Experimental deformation of partially-melted granite   总被引：18，自引：0，他引：18  

I. van der Molen  M. S. Paterson 《Contributions to Mineralogy and Petrology》1979,70(3):299-318

An account is given of the experimental deformation of partially-melted granite with melt fractions up to 25% at 800 °C and 300 MPa confining pressure in constant strainrate tests between 10^–3 and 10^–6 S^–1, creep tests and cycling tests. Microscopic study reveals that under these conditions most of the uniform deformation prior to macroscopic shear failure is accomplished by melt redistribution into films perpendicular to the least compressive stress, and by axial fracturing of grains, the latter occurring even at low macroscopic differential stress. The strenght of the partially-melted rock at 10^–5 S^–1 is found to decrease gradually from about 250 MPa at 5 vol.% melt to about 60 MPa at 15 % melt, and then to drop rapidly to less than 1 MPa at 24% melt. The critical melt fraction separating granular-framework-controlled flow behaviour from suspension-like behaviour is deduced to be approximately 30 to 35 vol.%. At low melt fractions the deforming rock tends to take up externally available melt by a mechanism of dilatancy pumping. The relevance of these results to natural conditions involving partially-melted rocks is discussed.  相似文献   

Experiental deformation of single crystals of biotite     

Dr. M. A. Etheridge  B. E. Hobbs  M. S. Paterson 《Contributions to Mineralogy and Petrology》1973,38(1):21-36

Single crystals of biotite have been shortened up to 20% in compression tests parallel to [100], [110] and [010] directions at 3 Kbar confining pressure and temperatures from 300 to 700° C, and at a strain rate of 10^–4 sec^–1. Thick metal constraining sleeves were used and led to a distribution of kinking throughout the crystals. The orientation of kink boundaries, angle of bending and asymmetry of the basal plane across the kink boundaries and the axes of bending were measured. A minor amount of unidentified non-basal slip must have occurred to account for the assymmetry, but basal slip predominates at all temperatures. From the axes of bending, the discrete slip directions [100], [110] and [110] for basal slip are deduced. Increase in temperature mainly leads to a simpler pattern of kinking associated with the kinks being wider and the kinking angle larger, presumably as a result of greater mobility of dislocation walls that form the kink boundaries.In his summary table, Mügge lists these axes as [010] and [130] but the latter seems to be quoted in error, and in conflict with his text, in place of [310]. Borg and Handin (1966) have quoted the [130] indices as given by Mügge in his table. In the analysis of their own observations there has been a confusion between direction indices and plane normal indices. When this is corrected, their results would also indicate [100] and [110] as active slip directions in [001] (Borg, private communication).  相似文献   

Inversion of the electromagnetic induction problem using Parker's algorithms with both precise and practical data     

R. J. Jady  G. A. Paterson  K. A. Whaler 《Geophysical Journal International》1983,75(1):125-142

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A novel shear vane used to determine the evolution of hydraulic dredge tracks in sub-tidal marine sediments     

C. Hauton  D. M. Paterson 《Estuarine, Coastal and Shelf Science》2003,57(5-6):1151-1158

A novel shear vane is described which can be used to record the shear strength of discrete depth horizons of a variety of marine sediment types in situ. This vane, or modifications of it, has great potential in allowing measurement of in situ shear strength without requiring any samples to be removed from the sea bed, a process which can often destroy the fine structure of the sediment. The vane was used to monitor the change in sediment shear strength caused by a hydraulic dredge, which was used to fish razor clams (Ensis arcuatus) in a sheltered bay within the Clyde Sea area, Scotland. Data collected using this apparatus provided valuable and immediate information on the stratification of the sea bed post-dredging and allowed the evolution of the dredge track to be regularly monitored by divers over a period of 100 d.  相似文献   

Early presence of Bythotrephes cederströmii (Cladocera: Cercopagidae) in lake sediments in North America: evidence or artifact?     

DeWeese  Nichole E.  Favot  Elizabeth J.  Branstrator  Donn K.  Reavie  Euan D.  Smol  John P.  Engstrom  Daniel R.  Rantala  Heidi M.  Schottler  Shawn P.  Paterson  Andrew M. 《Journal of Paleolimnology》2021,66(4):389-405

Journal of Paleolimnology - The spiny water flea (Bythotrephes cederströmii), a freshwater crustacean considered to be the world’s best-studied invasive zooplankter, was first recorded...  相似文献   

Corrigendum to: Why is the relative abundance of Asterionella formosa increasing in a Boreal Shield lake as nutrient levels decline?     

Branaavan Sivarajah  Kathleen M. Rühland  Andrew L. Labaj  Andrew M. Paterson  John P. Smol 《Journal of Paleolimnology》2016,56(1):93-93

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How late are K-feldspar megacrysts in granites?   总被引：1，自引：0，他引：1  

R.H. Vernon  S.R. Paterson 《Lithos》2008,104(1-4):327-336

Various petrologists have suggested that K-feldspar megacrysts grow in granites that are extensively crystallized, even at subsolidus conditions. However, experimental evidence indicates that, though K-feldspar nucleates relatively late in the crystallization history, abundant liquid is available for development of large crystals. A great deal of evidence, involving many different factors, favours a magmatic/phenocrystic origin for K-feldspar megacrysts in granites, namely simple twinning, oscillatory zoning, euhedral plagioclase inclusions, and concentric, crystallographically controlled arrangements of inclusions. In addition, abundant evidence has been presented of (1) mechanical accumulation of K-feldspar megacrysts in granites, (2) alignment of megacrysts and megacryst concentrations in magmatic flow foliations, (3) involvement of megacrysts in zones of magma mixing in granite plutons, and (4) occurrence of megacrysts in some volcanic rocks, implying that the megacrysts were suspended in enough liquid to be moved without fracturing or plastic deformation. Detailed trace element and isotopic data also indicate that megacrysts can move between coexisting felsic and more mafic magmas. Irregular overgrowths on megacrysts are consistent with continued magmatic growth after euhedral megacrystic growth ceased, the overgrowths being impeded by simultaneously crystallizing quartz and feldspar grains.  相似文献   

The impact of organic pollution on the macrobenthic fauna of Dubai Creek (UAE)   总被引：1，自引：0，他引：1  

Saunders JE  Al Zahed KM  Paterson DM 《Marine pollution bulletin》2007,54(11):1715-1723

Dubai Creek is a tidal marine intrusion bisecting Dubai within the United Arab Emirates (UAE). The creek extends 14km inland from its opening into the Arabian Gulf, with a narrow lower creek channel leading to a lagoon section in the upper creek. The creek contains numerous sources of organic pollution including sewage outlet flows and boat waste. A survey of the creek was performed, assessing organic pollution, water properties, and the benthic macrofaunal community. The upper creek was heavily polluted with macrofauna communities commonly associated with organic pollution and eutrophication, while the lower creek contained low pollution and relatively healthy macrofauna communities. There is little net tidal flow of water within the creek and residence time in the lagoon is high, which may account for the high organic pollution levels. However, some evidence of the pollution effect moving into the lower creek was found. The results are considered in light of current and historic organic loading within the creek and future developments in the area.  相似文献   

The oldest bivalved arthropods from the early Cambrian of East Gondwana: Systematics,biostratigraphy and biogeography     

Timothy P. Topper  Christian B. Skovsted  Glenn A. Brock  John R. Paterson 《Gondwana Research》2011,19(1):310-326

The oldest bradoriid fauna from Australia, occurring in the lower Cambrian Ajax and Wirrapowie limestones of the Flinders Ranges, South Australia consists of eleven taxa, including one new genus and species, Quadricona madonnae gen. et sp. nov. and two new species, Liangshanella circumbolina sp. nov. and Zepaera jagoi sp. nov. In the Ajax Limestone, Liangshanella circumbolina sp. nov. occurs c. 20 m below the FAD of the zonal trilobite Abadiella huoi. This pre-trilobitic occurrence represents the oldest bivalved arthropod hitherto known from East Gondwana and suggests a lower Cambrian (Series 2, Stage 3) age for the assemblage. The recognition of distinct bradoriid assemblages associated with the Abadiella huoi (Atdabanian), Pararaia tatei, P. bunyerooensis and P. janeae (all Botoman) trilobite biozones in South Australia indicates great potential for future regional biostratigraphic correlation. Quantitative biogeographic analysis including new taxonomic data from the lower Cambrian of South Australia, highlights the strong endemism displayed by early Cambrian bradoriid communities and strengthens the close faunal affinities with South China and Antarctica.  相似文献   

Global zoogeography of fragile macrozooplankton in the upper 100-1000 m inferred from the underwater video profiler     

Stemmann  Lars; Youngbluth  Marsh; Robert  Kevin; Hosia  Aino; Picheral  Marc; Paterson  Harriet; Ibanez  Frederic; Guidi  Lionel; Lombard  Fabien; Gorsky  Gabriel 《ICES Journal of Marine Science》2008,65(3):433-442

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