Petrogenesis of collision-related plutonics in Central Anatolia, Turkey

Central Anatolia exhibits good examples of calc-alkaline and alkaline magmatism of similar age in a collision-related tectonic setting (continent–island arc collision). In the Central Anatolia region, late Cretaceous post-collisional plutonic rocks intrude Palaeozoic–Mesozoic metamorphic rocks overthrust by Upper Cretaceous ophiolitic units to make up the Central Anatolian Crystalline Complex.

In the complex, three different intrusive rock types may be recognised based on their geochemical characteristics: (i) calc-alkaline (Behrekdag, Cefalikdag, and Celebi); (ii) subalkaline-transitional (Baranadag); and (ii) alkaline (Hamit). The calc-alkaline and subalkaline plutonic rocks are metaluminous I-type plutons ranging from monzodiorite to granite. The alkaline plutonic rocks are metaluminous to peralkaline plutons, predominantly A-type, ranging from nepheline monzosyenite to quartz syenite.

All intrusive rocks show enrichment in LILE and LREE relative to HFSE, and have high ⁸⁷Sr/⁸⁶Sr and low ¹⁴³Nd/¹⁴⁴Nd ratios. These characteristics indicate an enriched mantle source region(s) carrying a subduction component inherited from pre-collision subduction events. The tectonic discrimination diagram of Rb vs. (Y+Nb) suggests that the calc-alkaline, subalkaline, and alkaline plutonic rocks have been affected by crustal assimilation combined with fractional crystallisation processes.

The coexistence of calc-alkaline and alkaline magmatism in the Central Anatolian Crystalline Complex may be attributed to mantle source heterogeneity before collision. The former carries a smaller intraplate component and pre-subduction enrichment compared to the latter. Either thermal perturbation of the metasomatised lithosphere by delamination of the thermal boundary layer (TBL), or removal of a subducted plate (slab breakoff) is the likely mechanism for the initiation of the post-collisional magmatism in the Complex.     

Charting the territory: Exploring stakeholder reactions to the prospect of seafloor exploration and mining in Australia

Geological surveys of Australia’s marine territory have revealed significant potential for development of a marine resource industry. As onshore mineral deposits become harder to find, less accessible to their market and more challenging to extract, seafloor exploration and mining becomes an economically viable option. However, evidence from industry and environmental literature suggests that social acceptance will be important in determining the future of this industry in Australia. This paper reports on findings from research investigating the social viability of seafloor mining in Australia. A combination of interviews and focus groups were used to explore industry and community reactions to the possible development of seafloor mining in Australia. Although stakeholders’ reactions were variable, the majority of the participants were reluctant to see development of seafloor mining in Australia, primarily because of concerns about the industry’s potential environmental impact. All stakeholders sought further information about the benefits and costs associated with the industry suggesting that they did not yet have a fixed attitude towards the industry. Stakeholders favoured a precautionary approach towards the industry, supported by rigorous scientific analysis of the potential environmental impacts, transparent and socially responsive management processes and meaningful engagement with stakeholders.     

Hydrology and related changes after harvesting native forest catchments and establishing pinus radiata plantations. Part 1. Introduction to study

The hydrology of eight small catchments (1.63–8.26 ha) has been monitored in Westland, New Zealand since 1975. Two of these catchments were left in indigenous beech-podocarp-hardwood forest and the rest were subjected to various harvesting and land preparation treatments before being planted with Pinus radiata. This paper introduces a series of papers on the hydrology of the indigenous forest catchments and the changes that occurred after treatment. The catchments, experimental programme, climate of the area and the rainfall regime experienced between 1975 and 1987 are described.     

Hydrology and related changes after harvesting native forest catchments and establishing pinus radiata plantations. Part 2. The native forest water balance and changes in streamflow after harvesting

Six small, steep, south-west facing catchments (1.63–4.62 ha) have been monitored in Westland, New Zealand since 1974. Two catchments were retained in native mixed evergreen forest and the rest were subjected to various harvesting and land preparation techniques before being planted with Pinus radiata between 1977 and 1980. The 11-year water balance for the native forest catchments was: rain = streamflow + interception loss + transpiration + seepage (2370mm = 1290mm + 620mm + 360mm + 100mm). In the year after treatment streamflow generally increased by 200–250 mm, except for one treatment (clearfelling, herbicide application, no riparian reserve) where the increase was 550 mm. The catchments were planted with Pinus radiata, but rapid colonization by bracken (Pteridium esculentum) and Himalayan honeysuckle (Leycesteria formosa) led to a rapid decline in streamflow, which returned to pre-treatment levels after an average of about five years. Streamflow yields then continued to decline for another two to three years before stabilizing at a level about 250mm yr^?1 lower than pre-treatment levels. At this time the catchments had a dense bracken/honeysuckle understorey beneath 5 m tall pine trees.     

Maintaining environmental quality in Chinese rural areas: the case of Sanshui County

This paper deals with the tension between national environmental objectives and rapid industrial growth in a Chinese provincial area. The case study relates to Sanshui County in Guangdong Province, where the authors worked for six months. The paper initially looks at the nature of Chinese national environmental objectives. It considers the legislation and administrative machinery in place to enforce such legislation and how effective this machinery is at the county level. It then argues that in Sanshui County, a rich and densely populated part of the Pearl River delta, there is a critical need for effective planning and strict control on industrial development, lest the overall continuing viability of the region is threatened. It concludes that, at present, there is both a lack of political will and environmental expertise at the county level to ensure protection of the environment.     

Determination of dead-time in photon counting photometers by a polarimetric method

Experiments are described which demonstrate that the dead-time constant associated with a photon counting stellar photometer/polarimeter is readily determinable by the application of the Malus law. It is also proposed that corrections for dead-time losses should be applied by an iteration technique to the exact equation rather than using the available approximation formulae.     

The identification of runoff-production mechanisms using environmental isotopes in a tussock grassland catchment,eastern otago,New Zealand

A previous hydrometric study of runoff production in tussock grassland drainage basins in Otago (45°50′S, 169°45′E), New Zealand, revealed a marked change of slope in storm hydrograph recessions. An environmental isotope study was initiated to investigate the runoff mechanisms operating and to test specific hypotheses to explain this break in the hydrograph recession. The results indicated that for quickflow volumes in excess of 10mm, the first part of the storm hydrograph can be attributed to two separate sources, namely, ‘old’ water from a shallow, unconfined groundwater reservoir and ‘new’ water from saturation overland flow on the lower wetlands of concave slopes. Despite the extensive area of wetlands, ‘old’ water runoff from the unconfined groundwater reservoir is delivered more rapidly to the stream than ‘new’ water from saturation overland flow. Substantial surface storage in the wetlands has first to be exceeded before rain becomes a significant part of stream discharge. For quickflow volumes less than 10mm, only ‘old’ water from groundwater contributes to the first part of the hydrograph recession. This means that only the largest 7 per cent of storms (in terms of quickflow volume) generate quickflow containing significant amounts of ‘new water’. The second part of the recession of the storm hydrograph consists of ‘old’ water derived from a remarkably well-mixed shallow unconfined groundwater body.     

The spectacular Supernova SN1987A: Grain evaporation and condensation

Non-similarity solutions of the equations governing the motion of a perfect gas behind a cylindrical shock wave of variable strength have been obtained. These solutions are applicable to both the weak and the strong shocks. The nature of flow and field variables are illustrated through graphs. The total energy of the wave is taken to be constant.