and gypsum beds. 
The three Ross Sea II(?) lake beds may be differentiated from one another by an increasing calcite content with age, and a systematic change in the crystal type and morphology of the carbonates. 
Chemical analysis of the lake beds reveals that their components have differing sources. The freezing on of seawater and/or frozen out seawater precipitates can quantitatively provide the salts required. However U isotope studies shows that a weathered crustal component is present in the lake beds. Stable isotope analysis indicates that the meltwaters were formed at high altitudes of 1,900 m (Ross Sea I) and 2,500 m (Ross Sea II(?)), and originated as snow, precipitated approximately 5,000 km to the south. 
Ice sheet incursion into the valley created a proglacial lake. Calcium carbonate and gypsum were precipitated due to increased lake saturation conditions. Stable isotope studies show that the calcium carbonate deposition was triggered biologically by phytoplankton. The morphology of the calcium carbonate and the presence of gypsum indicates that evaporitic conditions were also necessary for lake bed deposition, with the distribution of gypsum and calcium carbonate within the lake being controlled by depth of water. 
Correlation of lake bed geochronology and geochemistry, together with the stratigraphy of the stream sections provides a glacial history of Marshall Valley for the last 180,000 years B.P. The last two Ross Sea glacial sequences rest upon an unconformably eroded glacial surface. The Ross Sea II(?) Glaciation commenced at 180,000 years with a glacial ice incursion into the valley, a stillstand, proglacial lake occupation and deposition of a lake bed. The ice front then advance farther up the valley, depositing large terminal loop moraines between Sections III and IV. The ice then retreated at least 2 km. 
A second glacial advance commenced prior to 160,000 years, stillstanded and produced the 160,000 year lake bed, before retreating. A minor fluctuation and readvance, deposited another lake bed (160,000 years) or reworked the previous lake bed into the overlying stratigraphy, before the ice retreat. 
The deposition of the 130,000 year lake bed was also a the result of a stillstand, before the retreat and cessation of the Ross Sea II(?) glaciation. 
The Ross Sea I Glaciation involved the advance of a glacier front from an ice sheet occupying the McMurdo Sound and the deposition of a gypsum lake bed (15-30,000 years B.P.). With the retreat of the ice front, downwasting of ice-cored moraines in the mouth of the valley began, and currently continues.
The geochronology of the Ross Sea II(?) Glaciation correlates with eustatic sea level lowering in the Illinoian (Isotope Stage 6). Subsurface drilling indicates that the calcium carbonate deposition was a unique event but at least 8 earlier glacial incursions had occurred in the Marshall Valley. 
The geochronology of the Ross Sea I Glaciation correlates with the eustatic sea level lowering in the Wisconsin (Isotope Stage 2). 
The chronology and isotopic composition of the proglacial lake deposits can be matched to those in other ice-free valleys exposed to McMurdo Sound.

text: The Chronology of the Ross Sea II glaciation, an Antarctic glaciation of Illinoian Age A meltwater stream in the Marshall Valley, southern Victoria Land, Antarctica has revealed a stratigraphy of glacial drift and lacustrine lake beds. 
The sequence has been differentiated by U/Th dating into the Ross Sea I Glaciation (15-30,000 years B.P.), represented by a gypsum bed and the Ross Sea II(?) Glaciation (130-180,000 years B.P.), represented by three calcium carbonate and gypsum beds. 
The three Ross Sea II(?) lake beds may be differentiated from one another by an increasing calcite content with age, and a systematic change in the crystal type and morphology of the carbonates. 
Chemical analysis of the lake beds reveals that their components have differing sources. The freezing on of seawater and/or frozen out seawater precipitates can quantitatively provide the salts required. However U isotope studies shows that a weathered crustal component is present in the lake beds. Stable isotope analysis indicates that the meltwaters were formed at high altitudes of 1,900 m (Ross Sea I) and 2,500 m (Ross Sea II(?)), and originated as snow, precipitated approximately 5,000 km to the south. 
Ice sheet incursion into the valley created a proglacial lake. Calcium carbonate and gypsum were precipitated due to increased lake saturation conditions. Stable isotope studies show that the calcium carbonate deposition was triggered biologically by phytoplankton. The morphology of the calcium carbonate and the presence of gypsum indicates that evaporitic conditions were also necessary for lake bed deposition, with the distribution of gypsum and calcium carbonate within the lake being controlled by depth of water. 
Correlation of lake bed geochronology and geochemistry, together with the stratigraphy of the stream sections provides a glacial history of Marshall Valley for the last 180,000 years B.P. The last two Ross Sea glacial sequences rest upon an unconformably eroded glacial surface. The Ross Sea II(?) Glaciation commenced at 180,000 years with a glacial ice incursion into the valley, a stillstand, proglacial lake occupation and deposition of a lake bed. The ice front then advance farther up the valley, depositing large terminal loop moraines between Sections III and IV. The ice then retreated at least 2 km. 
A second glacial advance commenced prior to 160,000 years, stillstanded and produced the 160,000 year lake bed, before retreating. A minor fluctuation and readvance, deposited another lake bed (160,000 years) or reworked the previous lake bed into the overlying stratigraphy, before the ice retreat. 
The deposition of the 130,000 year lake bed was also a the result of a stillstand, before the retreat and cessation of the Ross Sea II(?) glaciation. 
The Ross Sea I Glaciation involved the advance of a glacier front from an ice sheet occupying the McMurdo Sound and the deposition of a gypsum lake bed (15-30,000 years B.P.). With the retreat of the ice front, downwasting of ice-cored moraines in the mouth of the valley began, and currently continues.
The geochronology of the Ross Sea II(?) Glaciation correlates with eustatic sea level lowering in the Illinoian (Isotope Stage 6). Subsurface drilling indicates that the calcium carbonate deposition was a unique event but at least 8 earlier glacial incursions had occurred in the Marshall Valley. 
The geochronology of the Ross Sea I Glaciation correlates with the eustatic sea level lowering in the Wisconsin (Isotope Stage 2). 
The chronology and isotopic composition of the proglacial lake deposits can be matched to those in other ice-free valleys exposed to McMurdo Sound.

year: 1986

title: Nitrogen fixation and bulk organic removal in a bleached krall pulp and paper mill treatment system

authors: Frost, Nicola M.

subjects: New Zealand Pulp & Paper industry

abstract: A study was undertaken to assess some effects of nitrogen fixation and bulk organic substrate removal in a New Zealand bleached kraft pulp and paper mill wastewater treatment system. A novel wastewater biological treatment system based on nitrogen fixation has been identified as having significant potential for application in full scale treatment of pulp and paper and other nitrogen deficient wastewaters. This study contributes information about the significance and role of nitrogen fixing bacteria in such a system and will benefit development and optimisation of a wastewater treatment system based on nitrogen fixation. 
The specific aims of the study were i) to identify the bulk organic substrates present in the mill's treatment system, ii) to study some effects of changing the wastewater composition on the processes occurring in a nitrogen fixing biological treatment system and iii) to obtain and characterise some of the nitrogen fixing microorganisms present in this system. 
Methanol, acetic acid and glucose accounted for approximately 43% of the soluble chemical oxygen demand entering the treatment system. The remaining 57% was unidentified in this study. Acetic acid was the first identified substrate removed from the treatment system, implicating this compound as the preferred substrate under these conditions. 
A laboratory continuous culture experiment demonstrated that increases in acetate and methanol concentrations in the wastewater did not affect specific substrate removal and nitrogen fixation rates in the system but may have changed the microbial population. Low biomass nitrogen results were obtained in this experiment and attributed to microbial intracellular storage of poly-β-hydroxybutyrate. 
Isolates were obtained from the mill's treatment system which were able to fix nitrogen under microaerophilic conditions. Four selected isolates were able to utilise methanol, acetic acid and glucose under nitrogen fixing conditions. All of these isolates removed acetic acid from a mixed carbon substrate medium before methanol and glucose, consistent with individual substrate removal found in the Tasman treatment system.

text: Nitrogen fixation and bulk organic removal in a bleached krall pulp and paper mill treatment system A study was undertaken to assess some effects of nitrogen fixation and bulk organic substrate removal in a New Zealand bleached kraft pulp and paper mill wastewater treatment system. A novel wastewater biological treatment system based on nitrogen fixation has been identified as having significant potential for application in full scale treatment of pulp and paper and other nitrogen deficient wastewaters. This study contributes information about the significance and role of nitrogen fixing bacteria in such a system and will benefit development and optimisation of a wastewater treatment system based on nitrogen fixation. 
The specific aims of the study were i) to identify the bulk organic substrates present in the mill's treatment system, ii) to study some effects of changing the wastewater composition on the processes occurring in a nitrogen fixing biological treatment system and iii) to obtain and characterise some of the nitrogen fixing microorganisms present in this system. 
Methanol, acetic acid and glucose accounted for approximately 43% of the soluble chemical oxygen demand entering the treatment system. The remaining 57% was unidentified in this study. Acetic acid was the first identified substrate removed from the treatment system, implicating this compound as the preferred substrate under these conditions. 
A laboratory continuous culture experiment demonstrated that increases in acetate and methanol concentrations in the wastewater did not affect specific substrate removal and nitrogen fixation rates in the system but may have changed the microbial population. Low biomass nitrogen results were obtained in this experiment and attributed to microbial intracellular storage of poly-β-hydroxybutyrate. 
Isolates were obtained from the mill's treatment system which were able to fix nitrogen under microaerophilic conditions. Four selected isolates were able to utilise methanol, acetic acid and glucose under nitrogen fixing conditions. All of these isolates removed acetic acid from a mixed carbon substrate medium before methanol and glucose, consistent with individual substrate removal found in the Tasman treatment system.

year: 1998

title: Food insecurity in urban New Zealand. The case of the Kopa family

authors: Graham, Rebekah Sarah

abstract: Poverty brings insecurity and chaos into the home, forcing families to develop strategies for navigating the difficulties of food insecurity. We document how one household, the Kopa family, responds to poverty in ad hoc and agentive ways that assist and hinder their attempts to keep themselves fed. This study is based on a series of eight qualitative interviews with family members, including photo-elicitation and go-along techniques, as well as extensive field notes from more casual research interactions such as shared meals. Our analysis demonstrates how food insecurity shapes this family’s culturally patterned social practices surrounding the procurement, consumption, and sharing of food.

text: Food insecurity in urban New Zealand. The case of the Kopa family Poverty brings insecurity and chaos into the home, forcing families to develop strategies for navigating the difficulties of food insecurity. We document how one household, the Kopa family, responds to poverty in ad hoc and agentive ways that assist and hinder their attempts to keep themselves fed. This study is based on a series of eight qualitative interviews with family members, including photo-elicitation and go-along techniques, as well as extensive field notes from more casual research interactions such as shared meals. Our analysis demonstrates how food insecurity shapes this family’s culturally patterned social practices surrounding the procurement, consumption, and sharing of food.

year: 2018