title: The role of tectonism in sequence development and facies distribution of Upper Oligocene cool-water carbonates: Coromandel Peninsula, New Zealand

authors: Dix, George R.

subjects: cool-water carbonates

abstract: The Torehina Formation is part of a cool-water carbonate succession of Oligocene age in New Zealand that crops out on the Coromandel Peninsula, North Island. It contains two major transgressive sequences that record successive onlap of a once emergent landmass. The first sequence records marine flooding of non-marine to marginal marine fan delta/estuarine facies, followed by deepening upward and formation of a low-energy, deep (100+ m) muddy carbonate ramp. The capping sequence boundary is characterized by differential uplift and varies considerably in its character over a small (9 km2) area, varying from a burrowed glauconitic firmground to an erosional hardground to an undulatory marine contact to a palaeokarst with < 25 m relief. Sequence 2 sediments, which overlie the palaeokarst with minor (< 10°) angular unconformity, are clayey, marine (offshore) siltstones, whereas open-marine limestones of equivalent age overlie the other boundary types with no apparent angular discordance. The siliciclastics could either represent lowstand channel deposits or may define interbank deposits contemporary with adjacent carbonates. Palaeogeographic restriction of palaeokarst and sequence 2 siliciclastics identifies a structural corridor oriented strike-parallel to the adjacent Harauki Graben, which began to develop by this time. Palaeogeographical differences in the character of the basal limestone facies of sequence 2 also occur. These differences identify variation in accommodation during initial stages of deposition imposed by previous differential movement of fault blocks. As a result, relatively warm-water (20 °C) Amphistegina-bearing limestones in one area contrast with co-existing deeper water, silty foraminiferal (benthic > planktic), echinoderm and bivalve limestones in another. This variation disappears upsection, which suggests that initial bathymetric differences were eliminated with renewed rise in sea level, yielding deeper water inner-shelf sediment facies followed by the accumulation of still deeper, but higher energy, outer-shelf bivalve and bryozoan facies. The sequence architecture of the Torehina Formation is controlled by tectonism, both long-term subsidence and short-term differential uplift. This arose as a result of increasing tectonic activity throughout proto-New Zealand during the Late Oligocene. In such a system, local and regional variation in tectonism among adjacent basins can impose subtle to marked differences in the timing of sequence boundaries and the character of basin-fill patterns.

text: The role of tectonism in sequence development and facies distribution of Upper Oligocene cool-water carbonates: Coromandel Peninsula, New Zealand The Torehina Formation is part of a cool-water carbonate succession of Oligocene age in New Zealand that crops out on the Coromandel Peninsula, North Island. It contains two major transgressive sequences that record successive onlap of a once emergent landmass. The first sequence records marine flooding of non-marine to marginal marine fan delta/estuarine facies, followed by deepening upward and formation of a low-energy, deep (100+ m) muddy carbonate ramp. The capping sequence boundary is characterized by differential uplift and varies considerably in its character over a small (9 km2) area, varying from a burrowed glauconitic firmground to an erosional hardground to an undulatory marine contact to a palaeokarst with < 25 m relief. Sequence 2 sediments, which overlie the palaeokarst with minor (< 10°) angular unconformity, are clayey, marine (offshore) siltstones, whereas open-marine limestones of equivalent age overlie the other boundary types with no apparent angular discordance. The siliciclastics could either represent lowstand channel deposits or may define interbank deposits contemporary with adjacent carbonates. Palaeogeographic restriction of palaeokarst and sequence 2 siliciclastics identifies a structural corridor oriented strike-parallel to the adjacent Harauki Graben, which began to develop by this time. Palaeogeographical differences in the character of the basal limestone facies of sequence 2 also occur. These differences identify variation in accommodation during initial stages of deposition imposed by previous differential movement of fault blocks. As a result, relatively warm-water (20 °C) Amphistegina-bearing limestones in one area contrast with co-existing deeper water, silty foraminiferal (benthic > planktic), echinoderm and bivalve limestones in another. This variation disappears upsection, which suggests that initial bathymetric differences were eliminated with renewed rise in sea level, yielding deeper water inner-shelf sediment facies followed by the accumulation of still deeper, but higher energy, outer-shelf bivalve and bryozoan facies. The sequence architecture of the Torehina Formation is controlled by tectonism, both long-term subsidence and short-term differential uplift. This arose as a result of increasing tectonic activity throughout proto-New Zealand during the Late Oligocene. In such a system, local and regional variation in tectonism among adjacent basins can impose subtle to marked differences in the timing of sequence boundaries and the character of basin-fill patterns.

year: 2004

title: Human-competitive automatic topic indexing

authors: Medelyan, Olena

subjects: topic indexing

abstract: Topic indexing is the task of identifying the main topics covered by a document. These are useful for many purposes: as subject headings in libraries, as keywords in academic publications and as tags on the web. Knowing a document's topics helps people judge its relevance quickly. However, assigning topics manually is labor intensive. This thesis shows how to generate them automatically in a way that competes with human performance.

Three kinds of indexing are investigated: term assignment, a task commonly performed by librarians, who select topics from a controlled vocabulary; tagging, a popular activity of web users, who choose topics freely; and a new method of keyphrase extraction, where topics are equated to Wikipedia article names. A general two-stage algorithm is introduced that first selects candidate topics and then ranks them by significance based on their properties. These properties draw on statistical, semantic, domain-specific and encyclopedic knowledge. They are combined using a machine learning algorithm that models human indexing behavior from examples.

This approach is evaluated by comparing automatically generated topics to those assigned by professional indexers, and by amateurs. We claim that the algorithm is  human-competitive  because it chooses topics that are as consistent with those assigned by humans as their topics are with each other. The approach is generalizable, requires little training data and applies across different domains and languages.

text: Human-competitive automatic topic indexing Topic indexing is the task of identifying the main topics covered by a document. These are useful for many purposes: as subject headings in libraries, as keywords in academic publications and as tags on the web. Knowing a document's topics helps people judge its relevance quickly. However, assigning topics manually is labor intensive. This thesis shows how to generate them automatically in a way that competes with human performance.

Three kinds of indexing are investigated: term assignment, a task commonly performed by librarians, who select topics from a controlled vocabulary; tagging, a popular activity of web users, who choose topics freely; and a new method of keyphrase extraction, where topics are equated to Wikipedia article names. A general two-stage algorithm is introduced that first selects candidate topics and then ranks them by significance based on their properties. These properties draw on statistical, semantic, domain-specific and encyclopedic knowledge. They are combined using a machine learning algorithm that models human indexing behavior from examples.

This approach is evaluated by comparing automatically generated topics to those assigned by professional indexers, and by amateurs. We claim that the algorithm is  human-competitive  because it chooses topics that are as consistent with those assigned by humans as their topics are with each other. The approach is generalizable, requires little training data and applies across different domains and languages.

year: 2009

title: Too many Māori and Asian people are drowning – can better cultural understanding reverse the trend?

authors: Wheaton, Belinda

abstract: The article discusses the high rate of drownings in New Zealand, particularly among Māori and Asian communities. It highlights the need for culturally specific water safety education to address this issue. The Asian community, in particular, includes many first-generation migrants who may lack water skills due to their upbringing and fear of water. Overprotectiveness towards children around water is also common among Asian parents. The article emphasizes the importance of providing support and learning opportunities to help Asian migrants develop water skills and feel more comfortable in outdoor activities. Additionally, it mentions the declining water skills among New Zealand children in general and the need for better resourcing of school programs and community initiatives like ActivAsian. Culturally relevant knowledge and education are deemed crucial in changing attitudes and behaviors towards water safety. The article stresses that making New Zealand's beaches and waterways safe for all residents, including migrants, requires targeted funding and a collaborative effort to prevent tragic drowning incidents.

text: Too many Māori and Asian people are drowning – can better cultural understanding reverse the trend? The article discusses the high rate of drownings in New Zealand, particularly among Māori and Asian communities. It highlights the need for culturally specific water safety education to address this issue. The Asian community, in particular, includes many first-generation migrants who may lack water skills due to their upbringing and fear of water. Overprotectiveness towards children around water is also common among Asian parents. The article emphasizes the importance of providing support and learning opportunities to help Asian migrants develop water skills and feel more comfortable in outdoor activities. Additionally, it mentions the declining water skills among New Zealand children in general and the need for better resourcing of school programs and community initiatives like ActivAsian. Culturally relevant knowledge and education are deemed crucial in changing attitudes and behaviors towards water safety. The article stresses that making New Zealand's beaches and waterways safe for all residents, including migrants, requires targeted funding and a collaborative effort to prevent tragic drowning incidents.

year: 2022-12-20