Low-altitude periglacial activity in southeastern Australia during the late Pleistocene

Only a small area of the Australian mainland was glaciated during the Pleistocene, whereas periglacial deposits are far more common, indicating that cold environments were extensive and a major influence on landscape evolution. Here we identify representative low-elevation examples of scree slopes and frost action, together with fans and valley fills, indicating pronounced erosion cycles during the Pleistocene. To date the deposits, we explore approaches using radiocarbon, optically stimulated luminescence, and profile dating using the cosmogenic nuclide 10Be. The radiocarbon and optical ages show that screes, alluvial valley fill, and fans were deposited between 66–13 ka during the coldest part of the last glacial cycle, and within the previous glacial cycle. Exposure dating indicates further landscape erosion cycles back to the mid Pleistocene. Together, the deposits indicate the frost cracking limit was ~1300 m lower at 680 ± 10 m and mean winter temperature was 8.2 ± 0.5°C colder than present. Periglacial conditions probably affected much of southeastern Australia. The treeless and dry conditions resulted in widespread erosion and increased run off. Combined with increased snow storage within catchments, rivers were paradoxically larger, with high seasonal discharge and sediment loads.

Revision of Anomalomorpha Arrow, 1908 and Enracius Dechambre, 1999, with Erbmahcedius new genus from southeastern Australia (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini: Cheiroplatina)

The Australian genera Anomalomorpha Arrow, 1908 and Enracius Dechambre, 1999 (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini: Cheiroplatina) are revised and compared with Adoryphorus Blackburn, 1889. Anomalomorpha giveni Carne, 1957, is transferred to Erbmahcedius Hutchinson & Allsopp new genus, becoming Erbmahcedius giveni new combination. Anomalomorpha pilbara Hutchinson & Allsopp new species and Enracius richardsi new species are described from Western Australia. Keys are given to identify the three species of Anomalomorpha and the two species of Enracius and to separate all four genera from other Cheiroplatina. New distributional records are presented, and habitats of the two new species are discussed.

Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand

<p>Molybdenite mineralization occurs within the Bald Hill Prospect (West Nelson) in brecciated and hornfelsed Greenland Group slates and metagreywackes and associated quartz trondhjemite porphyry minor intrusions (Lyell Porphyry). Potassium argon (K-Ar) ages of the Lyell Porphyry, several granites forming part of the adjacent Karamea Granite batholith (Bald Hill Granites) and mineralized hornfelsic country rocks fall in the range 102-120 Ma (mid-Cretaceous). Adjacent lower Ordovician Greenland Group slates yielded four K-Ar ages in the range 112-226 Ma indicating partial argon outgassing of these older metasediments. The Bald Hill Granites and the Lyell Porphyry granitic rocks belong to separate petrogenic provinces. Bald Hill Granites forming the western margin of the Karamea Granite batholith occur as a suite of foliated, medium-grained, muscovite-bearing leucogranites, pink microgranites and biotite-granites. Chemically these rocks are peraluminous-potash granites with 72-75% SiO2, MgONa2O with Rb > Sr and always contain more than 30% normative quartz and 3% normative corundum. In contrast, the Lyell Porphyry rocks intruding both Greenland Group and Bald Hill Granite country rocks, form a series of small, high-level plutons and cross-cutting dykes of quartz trondhjemite, granodiorite, quartz diorite, lamprophyre and quartz-bearing gabbroporphyry. Chemically the Lyell Porphyry intrusive rocks are soda-rich calc-alkaline granitoids containing 46-70% SiO2, >1% MgO, >2.2% CaO, with Na2O>K2O and Sr>Rb with less than 28% normative quartz and less than 2% normative corundum. From their studies of granite batholiths in southeastern Australia, Chappell and White (1974) recognise two contrasting granitoid types called I-type and S-type granites. The Lyell Porphyry and several other intrusive stocks associated with molybdenum mineralization in West Nelson and North Westland are shown to correspond to I-type granites, in contrast to the Karamea batholith granites (including Bald Hill Granites) which conform to S-type granites. Sulphur isotopic analyses of mineralization for ten molybdenum prospects in West Nelson indicate uniformly high temperatures of mineralization in the range 400° to 500°C, with a probable magmatic source for sulphur. The Bald Hill and other S-type granites forming the Karamea batholith were probably formed by the ultrametamorphism of crustal sedimentary material. The Lyell Porphyry and other molybdenum-bearing calc-alkaline intrusive stocks represent melt phases of deeper origin intruding the overlying granites and sediments. The emplacement of these stocks appears to equate with north-south lineaments and large scale circular features in the granite terranes of West Nelson. The geological setting, age, petrological characteristics and molybdenite mineralization of the Lyell Porphyry and Bald Hill Granites are similar to that of other West Nelson occurrences. All are associated with mid-Cretaceous minor granitic porphyry intrusions, emplaced in Paleozoic metasediments, close to the margins of the Karamea and Separation Point batholiths.</p>

Geology and Mineralization of the Bald Hill Molybdenum Occurrence, Buller District, West Nelson, New Zealand

<p>Molybdenite mineralization occurs within the Bald Hill Prospect (West Nelson) in brecciated and hornfelsed Greenland Group slates and metagreywackes and associated quartz trondhjemite porphyry minor intrusions (Lyell Porphyry). Potassium argon (K-Ar) ages of the Lyell Porphyry, several granites forming part of the adjacent Karamea Granite batholith (Bald Hill Granites) and mineralized hornfelsic country rocks fall in the range 102-120 Ma (mid-Cretaceous). Adjacent lower Ordovician Greenland Group slates yielded four K-Ar ages in the range 112-226 Ma indicating partial argon outgassing of these older metasediments. The Bald Hill Granites and the Lyell Porphyry granitic rocks belong to separate petrogenic provinces. Bald Hill Granites forming the western margin of the Karamea Granite batholith occur as a suite of foliated, medium-grained, muscovite-bearing leucogranites, pink microgranites and biotite-granites. Chemically these rocks are peraluminous-potash granites with 72-75% SiO2, MgONa2O with Rb > Sr and always contain more than 30% normative quartz and 3% normative corundum. In contrast, the Lyell Porphyry rocks intruding both Greenland Group and Bald Hill Granite country rocks, form a series of small, high-level plutons and cross-cutting dykes of quartz trondhjemite, granodiorite, quartz diorite, lamprophyre and quartz-bearing gabbroporphyry. Chemically the Lyell Porphyry intrusive rocks are soda-rich calc-alkaline granitoids containing 46-70% SiO2, >1% MgO, >2.2% CaO, with Na2O>K2O and Sr>Rb with less than 28% normative quartz and less than 2% normative corundum. From their studies of granite batholiths in southeastern Australia, Chappell and White (1974) recognise two contrasting granitoid types called I-type and S-type granites. The Lyell Porphyry and several other intrusive stocks associated with molybdenum mineralization in West Nelson and North Westland are shown to correspond to I-type granites, in contrast to the Karamea batholith granites (including Bald Hill Granites) which conform to S-type granites. Sulphur isotopic analyses of mineralization for ten molybdenum prospects in West Nelson indicate uniformly high temperatures of mineralization in the range 400° to 500°C, with a probable magmatic source for sulphur. The Bald Hill and other S-type granites forming the Karamea batholith were probably formed by the ultrametamorphism of crustal sedimentary material. The Lyell Porphyry and other molybdenum-bearing calc-alkaline intrusive stocks represent melt phases of deeper origin intruding the overlying granites and sediments. The emplacement of these stocks appears to equate with north-south lineaments and large scale circular features in the granite terranes of West Nelson. The geological setting, age, petrological characteristics and molybdenite mineralization of the Lyell Porphyry and Bald Hill Granites are similar to that of other West Nelson occurrences. All are associated with mid-Cretaceous minor granitic porphyry intrusions, emplaced in Paleozoic metasediments, close to the margins of the Karamea and Separation Point batholiths.</p>

68Maternal exposure to PM2.5 from a severe smoke event and birth outcomes in Victoria, Australia

Background The 2014 Hazelwood coal mine fire was an unprecedented six-week severe smoke event in the Latrobe Valley, southeastern Australia. We aimed to determine whether maternal exposure to fine particulate matter (PM2.5) attributable to the event was associated with adverse fetal growth or maturity, including birthweight, small for gestational age, term low birthweight or preterm birth. Methods A cohort of babies born within the affected region was defined used administrative perinatal data. Maternal average and peak PM2.5 was assigned to residential address at time of delivery using a chemical transport model. Maternal, infant, meteorological and temporal variables were included in final linear and log-binomial regression models. Results 3,591 singleton livebirths were included; 763 were exposed in utero. Average PM2.5 exposure was 4.4 µg/m3 (IQR 2.1 µg/m3); average peak was 45.0 µg/m3 (IQR 35.1 µg/m3). No association between PM2.5 and fetal growth or maturity was observed. Gestational diabetes mellitus was an effect modifier in the relationship; babies of exposed gestational diabetic mothers were 97 grams heavier per 10 µg/m3 increase in average PM2.5 exposure (95%CI 74, 120 grams), compared to mothers without gestational diabetes. Conclusions Maternal PM2.5 exposure from a smoke event was not associated with adverse fetal growth or maturity. There was a trophic response amongst babies of mothers with gestational diabetes. Key messages Babies born to mothers with gestational diabetes may be more susceptible to the effects of smoke events on birthweight.

Biodiversity of intertidal marine flatworms (Polycladida, Platyhelminthes) in southeastern Australia

Flatworms of the Order Polycladida are a group of free-living invertebrates found in a diversity of marine habitats, with over 800 species described worldwide. Marine flatworms are a conspicuous component of Australia’s marine fauna yet have received little attention. Less than 30 scientific articles have been published on Australian marine flatworms since 1855, of which only nine include species from southeastern Australia. Here, the biodiversity and distribution of species belonging to the Order Polycladida inhabiting intertidal rocky beaches in southeastern Australian waters were identified and analysed. Sampling was conducted at low tide along the coasts of New South Wales and Victoria. Collected samples were serially sectioned for comparative anatomical studies, and tissue was removed from each individual for molecular sequencing and analyses. Both nuclear and mitochondrial DNA sequences were obtained and used as an additional source of evidence for the description of new species as well as providing further insight into the phylogenetic relationships between them. A total of 20 species, six of which are new (e.g., Eulatocestus australis sp. nov.), and a new genus (Parabolia gen. nov.) have been described, as well as two new records for Australia (e.g., Stylochoplana clara Kato, 1937) have been identified increasing our knowledge of this important component of the Australian marine biota.