Broken Hill (break + hill)

Distribution by Scientific Domains

Selected Abstracts

Constraints on the early metamorphic evolution of Broken Hill, Australia, from in situ U-Pb dating and REE geochemistry of monazite

Abstract The Broken Hill Pb-Zn deposit, New South Wales Australia, is hosted in granulite facies gneisses of the Southern Curnamona Province (SCP) that have long been known to record a polydeformational and polymetamorphic history. The details of this potentially prolonged tectonothermal history have remained poorly understood because of a historical emphasis on conventional (i.e. grain mount) U-Pb zircon geochronology to reveal details of the sedimentary, magmatic and metamorphic history of the rock that crops out in the vicinity of the city of Broken Hill. An alternative approach to unravelling the metamorphic history of the granulite facies gneisses in and around Broken Hill is to date accessory minerals, such as monazite, that participate in sub-solidus metamorphic reactions. We have taken advantage of the high spatial resolution and high sensitivity afforded by SHRIMP monazite geochronology to reconstruct the early history of the metamorphic rocks at Broken Hill. In contrast to previous studies, in situ analysis of monazite grains preserved in their original textural context in polished thin sections is used. Guided by electron microprobe X-ray maps, SHRIMP U-Pb dates for three distinct monazite compositional domains record pulses of monazite growth at c. 1657 Ma, c.1630 Ma and c.1602 Ma. It is demonstrated that these ages correspond to monazite growth during lower amphibolite facies, upper amphibolite facies and granulite facies metamorphism, respectively. It is speculated that this progressive heating of the SCP crust may have been driven by inversion of the upper crust during the Olarian Orogeny that was pre-heated by magmatic underplating at c.1657 Ma. [source]

Brain size and encephalization in early to Mid-Pleistocene Homo

G. Philip Rightmire
Abstract Important changes in the brain have occurred during the course of human evolution. Both absolute and relative size increases can be documented for species of Homo, culminating in the appearance of modern humans. One species that is particularly well-represented by fossil crania is Homo erectus. The mean capacity for 30 individuals is 973 cm3. Within this group there is substantial variation, but brain size increases slightly in specimens from later time periods. Other Middle Pleistocene crania differ from those of Homo erectus. Characters of the facial skeleton, vault, and cranial base suggest that fossils from sites such as Arago Cave in France, the Sima de los Huesos in Spain, Bodo in Ethiopia, Broken Hill in Zambia, and perhaps Dali in China belong to the taxon Homo heidelbergensis. Ten of these mid-Quaternary hominins have brains averaging 1,206 cm3 in volume, and many fall beyond the limits of size predicted for Homo erectus of equivalent age. When orbit height is used to construct an index of relative brain size, it is apparent that the (significant) increase in volume documented for the Middle Pleistocene individuals is not simply a consequence of larger body mass. Encephalization quotient values confirm this finding. These changes in absolute and relative brain size can be taken as further corroborative evidence for a speciation event, in which Homo erectus produced a daughter lineage. It is probable that Homo heidelbergensis originated in Africa or western Eurasia and then ranged widely across the Old World. Archaeological traces indicate that these populations differed in their technology and behavior from earlier hominins. Am J Phys Anthropol, 2003. 2003 Wiley-Liss, Inc. [source]

Operational teledermatology in Broken Hill, rural Australia

Adrian See
SUMMARY From January 2001 to January 2002, Broken Hill, New South Wales, served as a trial site for teledermatology as one method of access to dermatologists. Fourteen participating general practitioners referred 46 patients making up 48 teledermatology cases. The mean diagnostic agreement between general practitioners and dermatologists was 35% and 50% for primary and differential diagnoses, respectively. Teledermatology patients formed 12% of the collectively referred dermatology patients (outpatients and teledermatology). In this project, high patient and general practitioner acceptability and positive medical outcomes confirm the value of rural teledermatology. However, this project also revealed unexpected barriers and pitfalls in the effective operation of rural teledermatology. Lack of education of participants, inertia among potential users and patient inconvenience are issues that may adversely affect the effective implementation of rural teledermatology. [source]

Evaluation of a mobile screening service for abdominal aortic aneurysm in Broken Hill, a remote regional centre in far western NSW

Margaret S. Lesjak
Abstract Objectives:,To evaluate the feasibility of a mobile screening service model for abdominal aortic aneurysm (AAA) in a remote population centre in Australia. Design:,Screening test evaluation. Setting:,A remote regional centre (population: 20 000) in far western NSW. Participants:,Men aged 65,74 years, identified from the Australian Electoral roll. Interventions:,A mobile screening service using directed ultrasonography, a basic health check and post-screening consultation. Main outcome measures:,Attendance at the screening program, occurrence of AAA in the target population and effectiveness of screening processes. Results:,A total of 516 men without a previous diagnosis of AAA were screened, an estimated response rate of 60%. Of these, 463 (89.7%) had a normal aortic diameter, 28 (5.4%) ectatic and 25 (4.9%) a small, moderate or significant aneurysm. Two men with AAA were recommended for surgery. Feedback from participants indicated that the use of a personalised letter of invitation helped with recruitment, that the screening process was acceptable and the service valued. Conclusions:,It is feasible to organise and operate a mobile AAA screening service from moderate sized rural and remote population centres. This model could be scaled up to provide national coverage for rural and remote residents. [source]


John S. Humphreys
ABSTRACT Since 1996, University Departments of Rural Health (UDRH) have been established at Broken Hill, Mount Isa, Shepparton, Launceston, Whyalla, Alice Springs and Geraldton. Each UDRH is underpinned by Commonwealth funding for an initial period of 5 years. The role of the UDRHs is to contribute to an increase in the rural and remote health workforce through education and training programs, as well as a reduction in the health differentials between rural and urban people and between indigenous and non-indigenous peoples. A strong population health focus involving partnerships between existing health providers in a targeted region and the university sector underpins their operation. While UDRHs have been established as a means of addressing a national workforce problem, their organisational arrangements with universities and local service providers vary widely, as does the program mix of activities in education, research service development, facilitation and advocacy. This article outlines some of the activities and progress of the UDRHs to date. [source]