title: Exposure frequency and affect

authors: Hamid, P.N.

abstract: Three experiments were conducted to examine the hypothesis that attitudinal affect is a monotonic function of frequency of exposure. In the first experiment while supporting the frequency-affect relationship a non significant difference between males and females and positive and negative set conditions were obtained. In the second experiment low association value stimuli produced significantly greater increases in affect over exposure than relatively higher association stimuli. Duration of exposure at 2 and 5 second intervals only were shown to enhance evaluative rating while frequency of exposure again showed the predicted increase in affect, in a third experiment. Further inspection of the results of the first and third experiment indicated that whilst most showed greater preference for familiar stimuli there was a group of subjects preferring low exposure stimuli.

In the second part of the study subjects were presented with stimuli at different exposure frequencies and stimulus complexity to test the hypothesis that affect was an inverted U shape function of stimulus complexity with subjects preferring stimuli of medium complexity regardless of exposure frequency. Although the hypothesis was supported marked individual differences were obtained by examining the complexity level at which the increase in positive affect as a function of exposure was most pronounced for each subject.

The results were interpreted as supporting the theory of optimum levels of arousal and it was suggested that not only do the differences in the point of maximum increase in affect over exposure frequency provide a measure of an individual’s optimal level but also they reflect a cognitive style of search for novel as opposed to familiar environmental contingencies.

It is suggested that the need for familiar versus novel stimulation is not only a crucial determinant of an organism’s affect arousal but also the distinction underlies many of the more well known and researched cognitive styles.

Some of the factors determining the development of orientations towards familiar versus novel stimulation are discussed together with directions for future research.

text: Exposure frequency and affect Three experiments were conducted to examine the hypothesis that attitudinal affect is a monotonic function of frequency of exposure. In the first experiment while supporting the frequency-affect relationship a non significant difference between males and females and positive and negative set conditions were obtained. In the second experiment low association value stimuli produced significantly greater increases in affect over exposure than relatively higher association stimuli. Duration of exposure at 2 and 5 second intervals only were shown to enhance evaluative rating while frequency of exposure again showed the predicted increase in affect, in a third experiment. Further inspection of the results of the first and third experiment indicated that whilst most showed greater preference for familiar stimuli there was a group of subjects preferring low exposure stimuli.

In the second part of the study subjects were presented with stimuli at different exposure frequencies and stimulus complexity to test the hypothesis that affect was an inverted U shape function of stimulus complexity with subjects preferring stimuli of medium complexity regardless of exposure frequency. Although the hypothesis was supported marked individual differences were obtained by examining the complexity level at which the increase in positive affect as a function of exposure was most pronounced for each subject.

The results were interpreted as supporting the theory of optimum levels of arousal and it was suggested that not only do the differences in the point of maximum increase in affect over exposure frequency provide a measure of an individual’s optimal level but also they reflect a cognitive style of search for novel as opposed to familiar environmental contingencies.

It is suggested that the need for familiar versus novel stimulation is not only a crucial determinant of an organism’s affect arousal but also the distinction underlies many of the more well known and researched cognitive styles.

Some of the factors determining the development of orientations towards familiar versus novel stimulation are discussed together with directions for future research.

year: 1972

title: Petrogenesis of Pliocene limestones in southern Hawke’s Bay, New Zealand: a contribution to unravelling the sequence stratigraphy and diagenetic pathways of cool-water shelf carbonate facies

authors: Caron, Vincent

abstract: Among carbonate sedimentologists, it is now appreciated that shallow-marine carbonates are not restricted to warm-water tropical settings, but can also be produced on modern cool-water shelves outside tropical latitudes. In the last two decades, many publications have not only advanced our knowledge about modern non-tropical carbonates, but have documented ancient skeletal limestones that are fossil analogues of these modern deposits. While the broad environmental and sedimentary characteristics of non-tropical deposits are becoming well established, the nature, timing, and relative importance of the various diagenetic processes affecting their evolution into limestones are yet to be fully appreciated, a topic addressed in the present study.

In New Zealand, the Plio-Pleistocene (5-1.5 Ma) Te Aute limestones in southern Hawke’s Bay (eastern North Island) are non-tropical in origin, and formed in shoal areas about the margins of a forearc basin seaway adjacent to the convergent Pacific-Australian Plate boundary. Because of the dynamic tectonic setting, which led to narrowing and shallowing of the host basin over time, the studied carbonates exhibit a variety of sedimentary facies (i.e., from pure coquina to mixed carbonate-siliciclastic) and mineralogical signatures (i.e., calcite- to, more rarely, aragonite-dominated), and have undergone varying degrees of burial before being uplifted to their present position. As such, the Te Aute deposits provide a unique opportunity to: (1) decipher the suite of processes that have altered their texture and composition through time; (2) address the questions of what likely regional and more global parameters, namely tectonics and eustasy, may have driven diagenetic pathways, and how this occurred; and (3) more generally advance fundamental knowledge about models of porosity evolution in non-tropical carbonates.

The present study integrates the combined results of detailed field investigations with a variety of analytical techniques, including standard, stained, and cathodoluminescence (CL) microscopic examinations of rock thin-sections, X-ray diffraction (XRD), and elemental (ICP-OES and microprobe) and stable isotope (δ¹⁸O and δ¹³C) geochemistry.

Sedimentologic analysis has identified 14 different facies types that correspond to a spectrum of depositional settings associated with both continent-attached shelves and isolated upthrust-cored antiforms within the forearc seaway. Facies are representative of environments ranging from below storm-wave base, in outer shelf-type locations, to predominantly shallow-water shoreface-type conditions under the influence of strong tidal current flows and storm waves.

A new petrographic approach for studying cool-water carbonate diagenesis has been developed. The method entails recording the high-resolution chronological occurrence of all diagenetic features within samples, and noting their vertical and lateral distribution within sedimentary formations. It is demonstrated that the attributes of pre-compaction diagenetic suites between consecutive sedimentary discontinuities change vertically in relation to the stacking of depositional facies. This original approach, by also revealing marine-cemented condensed horizons and key surfaces otherwise unrecognized in the field, has helped unlock the cryptic sedimentary architecture within the limestones. Thus, the Te Aute deposits appear to be constructed of metre-scale (1-15m) sequences that could be integrated into a sequence stratigraphic scheme, emphasizing that not only the production and deposition, but also the diagenesis of these carbonate deposits, were forced by glacio-eustatically and tectonically-driven processes.

In order to better explain the probable progression of diagenetic environments that moved through Te Aute limestones, concepts that classically underpin the sequence stratigraphic analysis of sedimentary successions have been used to group cement zones, revealed under cathodoluminescent (CL) light, into diagenetic discontinuity-bounded CL sequences. In most Pliocene limestones, the procedure, in combination with geochemical data, has: (1) identified recurring and correlative motifs of pre- and post-compaction CL sequence stratigraphies; (2) enabled regional mapping of CL sequences; (3) highlighted the spatial geometry and timing of emplacement of cementing aquifers; and (4) led to the construction of paleohydrologic models, invoking location of recharge areas and fluid-flow directions. Pre-compaction CL sequences formed locally from marine and more widely from oxidized meteoric (or mixed marine-meteoric) waters after exposure of limestone caps due to relative drops in sea level. Post-compaction burial CL sequences precipitated from reduced fluids recharged from areas of basin margin exposure, while the next CL sequences in the chronological suite are related to the ingress of oxidized meteoric waters as a result of uplift.

text: Petrogenesis of Pliocene limestones in southern Hawke’s Bay, New Zealand: a contribution to unravelling the sequence stratigraphy and diagenetic pathways of cool-water shelf carbonate facies Among carbonate sedimentologists, it is now appreciated that shallow-marine carbonates are not restricted to warm-water tropical settings, but can also be produced on modern cool-water shelves outside tropical latitudes. In the last two decades, many publications have not only advanced our knowledge about modern non-tropical carbonates, but have documented ancient skeletal limestones that are fossil analogues of these modern deposits. While the broad environmental and sedimentary characteristics of non-tropical deposits are becoming well established, the nature, timing, and relative importance of the various diagenetic processes affecting their evolution into limestones are yet to be fully appreciated, a topic addressed in the present study.

In New Zealand, the Plio-Pleistocene (5-1.5 Ma) Te Aute limestones in southern Hawke’s Bay (eastern North Island) are non-tropical in origin, and formed in shoal areas about the margins of a forearc basin seaway adjacent to the convergent Pacific-Australian Plate boundary. Because of the dynamic tectonic setting, which led to narrowing and shallowing of the host basin over time, the studied carbonates exhibit a variety of sedimentary facies (i.e., from pure coquina to mixed carbonate-siliciclastic) and mineralogical signatures (i.e., calcite- to, more rarely, aragonite-dominated), and have undergone varying degrees of burial before being uplifted to their present position. As such, the Te Aute deposits provide a unique opportunity to: (1) decipher the suite of processes that have altered their texture and composition through time; (2) address the questions of what likely regional and more global parameters, namely tectonics and eustasy, may have driven diagenetic pathways, and how this occurred; and (3) more generally advance fundamental knowledge about models of porosity evolution in non-tropical carbonates.

The present study integrates the combined results of detailed field investigations with a variety of analytical techniques, including standard, stained, and cathodoluminescence (CL) microscopic examinations of rock thin-sections, X-ray diffraction (XRD), and elemental (ICP-OES and microprobe) and stable isotope (δ¹⁸O and δ¹³C) geochemistry.

Sedimentologic analysis has identified 14 different facies types that correspond to a spectrum of depositional settings associated with both continent-attached shelves and isolated upthrust-cored antiforms within the forearc seaway. Facies are representative of environments ranging from below storm-wave base, in outer shelf-type locations, to predominantly shallow-water shoreface-type conditions under the influence of strong tidal current flows and storm waves.

A new petrographic approach for studying cool-water carbonate diagenesis has been developed. The method entails recording the high-resolution chronological occurrence of all diagenetic features within samples, and noting their vertical and lateral distribution within sedimentary formations. It is demonstrated that the attributes of pre-compaction diagenetic suites between consecutive sedimentary discontinuities change vertically in relation to the stacking of depositional facies. This original approach, by also revealing marine-cemented condensed horizons and key surfaces otherwise unrecognized in the field, has helped unlock the cryptic sedimentary architecture within the limestones. Thus, the Te Aute deposits appear to be constructed of metre-scale (1-15m) sequences that could be integrated into a sequence stratigraphic scheme, emphasizing that not only the production and deposition, but also the diagenesis of these carbonate deposits, were forced by glacio-eustatically and tectonically-driven processes.

In order to better explain the probable progression of diagenetic environments that moved through Te Aute limestones, concepts that classically underpin the sequence stratigraphic analysis of sedimentary successions have been used to group cement zones, revealed under cathodoluminescent (CL) light, into diagenetic discontinuity-bounded CL sequences. In most Pliocene limestones, the procedure, in combination with geochemical data, has: (1) identified recurring and correlative motifs of pre- and post-compaction CL sequence stratigraphies; (2) enabled regional mapping of CL sequences; (3) highlighted the spatial geometry and timing of emplacement of cementing aquifers; and (4) led to the construction of paleohydrologic models, invoking location of recharge areas and fluid-flow directions. Pre-compaction CL sequences formed locally from marine and more widely from oxidized meteoric (or mixed marine-meteoric) waters after exposure of limestone caps due to relative drops in sea level. Post-compaction burial CL sequences precipitated from reduced fluids recharged from areas of basin margin exposure, while the next CL sequences in the chronological suite are related to the ingress of oxidized meteoric waters as a result of uplift.

year: 2002

title: Adopting a Maori property rights approach to fisheries

authors: Toki, Valmaine

abstract: For Maori, tikanga Maori or custom law not only underpinned the recognition of property rights to their fishery but also their environmental ethics and the sustainable management of that fishery. In comparison, the property right of non-indigenous peoples was sourced from a rights system determined by the State. The nature of these property rights, for Maori, has been acknowledged by legislation. The challenge for Maori is to effectively maintain, develop and manage this allocated resource in a way that will not only sustain the resource but also ensure its longevity both socially and economically for future generations. Among the issues Maori will face are how to balance effective governance and efficient management, together with the requirement to address global issues of over-fishing and property rights, all the while preserving and respecting tradition. Irrespective of these challenges, it is the tikanga, or philosophy, intrinsic to the traditional Maori worldview which will guide Maori through these challenges, and provide a way forward for global issues such as climate change.

text: Adopting a Maori property rights approach to fisheries For Maori, tikanga Maori or custom law not only underpinned the recognition of property rights to their fishery but also their environmental ethics and the sustainable management of that fishery. In comparison, the property right of non-indigenous peoples was sourced from a rights system determined by the State. The nature of these property rights, for Maori, has been acknowledged by legislation. The challenge for Maori is to effectively maintain, develop and manage this allocated resource in a way that will not only sustain the resource but also ensure its longevity both socially and economically for future generations. Among the issues Maori will face are how to balance effective governance and efficient management, together with the requirement to address global issues of over-fishing and property rights, all the while preserving and respecting tradition. Irrespective of these challenges, it is the tikanga, or philosophy, intrinsic to the traditional Maori worldview which will guide Maori through these challenges, and provide a way forward for global issues such as climate change.

year: 2010