THE EVOLUTION OF GEOMORPHOLOGY: A NATION-BY-NATION SUMMARY OF DEVELOPMENT edited by H. J. Walker and W. E. Grabau,John Wiley & Sons,Chichester, 1993. No. of pages: xvi + 539. Price: £95.00. ISBN 0-471-93858-0.     

GORDON L. HERRIES DAVIES 《地球表面变化过程与地形》1996,21(4):397-397

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Long-distance marker horizons from small-scale eruptions: British tephra deposits from the AD 1510 eruption of Hekla,Iceland     

ANDREW J. DUGMORE  ANTHONY J. NEWTON  KEVIN J. EDWARDS  GUDRÚN LARSEN  JEFFREY J. BLACKFORD  GORDON T. COOK 《第四纪科学杂志》1996,11(6):511-516

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The Care and Conservation of Palaeontological Material,C. COLLINS (ed.), Publisher Butterworth-Heinemann,Oxford 1995; (139pp) £50 ISBN 0-7506-1742-X     

GORDON TURNER-WALKER 《第四纪科学杂志》1997,12(1):79-81

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Sedimentation in ice-covered Lake Hoare, Antarctica   总被引：2，自引：0，他引：2  

SUSAN S. NEDELL  DAVID W. ANDERSEN  STEVEN W. SQUYRES†  F. GORDON LOVE‡ 《Sedimentology》1987,34(6):1093-1106

The sedimentation mechanisms that occur in ice-covered Lake Hoare, Antarctica are examined, to determine how sediment enters the lake, and how the sedimentation pattern affects blue-green algal growth at the lake bottom. The 3 m-thick ice cover contains pebbly sand as much as 2 m below the surface. Sediment with similar texture and mineralogy is found at the lake bottom. This evidence, together with the lack of sediment in the inflowing stream and the markedly different texture of sediment from the other terrains around the lake suggest that most of the sediment at the lake bottom comes in through the ice cover. Sand grains intermittently migrate through porous ice on the surface, water-filled vertical gas-channels penetrating two-thirds of the ice cover, and possibly through cracks in the ice that act as conduits. The algae at the lake bottom are able to survive in part because sediment that comes through the ice cover does not obliterate them.  相似文献   

Lichenometry in dating recent glacial landforms and deposits, southeast Iceland   总被引：1，自引：0，他引：1  

JOHN E. GORDON  MARTIN SHARP 《Boreas: An International Journal of Quaternary Research》1983,12(3):191-200

Lichenometry curves were derived for the glacier forelands of Breidamerkurjokull and Skalafellsjökull using measurements of the collective species, Rhizocarpon geographicum , from independently dated surfaces deglaciated during the period since the late-19th century ice maximum episode in the area. The form of the curves appears to be linear. Several methods of predicting the ages of undated surfaces were compared for specific test examples, including single lichenometry curves, families of curves and multiple curves based on randomly selected largest lichens. The last method provided a useful means of assessing the reproducibility of predicted ages. Where substrate conditions were highly variable, a lichenometry curve based on single largest lichens provided a preferred result.  相似文献   

Critical perspectives on integrated water managementEditorial     

NIGEL WATSON  GORDON WALKER  WILL MEDD 《The Geographical journal》2007,173(4):297-299

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Mineralogy of Antarctic basaltic shergottite Queen Alexandra Range 94201: Similarities to Elephant Moraine A79001 (Lithology B) martian meteorite     

TAKASHI MIKOUCHI  MASAMICHI MIYAMOTO  GORDON A. McKAY 《Meteoritics & planetary science》1998,33(2):181-189

Abstract— Antarctic meteorite QUE 94201 is a new basaltic shergottite that is mainly composed of subequal amounts of maskelynite and pyroxenes (pigeonite and augite) plus abundant merrillite and accessory phases. It also contains impact melt. Complex zoning patterns in QUE 94201 pyroxenes revealed by elemental map analyses using an electron microprobe suggest a crystallization sequence from Mg-rich pigeonite (En₆₂Fss₃₀Wo_g) to extremely Fe-rich pigeonite (En₅Fs₈₁Wo₁₄) via {110} Mg-rich augite bands (En₄₄Fs₂₀Wo₃₆) in a single crystal. These textures, along with the abundant plagioclase (maskelynite), indicates single-stage rapid cooling (>5 °C/year) of this rock from a supercooled magma. Transition from Mg-rich augite to Fe-rich pigeonite reflects the onset of plagioclase crystallization. Enrichment of late-stage phases in QUE 94201 implies crystallization from an evolved magma and suggests a different parent magma composition from the other basaltic shergottites. Lithology B of EETA79001 basaltic shergottite contains pyroxenes that show complex zoning with augite bands similar to those in QUE 94201 pyroxene, which suggests similar one-stage rapid cooling. Lithology B of EETA79001 also resembles QUE 94201 in its coarse-grained texture of silicates and its high abundance of maskelynite, although QUE 94201 probably crystallized from a more fractionated magma. We also note that some Apollo lunar mare basalts (e.g., 12020 and 12021) have similar mineralogy and petrology to QUE 94201, especially in pyroxene zoning. All these basaltic rocks with complex pyroxene zoning suggest rapid metastable crystallization from supercooled magmas.  相似文献   

Dissimilarity of Continental and Oceanic Rock Types     

MACDONALD  GORDON A. 《Journal of Petrology》1960,1(1):172-177

Recent papers, cite the similarity of rocks, particularly andesites,in continental and oceanic regions, but the similarity is primarilyone of name. The oceanic ‘andesites’ belong to thealkaline suite, whereas the typical continental andesitesarecalc alkaline and hypersthene-or hornblende-bearing. To avoidfurther confusion it is suggested that the name ‘andesite’for the oceanic rocks be replaced by the names hawaiite andmugearite. Whatever name is used, it is essential to emphasizethe difference between the oceanic ‘andesites’ andthe andesites of continental orogenic regions. All members of the oceanic suite are present also in continentalregions, but the calc alkaline rocks characteristic of orogenicregions on the continents are absent within the true ocean basins,except in island arcs near the continets that were formerlyregarded as the continental border.  相似文献   

Evaluation of the Crystallization Conditions for the Calcalkaline Russian Peak Intrusive Complex, Klamath Mountains, Northern California     

COTKIN  SPENCER J.; MEDARIS  L. GORDON  JR. 《Journal of Petrology》1993,34(3):543-571

The mid-Jurassic calcalkaline Russian Peak intrusive complex,located in the Klamath Mountains of northern California, consistsof an elliptical peridotite-to-quartz diorite suite intrudedby two plutons of granodiorite. Several techniques were usedto decipher the crystallization conditions for ultramafic rocks,quartz diorite, and granodiorite, including comparison of parageneseswith crystallization experiments, application of geothermometersand barometers, and evaluation of phase equilibria. Contactmetamorphic assemblages, hornblende barometry, and amphibolesubstitution schemes indicate that pressures of intrusion were{small tilde}3 kbar. Plagioclase and pyroxene thermometry indicateintrusion temperatures of {small tilde}1000C for quartz dioriteand 900C for granodiorite. Phase equilibrium analysis for thereaction phlogopite+quartz=K-feldspar+enstatite+H₂O, coupledwith an estimate of the water-saturated quartz diorite solidus,suggests that the solidus of two-pyroxene quartz diorite wasat {small tilde}780C with a mole fraction of water of {smalltilde}0•55. The composition of granodiorite is very similarto that used in several crystallization experiments and indicatesa solidus of 70025C. Estimates of oxygen fugacity, obtainedfrom equilibrium relations of olivine, orthopyroxene, and spinelin ultramafic rocks, magnetite and ilmenite in quartz diorite,and magnetite, K-feldspar, and biotite in quartz diorite andgranodiorite are 2•1–2•5 and 1•0–1•3log units above the quartz-fayalite-magnetite (QFM) buffer forgranodiorite and quartz diorite at their respective solidustemperatures; and 1•0–4•0 log units above QFMfor ultramafic rocks and quartz diorite at subsolidus temperatures.Thus, the quartz diorite magma was hotter, drier, and slightlyreduced relative to the grandiorite magma, differences thatset important constraints on the genesis of the Russian Peakmagmas. These results also indicate that quartz diorite wasundersaturated with respect to H₂O as it reached its solidus,a condition that is consistent with the absence of deutericalteration in this unit. In contrast, granodiorite shows extensivedeuteric alteration and features pegmatites, quartz pods, andradial dikes as might be expected for H₂O-saturated conditions. Although calcalkaline plutonic complexes present serious difficultiesin estimating the intensive parameters of crystallization, judiciousapplication of appropriate methods may result in the successfulevaluation of the conditions of crystallization of such complexes.  相似文献   

Trace Element and Platinum Group Element Distributions and the Genesis of the Merensky Reef, Western Bushveld Complex, South Africa   总被引：5，自引：0，他引：5  

WILSON  ALLAN; CHUNNETT  GORDON 《Journal of Petrology》2006,47(12):2369-2403

The Merensky Reef of the Bushveld Complex is one of the world'slargest resources of platinum group elements (PGE); however,mechanisms for its formation remain poorly understood, and manycontradictory theories have been proposed. We present precisecompositional data [major elements, trace elements, and platinumgroup elements (PGE)] for 370 samples from four borehole coresections of the Merensky Reef in one area of the western BushveldComplex. Trace element patterns (incompatible elements and rareearth elements) exhibit systematic variations, including small-scalecyclic changes indicative of the presence of cumulus crystalsand intercumulus liquid derived from different magmas. Ratiosof highly incompatible elements for the different sections areintermediate to those of the proposed parental magmas (CriticalZone and Main Zone types) that gave rise to the Bushveld Complex.Mingling, but not complete mixing of different magmas is suggestedto have occurred during the formation of the Merensky Reef.The trace element patterns are indicative of transient associationsbetween distinct magma layers. The porosity of the cumulatesis shown to affect significantly the distribution of sulphidesand PGE. A genetic link is made between the thickness of theMerensky pyroxenite, the total PGE and sulphide content, petrologicaland textural features, and the trace element signatures in thesections studied. The rare earth elements reveal the importantrole of plagioclase in the formation of the Merensky pyroxenite,and the distribution of sulphide. KEY WORDS: Merensky Reef; platinum group elements; trace elements  相似文献