 | Swanson-Hysell, Nicholas L., Hoaglund, Steven A., Crowley, James L., Schmitz, Mark D., Zhang, Yiming, Miller, James D. (2021) Rapid emplacement of massive Duluth Complex intrusions within the North American Midcontinent Rift. Geology, 49 (2). 185-189 doi:10.1130/g47873.1 | Journal (article/letter/editorial) | | Planetary Science, University of California, Berkeley, California 94720, USA D Department of Earth and Environmental...Minnesota 55812, USA 3 Department of Geosciences, Boise State University, Boise, Idaho 83725, USA 1 2 ABSTRACT...ABSTRACT The Duluth Complex (Minnesota, USA) is one of the largest mafic intrusive complexes on Earth. It...intervals of more voluminous magmatism. New 206Pb/238U zircon dates for the anorthositic and layered series of...Rift geochronology utilized 207Pb/206Pb dates on zircon from volcanics (Davis and Green, 1997) and intrusions |  | Van Reenen, D.D., Boshoff, R., Smit, C.A., Perchuk, L.L., Kramers, J.D., McCourt, S., Armstrong, R.A. (2008) Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa. Gondwana Research, 14 (4) 644-662 doi:10.1016/j.gr.2008.01.013 | Journal (article/letter/editorial) | | folds developed before ~ 2.63 Ga based on UâPb zircon age data for precursors to leucocratic anatectic...the supracrustal rocks of the Beit Bridge Complex (BBC) comprising marble and calcsilicate gneisses, metaquartzite...gneisses are a minor component of the BBC. The rocks of the BBC are intruded (e.g. Bahnemann, 1972; Brandl...the SRG and the infolded supracrustal rocks of the BBC (e.g. Hofmann et al., 1998). D1/M1 has been dated...gneisses intruded into the supracrustal gneisses of the BBC during the Neoarchaean (~2.65â2.64 Ga, Table 1; Kröner |  | | Journal (issue) | | the Cedar Hill serpentinite quarry in Lancaster County. The rarest of these is the magn esium -ca lcium...speci men were small but visible tan crystals of zircon, a mineral that is rare ly large enough to see...Showalter limestone quarry in Blue Ball, Lancaster County, several unusual minera ls have been confirmed...t e c r ystal in ch lorite sch ist, Lancast er County, magni· fied two times (photo by Les Chubb). STATE...percen t. The high percentage of lube oi l in a barr el ·r·--· of th is cr ude is w hy Pen nsylvan ia ~·-3~~~ |  | | Journal (issue) | | up on sleep, I am already away two weeks from the USA. This journey started with an early trip to Munich...lot of topazes in matrix from Shamoozi, a famous mine producing fine pinks. This was a better lot than...Alvemon Way, near the University of Arizona campus and El Con Mall. With expanded shuttle service and other...Tucson show in 2005 and beyond! Too bad about the El; its demise is a sorrowful tale in Tucson lore. ...and the moon. Anyway, what we had labcled ·'the BBC" had started, the spread of news by word of mouth |  | | Journal (article/letter/editorial) | | Precambrian Research 93 (1999) 299â337 Single zircon ages for granitoid gneisses in the Central Zone...microprobe, evaporation and vapour digestion single zircon emplacement ages for granitoid rocks throughout...gneisses; Granulite metamorphism; Limpopo belt; Zircon 1. Introduction The Limpopo belt of southern Africa...indicated here. We have undertaken single grain zircon geochronology on a number of granitoid gneisses...adjacent supracrustal rocks of the Beit Bridge Complex (BBC ) ( Hofmann et al., 1998; KroÌner et al., 1998). |  | | Journal (article/letter/editorial) | | chemical composition of the seafloor sediments. Zircon, Cr-spinel and rare phosphate minerals are the...0.01 0.04 0.13 bd 0.27 bd 0.44 99.38 MM UQ MM2 BBC mass. lam. 1.23 9.48 67.75 12.82 84.36 43.27 105...004 0.13 0.01 0.04 0.02 0.60 0.13 0.11 MM UQ MM7 BBC mass./ lam. 1.40 7.31 99.67 11.04 83.59 23.60 4...01 0.07 0.18 bd 0.36 0.07 0.60 99.06 H3c UQ H12 BBC 0.64 5.01 13.13 11.57 76.82 18.28 85.04 0.25 0.77...01 0.02 0.06 bd 0.26 bd 0.13 98.90 H3c UCT AH5 BBC mass. 2.20 21.01 139.0 24.22 135.0 29.70 48.42 6 |  | Mateen, Abdul, Wahid, Ali, Janjuhah, Hammad Tariq, Mughal, Muhammad Saleem, Ali, Syed Haroon, Siddiqui, Numair Ahmed, Shafique, Munib Ahmed, Koumoutsakou, Olga, Kontakiotis, George (2022) Petrographic and Geochemical Analysis of Indus Sediments: Implications for Placer Gold Deposits, Peshawar Basin, NW Himalaya, Pakistan. Minerals, 12 (8) 1059 doi:10.3390/min12081059 | Journal (article/letter/editorial) | | through the Main Mantle Thrust Complex (MMT), it(BBC) eventually enters the Indian Plateâs Besham Indian...Complexof(BBC) and flows gneisses, through the Indian Plate rocks. The BBC consists of The BBC consists...(Bioevopeak (BioevopeakInc, Inc.,Seattle, Seattle,WA, WA, USA), and gold granules were recovered for scanning electron...identification was also analyzed using a stereoscope. Zircon, olivine (Figure 4l), pyroxene (Figure 4b), biotite...percentage of heavy minZTR = ultrastable minerals (zircon, tourmaline, rutile), A = amphibole, Px = pyroxene |  | | Journal (article/letter/editorial) | | where metasediments of the Beit Bridge Complex (BBC) are closely intercalated with tonalitic, trondhjemitic...et al., 1983), it is ambiguous as to whether the BBC forms a supracrustal unit deposited on top of the...metamorphosed sediments of the BBC. On the basis of comprehensive zircon dating, Jaeckel et al. (1997)...ages of 2575â2560 Ma, obtained from metamorphic zircon in leucosome layers within the 2.7â 2.6 Ga old...metamorphic zircon with spherical multifaceted shapes in metasedimentary gneisses of the BBC yielded a |  | | Book | | and laboratory. We also thank Prof. Larry Brown (USA), Dr. Chris Clark (Australia); Dr. Teale (Australia)...orthopyroxenes, garnet, opaque minerals, and accessory zircon. In addition, metapelitic rocks with variable amount...Ion Microprobe (SHRIMP) UePb isotope analyses of zircon from a charnockite and a charnockite-hosted leucosome...together with several ultrapotassic dykes. The UePb zircon yielded a weighted mean age of 819 2.4 Ma, suggesting...The A-type granite of Ayyermalai has yielded UePb zircon age of w590 Ma and that the granitic magmatism |  | Maes, S.M., Tikoff, B., FerrĂ©, E.C., Brown, P.E., Miller Jr., J.D. (2007) The Sonju Lake layered intrusion, northeast Minnesota: Internal structure and emplacement history inferred from magnetic fabrics. Precambrian Research, 157 (1) 269-288 doi:10.1016/j.precamres.2007.02.021 | Journal (article/letter/editorial) | | University of Wisconsin-Madison, Madison, WI 53706, USA b Department of Geology, Southern Illinois University-Carbondale...62901, USA c Minnesota Geological Survey, University of Minnesota-Duluth, Duluth, MN 55812, USA Received...University of Wisconsin-Eau Claire, Eau Claire, WI 54702, USA. Tel.: +1 715 836 5504. E-mail address: maessm@uwec...Research 157 (2007) 269â288 Beaver Bay Complex (BBC), which occurs as a cluster of small to medium sized...m thick tholeiitic layered intrusion within the BBC, exposed north of Finland, Minnesota. It is also |  | | Journal (issue) | | epimorph Ladyâs slipper After barite, Virtuous Lady Mine Fig. 5 Copper after aragonite Fig..2 Goethite...conditions e.g contact with the atmosphere, rain or mine water, while further down is increasing low oxygen...Gneiss of North-west Canada, although detrital zircon crystals found in a deltaic conglomerate in the...knowledge resulted in Chris being approached by the BBC to be a presenter on the two part programme âExpedition...dangerous for the surrounding people and towns. The BBC film focused on Nyiragongo , the largest volcano |  | | Journal (issue) | | Reveals Largest Violet Diamond Recovered from Argyle Mine Gemology 32 18 21 26 Harvard Mineral Heritage...provenance of colored gemstones all the way to the mine that produce the stone. The vertically integrated...price. Confidence is increasingly InColor Bureau USA Claudiu Margarit claudiu@gemstone.org [1] (212) 620-0900...possible tied to transparency and provenance. from mine to market is being developed strongly. As a result...branding strategies are increasingly being related to mine sites, local towns or geographical areas. There |  | | Journal (article/letter/editorial) | | grains in five samples from the Bella Coola Valley (BBC-6, -7, -11, -14, -25), and one sample from Mt. Waddington...track results Parrish [14] determined apatite and zircon fission track ages from surface granitic rocks...(xlO6alr2, BBC-5s BBC-Sb BBC-4a BBC-4b BBC-6a BBC-6b BBC-la BBCJb BBC-l 1 BBC-28 BBC-13 BBC-14 BBC-15 BBC-21...BBC-21 BBC-22 BBC-24 BBC-25 5715-w I27âSYO 52â15*35â 12P520â 52w40 126wllOâ 52â18w 126â4SQOâ 527u45â 127â1#45â...the composite age for four of the samples shown (BBC-6, -11, -25, and 56035) represents a mixture of old |  | | Journal (issue) | | 1nlorma11on dOCI requests 10 ine Ameucan Federation CALIFORNIA FEDERATION OF MINERALOGICAL SOCIETIES Otlicus...LAPIDARY EQUIPMENT P()\\ ERGLID E CO:\TROL PA:\EL ..--- I 16''-18'' âą 20'' -24 '' âą 36'' Slab Saws...secretary-treasurer of the those with common interests. California Federation). A major portion of the clubs in...Among the features is the most to the Yern10. California area. recent edition of the American Fcderaci...San Mateo Previouslv mentioned were the annual County. Federation · convention!> and shows; Third Row |  | | Journal (issue) | | BBD 50 fastest hitting for stoping ATLAS have BBC 15 in the line. Ideal general-purpose and development...drilling in all of rock! PUMA, one and flushing BBC 22 hand, LION dependable automatically aL: BBD...so oan BBC 15 ay a s ins New York 17, N.Y. 930 Brittan Avenue San Carlos, California LYtell 1-0375...1-0375 13/4 mee BBC 22 Ss 65 89 939 a. Sltlas Copco 545 Fifth Avenue, for Comparison of the...the Independent Coal and Coke mines of âarbon County, Utah, Anaconda AC Shuttle Car Cable is still in |  | Laurent, Oscar, Doucelance, RĂ©gis, Martin, HervĂ©, Moyen, Jean-François (2013) Differentiation of the late-Archaean sanukitoid series and some implications for crustal growth: Insights from geochemical modelling on the Bulai pluton, Central Limpopo Belt, South Africa. Precambrian Research, 227. 186-203 doi:10.1016/j.precamres.2012.07.004 | Journal (article/letter/editorial) | | magnetite and ilmenite together with apatite, zircon and allanite as accessory phases. Monzodiorites...of ΔNd at 2.6 Ga vs. Nd concentration (data for BBC metapelites and Sand River Gneisses are from Harris...hornblendeâbiotite gabbro from the Sierra Nevada Batholith (California, USA; starting composition in experimental study...0.5 0.65 0.85 3 15 0.05 0.25 0.3 0.8 0.75 Max Zircon Max Min Max 0.02 0.05 0.05 0.02 0.02 0.075 0...granodiorites contain accessory phases such as allanite and zircon that appear as euhedral crystals in inclusion within |  | | Journal (article/letter/editorial) | | attraction was a microscopic crystal of zircon. In 1999, this zircon was dated at 4.4 billion years by Wilde...elements by John Valley and Looking at the 4.4 Ga zircon. PHOTO NEAL LORD BY Aaron Cavosie (UWâMadison);...possibly continents (see: www.geology.wisc.edu/zircon). To create a buzz about an otherwise arcane subject...KUCHTA Press story. âApart from that, we were on BBC live twice, on ABC and CNN Broadcast News, on NPRâs |  | Kakar, Mohammad Ishaq, Kerr, Andrew C., Mahmood, Khalid, Collins, Alan S., Khan, Mehrab, McDonald, Iain (2014) Supra-subduction zone tectonic setting of the Muslim Bagh Ophiolite, northwestern Pakistan: Insights from geochemistry and petrology. Lithos, 202. 190-206 doi:10.1016/j.lithos.2014.05.029 | Journal (article/letter/editorial) | | pelagic sediments and known as the basalt-chert unit (Bbc), and b) a basaltic hyaloclastite-mudstone unit (Bhm)...ultimately formed the present day Muslim Bagh Ophiolite. Zircon in a plagiogranite from the Muslim Bagh Ophiolite...chlorite and opaques and accessory apatite and zircon. 3.4. The mafic dyke swarm MA One of the striking...1995; Polat et al., 1996). The basalt-chert unit (Bbc) of the Bagh Complex (Figure 1) was previously regarded...plagiogranite (1), mafic dyke swarm (3), gabbros (2), basalt Bbc (1) and basalt Bhm (1); were analysed for SmâNd and |  | Perchuk, L. L., van Reenen, D. D., Smit, C. A., Boshoff, R., Belyanin, G. A., Yapaskurt, V. O. (2008) Role of granite intrusions for the formation of ring structures in granulite complexes: Examples from the Limpopo belt, South Africa. Petrology, 16 (7) 652-678 doi:10.1134/s0869591108070023 | Journal (article/letter/editorial) | | composed of the Beit Bridge supracrustal complex (BBC), several grey gneiss formations, and the Messina...metamict allanite, zoned zircon, and apatite; allanite is usually intergrown with zircon and apatite. The secondary...Neoarchean structure in the Bait Bridge Complex (BBC) within the Central Zone of the Limpopo complex (Fig...gneissic framing, whose protolith is the rocks of the BBC. The rocks of this structure have been described...deformed (D2) and metamorphosed (M2) rocks of the BBC. The available age estimates are close to the ages |  | | Show/Event (guide) | | Croydon-based Microsoft consultancy. One of his clients was BBC News where Jolyon spent much o f his time with Windows...during highway construction, Hull Township, Gatineau County, Quebec. P. M. Bellev, R. Rowe & M. Picard. 2:45...e " from the Harder Farm, Hammond, St. Lawrence County, NY. M. Lupulescu. 3:45 H i s t o r y of the Powers...Powers farm streamside veins, St. Lawrence County, New York. M. R. Walter & S. C. Chamberlain. 4:00 M...assemblage from the Allah Cooper/Valcooper mine, Louisa County, Virginia. L. E. Kearns & M. D. Dunn. 4:30 |  | | Journal (article/letter/editorial) | | com/locate/gca UâPb and LuâHf isotope record of detrital zircon grains from the Limpopo Belt â Evidence for crustal...available online 26 August 2008 Abstract Detrital zircon grains from Beit Bridge Group quartzite from the...± 11 Ma and 3909 ± 26 Ma, which are the oldest zircon grains so far found in Africa. The combined UâPb...at 2.65â2.60 Ga. The ïŹnding of abundant magmatic zircon detritus with concordant UâPb ages of 3.35â3.15...were a predominant source. In contrast, detrital zircon grains older than approximately 3.35 Ga were derived |  | | Journal (article/letter/editorial) | | Ga Barberton Greenstone Belt revisited: a single zircon ion microprobe study R.A. A r m s t r o n g a,b...inter-element ratios were measured relative to a standard zircon (SL3) of known isotopic composition, constant 2°6pb/238U...quadratic relationship determined on the standard zircon. Reproducibility of 2°6pb/238U in the standard...uncertainties given for the mean Z°vpb/2°6pb ages of zircon populations are 95% confidence limits (+2Omea,)...The mounts were polished to half the width of the zircon grains to expose their internal structure. U - |  | Laurent, Oscar, Martin, HervĂ©, Doucelance, RĂ©gis, Moyen, Jean-François, Paquette, Jean-Louis (2011) Geochemistry and petrogenesis of high-K âsanukitoidsâ from the Bulai pluton, Central Limpopo Belt, South Africa: Implications for geodynamic changes at the ArchaeanâProterozoic boundary. Lithos, 123 (1) 73-91 doi:10.1016/j.lithos.2010.12.009 | Journal (article/letter/editorial) | | granitic compositions. New UâPb LA-ICP-MS dating on zircon yield pluton-emplacement ages ranging between 2...referred to as the Beit Bridge Complex (BBC). The age of the BBC still remains imprecise: its maximum age...the ~2.0 Ga tectono-metamorphic event M3/D3. The BBC thrusted over the Bulai Pluton during M3/D3 as evidenced...enderbitic sample by stepwise evaporation of four zircon grains, which yielded a minimum 207Pb/206Pb age...subordinated amounts of magnetite, ilmenite and apatite). Zircon and epidote (including allanite) can be also abundant |  | | Book | | Photos, 21 ; Ken Lucas/Visuals Unlimited, 23 (left); BBC Microimaging/Visuals Unlimited, 25; Doug Sokell/...crystals. I -- C H A P T E R T W 0 AN EL E MEN T is a substance made up of only one kind of...extract aluminum from ore, companies generally only mine aluminum ore that has at least 30 percent metal...deposits around the wor ld. M N E R A L s California Gold Rush One January day in 1848, a carpenter...Marshall was working on the American _River in California, building a sawmill for John Sutter. He saw something |  | | Journal (issue) | | Characterisation and In Situ Age Determination of Zircon Inclusions in Sapphires from Muling, North-east...Nineteenth Annual Sinkankas Symposium: San Diego County Gems and Minerals Learning Opportunities 625...Alonso-Perez Harvard University, Cambridge, Massachusetts, USA Alan D. Hart Gem-A, London Karl Schmetzer Petershausen...Edward Boehm RareSource, Chattanooga, Tennessee, USA Brian Jackson National Museums Scotland, Edinburgh...Johnson Mary Johnson Consulting, San Diego, California, USA Alan T. Collins Kingâs College London Stefanos |
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