Detailed models of the binary pulsars J1141−6545 and B2303+46     

Ross P. Church  Stephanie J. Bush  Christopher A. Tout  Melvyn B. Davies 《Monthly notices of the Royal Astronomical Society》2006,372(2):715-727

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Genesis of marine terrace soils,Barbados, West Indies: Evidence from mineralogy and geochemistry     

Daniel R. Muhs  Russell C. Crittenden  John N. Rosholt  Charles A. Bush  Kathleen C. Stewart 《地球表面变化过程与地形》1987,12(6):605-618

Well-developed, clay-rich soils dominated by interstratified kaolinite-smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO₃ and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on the island itself are the parent materials for the soils.  相似文献   

Spatial variation in delaware bay (U.S.A.) marsh creek fish assemblages     

Kenneth W. Able  David M. Nemerson  Ralph Bush  Phillip Light 《Estuaries and Coasts》2001,24(3):441-452

Delaware Bay is one of the largest estuaries on the U.S. eastern seaboard and is flanked by some of the most extensive salt marshes found in the northeastern U.S. While physicochemical and biotic gradients are known to occur along the long axis of the bay, no studies to date have investigated how the fish assemblage found in salt marsh creeks vary along this axis. The marshes of the lower portion of the bay, with higher salinity, are dominated bySpartina spp., while the marshes of the upper portion, with lower salinity, are currently composed primarily of common reed,Phragmites australis, S. alterniflora, or combinations of both. Extensive daytime sampling (n=815 tows) during May–November 1996 was conducted with otter trawls (4.9 m, 6 mm mesh) in six intertidal and subtidal marsh creek systems (upper and lower portions of each creek) where creek channel depths ranged from 1.4–2.8 m at high tide. The fish taxa of the marsh creeks was composed of 40 species that were dominated by demersal and pelagic forms including sciaenids (5 species), percichthyids (2), and clupeids (7), many of which are transients that spawn outside the bay but the early life history stages are abundant within the bay. The most abundant species wereMorone americana (24.3% of the total catch),Cynoscion regalis (15.4%),Micropogonias undulatus (15.3%),Anchoa mitchilli (12.0%), andTrinectes maculatus (10.8%). Non-metric Multi-Dimensional Scaling ordination of catch per unit effort (CPUE) data indicated two fish assemblages that were largely independent of the two major vegetation types, but generally corresponded with spatial variation in salinity. This relationship was more complex because some of the species for which we could discriminate different age classes by size had different patterns of distribution along the salinity gradient.  相似文献   

Scales and Sales: Changing Social and Spatial Fish Trading Networks in the Siiphandone Fishery, Lao PDR     

Simon R. Bush 《Singapore journal of tropical geography》2004,25(1):32-50

The Siiphandone wetland in Khong district, Champasak province, Lao PDR, is one of the most important fisheries in the Mekong River basin. The resource, situated along the Laos‐Cambodia border, supports the livelihoods of around 65,000 inhabitants, mainly semi‐subsistence rice farmers or fishers. In January 2000, the provincial authority was given a special dispensation by the Lao government to allow the importation of Cambodian fish through Khong district, for export to Thailand. Previously, in large part due to the government's policy of food self‐sufficiency, the export of Lao fish was illegal. This paper examines how the implementation of this law has influenced existing legal and illegal trade networks from the Siiphandone fishery by comparing the findings of two studies, one conducted before and the other after the change in the law. In doing so, the transition of the fishery from a local, food‐important resource to an increasingly regional, market‐oriented resource is examined. Conclusions are drawn as to the impact this change has had on the livelihoods of fishers and traders involved in the fishery.  相似文献   

Resolving the Holocene alluvial record in southeastern Australia using luminescence and radiocarbon techniques     

Michael D. Cheetham  Annabelle F. Keene  Wayne D. Erskine  Richard T. Bush  Kathryn Fitzsimmons  Geraldine E. Jacobsen  Stewart J. Fallon 《第四纪科学杂志》2010,25(7):1160-1168

A previous assessment of radiocarbon (¹⁴C) dates from alluvial units in southeastern Australia revealed a gap in the geochronological record that coincides with the Holocene climatic optimum. This gap in the alluvial record can be further refined using optically stimulated luminescence (OSL). The chronology of Holocene river terraces on Widden Brook, a sandy alluvial stream in southeastern Australia, was established using ¹⁴C and OSL techniques. Combined use of these independent techniques allows for a more rigorous assessment of the alluvial record. The robust chronology, consisting of 38 ¹⁴C and 11 OSL samples, permitted identification of significant depositional variation within the catchment, resulting from localised geomorphic processes. The three terrace sequences identified yielded distinct chronologies, suggesting alluvial deposition at different times. The sequences exhibited a continuous chronology, which indicated continuous deposition throughout the Holocene. The chronology of terrace sequences within this catchment suggests that terrace formation can be attributed to localised geomorphic processes rather than climatic forcing. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Landforms and landscape evolution in the Skardu,Shigar and Braldu Valleys,Central Karakoram     

Yeong Bae Seong  Michael P. Bishop  Andrew Bush  Penny Clendon  Luke Copland  Robert C. Finkel  Ulrich Kamp  Lewis A. Owen  John F. Shroder 《Geomorphology》2009,103(2):251-267

The Central Karakoram, which includes K2 in Pakistan, is one of the most rapidly rising areas on Earth and exhibits complex topography and extreme relief. Impressive valley fills and glacial landforms are present throughout the valleys. The dynamics of landscape evolution of the region are currently not well understood. Consequently, the landforms were mapped and assessed in the Skardu, Shigar, and Braldu valleys, to elucidate the spatio-temporal scale dependencies of surface processes active in the region. These valleys were examined using geomorphic field methods, remote sensing, geomorphometry, and terrestrial cosmogenic nuclides (TCNs) surface exposure dating. The glaciers in this region have oscillated considerably throughout the Late Quaternary, and four glacial stages have been recognized including at least six glacial advances. Surface processes readjusted after glacier retreat, and ubiquitous mass movements and catastrophic landsliding transported material from steep slopes to valley bottoms, while glaciofluvial meltwater and glacier outburst floods redistributed sediment down valley. Glacier geochronology and late Holocene ages of the outburst flood deposits indicate that landscape evolution has been dominated by glaciation and paraglaciation during the late Quaternary.  相似文献   

Reports     

William W. Dressler  Stephen B. Bush  Ben Wisner  Dennis DiPietre 《GeoJournal》1990,22(1):116-120

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