Cave Aragonites of New South Wales

Abstract Aragonite is a minor secondary mineral in many limestone caves throughout the world. It has been claimed that it is the second-most common cave mineral after calcite (Hill & Forti 1997). Aragonite occurs as a secondary mineral in the vadose zone of some caves in New South Wales. Aragonite is unstable in fresh water and usually reverts to calcite, but it is actively depositing in some NSW caves. A review of current literature on the cave aragonite problem showed that chemical inhibitors to calcite deposition assist in the precipitation of calcium carbonate as aragonite instead of calcite. Chemical inhibitors work by physically blocking the positions on the calcite crystal lattice which would have otherwise allowed calcite to develop into a larger crystal. Often an inhibitor for calcite has no effect on the aragonite crystal lattice, thus aragonite may deposit where calcite deposition is inhibited. Another association with aragonite in some NSW caves appears to be high evaporation rates allowing calcite, aragonite and vaterite to deposit. Vaterite is another unstable polymorph of calcium carbonate, which reverts to aragonite and calcite over time. Vaterite, aragonite and calcite were found together in cave sediments in areas with low humidity in Wollondilly Cave, Wombeyan. Several factors were found to be associated with the deposition of aragonite instead of calcite speleothems in NSW caves. They included the presence of ferroan dolomite, calcite-inhibitors (in particular ions of magnesium, manganese, phosphate, sulfate and heavy metals), and both air movement and humidity. Aragonite deposits in several NSW caves were examined to determine whether the material is or is not aragonite. Substrates to the aragonite were examined, as was the nature of the bedrock. The work concentrated on Contact Cave and Wiburds Lake Cave at Jenolan, Sigma Cave, Wollondilly Cave and Cow Pit at Wombeyan and Piano Cave and Deep Hole (Cave) at Walli. Comparisons are made with other caves. The study sites are all located in Palaeozoic rocks within the Lachlan Fold Belt tectonic region. Two of the sites, Jenolan and Wombeyan, are close to the western edge of the Sydney Basin. The third site, Walli, is close to a warm spring. The physical, climatic, chemical and mineralogical influences on calcium carbonate deposition in the caves were investigated. Where cave maps were unavailable, they were prepared on site as part of the study. %At Jenolan Caves, Contact Cave and Wiburds Lake Cave were examined in detail, %and other sites were compared with these. Contact Cave is located near the eastern boundary of the Late Silurian Jenolan Caves Limestone, in an area of steeply bedded and partially dolomitised limestone very close to its eastern boundary with the Jenolan volcanics. Aragonite in Contact Cave is precipitated on the ceiling as anthodites, helictites and coatings. The substrate for the aragonite is porous, altered, dolomitised limestone which is wedged apart by aragonite crystals. Aragonite deposition in Contact Cave is associated with a concentration of calcite-inhibiting ions, mainly minerals containing ions of magnesium, manganese and to a lesser extent, phosphates. Aragonite, dolomite and rhodochrosite are being actively deposited where these minerals are present. Calcite is being deposited where minerals containing magnesium ions are not present. The inhibitors appear to be mobilised by fresh water entering the cave as seepage along the steep bedding and jointing. During winter, cold dry air pooling in the lower part of the cave may concentrate minerals by evaporation and is most likely associated with the ``popcorn line'' seen in the cave. Wiburds Lake Cave is located near the western boundary of the Jenolan Caves Limestone, very close to its faulted western boundary with Ordovician cherts. Aragonite at Wiburds Lake Cave is associated with weathered pyritic dolomitised limestone, an altered, dolomitised mafic dyke in a fault shear zone, and also with bat guano minerals. Aragonite speleothems include a spathite, cavity fills, vughs, surface coatings and anthodites. Calcite occurs in small quantities at the aragonite sites. Calcite-inhibitors associated with aragonite include ions of magnesium, manganese and sulfate. Phosphate is significant in some areas. Low humidity is significant in two areas. Other sites briefly examined at Jenolan include Glass Cave, Mammoth Cave, Spider Cave and the show caves. Aragonite in Glass Cave may be associated with both weathering of dolomitised limestone (resulting in anthodites) and with bat guano (resulting in small cryptic forms). Aragonite in the show caves, and possibly in Mammoth and Spider Cave is associated with weathering of pyritic dolomitised limestone. Wombeyan Caves are developed in saccharoidal marble, metamorphosed Silurian Wombeyan Caves Limestone. Three sites were examined in detail at Wombeyan Caves: Sigma Cave, Wollondilly Cave and Cow Pit (a steep sided doline with a dark zone). Sigma Cave is close to the south east boundary of the Wombeyan marble, close to its unconformable boundary with effusive hypersthene porphyry and intrusive gabbro, and contains some unmarmorised limestone. Aragonite occurs mainly in a canyon at the southern extremity of the cave and in some other sites. In Sigma Cave, aragonite deposition is mainly associated with minerals containing calcite-inhibitors, as well as some air movement in the cave. Calcite-inhibitors at Sigma Cave include ions of magnesium, manganese, sulfate and phosphate (possibly bat origin), partly from bedrock veins and partly from breakdown of minerals in sediments sourced from mafic igneous rocks. Substrates to aragonite speleothems include corroded speleothem, bedrock, ochres, mud and clastics. There is air movement at times in the canyon, it has higher levels of CO2 than other parts of the cave and humidity is high. Air movement may assist in the rapid exchange of CO2 at speleothem surfaces. Wollondilly Cave is located in the eastern part of the Wombeyan marble. At Wollondilly Cave, anthodites and helictites were seen in an inaccessible area of the cave. Paramorphs of calcite after aragonite were found at Jacobs Ladder and the Pantheon. Aragonite at Star Chamber is associated with huntite and hydromagnesite. In The Loft, speleothem corrosion is characteristic of bat guano deposits. Aragonite, vaterite and calcite were detected in surface coatings in this area. Air movement between the two entrances of this cave has a drying effect which may serve to concentrate minerals by evaporation in some parts of the cave. The presence of vaterite and aragonite in fluffy coatings infers that vaterite may be inverting to aragonite. Calcite-inhibitors in the sediments include ions of phosphate, sulphate, magnesium and manganese. Cave sediment includes material sourced from detrital mafic rocks. Cow Pit is located near Wollondilly Cave, and cave W43 is located near the northern boundary of the Wombeyan marble. At Cow Pit, paramorphs of calcite after aragonite occur in the walls as spheroids with minor huntite. Aragonite is a minor mineral in white wall coatings and red phosphatic sediments with minor hydromagnesite and huntite. At cave W43, aragonite was detected in the base of a coralloid speleothem. Paramorphs of calcite after aragonite were observed in the same speleothem. Dolomite in the bedrock may be a source of magnesium-rich minerals at cave W43. Walli Caves are developed in the massive Belubula Limestone of the Ordovician Cliefden Caves Limestone Subgroup (Barrajin Group). At the caves, the limestone is steeply bedded and contains chert nodules with dolomite inclusions. Gypsum and barite occur in veins in the limestone. At Walli Caves, Piano Cave and Deep Hole (Deep Cave) were examined for aragonite. Gypsum occurs both as a surface coating and as fine selenite needles on chert nodules in areas with low humidity in the caves. Aragonite at Walli caves was associated with vein minerals and coatings containing calcite-inhibitors and, in some areas, low humidity. Calcite-inhibitors include sulfate (mostly as gypsum), magnesium, manganese and barium. Other caves which contain aragonite are mentioned. Although these were not major study sites, sufficient information is available on them to make a preliminary assessment as to why they may contain aragonite. These other caves include Flying Fortress Cave and the B4-5 Extension at Bungonia near Goulburn, and Wyanbene Cave south of Braidwood. Aragonite deposition at Bungonia has some similarities with that at Jenolan in that dolomitisation of the bedrock has occurred, and the bedding or jointing is steep allowing seepage of water into the cave, with possible oxidation of pyrite. Aragonite is also associated with a mafic dyke. Wyanbene cave features some bedrock dolomitisation, and also features low grade ore bodies which include several known calcite-inhibitors. Aragonite appears to be associated with both features. Finally, brief notes are made of aragonite-like speleothems at Colong Caves (between Jenolan and Wombeyan), a cave at Jaunter (west of Jenolan) and Wellington (240\,km NW of Sydney)

Franklin Roosevelt\u27s advisory system: The institutionalization of the Executive office of the President

Since its inception in 1787, the Office of the President of the United States has had to deal with many governmental problems, burdening the President with extraordinary decisions. As the country has grown in population, in geography, and in world influence the number of problems and decisions has escalated, placing immense pressure upon the decision making procress. Today, decisions made by the President of the United States can affect the future of the entire world. Consequently, the advice and administrative assistance a president receives when he is making these decisions is crucial. Furnishing the President with this advice and assistance is one of the most influential elements in the Executive Branch of the Federal Government, the Presidential Advisory System

Top tagging: an analytical perspective

In this paper we study aspects of top tagging from first principles of QCD. We find that the method known as the CMS top tagger becomes collinear unsafe at high pt and propose variants thereof which are IRC safe, and hence suitable for analytical studies, while giving a comparable performance to the CMS tagger. We also develop new techniques to identify three-pronged jet substructure, based on adaptations of the Y-splitter method and its combination with grooming. A novel feature of our studies, relative to previous calculations of two-pronged substructure, is our use of triple-collinear splitting functions combined with all-order resummation, which owes to the presence of two mass scales of the same order, mt and mW , in the signal jet. We carry out leading logarithmic resummed calculations for the various top-taggers, for both background and signal jets, and compare the results to those from parton showers. We also identify and comment on the main features driving tagger performance at high pt and discuss the role of non-perturbative effects

Open textbook publishing at Australian universities

Studies show university students struggle to afford textbooks, which can lead them to go hungry or withdraw altogether. Universities are combating this problem by using open textbooks to increase participation and improve student outcomes. Little research has been conducted on open textbook publishing at Australian universities. Most existing research focuses on the international context, where differences in funding and legislation affect not only how, but the extent to which publishing work is undertaken. This editing and publishing doctoral research project is the first national study of open textbook publishing activities and experiences at Australian universities and will advance understanding of emerging trends in library and university publishing in Australia. Adopting a mixed methods approach, I will collect quantitative and qualitative data about open textbook publishing practices and experiences at Australian universities. Using statistical and thematic analysis, I will identify and explore facilitators and barriers that contribute to the success or failure of open textbook publishing projects. I will use these results to make evidence-based recommendations for how Australian universities can build sustainable open textbook publishing programs that provide more students with access to zero-cost course materials

Marcadores del discurso derivados de los verbos de percepción: un análisis comparativo entre el español y el italiano

Despite the growing interest in discourse markers over the past two decades, few studies are dedicated to the interlinguistic comparison of discourse markers. By means of a corpus-based approach the present study proposes a comparison between the discourse markers derived from verbs of perception in Italian (guarda/guardi, senti/senta) and Spanish (mira/mire, oye/oiga). The results of a comparable corpus study reveals that the discourse markers sharing the original perception modality display a similar formal behaviour (mira/mire ~ guarda/guardi, oye/oiga ~ senti/senta). From the parallel corpus on the other hand it results that the most frequent equivalent of mira/mire is senti/senta, which can be linked to the original semantics of both verbs. These two main observations confirm the relevance of a parallel corpus as a complementary source to a comparable corpus when comparing phenomena in two (or more) languages. This combined corpus approach brings about not only interlinguistic insights but provides at the same time knowledge about the relation and uses of the discourse markers within the languages

Public sector supply chain management: A Triple Helix approach to aligning innovative environmental initiatives

© 2015 National Research University Higher School of Economics. This paper argues that in order to deliver greater levels of sustainable performance, environmental strategy should be addressed at the supply chain level and not just at the level of the individual organisation. It demonstrates the similarities between the environmental statements of companies in both the private and public sectors and proposes that public sector organisations, by virtue of their considerable spend with private sector organisations, are in a powerful position to encourage and support environmental initiatives throughout their supply chains. Drawing upon Triple Helix Theory the paper discusses the importance of unifying the efforts of government, industry and academia in order to identify and operationalise innovative thinking in economies. It explores the roles of public and private sector organisations along with universities in developing environmental strategies and practices within supply chains. Environmental Management Systems (EMS) are discussed and the Eco-Management and Audit Scheme (EMAS) is identified as a potential mechanism for structuring and reporting the collaborative environmental improvement performance of supply chains

Parallel and Sequential Pathways of Molecular Recognition of a Tandem-Repeat Protein and Its Intrinsically Disordered Binding Partner.

The Wnt signalling pathway plays an important role in cell proliferation, differentiation, and fate decisions in embryonic development and the maintenance of adult tissues. The twelve armadillo (ARM) repeat-containing protein β-catenin acts as the signal transducer in this pathway. Here, we investigated the interaction between β-catenin and the intrinsically disordered transcription factor TCF7L2, comprising a very long nanomolar-affinity interface of approximately 4800 Å2 that spans ten of the twelve ARM repeats of β-catenin. First, a fluorescence reporter system for the interaction was engineered and used to determine the kinetic rate constants for the association and dissociation. The association kinetics of TCF7L2 and β-catenin were monophasic and rapid (7.3 ± 0.1 × 107 M-1·s-1), whereas dissociation was biphasic and slow (5.7 ± 0.4 × 10-4 s-1, 15.2 ± 2.8 × 10-4 s-1). This reporter system was then combined with site-directed mutagenesis to investigate the striking variability in the conformation adopted by TCF7L2 in the three different crystal structures of the TCF7L2-β-catenin complex. We found that the mutation had very little effect on the association kinetics, indicating that most interactions form after the rate-limiting barrier for association. Mutations of the N- and C-terminal subdomains of TCF7L2 that adopt relatively fixed conformations in the crystal structures had large effects on the dissociation kinetics, whereas the mutation of the labile sub-domain connecting them had negligible effect. These results point to a two-site avidity mechanism of binding with the linker region forming a "fuzzy" complex involving transient contacts that are not site-specific. Strikingly, the two mutations in the N-terminal subdomain that had the largest effects on the dissociation kinetics showed two additional phases, indicating partial flux through an alternative dissociation pathway that is inaccessible to the wild type. The results presented here provide insights into the kinetics of the molecular recognition of a long intrinsically disordered region with an elongated repeat-protein surface, a process found to involve parallel routes with sequential steps in each