Reply to: Comments on "Notes on the appropriateness of 'bred modes' for generating initial perturbations"     

RONALD M. ERRICO  ROLF LANGLAND 《地球，A辑:动力气象学与海洋学》1999,51(3):450-451

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Petrological significance of prograde homogenization of growth zoning in garnet: an example from the Llano Uplift'pa     

W. CARLSON  & E. SCHWARZE 《Journal of Metamorphic Geology》1997,15(5):631-644

In the Llano Uplift of central Texas (USA), prograde homogenization of garnet growth zoning took place during moderate- to high-pressure dynamothermal metamorphism over a narrow temperature range near the transition from the amphibolite to the granulite facies. This subtle record of early dynamothermal metamorphism survived subsequent static metamorphism at low pressures in the middle-amphibolite facies, despite the destruction of most high-pressure mineral assemblages that originated in the early metamorphic episode. Geographically systematic variations in the degree of homogenization indicate that the uplift as a whole underwent high-pressure metamorphism, in accord with emerging tectonic models for the mid-Proterozoic evolution of the southern margin of the North American continent.  相似文献   

The Ymer-Formation - an interglacial sequence in northeasternmost Greenland     

CHRISTIAN HJORT  ROLF W. FEYLING-HANSSEN 《Polar research》1987,5(3):347-350

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Coupled W and Os Isotopic Variations in IID Iron Meteorite Carbo,Implications on the Hf-W Chronology     

QIN Liping  Nicolas DAUPHAS  Mary HORAN  Richard W. CARLSON  LEYAIngo 《《地质学报》英文版》2013,87(Z1):264-264

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RECENT DEVELOPMENT IN FAROESE FISHING INDUSTRY     

ROLF GUTTESEN M.Sc. 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):102-108

Guttesen, Rolf: Recent development in Faroese fishing industry. Geografisk Tidsskrift 80: 102–108. Copenhagen, June 1980.

The comprehensive changes experienced by the Faroese fishing and fish-processing industries during the last decade are outlined; the impact caused by the new fishing limits in the North Atlantic, introduced 1977, combined with presentday's advanced equipment is discussed.  相似文献   

Radiocarbon dating the extinct caribou on Franz Josef Land     

ROLF ZALE  REY GLAZOVSKIY  JENS-OVE NASLUND 《Boreas: An International Journal of Quaternary Research》1994,23(3):254-258

Seven old, shed caribou ( Rangifer tarandus ) antlers from Alexandra Land, in the high arctic Franz Josef Land archipelago where no caribou are found today, were dated to between 3870 ± 70 and 2245 ± 70 radiocarbon years BP. All were found on the ground above the highest shoreline, thus not transported there by sea-ice. That the ages all fall into a relatively narrow time-span suggests that they originate from a population of caribou that really lived on Alexandra Land. We suggest that they migrated there after the culmination of the Holocene climatic optimum ( c . 6000 to 4500 BP) when the climate again became colder and the sea-ice more persistent. The climate during that period can be compared with that of Nordaustlandet on Svalbard today, where a population of caribou still exists.  相似文献   

The biostratigraphic position of the Kap København Formation based upon its foraminifera     

ROLF W. FEYLING-HANSSEN 《Polar research》1987,5(3):345-346

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Re-Os and Sm-Nd Isotope and Trace Element Constraints on the Origin of the Chromite Deposit of the Ipueira-Medrado Sill, Bahia, Brazil     

MARQUES  J. C.; FERREIRA FILHO  C. F.; CARLSON  R. W.; PIMENTEL  M. M. 《Journal of Petrology》2003,44(4):659-678

The chromite deposit of the Paleoproterozoic Ipueira–Medradosill is hosted in a single, thick (5–8 m), massive layer,which sets severe constraints for the origin of chromitites.It is divided from bottom to top into: (1) a Marginal Zone (5–20m); (2) an Ultramafic Zone (<250 m) consisting of duniteand harzburgite that host the chromitite layer, in which intercumulusamphibole is important and more abundant toward the top; (3)a Mafic Zone (<40 m). The parental magma was large ion lithophileelement and light rare earth element enriched and high fieldstrength element depleted. Sm–Nd isotopic compositionsare consistent with a 2 Ga age, but suggest a variable initialNd isotopic composition that correlates with the abundance ofamphibole. The more negative  相似文献   

The Role of Open-System Processes in the Development of Silicic Magma Chambers: a Chemical and Isotopic Investigation of the Fogo A Trachyte Deposit, Sao Miguel, Azores     

SNYDER  DARIN C.; WIDOM  ELISABETH; PIETRUSZKA  AARON J.; CARLSON  RICHARD W. 《Journal of Petrology》2004,45(4):723-738

The processes operating in the development of chemical zonationin silicic magma chambers have been addressed with a Sr–Nd–Pb–Hf–Thisotope study of the chemically zoned trachyte pumice depositof the Fogo A eruption, Fogo volcano, Azores. Sr isotopic variationis observed in whole rocks, glass separates and sanidine phenocrysts(whole-rock ⁸⁷Sr/⁸⁶Sr: 0·7049–0·7061; glass⁸⁷Sr/⁸⁶Sr: 0·7048–0·7052; sanidine ⁸⁷Sr/⁸⁶Sr:0·7048–0·7062). Thorium isotopic variationis observed in glass separates, with (²³⁰Th/²³²Th)_o rangingfrom 0·8737 to 0·8841, and exhibiting a negativecorrelation with Sr isotopes. The Nd, Pb and Hf isotopic compositionsof the whole-rock trachytic pumices are invariant and indistinguishablefrom basalts flanking the volcano. The Sr isotope variationsin the whole rocks are proposed to be the result of three distinctprocesses: contamination of the Fogo A magma by assimilationof radiogenic seawater-altered syenite wall rock, to explainthe Sr and Th isotopic compositions of the glass separates;incorporation of xenocrysts into the trachytic magma, requiredto explain the range in feldspar Sr isotopic compositions; andpost-eruptive surface alteration. This study emphasizes theimportance of determining the isotopic composition of glassand mineral separates rather than whole rocks when pre-eruptivemagmatic processes are being investigated. KEY WORDS: Azores; open-system processes; Sr isotopes; trachytic pumices; zoned magma chambers  相似文献   

Hf Isotope Systematics of Kimberlites and their Megacrysts: New Constraints on their Source Regions   总被引：10，自引：5，他引：10  

NOWELL  G. M.; PEARSON  D. G.; BELL  D. R.; CARLSON  R. W.; SMITH  C. B.; KEMPTON  P. D.; NOBLE  S. R. 《Journal of Petrology》2004,45(8):1583-1612

Kimberlites from Southern Africa, along with their low-Cr megacrysts,have unusual Hf–Nd isotopic characteristics. Group I andTransitional kimberlites define arrays trending oblique to,and well below, the Nd–Hf isotope ‘mantle array’,defined by oceanic basalts, i.e. they have negative  相似文献