The Natural Resource Management Planning Portal : Perspectives for NRM planning and reporting

Natural Resource Management (NRM) is often conducted as a partnership between government and citizens. In Australia, government agencies formulate policy and fund implementation that may be delivered on-ground by community groups (such as Landcare). Since the late 1980s, over AUS$8b of Commonwealth investment has been made in NRM. However, quantitative evidence of environmental improvements is lacking. The NRM Planning Portal has been developed to (1) provide an online spatial information system for sharing Landcare and agency data; and (2) to facilitate NRM priority setting at local and regional planning scales. While the project successfully federates Landcare NRM activity data, challenges included (1) unstructured, non-standardized data, meaning that quantitative reporting against strategic objectives is not currently possible, and (2) a lack of common understanding about the value proposition for adopting the portal approach. Demonstrating the benefit of technology adoption is a key lesson for digital NRM planning

Tungsten

Tungsten deposits usually occur within, or near to, orogenic belts resulting from subduction related plate tectonics. All major deposit types are associated with granitic intrusions or with medium- to high-grade metamorphic rocks. By far the largest producing country is China with lesser quantities mined in Russia, Canada, Bolivia and other countries. Tungsten's main uses are in hard metals, e.g. tungsten carbide, for cutting, drilling and wear-resistant parts or coatings; as an alloy with steel or other metals were heat resistance is important; as wire, sheets or rods in electrical or elecontric applications; and in chemicals. Tungsten is important for these uses because of its very high melting point, very high density, extreme strength, high wear resitance, high tensile strength, low coefficient of expansion and high thermal and electrical conductivity

Two Mesoarchaean terranes in the Reguibat shield of NW Mauritania

Two domains have previously been recognized in the Archaean Reguibat Shield of NW Mauritania, based primarily on their gross lithological differences (Rocci et al., 1991). New fieldwork has identified a major ductile shear zone (Tâçarât -Inemmaûdene Shear Zone) se-parating these domains and new geochronological studies show that the two domains record different Mesoarchaean histories. As such, the two domains are redefined as the Choum-Rag el Abiod Terrane and Tasiast-Tijirit Terrane. Previous isotopic studies of metamorphic litholo-gies of the eastern Choum-Rag el Abiod Terrane indicate a succession of crustal growth from about 3.5-3.45 Ga to between about 3.2 and 2.99 Ga. Isotopic data presented in this contribu-tion from the Tasiast-Tijirit Terrane indicate that emplacement of major calc-alkaline plutons occurred at c.2.93 Ga after volcanism (preserved as greenstone belts) that included late felsic eruptive centres dated at c.2965 Ma. This Mesoarchaean intrusive and extrusive magmatism was confined to the Tasiast-Tijirit Terrane where it was emplaced through migmatitic or-thogneisses that are the oldest lithodemic unit of the Tasiast-Tijirit Terrane. Widespread bi-modal, post-tectonic magmatism in both terranes included major granitic magmatism dated at c.2730 Ma. The N- to NNE-trending curvilinear Tâçarât -Inemmaûdene Shear Zone that separates the two terranes records late intense transpressive ductile shearing. It has a flower structure over a horizontal distance of about 70 km across its southern portion with unquantifiable sinistral horizontal offset, and east-directed thrusting on its eastern side where it cuts into the Choum-Rag el Abiod Terrane. A new U-Pb zircon age of 2954±11 Ma is presented for a deformed granite confined within the central part of this shear zone. A minimum age for the shearing is provided by a previously determined c. 2.73 Ga age for a post-tectonic granite that cuts across the easternmost part of the shear zone in the Choum-Rag el Abiod Terrane

Punching above their weight: large release of greenhouse gases from small agricultural dams

Freshwater ecosystems play a major role in global carbon cycling through the breakdown of organic material and release of greenhouse gases (GHGs). Carbon dioxide (CO2) and methane (CH4) emissions from lakes, wetlands, reservoirs and small natural ponds have been well studied, however, the GHG emissions of highly abundant, small‐scale (\u3c0.01 km2) agricultural dams (small stream and run‐off impoundments) are still unknown. Here, we measured the diffusive CO2 and CH4 flux of 77 small agricultural dams within south‐east Australia. The GHG emissions from these waterbodies, which are currently unaccounted for in GHG inventories, amounted to 11.12 ± 2.59 g CO2‐equivalent m2/day, a value 3.43 times higher than temperate reservoir emissions. Upscaling these results to the entire state of Victoria, Australia, resulted in a farm dam CO2‐equivalent/day emission rate of 4,853 tons, 3.1 times higher than state‐wide reservoir emissions in spite of farm dams covering only 0.94 times the comparative area. We also show that CO2 and CH4 emission rates were both significantly positively correlated with dissolved nitrate concentrations, and significantly higher in livestock rearing farm dams when compared to cropping farm dams. The results from this study demonstrate that small agricultural farm dams can be a major source of greenhouse gas emissions, thereby justifying their inclusion in global carbon budgets

Geochemical mapping using stream sediments in west-central Nigeria : implications for environmental studies and mineral exploration in West Africa

This paper provides an overview of regional geochemical mapping using stream sediments from central and south-western Nigeria. A total of 1569 stream sediment samples were collected and 54 major and trace elements determined by ICP-MS and Au, Pd and Pt by fire assay. Multivariate statistical techniques (e.g., correlation analysis and principal factor analysis) were used to explore the data, following appropriate data transformation, to understand the data structure, investigate underlying processes controlling spatial geochemical variability and identify element associations. Major geochemical variations are controlled by source geology and provenance, as well as chemical weathering and winnowing processes, more subtle variations are a result of land use and contamination from anthropogenic activity. This work has identified placer deposits of potential economic importance for Au, REE, Ta, Nb, U and Pt, as well as other primary metal deposits. Areas of higher As and Cr (>2 mg/kg and >70 mg/kg respectively) are associated with Mesozoic and younger coastal sediments in SW Nigeria. High stream sediment Zr concentrations (mean>0.2%), from proximal zircons derived from weathering of basement rocks, have important implications for sample preparation and subsequent analysis due to interferences. Associated heavy minerals enriched in high field strength elements, and notably rare earths’, may also have important implications for understanding magmatic processes within the basement terrain of West Africa. This study provides important new background/baseline geochemical values for common geological domains in Nigeria (which extend across other parts of West Africa) for assessment of contamination from urban/industrial land use changes and mining activities. Regional stream sediment mapping is also able to provide important new information with applications across a number of sectors including agriculture, health, land use and planning