title: Rhodolith-bearing limestones as transgressive marker beds: fossil and modern examples from North Island, New Zealand

authors: Nalin, Ronald

subjects: calcareous red algae

abstract: Rhodoliths are nodular structures composed mainly of the superimposed thalli of calcareous red algae. Because their development is controlled by an array of ecological parameters, rhodoliths are a valuable source of palaeoenvironmental information. However, despite their common use in palaeoecological reconstructions, the stratigraphic significance of rhodolith accumulations seldom has been addressed in detail. In a study of Cenozoic rhodolith-bearing deposits from the North Island of New Zealand, rhodolithic units, usually of limited lateral extent, typically occur above major unconformities at the base of deepening upwards successions. Two types of transgressive rhodolith-bearing deposits may be distinguished on the basis of texture and rhodolith internal structure: (i) type A deposits are clast-supported rhodolithic rudstones containing abundant pebbles and cobbles reworked from the substrate, and are characterized by rhodoliths with a compact concentric to columnar internal structure and a high nucleus to algal cover ratio; (ii) type B deposits are rhodolithic floatstones with a matrix usually consisting of bryozoan fragments, benthic foraminifera and echinoid fragments or terrigenous silty fine sand. The rhodoliths of type B units usually have a loose internal framework with irregular to branched crusts. The two contrasting rhodolith-bearing units are interpreted as characteristic facies of transgressive systems tract deposits, analogous to shell concentrations formed under conditions of low net sedimentation. Type A deposits are correlated with relatively high-energy settings and/or narrow submerged palaeotopographic lows, whereas type B deposits are interpreted as forming in lower-energy settings. The association between transgression and development of rhodolithic facies is confirmed by observations of a modern rhodolith production site at Whangaparaoa Peninsula in North Island, where algal nodules grow above a ravinement surface cut during the Holocene sea-level rise, and also by a review of published fossil examples, many of which show stratigraphic and compositional attributes analogous to those of the New Zealand occurrences. The review indicates that transgressive rhodolith accumulations develop more commonly in, but are not restricted to, non-tropical settings. It is suggested that a combination of factors, such as low net sedimentary input, nature of the substrate, sea-level rise and inherited physiography contribute to determine the relationship between rhodolith-bearing deposits and transgressive settings.

text: Rhodolith-bearing limestones as transgressive marker beds: fossil and modern examples from North Island, New Zealand Rhodoliths are nodular structures composed mainly of the superimposed thalli of calcareous red algae. Because their development is controlled by an array of ecological parameters, rhodoliths are a valuable source of palaeoenvironmental information. However, despite their common use in palaeoecological reconstructions, the stratigraphic significance of rhodolith accumulations seldom has been addressed in detail. In a study of Cenozoic rhodolith-bearing deposits from the North Island of New Zealand, rhodolithic units, usually of limited lateral extent, typically occur above major unconformities at the base of deepening upwards successions. Two types of transgressive rhodolith-bearing deposits may be distinguished on the basis of texture and rhodolith internal structure: (i) type A deposits are clast-supported rhodolithic rudstones containing abundant pebbles and cobbles reworked from the substrate, and are characterized by rhodoliths with a compact concentric to columnar internal structure and a high nucleus to algal cover ratio; (ii) type B deposits are rhodolithic floatstones with a matrix usually consisting of bryozoan fragments, benthic foraminifera and echinoid fragments or terrigenous silty fine sand. The rhodoliths of type B units usually have a loose internal framework with irregular to branched crusts. The two contrasting rhodolith-bearing units are interpreted as characteristic facies of transgressive systems tract deposits, analogous to shell concentrations formed under conditions of low net sedimentation. Type A deposits are correlated with relatively high-energy settings and/or narrow submerged palaeotopographic lows, whereas type B deposits are interpreted as forming in lower-energy settings. The association between transgression and development of rhodolithic facies is confirmed by observations of a modern rhodolith production site at Whangaparaoa Peninsula in North Island, where algal nodules grow above a ravinement surface cut during the Holocene sea-level rise, and also by a review of published fossil examples, many of which show stratigraphic and compositional attributes analogous to those of the New Zealand occurrences. The review indicates that transgressive rhodolith accumulations develop more commonly in, but are not restricted to, non-tropical settings. It is suggested that a combination of factors, such as low net sedimentary input, nature of the substrate, sea-level rise and inherited physiography contribute to determine the relationship between rhodolith-bearing deposits and transgressive settings.

year: 2008

title: Field guide for didymo DNA sample collection

authors: Hicks, Brendan J.

subjects: Field guide

abstract: This protocol is designed for work in two-person teams for both safety and to maximise
sample integrity.

text: Field guide for didymo DNA sample collection This protocol is designed for work in two-person teams for both safety and to maximise
sample integrity.

year: 2007-11

title: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002

authors: Ashwell, Allanah

subjects: Maori students

abstract: The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

text: Māori in the Faculty of Arts and Social Sciences: An analysis of the Faculty of Arts and Social Science data records from 1997-2002 The Ministry of Education has compiled annual reports on the participation of Maori in
tertiary education. The 2002 report presented a comprehensive description of Maori
participation across all tertiary institutions within New Zealand in that year. The figures
show that Maori are markedly under-represented in tertiary institutions, particularly
universities.
The barriers encountered by Maori students can either directly or indirectly impact on
Maori participation, retention and success. The more disturbing outcome is that of
withdrawal or dropping out of higher education, is more likely when a Maori student
experiences and has to confront multiple rather than single barriers.
With this in mind, the aim of this study was to examine and identify trends apparent in
data records of Maori students enrolled in courses offered by the Faculty of Arts and
Social Sciences at the University of Waikato between 1997 and 2002 and to make
recommendations to the Faculty about how negative trends might be addressed. Specific
areas for analysis are detailed in the report.

year: 2003-06