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1000 results for “silicatefondue”

  1. Andrew Frederiksen (U. Manitoba) gave us a very clear explanation of a better way to analyze shear-wave splitting as a way to probe the fabric (heterogeneities) of the upper mantle under continents.

    The red and orange contours of large split times in British Columbia represent aligned olivine from present-day horizontal mantle flow. Splitting in Alberta represents fabrics formed and preserved from the Precambrian.

    #UManitoba #McGillUniversity #Seismology #Lithosphere #Mantle #Olivine

  2. Andrew Frederiksen (U. Manitoba) gave us a very clear explanation of a better way to analyze shear-wave splitting as a way to probe the fabric (heterogeneities) of the upper mantle under continents.

    The red and orange contours of large split times in British Columbia represent aligned olivine from present-day horizontal mantle flow. Splitting in Alberta represents fabrics formed and preserved from the Precambrian.

    #UManitoba #McGillUniversity #Seismology #Lithosphere #Mantle #Olivine

  3. A mural of Karl Tremblay (who died last year of cancer), lead singer of the band Les Cowboys Fringants, was inaugurated today in near .

    ici.radio-canada.ca/nouvelle/2

  4. Repost: Kyanite isn't just a fetching blue mineral that documents the experience of sediments under extreme duress.
    It's an ore: Virginia alone mined 83,000 tonnes in 2023. Kyanite in furnace insulation transforms to mullite when heated, expanding to reduce porosity and shrinkage.

    Virginia Kyanite (photo: J. Wyman) from:
    energy.virginia.gov/geology/Ky

  5. This is one of the dykes found near Ayer's Cliff, just SE of Magog, Quebec. It's a set of three dykes, one of which has the deep-derived xenoliths. That one dyke (not photogenic) has weathered much faster, perhaps due to a higher carbonate content.

  6. A photo of a Cretaceous dyke intruding into Appalachian-deformed sedimentary rocks deposited in the lower Paleozoic: Earth history from 110 to almost 500 million years ago.

    But records more of the story: it's part of xenoliths brought to the surface by these dykes that document Grenville crust (1.1 billion years old) at depth.

    See: Trzcienski: Kyanite-garnet-bearing Cambrian rocks and Grenville granulites from the Ayer's Cliff, Quebec... Geology (1989)

  7. Quite a bit of was extracted from the Jeffrey Mine, Quebec. It is located on a line of oceanic lithosphere attached to North America during the growth of the Appalachians.

    The town of Asbestos, home of the mine, has been renamed 'Val-des-Sources'.

    Much of the expense of renovating buildings in Quebec is the cost of removing the asbestos insulation.

  8. A thought-provoking talk by Dr. Jobst Heitzig of Potsdam Institute for Climate Impact Research on building a framework for combining physical processes of the Earth system with human interactions (politics, public opinion, etc.). Objects can be gridded data, groups/communities, or individuals; they can be part of natural systems, human-environment interactions, or cultural constructs. Sometimes several at the same time.

  9. Re-post from MinCup past:
    The non-detection of in non-stars shows that it's there.

    Cool red dwarf stars have deep absorption bands from TIO gas in their atmospheres. In yet cooler brown dwarfs those bands have disappeared: opaque perovsite dust has condensed, making the titanium invisible.

    Spectra from Kesseli et al. (2017), images from Gabicca, LEAP group.

  10. Wednesday, early afternoon posters at
    MR31B-0084 Effects of melt-rock interactions on deformation fabrics and rock physical properties in the shallow mantle lithosphere
    James Kirkpatrick presenting, but this is the the M.Sc. work of Arvid Gonzalez (now core-logging in n. QC). Other authors are myself and Caroline Seyler (U. Minnesota).

    Arvid found that infiltrating mafic melt reduces the preserved strain in mantle olivine.

  11. @Kaetchi I am not very knowledgeable about the Congo Copper Belt. Congo has very old copper-rich rocks (the Katanga Supergroup, 700-800 million year-old sediments). Malachite forms when underground water rich in CO2 reacts with existing copper minerals. Congo has not been glaciated for a long time, so that shallow-formed malachite is still preserved.

    Others who know more may pipe up or correct what I've written.

  12. can form in the oxidized supergene zone of copper-rich rocks. More carbon dioxide favors azurite over . Our atmosphere doesn't have enough CO2 (yet) to stabilize azurite, but malachite at the surface persists kinetically rather than convert to black copper oxide. Sulfur and other species can modify these relations.

    Hence copper roofs weather to green, not blue!

    Diagram from Kiselcva et al. (1992)

  13. @sellathechemist Heat engines with the Carnot limit increasing as the temperature difference between surface and the top of the atmosphere increases.

  14. Not nearly as nice as those of @palaeokatie but crinoid rings and brachiopods still please me and the students who find their own! Ordovician Lorraine Formation, old Hanson Brickyard (Briqueterie St-Laurent) near La Prairie, south of Science

  15. @oldclumsy_nowmad @mineralsocamerica.bsky.social @FaithfullJohn

    This EBSD scan was part of an M.Sc. thesis by Arvid Gonzalez -we're working getting it published, but in the meantime, his unpublished thesis can be downloaded from:

    escholarship.mcgill.ca/concern

  16. Imagine parting the veils of clouds that obscure Venus, and seeing through the crustal basalts to understand the mantle beneath. This is the journey Julia Semprich (@planetju) took us on as the Mineralogical Society of America Distinguished Lecturer.

  17. Native copper in a sedimentary conglomerate. It is proposed that detrital hematite reacts with copper sulfate solutions to reduce the copper and the fluids carry away the iron and sulfur.

    From Calumet and Hekla Mine, Michigan. University of Waterloo Earth Sciences Museum Collection.

  18. Early career presenter at tomorrow:
    Dr. Jillian Kendrick
    Monday, 23 Sep, 10:55 AM - 11:10 AM, Room 206B
    speaking on:
    THE HAMMER AND THE CRUCIBLE: PETROLOGICAL RESEARCH FROM THE 18TH TO THE 21ST CENTURY
    the talk is part of the Chris Yakymchuk Session.

  19. An amazing image shown to us in a talk by Elliott Skierszkan of . He is exploring the mobilization of metals into water from thawing permafrost. The XRF image shows uranium (pink, top right image) concentrated along the wall of a plant stem, found in a fresh core of permafrost mud. This uranium (sourced from bedrock) is then soluble in the pore water when the permafrost melts.

  20. Leucite has a range of volcanic hills named after it, see:
    geowyo.com/leucite-hills.html

    These are strange, high potassium lamproites from the mantle, only 1-2 million years old.

    Match that, organic goo !

    Students at Smith College have a nice page of thin section images:
    science.smith.edu/geosciences/

  21. @sellathechemist Heat engines with the Carnot limit increasing as the temperature difference between surface and the top of the atmosphere increases.

    #Hurricane #Carnot

  22. @sellathechemist Heat engines with the Carnot limit increasing as the temperature difference between surface and the top of the atmosphere increases.

    #Hurricane #Carnot

  23. @sellathechemist Heat engines with the Carnot limit increasing as the temperature difference between surface and the top of the atmosphere increases.

    #Hurricane #Carnot

  24. @sellathechemist Heat engines with the Carnot limit increasing as the temperature difference between surface and the top of the atmosphere increases.

    #Hurricane #Carnot

  25. Native copper in a sedimentary conglomerate. It is proposed that detrital hematite reacts with copper sulfate solutions to reduce the copper and the fluids carry away the iron and sulfur.

    From Calumet and Hekla Mine, Michigan. University of Waterloo Earth Sciences Museum Collection.

    #OreCup25 #MinCup25 #Copper #Michigan #UpperPeninsula #UWaterloo

  26. Native copper in a sedimentary conglomerate. It is proposed that detrital hematite reacts with copper sulfate solutions to reduce the copper and the fluids carry away the iron and sulfur.

    From Calumet and Hekla Mine, Michigan. University of Waterloo Earth Sciences Museum Collection.

    #OreCup25 #MinCup25 #Copper #Michigan #UpperPeninsula #UWaterloo