Irrigated agriculture and place‐making in the East Kimberley     

Ruth Lane 《The Australian geographer》2004,35(1):77-94

This paper explores the way in which lived experiences of farmers in the Ord Valley have intersected with representations of the Ord Valley over time. I contrast the development of Stage 1 of the Ord River Irrigation Scheme in the 1960s with a proposal put forward in the late 1990s for greatly expanding the area of irrigated agriculture as Stage 2 of the scheme. I examine the rhetoric employed in planning documents and public media coverage of the first and proposed second stages of the Ord Irrigation Scheme and explore its connections with social identifications of farmers in the Ord Valley since the 1960s. I then argue the value of this approach for understanding the dynamic relationship between the spatial practices and social identifications of farmers and representations of place and land use in public media and planning processes.  相似文献   

Geochemistry, Petrogenesis and Metallogenesis of the Panzhihua Gabbroic Layered Intrusion and Associated Fe-Ti-V Oxide Deposits, Sichuan Province, SW China   总被引：31，自引：0，他引：31  

ZHOU  MEI-FU; ROBINSON  PAUL T.; LESHER  C. MICHAEL; KEAYS  REID R.; ZHANG  CHENG-JIANG; MALPAS  JOHN 《Journal of Petrology》2005,46(11):2253-2280

The Panzhihua gabbroic layered intrusion is associated withthe 260 Ma Emeishan Large Igneous Province in SW China. Thissill-like body hosts a giant Fe–Ti–V oxide depositwith 1333 million ton ore reserves, which makes China a majorproducer of these metals. The intrusion has a Marginal zoneof fine-grained hornblende-bearing gabbro and olivine gabbro,followed upward by Lower, Middle, and Upper zones. The Lowerand Middle zones consist of layered melanogabbro and gabbrocomposed of cumulate clinopyroxene, plagioclase, and olivine.These zones also contain magnetite layers. The Upper zone consistschiefly of leucogabbro composed of plagioclase and clinopyroxenewith minor olivine. Most rocks in the body show variable-scalerhythmic modal layering in which dark minerals, primarily clinopyroxene,dominate in the lower parts of each layer, and lighter minerals,primarily plagioclase, dominate in the upper parts. The oxideores occur as layers and lenses within the gabbros and are concentratedin the lower parts of the intrusion. Ore textures and associatedmineral assemblages indicate that the ore bodies formed by verylate-stage crystallization of V-rich titanomagnetite from animmiscible oxide liquid in a fluid-rich environment. The rocksof the Panzhihua intrusion become more evolved in chemistryupward and follow a tholeiitic differentiation trend with enrichmentin Fe, Ti, and V. They are enriched in light rare earth elementsrelative to heavy rare earth elements, and exhibit positiveNb, Ta, and Ti anomalies and negative Zr and Hf anomalies. Thesilicate rocks and oxide ores of the Panzhihua intrusion formedfrom highly evolved Fe–Ti–V-rich ferrobasaltic orferropicritic magmas. The textures of the ores and the abundanceof minor hydrous phases indicate that addition of fluids fromupper crustal wall-rocks induced the separation of the immiscibleoxide melts from which the Fe–Ti–V oxide ore bodiesin the lower part of the intrusion crystallized. KEY WORDS: magnetite; Fe–Ti-rich gabbro; layered intrusion; Panzhihua; SW China  相似文献   

Claiming space and community: rural women’s strategies for living with, and beyond, fear     

Ruth Panelli  Anna Kraack 《Geoforum》2005,36(4):495-508

Following the well-established literature on women’s fear in urban contexts, a small but important literature has also begun to document accounts of boldness, fearlessness and empowerment. We extend this work by considering ways in which women live with, and beyond, experiences of fear. We argue that fear and fearlessness are not discrete and separate states, but rather they are often simultaneous conditions that women negotiate in complex ways. Moving away from a sense of victims and passivity, we suggest that women have spatial and social strategies that can be adopted when they face fear or take up forms of action that might be termed ‘bold’ or ‘courageous’. Consequently, this work draws on Koskela’s [Gender, Place and Culture 4 (1997) 301] previous discussion of ‘bold women’ in Finland to develop a notion of agency and highlight strategies that some rural women adopt in New Zealand.  相似文献   

The Greenland Ice Core Chronology 2005, 15–42 ka. Part 1: constructing the time scale     

Katrine K. Andersen  Anders Svensson  Sigfus J. Johnsen  Sune O. Rasmussen  Matthias Bigler  Regine Rthlisberger  Urs Ruth  Marie-Louise Siggaard-Andersen  Jrgen Peder Steffensen  Dorthe Dahl-Jensen  Bo M. Vinther  Henrik B. Clausen 《Quaternary Science Reviews》2006,25(23-24):3246

The Greenland Ice Core Chronology 2005, GICC05, is extended back to 42 ka b2k (before 2000 AD), i.e. to the end of Greenland Stadial 11. The chronology is based on independent multi-parameter counting of annual layers using comprehensive high-resolution measurements available from the North Greenland Ice Core Project, NGRIP. These are measurements of visual stratigraphy, conductivity of the solid ice, electrolytical melt water conductivity and the concentration of Na⁺, Ca²⁺, SO₄²⁻, NO₃⁻, NH₄⁺. An uncertainty estimate of the time scale is obtained from identification of ‘uncertain’ annual layers, which are counted as 0.5±0.5 years. The sum of the uncertain annual layers, the so-called maximum counting error of the presented chronology ranges from 4% in the warm interstadial periods to 7% in the cold stadials. The annual accumulation rates of the stadials and interstadials are on average one-third and half of the present day values, respectively, and the onset of the Greenland Interstadials 2, 3, and 8, based on 20 year averaged δ¹⁸O values, are determined as 23,340, 27,780, and 38,220 yr b2k in GICC05.  相似文献   

Women in agriculture: advocates for a gendered sustainable agriculture     

Ruth Liepins 《The Australian geographer》1995,26(2):118-126

A gendered consideration of rural geography has been barely discernible within Australian and New Zealand literature. The notable exceptions in this case have illustrated the complexity and merit of studying the gender patterns and relations of rural life. Outside geography, there is an expanding literature on rural women in Australia. These works parallel significant developments in the lives and politics of rural and agricultural women themselves. This paper reports selected findings from a study of the women in agriculture movement in Australia. As such, it illustrates the increased awareness of the gendered conditions of farming. The women in agriculture movement works to increase the recognition of women's contribution to agriculture. In doing so it affirms the legitimacy of women farmers’ voices and perspectives. There will be no sustainable rural systems while half the rural population is unseen or unheard. Women in agriculture demonstrate a social dimension of sustainability. They highlight the need to integrate gender equity and a ‘wider‐than‐economic’ conceptualisation of sustainable agriculture. Their actions can stimulate rural geographers to further consider the social and political aspects of rural sustainability beyond the conventional farm/industry and community service sites we usually consider.  相似文献   

Incipient metamorphism in the Lower Palaeozoic marginal basin of Wales   总被引：1，自引：0，他引：1  

D. ROBINSON  R. E. BEVINS 《Journal of Metamorphic Geology》1986,4(1):101-103

Abstract A diagenctic through anchizone to epizone transition is demonstrated in pelitic rocks of the Lower Palaeozoic marginal basin of Wales by examination of variations in phyllo-silicate mineralogy, illite crystallinity and b_o parameter of white micas. This transition represents a temperature range from ∼ 150°C to ∼ 400°C and the metamorphism is of a low-pressure facies series type, with a geothermal gradient of ∼ 40°Ckm^-1. Variations in grade can be correlated largely with the original basin and shelf form, suggesting a depth-related metamorphism. However, in areas closer to the site of Caledonian plate collision an increasingly syn-tectonic metamorphic event is apparent.
Correlation of pelite data with metabasite assemblages is variable, the most consistent relationship being between epizone crystallinity values andepidote-actinolite (greenschist facies) assemblages. Diagenetic clay mineral assemblages are found associated with prehnite-pumpellyite assemblages in metabasites and it is suggested that the latter represent non-buffered, and therefore non-diagnostic, assemblages.  相似文献   

Biological marker distribution in coexisting kerogen, bitumen and asphaltenes in Monterey Formation diatomite, California     

Tannenbaum E  Ruth E  Huizinga BJ  Kaplan IR 《Organic Geochemistry》1986,10(1-3 PT 1):531-536

Organic-rich (18.2%) Monterey Formation diatomite from California was studied. The organic matter consist of 94% bitumen and 6% kerogen. Biological markers from the bitumen and from pyrolysates of the coexisting asphaltenes and kerogen were analyzed in order to elucidate the relationship between the various fractions of the organic matter. While 17 alpha(H), 18 alpha(H), 21 alpha(H)-28,30-bisnorhopane was present in the bitumen and in the pryolysate of the asphaltenes, it was not detected in the pyrolysates of the kerogen. A C40-isoprenoid with "head to head" linkage, however, was present in pyrolysates of both kerogen and asphaltenes, but not in the bitumen from the diatomite. The maturation level of the bitumen, based on the extent of isomerization of steranes and hopanes, was that of a mature oil, whereas the pyrolysate from the kerogen showed a considerably lower maturation level. These relationships indicate that the bitumen may not be indigenous to the diatomite and that it is a mature oil that migrated into the rock. We consider the possibility, however, that some of the 28,30-bisnorhopane-rich Monterey Formation oils have not been generated through thermal degradation of kerogen, but have been expelled from the source rock at an early stage of diagenesis.  相似文献   

Overestimating the coronal density and its effect on the velocities derived from Lα Doppler dimming     

Ruth Esser  Shadia R. Habbal 《Solar physics》1993,147(2):241-254

It is shown that relatively small errors of the order of 10% in the electron densities, for example derived from polarization brightness measurements, might lead to large errors in the velocities inferred from intensity measurements of the L Hi 1216 spectral line in the inner corona. It is demonstrated that in some cases this effect can result in very high velocities close to the coronal base with subsequent small acceleration with heliocentric distance. It is also pointed out that the errors in the deduced velocities can be reduced if simultaneous observations that place constraints on the mass flux are available, and by ensuring that the mass flux computed from the derived velocities and densities is constant.  相似文献   

Long-term changes in salt marsh extent affected by channel deepening in a modified estuary   总被引：2，自引：0，他引：2  

Ruth Cox  R. A. Wadsworth  A. G. Thomson 《Continental Shelf Research》2003,23(17-19):1833

The aim of this study is to quantify the long-term (54 years) rates of marsh extension and retreat at two sites in the Westerschelde Estuary, SW Netherlands. Nine sets of aerial photographs were obtained for each of the two salt marsh sites, Zuidgors and Waarde, taken at various times between 1944 and 1998. The seaward edges of the marshes were digitised from rectified images after the photographs had been scanned and georegistered to the Dutch National Grid. Comparison of the extents of the marshes at these nine time points revealed that the areas of both marshes had fluctuated during these 54 years with periods of both extension and retreat of the seaward marsh edges. These periods of extension and retreat appeared to be approximately synchronised until the 1990s, with mean changes in position of marsh front ranging from −7.92 to 6.04 m a⁻¹.The rate of landward retreat and seaward extension of the marsh front is shown to be related to an increase in the tidal prism brought about by dredging operations to maintain or increase the depth of the main navigable channel of the estuary. The consequent greater frequency with which the high tides reach the edge of the fringing marshes increases the risk of erosion. Strong westerly winds may also be a factor in increasing erosion. No relationship between the volume of shipping traffic using the estuary and marsh erosion was found.  相似文献   

Acceptance of the 2002 F. W. Clarke Award     

Ruth Elaine Blake 《Geochimica et cosmochimica acta》2003,67(13):2315-2316

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