Revisiting frontiers as transitional spaces in Thailand     

PHILIP HIRSCH 《The Geographical journal》2009,175(2):124-132

This paper explores the notion of frontiers as 'in-between' spaces that define particular transitions. Three contexts of frontier and their rapidly changing nature form the basis of the analysis. Agricultural frontiers (typically between farmland and forest) are defined by new relations of production and interplays between conservation, shifting modes of agriculture and natural resource use and management. Peri-urban frontiers (between countryside and city) are taken beyond their desakota/chaan-meuang locations to a more generic interplay between urbanity and rurality in defining livelihood and identity. National frontiers (between nation states with sharply different political and economic conditions) are transcended from above in the form of new regionalisms, and, from below, in migrations and other transboundary influences and flows. The paper proposes the frontier as both a spatial and temporal heuristic for understanding development and associated societal transitions in Thailand.  相似文献   

The evolution of periglacial patterned ground in East Anglia,UK          下载免费PDF全文

MARK D. BATEMAN  JULIAN B. MURTON  JONATHAN R. LEE  PHILIP L. GIBBARD 《第四纪科学杂志》2014,29(4):301-317

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Stratigraphy and sedimentation of the stratotype sections of the Catfish Creek Drift Formation between Bradtville and Plum Point, north shore, Lake Erie, southwestern Ontario, Canada     

ALEKSIS DREIMANIS  PHILIP GIBBARD 《Boreas: An International Journal of Quaternary Research》2005,34(2):101-122

The Catfish Creek Drift Formation is a significant and extensive lithostratigraphical marker unit in SW Ontario. Here the stratotype, exposed in the Lake Erie bluffs of the Plum Point-Bradtville (Grandview) area south of London, Ontario, Canada, is proposed. It consists of subglacial and proglacial sediments deposited at the beginning of the Nissouri Phase of the Wisconsinan glaciation. In the 2.5-km-long stratotype section, the Catfish Creek Drift consists of 9 members. Five of them, the Dunwich and Grandview I-IV members, mainly consist of till, with minor components of stratified drift. The Dunwich till was deposited by the Huron-Georgian Bay lobe, but the Grandview I-IV tills by the Erie lobe. The Zettler Farm Member consists of co-lobal till in the central part of the section and of a proglacial waterlain flow diamicton and a subglacial undermelt diamicton in the SW part. Three members consist entirely of stratified drift; the glaciolacustrine silty and clayey Waite Farm Member, the ice-marginal deltaic Oosprink Farm Member and the Boy Scout Camp Member - deposited by meltwater streams in subglacial channels. The sequence of interbedded till and stratified drift represents the oscillating advance of the Laurentide Ice Sheet in the Lake Erie basin.  相似文献   

Sheet slides and rotational failures on a convergent margin: the Kidnappers Slide, New Zealand   总被引：1，自引：0，他引：1  

PHILIP M. BARNES  KEITH B. LEWIS 《Sedimentology》1991,38(2):205-221

The Kidnappers Slide, on the upper continental slope of the convergent margin off eastern North Island, New Zealand, has been re-examined using a grid of high-resolution seismic reflection profiles. The slide is not a single feature but a complex of sheet slides and rotational failures ranging from 20 to 140 m thick, and covering a total area of 720 km². Failures occurred in several phases, on slopes of 1–5°, in late Quaternary, muddy, shelf-edge clinoforms that have prograded into an accretionary, trench-slope basin. Piston cores and seismic stratigraphy show that the main failure probably occurred in early Holocene times but that movements ranged from mid last glacial to late Holocene times. The sheet slides exhibit tensional collapse via numerous listric normal faults that sole out on glide planes; there is no clear evidence of compressional structures anywhere within the complex. The glide planes occur at progressively deeper stratigraphic levels towards the northeastern end of the complex, and near the steep slope that defines the seaward edge of the trench-slope basin. There is retrogressive failure at the top of the slope. The surficial slides are being deformed by growth of active tectonic faults and folds associated with the convergent plate margin. This type of slope failure may be partially related to metastable sandy layers within the last glacial age progradational sequence, and possibly to formation of bubble phase gas at shallow depths. Failure was probably triggered by earthquake loading of sediments in this highly seismic region.  相似文献   

Water vapor transport in the NCAR CCM2   总被引：1，自引：0，他引：1  

DAVID L. WILLIAMSON  PHILIP J. RASCH 《地球，A辑:动力气象学与海洋学》1994,46(1):34-51

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A Younger Dryas (Loch Lomond Stadial) jökulhlaup deposit, Fort Augustus, Scotland     

ANDREW J. RUSSELL  PHILIP M. MARREN 《Boreas: An International Journal of Quaternary Research》1998,27(4):231-242

This study provides an insight into the impact of probably the largest flood ever to have been identified in mainland Britain by examining new sedimentary evidence from the Auchteraw terrace, Fort Augustus, Scotland. Study of three sections reveals a succession consisting of: (1) sheet gravels; (2) large trough-shaped depressions infilled with cross-stratified sands and gravels; (3) smaller-scale, finer-grained cross-strata; and (4) sheet-like, occasionally channelized, bimodal sand and gravel beds. This study shows that both the sedimentology and morphology of the Auchteraw terrace are consistent with jökulhlaup deposition and reveal a greater variety of lithofacies types than identified in previous studies of jökulhlaups from ice-dammed lakes. The fine-grained nature of the sediment discussed in this study emphasizes the importance of sediment supply for the formation of distinctive jökulhlaup successions. The sedimentary evidence recorded here provides a valuable tool for the interpretation of the magnitude and frequency of proglacial meltwater flows associated with Pleistocene ice sheets worldwide.  相似文献   

Mineralogy and Geochemistry of a Basanite to Phonolite Sequence at Hut Point Peninsula, Antarctica, based on Core from Dry Valley Drilling Project Drillholes 1, 2 and 3     

KYLE  PHILIP R. 《Journal of Petrology》1981,22(4):451-500

The Dry Valley Drilling Project (DVDP) cored three holes (DVDP1, 2 and 3) at Hut Point Peninsula (HPP) on Ross Island, Antarctica.DVDP 1 reached 201 m and penetrated 40 stratigraphic units,mainly basanite and Ne-hawaiite lava flows and associated pyroclasticrocks. DVDP 2 and 3 are nearly identical. DVDP 3 reached 381m and penetrated 15 stratigraphic units. The lower unit is a214 m thick basanite hyaloclastite, this is overlain by flowsand pyroclastic rocks of basanite, Ne-hawaiite, and then alternatingNe-mugearite and Ne-benmoreite flows. Phonolite stratigraphicallyoverlies the drill site. Primary olivine (Fo₈₈-Fo₇₄) is confined to the basanites, althoughxenocrysts occur in other rock types. Calcium-rich clinopyroxeneis ubiquitous but shows little variation in terms of Ca, Mg,Fe²⁺. Kaersutite is common in all lavas except the basanitesand shows very little compositional variation. It is believedto have crystallized at temperatures below 1100 °C and atpressures between 1·5 and 10 kb. Rhönite, a titanosilicateis a common groundmass phase in some basanite lavas. Oxide mineralsshow a wide range of compositions; spinel and chromian spineloccur as inclusions in olivine in the basanites. Titano-magnetiteoccurs in most samples examined. Labradorite is the predominantfeldspar in the basanite, with andesine and oligoclase importantin all other rock types. DVDP and HPP samples show a well-defined sequence of basanite-Ne-hawaiite-Ne-mugearite-Ne-benmoreite-phonolite,termed the DVDP lava lineage. Differentiation of the lineagehas been modeled using major element least squares mass balancemodels. Over 75 per cent of the evolution from basanite to phonoliteoccurs in the initial step from basanite to Ne-hawaiite, whichrepresents a 43 per cent residual. The phonolite is only a 25per cent residual from a basanite parent; thus even though Ne-mugeariteand Ne-benmoreite are common, they represent only minor stepsin the differentiation sequence. The mass balance models indicatethat olivine, clinopyroxene, kaersutite, opaque oxides and feldsparare the dominant fractionated phases. Trace element (includingrare earth element) contents calculated using the Rayleigh equationconfirm all models. ^* Present address: Department of Geoscience, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801.  相似文献   

Palaeoecology and post-Weichselian shore-level changes on the coast of Møre, western Norway     

ULF HAFSTEN  PHILIP A. TALLANTIRE 《Boreas: An International Journal of Quaternary Research》1978,7(2):109-122

Pollen analysis, macrosubfossil determinations and radiocarbon datings from a 0.95 m thick peat deposit resting on sand and buried by a 1.3 m thick beach ridge at Haramsøy (an outer-arc island off the coast of Møre og Romsdal province), reveal changes in the local vegetation and in the groundwater level of the landward lagoon-like area. These are considered to reflect the relative shore-level changes between late Preboreal and early Atlantic times: an initial section with a high groundwater level reflecting the early Boreal high shore level, an intervening section with a low groundwater level, from the time of the Boreal regression minimum, and a final section, with a rising groundwater level, reflecting the late Boreal eustatic rise in sea level, which led to complete burial of the peat and the formation of an extensive Tapes beach ridge. Radiocarbon dates reveal that the basal sand (approx. 8 m above sea level) rose above sea level at approx. 9500 B. P. and that the top of the peat (approx. 9 m above sea level) was transgressed by the sea at approx. 7300 B. P. The spread of alder ( Alnus ) within the area may have been delayed by a thousand years compared with other regions in south Norway.  相似文献   

Climatic control on Quaternary fluvial sedimentology of a Fenland Basin river, England   总被引：1，自引：0，他引：1  

REBECCA M. BRIANT  MARK D. BATEMAN†  G. RUSSELL COOPE‡  PHILIP L. GIBBARD 《Sedimentology》2005,52(6):1397-1423

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HABITAT ISLANDS AND THE PRESERVATION OF NEW ZEALAND'S AVIFAUNA*     

PHILIP R. PRYDE  CHRIS COCKLIN 《Geographical review》1998,88(1):86-113

ABSTRACT. Numerous avifauna species face extinction on New Zealand's two main islands, owing largely to forest clearance and to introduced mammals. In response, New Zealand selects certain offshore islands for the relocation of threatened native birds, first purging them of mammalian predators. Over the past few decades, this procedure has evolved to become fairly successful. Protected habitat “islands” within mainland forested areas are also being created, but with success less certain. As historic habitats are lost, small biopreservation islands may become a standard mechanism for protecting threatened species, a process that can be termed the “miniaturization” of nature.  相似文献