(U-Th)/He and 40Ar/39Ar Geochronology of Weathering, Hamersley Province, Australia: Implications for weathering history and landscape Evolution

(U–Th)/He dating of goethite, when combined with quantification of diffusive 4He loss by the 4He/3He methodology, provides reliable corrected ages for minerals precipitated in weathering profiles. We have combined (U–Th)/He dating of supergene goethite with 40Ar/39Ar dating of supergene manganese oxides to study the weathering history and landscape evolution in the Hamersley Province, northwestern Australia. Incremental heating 40Ar/39Ar analysis of 187 grains of Mn oxides from 65 samples (44 hand specimens) collected from weathering profiles at seven field sites across the Hamersley Province yield precipitation ages ranging from 63.4 ± 0.9 to 1.5 ± 0.2 Ma. These results, combined with previous results of 40Ar/39Ar dating of Mn oxides (Vasconcelos, 1998 Vasconcelos, P.V., 1998. Unpub. report, pp. 1–278.Vasconcelos, 1998 and Cochrane, 2003), reveal a protracted and episodic history of weathering and landscape evolution, which was already ongoing in Late Cretaceous and spans the Palaeogene and Neogene. Seventy-three grains of goethite from 39 samples extracted from 21 hand specimens, collected from the same field sites where the Mn oxides originated, were dated by the (U–Th)/He method. Internally consistent (U–Th)/He ages, which range from 84.3 ± 12.2 to 3.3 ± 0.5 Ma, have been obtained for most samples when corrections are applied for 10% helium diffusive loss. The geochronological results obtained show remarkable similarity in the distribution of ages associated with supergene mineral precipitation. The widespread occurrence of iron oxides such as goethite in soils and weathering profiles and the successful application of (U–Th)/He dating of goethite offers great opportunities for extracting the wealth of palaeoclimatic and palaeoenvironmental information recorded by these profiles on the surface of terrestrial planets such as Earth and Mars.

Wishing for political dominance: Representations of history and community in 'Queer Theory'

Suggests that one's sense of one's self and one's sexuality may also have a close relationship to non-fiction texts about gay and lesbian cultures. Reliance of people's sense of being gay on literary representations; Popularity and authority of the book "Queer Theory," by Annamarie Jagose; Disagreements that characterize lesbian and gay historiography in Australia.

Across the dividing range - bridging the divides: Pharmacy opportunities across the hospital/community and inter-professional divides in rural and remote Australia

Rural and remote areas of Australia offer many opportunities for innovation in healthcare services. Some true healthcare 'network' models based around rural pharmacy can be established and evaluated. The lines between community and hospital pharmacy are often blurred and communication between health professionals enhanced. The blurring divide between hospital and community pharmacy in rural and remote areas has provided significant advances in practice. Projects have been set up to investigate the feasibility of community pharmacists integrating care for patients. These projects take advantage of the dual roles and the enhanced interaction between pharmacists and other health professionals in the bush. Opportunities for provision of clinical services beyond the traditional supply role have been taken in a number of remote communities

Southeast Asia and China: The role of history and culture in shaping future relations

Despite the position of the United States as de facto global hegemon, China is a rising power in the world. As Chinese power grows, the projection of Chinese influence will be felt most acutely in Southeast Asia. Whether to accommodate, contain or resist China will depend on future developments that none can foresee, including Chinese ambitions, the policies of other international players (the U.S., Japan), and the cohesion or fragility of the Association of Southeast Asia Nations (ASEAN). This paper argues that in deciding how best to deal with China, two factors that will influence the countries of Southeast Asia are their own long histories of bilateral relations with China and their own differing conceptions of how foreign relations should be conducted. This is to argue that history and culture are central to any understanding of the likely future shape of China-Southeast Asia relations. Only by taking history and culture into account will analysts be in a position to predict how the mainland and maritime states of Southeast Asia are likely to respond to a more powerful, confident and assertive China.

Palaeoclimatic implications of the growth history and stable isotope (delta O-18 and delta C-13) geochemistry of a Middle to Late Pleistocene stalagmite from central-western Italy

The age structure and, stable isotope composition of a stalagmite (CC I) from an upland cave in central-western Italy were studied to investigate regional response to global climatic changes. Four growth phases are constrained by 28 thermal ionization and multi-collector inductively coupled plasma mass spectrometry Th-U ages and reveal intermittent deposition through the period between Marine isotope Stage (MIS) 11 and 3 (similar to380 and similar to43 kyr). Most of the growth took place between similar to380 and similar to280 kyr, a period punctuated briefly by a hiatus in deposition through the glacial maximum of MIS 10. Growth was terminated abruptly at 280 kyr just prior to the MIS 8 glacial maximum. With a present-day chamber temperature of 7.5 degreesC, the timing of hiatuses close to these glacial maxima point to freezing conditions at the time. No deposition was recorded through the entirety of MIS 7 and most of MIS 6, whilst two minor growth phases occurred at similar to141-125 and similar to43 kyr. Growth at 141 kyr indicates temperatures >0 degreesC at a time when MIS 6 ice volumes were close to their maximum. High stable carbon isotope (delta(13)C) values (similar to2.8parts per thousand to +3.1parts per thousand) throughout the stalagmite's growth reflect a persistently low input of biogenic CO2, indicating that the steep, barren and alpine-like recharge area of today ha's been in existence for at least the last similar to380 kyr. During MIS 9, the lowest delta(13)C values occur well after maximum interglacial conditions, suggesting a lag in the development of post-glacial soils in this high-altitude karst. The stable oxygen isotope (delta(18)O) trends match the main structural features of the major climate proxy records (SPECMAP, Vostok and Devils Hole), suggesting that the delta(18)O of CC1 has responded to global-scale climate changes, whilst remarkable similarity exists between CC1 delta(18)O and regional sea-surface temperature reconstructions from North Atlantic core ODP980 and southwest Pacific marine core MD97-2120 through the most detailed part of the CC1 record, MIS 9-8. The results suggest that CC1 and other stalagmites from the cave have the potential to capture a long record of regional temperature trends, particularly in regards to the relative severity of Pleistocene glacial stages. (C) 2004 Elsevier B.V. All rights reserved.