A comparison of mineral magnetic, geochemical and mineralogical techniques for compositional studies of glacial diamictons     

JOHN WALDEN  JOHN P. SMITH  ROGER V. DACKOMBE 《Boreas: An International Journal of Quaternary Research》1996,25(2):115-130

Data from heavy mineral analysis, X-ray fluorescence spectrometry (XRF) and X-ray diffractrometry (XRD) are compared with those obtained from mineral magnetic analysis for a range of glacial diamicton samples taken from the Quaternary sequence in the Isle of Man. These data show that the mineral magnetic approach offers a useful means of characterizing glacial sediments for purposes of lithostratigraphic correlation and provenance indication and that the magnetic data are of a comparable quality to those obtained from standard applications of the more traditional techniques. The heavy mineral and XRD data indicate that little post-depositional chemical alteration of the detrital composition of the sediments has taken place. The mineral magnetic, heavy mineral and XRF analysis suggests both similar lithostratigraphic relationships between the various diamicton units and consistent indications of their likely provenance. These are consistent with published, field-based, stratigraphic relationships of the same sediments and ice-flow directions in the Irish Sea Basin during the Devensian.  相似文献   

The geology and resources of Somalia     

A. G. SMITH 《Geology Today》1989,5(1):17-18

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Mineral Equilibria in the Searles Lake Evaporites, California   总被引：1，自引：0，他引：1  

EUGSTER  H. P.; SMITH  G. I. 《Journal of Petrology》1965,6(3):473-522

The Searles Lake evaporites (late Quaternary) consist of salineand mud layers permeated by brines. Two mineral pairs (gaylussite-pirssonite,mirabilite-thenardite) are used as indicators of relative aH₂othroughout the stratigraphic column. Variations are attributedmostly to changes in brine salinity and partly to temperature. These aH₂o-sensitive minerals locally coexist with trona, nahcolite,burkeite, northupite, tychite, hanksite, and aphthitalite, whichare sensitive to both aH₂o and a_co. Such assemblages permitconstruction of schematic isothermal aH₂o-a_co, diagrams. Fieldboundary sequences are derived from both theoretical considerationsand observed assemblages; their slopes are determined by thestoichiometry of possible reactions. Predicted assemblages invariablyagree with observed assemblages. By means of these diagrams, present-day lateral and stratigraphicvariations in relative aH₂o and aco₂ in the deposit are reconstructed.They show that aH₂o and a_co2 vary independently. Many of thepresent activities reflect depositional conditions; some indicatepost-depositional events.  相似文献   

Tephrochronology and the late Holocene volcanic and flood history of Eyjafjallajökull,Iceland     

ANDREW J. DUGMORE  ANTHONY J. NEWTON  KATE T. SMITH  KERRY‐ANN MAIRS 《第四纪科学杂志》2013,28(3):237-247

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Temporal and spatial distribution of dimethylsulfide in the subarctic northeast Pacific Ocean: a high-nutrient–low-chlorophyll region     

C. S. WONG  S. E. WONG  W. A. RICHARDSON  G. E. SMITH  M. D. ARYCHUK  J. S. PAGE 《Tellus. Series B, Chemical and physical meteorology》2005,57(4):317-331

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JOHANNES HUMLUM ATLAS OF ECONOMIC GEOGRAPHY     

WILLIAM SMITH 《New Zealand geographer》1977,33(1):43-43

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Requirements and principles for the implementation and construction of large-scale geographic information systems     

TERENCE R. SMITH  SUDHAKAR MENON  JEFFREY L. STAR  JOHN E. ESTES 《International journal of geographical information science》2013,27(1):13-31

Abstract

This paper provides a brief survey of the history, structure and functions of ‘traditional’ geographic information systems (GIS), and then suggests a set of requirements that large-scale GIS should satisfy, together with a set of principles for their satisfaction. These principles, which include the systematic application of techniques from several sub-fields of computer science to the design and implementation of GIS and the integration of techniques from computer vision and image processing into standard GIS technology, are discussed in some detail. In particular, the paper provides a detailed discussion of questions relating to appropriate data models, data structures and computational procedures for the efficient storage, retrieval and analysis of spatially-indexed data.  相似文献   

Algebraic approach to spatial reasoning     

TERENCE R. SMITH  KEITH K. PARK 《International journal of geographical information science》2013,27(3):177-192

Abstract

A simple, exemplary system is described that performs reasoning about the spatial relationships between members of a set of spatial objects. The main problem of interest is to make sound and complete inferences about the set of all spatial relationships that hold between the objects, given prior information about a subset of the relationships. The spatial inferences are formalized within the framework of relation algebra and procedurally implemented in terms of constraint satisfaction procedures. Although the approach is general, the particular example employs a new ‘complete’ set of topological relationships that have been published elsewhere. In particular, a relation algebra for these topological relations is developed and a computational implementation of this algebra is described. Systems with such reasoning capabilities have many applications in geographical analysis and could be usefully incorporated into geographical information systems and related systems.  相似文献   

Environmental decision support system project: an exploration of alternative architectures for geographical information systems     

D. J. ABEL  S. K. YAP  R. ACKLAND  M. A. CAMERON  D. F. SMITH  G. WALKER 《International journal of geographical information science》2013,27(3):193-204

Abstract

Recent changes in information technology offer the opportunity to explore alternative architectures for geographical information systems (GIS) which might better support advanced applications. This paper describes the architecture and implementation of the environmental decision support system (EDSS), a prototype GIS tool kit. The architecture is based on a simple yet powerful systems model using only data collections, views and operations as the basic entity types. The design of the user interface, data management and data analysis within the model are outlined, with particular emphasis on the advanced facilities for which implementation is simplified by the architecture. A prototype applications system, BANKSIA, is also described.  相似文献   

Determinism within human–environment research and the rediscovery of environmental causation     

GABRIEL JUDKINS  MARISSA SMITH  ERIC KEYS† 《The Geographical journal》2008,174(1):17-29

The popularity of the work Guns, germs and steel (GGS) has served to bring the question of human–environment connections once again to the forefront of popular thought. We assert that the recent success of GGS represents both a persistence of environmental determinist logic and a contemporary trend that privileges the environment as the primary influence on human–environment relationships. The historical development of the human–environment field is reviewed from the cultural and political ecology (CAPE) perspective, with particular attention to illustrating the varying emphasis between humans and their environment. GGS is situated within this developing field through a critical analysis of the arguments and methods forwarded by Jared Diamond. The book is found to mirror earlier environmental determinism by failing to take into account many of the advances in human–environmental thought since the early twentieth century. Its popular success suggests the pitfalls of failures to acknowledge the complex, intertwined and indivisible relationship that exists among humans and their environment. Furthermore, there is evidence that the environmental determinism espoused in GGS has caught the attention of international development policymakers potentially influencing future outlays of aid and assistance to the developing world. These conclusions raise cautionary flags against repeating past theoretical mistakes by accepting simplistic, causal explanations based largely on a deterministic conception of the natural environment.  相似文献