DOCSLIB.ORG

169060: Porphyritic Syenogranite, Yangibana Bore

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
169060: Porphyritic Syenogranite, Yangibana Bore 169060.1.pdfCompilation - ofGeochronology geochronology datasetdata, 2001 134 169060: porphyritic syenogranite, Yangibana Bore Location and sampling EDMUND (SF 50-14), EDMUND (2158) MGA Zone 50, 419130E 7355190N Sampled on 15 October 2000. The sample was taken from the edge of an undulating pavement located 5 km southeast of Yangibana Bore. Tectonic unit/relations This sample is a light to medium grey, undeformed seriate porphyritic syenogranite of the Pimbyana Granite (Pearson et al., 1996; Martin et al., 2002), Gascoyne Complex. The syenogranite contains scattered tabular, feldspar phenocrysts up to 5 cm long, within a dark, fine-grained groundmass. Feldspar phenocrysts are aligned and range from very abundant to sparse over distances of several metres. Petrographic description This sample consists principally of microcline and orthoclase (60–65 vol.%), quartz (20 vol.%), plagioclase (10 vol.%), biotite (4 vol.%), and muscovite (3 vol.%), with accessory apatite (trace) opaque oxide (trace), possible monazite (trace), and zircon (trace). This is a porphyritic syenogranite with partly altered biotite and muscovite, very minor opaque oxide and zircon, and possible monazite. Feldspar phenocrysts to 30 mm long are visible in hand specimen. In thin section these are perthitic K-feldspar, varying from orthoclase to microcline, with inclusions of quartz, altered plagioclase, fresh to altered biotite, and muscovite. The largest grain within the area of the thin section is only about 10 mm long, but larger crystals are more widely dispersed. Separate plagioclase grains are up to 4 mm long, with irregular flooding by sericite. Quartz occurs as lensoidal to rounded grains to 7 mm long, deformed with undulose extinction and subgrains. Biotite occurs as flakes to 3 mm long and is partly altered to chlorite or clay, with or without epidote. Muscovite is also common, passing into aggregates of fibrous muscovite and sericite of secondary origin. Inclusions of plagioclase and quartz in K-feldspar are locally rimmed by muscovite, some of which have myrmekite-like quartz inclusions, suggesting a subsolidus origin for the muscovite. Granular apatite occurs, to 0.5 mm in grain size, with rare possible monazite 0.2 mm in diameter. Very minor fine-grained opaque oxide is also present. Zircon morphology The zircons isolated from this sample are colourless, pale pinkish brown, dark brown or black, generally between 40 × 80 µm and 100 × 230 µm in size, and are commonly irregular fragments, or subhedral and elongate in shape. Many grains have faint internal zonation, and mineral inclusions are common. Many have irregular zones of dark alteration, and many are metamict. Analytical details This sample was analysed on 3 June 2001. The counter deadtime was 32 ns. Thirteen analyses of the CZ3 standard obtained during the analysis session indicated a Pb*/U calibration error of 1.82 (1σ%). Common-Pb corrections were applied assuming Broken Hill common-Pb isotopic compositions for all analyses, with the exception of analysis 56 Table 13. Ion microprobe analytical results for sample 169060: porphyritic syenogranite, Yangibana Bore Grain U Th Pb ƒ206% 207Pb/206Pb ±1σ 208Pb/206Pb ±1σ 206Pb/238U±1σ 207Pb/235U±1σ % 207Pb/206Pb ±1σ .spot (ppm) (ppm) (ppm) concordance age 1.1 212 188 75 0.513 0.10119 0.00093 0.24561 0.00212 0.2978 0.0055 4.155 0.090 102 1 646 17 2.1 179 74 71 0.349 0.12132 0.00089 0.11644 0.00162 0.3663 0.0068 6.128 0.127 102 1 976 13 3.1 167 165 73 0.438 0.11950 0.00098 0.27375 0.00221 0.3581 0.0066 5.900 0.125 101 1 949 15 4.1 273 297 109 0.240 0.10870 0.00064 0.31393 0.00155 0.3237 0.0059 4.851 0.097 102 1 778 11 5.1 213 188 81 0.459 0.10970 0.00089 0.25369 0.00201 0.3213 0.0059 4.860 0.102 100 1 794 15 6.1 276 145 92 1.467 0.10299 0.00116 0.15783 0.00254 0.2921 0.0054 4.148 0.094 98 1 679 21 7.1 77 47 28 0.517 0.10996 0.00159 0.17725 0.00338 0.3180 0.0060 4.822 0.122 99 1 799 26 8.1 163 97 59 0.324 0.11002 0.00098 0.17801 0.00203 0.3202 0.0059 4.858 0.105 100 1 800 16 9.1 231 214 145 0.188 0.18080 0.00066 0.25629 0.00118 0.5060 0.0093 12.615 0.243 99 2 660 6 10.1 234 152 78 0.375 0.10132 0.00079 0.18213 0.00167 0.2984 0.0055 4.168 0.087 102 1 648 14 11.1 535 242 171 0.543 0.10237 0.00056 0.12674 0.00113 0.2962 0.0054 4.181 0.082 100 1 668 10 12.1 52 49 34 0.703 0.18115 0.00180 0.25961 0.00359 0.5165 0.0100 12.901 0.295 101 2 663 16 13.1 175 212 65 0.315 0.10311 0.00090 0.35255 0.00229 0.2920 0.0054 4.151 0.089 98 1 681 16 14.1 790 20 224 0.088 0.10313 0.00033 0.00752 0.00037 0.2955 0.0054 4.202 0.079 99 1 681 6 15.1 153 117 57 1.819 0.12313 0.00154 0.20276 0.00340 0.3063 0.0057 5.200 0.123 86 2 002 22 16.1 168 75 59 0.353 0.10888 0.00091 0.12463 0.00174 0.3266 0.0060 4.903 0.104 102 1 781 15 17.1 150 45 53 4.888 0.11292 0.00251 0.10302 0.00594 0.2871 0.0054 4.471 0.138 88 1 847 40 18.1 84 67 37 1.595 0.11854 0.00205 0.22012 0.00458 0.3634 0.0069 5.940 0.161 103 1 934 31 19.1 30 9 19 0.985 0.19317 0.00268 0.07693 0.00491 0.5699 0.0117 15.179 0.396 105 2 769 23 GSWA Record 2002/2 GSWA 57 Compilation of geochronology data, 2001 0.60 Analysis 19.1 0.55 2800 2700 0.50 2600 Analyses 9.1 & 12.1 2500 2400 0.45 2300 Group 2: 6 analyses of 6 zircons Pb/ U 2200 206 238 1788 ± 17 Ma (95% confidence) 0.40 2100 2000 0.35 1900 Group 3: 4 analyses of 4 zircons 1967 ± 39 Ma (95% confidence) 1700 0.30 Group 1: 6 analyses of 6 zircons 1673 ± 15 Ma (95% confidence) 169060 0.25 345678910 11 12 13 14 15 16 DN126 207Pb/ 235 U 10.05.02 Figure 18. Concordia plot for sample 169060: porphyritic syenogranite, Yangibana Bore 17.1, for which isotopic compositions determined using the method of Cumming and Richards (1975) were assumed. Results Nineteen analyses were obtained from 19 zircons. Results are given in Table 13 and shown on a concordia plot in Figure 18. Interpretation Most analyses are concordant to slightly discordant with the discordance patterns consistent with at least one recent episode of radiogenic-Pb redistribution. A range of 207Pb/206Pb dates of from c. 1670 to 2770 Ma is indicated. On the basis of their 207Pb/ 206Pb ratios, many analyses may be assigned to one of three groups. Six concordant analyses of six zircons (1.1, 6.1, 10.1, 11.1, 13.1 and 14.1), assigned to Group 1, have 207Pb/206Pb ratios defining a single population and indicating a weighted mean 207Pb/ 206Pb date of 1673 ± 15 Ma (chi-squared = 1.38). Six concordant analyses of six zircons (4.1, 5.1, 7.1, 8.1, 16.1 and 17.1), assigned to Group 2, have 207Pb/206Pb ratios defining a single population and indicating a weighted mean 207Pb/206Pb date of 1788 ± 17 Ma (chi-squared = 0.73). Concordant analyses 2.1, 3.1, 15.1 and 18.1, assigned to Group 3, have 207Pb/206Pb ratios defining a single population and indicating a weighted mean 207Pb/206Pb date of 1967 ± 39 Ma (chi-squared = 1.55). The remaining analyses (9.1, 12.1 and 19.1) cannot be confidently grouped. The weighted mean 207Pb/206Pb date of 1673 ± 15 Ma indicated by the six analyses of Group 1 is interpreted as corresponding to the age of igneous crystallization of the syenogranite. The remaining analyses interpreted to be of xenocryst zircons. 58 GSWA Record 2002/2 STRATIGRAPHIC REFERENCE: MARTIN, D. Mc., THORNE, A. M., and OCCHIPINTI, S. A., 2002, Edmund, W.A. Sheet 2158: Western Australia Geological Survey, 1:100 000 Geological Series. PEARSON, J. M., TAYLOR, W. R., and BARLEY, M. E., 1996, Geology of the alkaline Gifford Creek Complex, Gascoyne Complex, Western Australia: Australian Journal of Earth Sciences, v. 43, p. 299309. Recommended reference for this publication: NELSON, D. R., 2002, 169060: porphyritic syenogranite, Yangibana Bore; in Compilation of geochronology data, 2001: Western Australia Geological Survey, Record 2002/2, p. 56–58. OR NELSON, D. R., 2002, 169060: porphyritic syenogranite, Yangibana Bore; Geochronology dataset 134; in Compilation of geochronology data, June 2006 update: Western Australia Geological Survey. Data obtained: 03/06/2001; Data released: 26/06/2002.
Load more

Recommended publications
  • Persson Mines 0052N 11296.Pdf
    THE GEOCHEMICAL AND MINERALOGICAL EVOLUTION OF THE MOUNT ROSA COMPLEX, EL PASO COUNTY, COLORADO, USA by Philip Persson A thesis submitted to the Faculty and Board of Trustees of the Colorado School of Mines in partial fulfillment of the requirements for the degree of Master of Science (Geology). Golden, Colorado Date ________________ Signed: ________________________ Philip Persson Signed: ________________________ Dr. Katharina Pfaff Thesis Advisor Golden, Colorado Date ________________ Signed: ________________________ Dr. M. Stephen Enders Professor and Interim Head Department of Geology and Geological Engineering ii ABSTRACT The ~1.08 Ga Pikes Peak Batholith is a type example of an anorogenic (A)-type granite and hosts numerous late-stage sodic and potassic plutons, including the peraluminous to peralkaline Mount Rosa Complex (MRC), located ~15 km west of the City of Colorado Springs in Central Colorado. The MRC is composed of Pikes Peak biotite granite, fayalite-bearing quartz syenite, granitic dikes, Mount Rosa Na-Fe amphibole granite, mafic dikes ranging from diabase to diorite, and numerous rare earth (REE) and other high field strength element (HFSE; e.g. Th, Zr, Nb) rich Niobium-Yttrrium-Fluorine (NYF)-type pegmatites. The aim of this study is to trace the magmatic evolution of the Mount Rosa Complex in order to understand the relationship between peraluminous and peralkaline rock units and concomitant HFSE enrichment and mineralization processes. Field work, petrography, SEM-based methods, whole rock geochemistry, and electron probe micro-analysis (EPMA) of micas was performed on all rock units to determine their textural, mineralogical and geochemical characteristics. Early peraluminous units such as the Pikes Peak biotite granite and fayalite-bearing quartz syenite contain annite-siderophyllite micas with high Fe/(Fe + Mg) ratios, and show relatively minor enrichments in REE and other HFSE compared to primitive mantle.
    [Show full text]
  • The New Cornwall Syenogranite, Nova Scotia: Petrology and Geochemistry G
    Document generated on 10/01/2021 7:25 p.m. Atlantic Geology The New Cornwall syenogranite, Nova Scotia: petrology and geochemistry G. Pe-Piper and S. Ingram Volume 37, Number 2-3, Summer 2001 Article abstract The New Cornwall syenogranite is a 1.7 km2 intrusion at the southern margin URI: https://id.erudit.org/iderudit/ageo37_2_3art01 of the Whale Lake mon7ogranitc of the South Mountain Batholilh of southwestern Nova Scotia- It has a mean SiO> content of 75 8%, and contains See table of contents accessory amounts of tourmaline, andalusite, and primary muscovitc. Ratios such as A-'CNK (- 1.25). Rb/K (-215), and NbH'a (- 3.5) show that the syenogranitc is not highly fractionated. Although binary clement plots for some elements Publisher(s) show the same regular trend for both monzogranite and syenogranite, variations in trace elements such as Rb, Ha, Th and LRI'E show that the Atlantic Geoscience Society syenogranite is not derived from the monzogranite by fractional crystalli7ation, as the syenogranite has lower Eu and HREE compared with the ISSN monzogranite. Similarities in LREI', Nd isotope composition (eNJ - -2) and other geochemical indicators between monzogranite and syenogranitc suggest that 0843-5561 (print) they were derived by partial melting of a common source Both the Whale Lake 1718-7885 (digital) monzogranite and the New Cornwall syenogranite then evolved independently by fractional crystallization and late fluids played only a minor role in the Explore this journal further evolution of the syenogranitc. This represents a third mode of development of mineralized Icucogranitc m the South Mountain Batholith, in addition to the previously recognized "associated" and "independent" Cite this article Icucogranitc Pe-Piper, G.
    [Show full text]
  • Mineral Potential of Felsic Plutonic Rocks in the North-Central Arabian Shield, Kingdom of Saudi Arabia By
    DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Mineral potential of felsic plutonic rocks in the north-central Arabian Shield, Kingdom of Saudi Arabia by !/ William J. Moore Open-File Report 85- Prepared for the Ministry of Petroleum and Mineral Resources, Deputy Ministry for Mineral Resources, Jiddah, Kingdom of Saudi Arabia This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature, I/ U.S. Geological Survey, Reston VA 22092 1985 CONTENTS Page ABSTRACT................................................ 1 ACKNOWLEDGEMENTS........................................ 2 INTRODUCTION............................................ 2 PAST WORK............................................... 4 OBJECTIVES.............................................. 5 METHODS................................................. 6 FELSIC PLUTONIC ROCKS................................... 10 Lithology........................................... 10 Distribution........................................ 12 Geochronology....................................... 13 Geochemistry........................................ 19 Radiometric responses............................... 24 DISCUSSION.............................................. 26 RECOMMENDATIONS......................................... 29 DATA FILE............................................... 29 APPENDIX................................................ 34 REFERENCES CITED........................................ 39 ILLUSTRATIONS Figure 1. Index
    [Show full text]
  • The Nature of C. 2.0 Ga Crust Along the Southern Margin of the Gascoyne Complex by S
    Geological Survey of Western Australia 1998–99 Annual Review The nature of c. 2.0 Ga crust along the southern margin of the Gascoyne Complex by S. Sheppard1, S. A. Occhipinti, I. M. Tyler, and D. R. Nelson Remapping of the ROBINSON RANGE* Abstract and GLENBURGH 1:250 000 map sheets in 1997 and 1998, as part of the The southern part of the Gascoyne Complex consists of foliated and Southern Gascoyne Complex Project, gneissic granites of the Dalgaringa Supersuite, as well as pelitic and combined with SHRIMP U–Pb zircon calc-silicate gneisses of the Camel Hills Metamorphics, the protoliths geochronology (Nelson, 1998, 1999), of which were deposited between c. 2025 and c. 1960 Ma. The confirms that rocks of the Yilgarn Dalgaringa Supersuite mainly consists of 2005–1975 Ma foliated and Craton are not present north of the gneissic tonalite, granodiorite, and monzogranite. SHRIMP U–Pb Errabiddy Shear Zone in the mapped dating has not yet found any trace of Archaean rocks of the Yilgarn area (Fig. 1). Instead, the crust along Craton in the southern Gascoyne Complex. The complex may have the southern margin of the Gascoyne formed as a convergent continental margin above a northwesterly Complex mainly, or entirely, formed dipping subduction zone before it was accreted to the Yilgarn between 2005 and 1975 Ma. Craton at c. 1960 Ma during the Glenburgh Orogeny. Furthermore, this crust was deformed and metamorphosed at KEYWORDS: Proterozoic, structural terranes, granite, medium to high grade up to 150 geochronology, Gascoyne Complex, Dalgaringa million years before collision of the Supersuite, Camel Hills Metamorphics, Glenburgh Yilgarn and Pilbara Cratons between Orogeny 1840 and 1800 Ma (Tyler et al., 1998; Occhipinti et al., 1998).
    [Show full text]
  • Petrography and Geochemistry of Porphyroid Granitoid Rocks in the Alvand Intrusive Complex, Hamedan (Iran)
    Australian Journal of Basic and Applied Sciences, 5(12): 2192-2199, 2011 ISSN 1991-8178 Petrography and Geochemistry of Porphyroid Granitoid Rocks in the Alvand Intrusive Complex, Hamedan (Iran) Farhad Aliani, Zahra Sabouri, Mohammad Maanijou Department of Geology, University of Bu Ali Sina, Hamedam, Iran. Abstract: Alvand granitoid complex with emplacement age upper to middle Jurassic (153-167 Ma) in Sanandaj-Sirjan zone, into intruded Hamedan schistes. This complex is located with 40 km length and 10 km width in south and west Hamedan. Alvand porphyroid granitoids based on lithological composition are granodiorite, monzogranite, syenogranite and alkali-feldspar granite. Based on mineralogical characteristics consist of mineral assemblages plagioclase, quartez, K-feldspar and biotite. Geochemically, these rocks are calc-alkaline series and based on saturation degree of aluminum (ASI) are peraluminous. The mineralogical, lithological, and geochemical studies indicate that the Alvand porphyroid granitoids have S-type characteristics. These rocks displays the geochemical characteristics typical of magmatic arc intrusions related to an active continental margin. Key words: Alvand porphyroid granitoids, S-type granites, calc-alkaline series. INTRODUCTION Peraluminous granitic rocks formed from partical melting of upper crustal rocks. In active continental margins, these rocks originated from melting of crustal protoliths (e.g., pelitics) in upper-middle crust (Wedepohl, 1991). The Sanandaj-Sirjan zone, which is the host of the Alvand granitoid complex, extends over 1500 km, with an average width of 200 km, from Urmia in the northwest of Iran to Sirjan in the southeast of Iran. The Sanandaj-Sirjan zone is bordered by the Zagros fold belt to the west and the western Central Iran belt (Urmia- Dokhtar belt).
    [Show full text]
  • Geology and Groundwater Resources of Park County
    OPEN FILE REPORT 15-11 Geology and Groundwater Resources of Park County By Peter E. Barkmann, Lesley Sebol, F Scot Fitzgerald, William Curtiss Colorado Geological Survey Colorado School of Mines Golden, Colorado 2015 TABLE OF CONTENTS TABLE OF CONTENTS ........................................................................................................................ ii LIST OF FIGURES ............................................................................................................................... iv LIST OF PLATES ................................................................................................................................. iv LIST OF TABLES .................................................................................................................................. v ACKNOWLEDGMENTS ....................................................................................................................... vi INTRODUCTION .................................................................................................................................... 1 BACKGROUND AND PURPOSE ............................................................................................................ 1 GEOLOGY OF PARK COUNTY ........................................................................................................... 3 REGIONAL SETTING .............................................................................................................................. 3 MAJOR ROCK UNITS AND STRATIGRAPHY ......................................................................................
    [Show full text]
  • Formation Age, Geochemical Characteristics And
    Turkish Journal of Earth Sciences Turkish J Earth Sci (2021) 30: 489-515 http://journals.tubitak.gov.tr/earth/ © TÜBİTAK Research Article doi:10.3906/yer-2103-4 Formation age, geochemical characteristics and petrogenesis of syenogranite in Chaihe area, central Daxingan Mountains: Constraints on Late Carboniferous evolution of the Xing’an and Songnen blocks 1 1,2, 1,2 1 Dong-Xue LI , Chang-Qing ZHENG *, Chen-Yue LIANG , Xiao ZHOU 1 College of Earth Sciences, Jilin University, Changchun, Jilin, China 2 Key laboratory of Mineral Resources Evaluation in Northeast Asia, Ministry of Land and Resources, Jilin University, Jilin, China Received: 11.03.2021 Accepted/Published Online: 20.06.2021 Final Version: 16.07.2021 Abstact: The tectonic evolutionary history between the Xing’an Block (XB) and Songnen Block (SB) in the eastern Central Asia Orogenic Belt (CAOB) has been hotly debated. In this study, we present a series of new data to provide a better constraint on the magmatic process during plate subduction and its implications for the regional tectonic evolution of XB and SB, even the CAOB. The whole-rock geochemistry and zircon U-Pb chronology of syenogranite in the Chaihe area of the Great Xing’an Range have been carried out. The dating results show that the syenogranite was formed in the Late Carboniferous during the 303.1–316.1 Ma. The SiO2 content of dated samples is around between 65.43%~75.88%, while the total alkali content (K2O+Na2O) is 7.23%~10.19%, the content of MgO (0.07%~0.63%) and the value of Mg# is 0.14~0.36.
    [Show full text]
  • Raschke Et Al 2021 Wellington Lake Pegmatite RMG 56-1.Pdf
    Bulk composition of a zoned rare-earth minerals-bearing pegmatite in the Pikes Peak granite batholith near Wellington Lake, central Colorado, U.S.A. Markus B. Raschke1*, Charles R. Stern2*, Evan J. D. Anderson1, M. Alexandra Skewes2, G. Lang Farmer2, Julien M. Allaz3, and Philip M. Persson4 1Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, CO 80309, U.S.A. 2Department of Geological Sciences, University of Colorado, 399-UCB, Boulder, CO 80309, U.S.A. 3ETH Zürich, Department of Earth Sciences, Institute of Geochemistry and Petrology, Clausiusstrasse 25, 8092 Zürich, Switzerland 4Department of Geology and Geological Engineering, 1516 Illinois St., Colorado School of Mines, Golden, CO 80401, U.S.A. *Correspondence should be addressed to: [email protected] and [email protected] ABSTRACT and HFSE compared to the F-rich melts, which formed the NYF-type A previously undescribed small lenticular (~5 × 5 × 5 m) pegmatite, located HREE-rich (LaN/YbN < 1) pegmatites in near Wellington Lake in the NW part of the 1.08 Ga ‘A-type’ (anorogenic) ferroan the South Platte district. Homogeniza‐ Pikes Peak granite batholith, ~15 km SW of the South Platte pegmatite district in tion temperatures of < 500°C for possi‐ central Colorado, is concentrically zoned around a mostly monomineralic quartz bly primary fluid inclusions in large core with interconnected miarolitic cavities. Major constituents of the Wellington quartz crystals from the core of the Lake pegmatite are quartz, perthitic microcline, albite (variety cleavelandite), Wellington Lake pegmatite are consis‐ hematite, and biotite. Accessory minerals include fluocerite, bastnäsite, columbite, tent with recent models of pegmatite zircon (var.
    [Show full text]
  • Author's Personal Copy
    Author's personal copy Precambrian Research 165 (2008) 221–242 Contents lists available at ScienceDirect Precambrian Research journal homepage: www.elsevier.com/locate/precamres Geochemistry and zircon geochronology of paleoproterozoic granitoids: Further evidence on the magmatic and crustal evolution of the São Luís cratonic fragment, Brazil Evandro L. Klein a,∗, Renê Luzardo b, Candido A.V. Moura c, Richard Armstrong d a CPRM/Geological Survey of Brazil – Av. Dr. Freitas 3645, Belém-PA CEP 66095-110, Brazil b CPRM/Geological Survey of Brazil – Av. André Araújo 2160, Manaus-AM CEP 69060-001, Brazil c Universidade Federal do Pará, Centro de Geociências, CP 1611, Belém-PA CEP 66075-900, Brazil d Research School of Earth Sciences, Mills Road, The Australian National University, Canberra 0200, Australia article info abstract Article history: The Tromaí Intrusive Suite is the predominant exposed unit of the São Luís cratonic fragment in Received 22 February 2008 northern Brazil. The suite forms batholiths and stocks of granitoids that were emplaced between Received in revised form 11 May 2008 2168 ± 4 Ma and 2149 ± 4 Ma and intruded a 2240 ± 5 Ma old metavolcano-sedimentary sequence. The Accepted 17 July 2008 batholiths are composed of a variety of petrographic types that have been grouped in three sub-units, based on the predominant petrographic type, and named Cavala Tonalite, Bom Jesus Granodiorite, Keywords: and Areal Granite, from the more primitive to the more evolved phases, in addition to subordinate São Luís cratonic fragment shallow felsic intrusions. The Tromaí Suite is an expanded magmatic association comprising minor Geochemistry Paleoproterozoic mafic rocks to predominantly intermediate and felsic, low- to high-K, and metaluminous to weakly Geochronology peraluminous granitoids that follow a Na-enriched calc-alkaline trend.
    [Show full text]
  • ARTICLE in PRESS + MODEL LITHOS-01490; No of Pages 21
    ARTICLE IN PRESS + MODEL LITHOS-01490; No of Pages 21 Lithos xx (2006) xxx–xxx www.elsevier.com/locate/lithos Petrogenesis of A-type granites and origin of vertical zoning in the Katharina pluton, Gebel Mussa (Mt. Moses) area, Sinai, Egypt ⁎ Y. Katzir a, M. Eyal a, B.A. Litvinovsky a,b, , B.M. Jahn c, A.N. Zanvilevich a, J.W. Valley d, Y. Beeri a, I. Pelly a, E. Shimshilashvili a a Department of Geological and Environmental Sciences, Ben-Gurion University of Negev, P.O. Box 653, Beer-Sheva 84105, Israel b Geological Institute, RAS, 6a, Sakhyanova Str, Ulan-Ude 670047, Russia c Institute of Earth Sciences, Academia Sinica, P.O. Box 1-55, Nankang, Taipei,11529, Taiwan d Department of Geology and Geophysics, University of Wisconsin, Madison WI53706, USA Received 5 September 2005; accepted 17 July 2006 Abstract The central pluton within the Neoproterozoic Katharina Ring Complex (area of Gebel Mussa, traditionally believed to be the biblical Mt. Sinai) shows a vertical compositional zoning: syenogranite makes up the bulk of the pluton and grades upwards to alkali- feldspar granites. The latters form two horizontal subzones, an albite–alkali feldspar (Ab–Afs) granite and an uppermost perthite granite. These two varieties are chemically indistinguishable. Syenogranite, as compared with alkali-feldspar granites, is richer in Ca, Sr, K, Ba and contains less SiO2, Rb, Y, Nb and U; Eu/Eu* values are 0.22–0.33 for syenogranite and 0.08–0.02 for alkali-feldspar granites. The δ18O (Qtz) is rather homogeneous throughout the pluton, 8.03–8.55‰.
    [Show full text]
  • Lithology Classification Using TASI Thermal Infrared Hyperspectral
    remote sensing Article Lithology Classification Using TASI Thermal Infrared Hyperspectral Data with Convolutional Neural Networks Huize Liu 1, Ke Wu 1,*, Honggen Xu 2 and Ying Xu 3,4 1 Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China; [email protected] 2 Changsha Center of Natural Resources Comprehensive Survey, China Geological Survey, Changsha 410699, China; [email protected] 3 National Satellite Ocean Application Service, Ministry of Natural Resources, Beijing 100081, China; [email protected] 4 Key Laboratory of Space Ocean Remote Sensing and Application, Ministry of Natural Resources, Beijing 100081, China * Correspondence: [email protected]; Tel.: +86-136-3862-2685 Abstract: In recent decades, lithological mapping techniques using hyperspectral remotely sensed imagery have developed rapidly. The processing chains using visible-near infrared (VNIR) and shortwave infrared (SWIR) hyperspectral data are proven to be available in practice. The thermal infrared (TIR) portion of the electromagnetic spectrum has considerable potential for mineral and lithology mapping. In particular, the abovementioned rocks at wavelengths of 8–12 µm were found to be discriminative, which can be seen as a characteristic to apply to lithology classification. Moreover, it was found that most of the lithology mapping and classification for hyperspectral thermal infrared data are still carried out by traditional spectral matching methods, which are not very reliable due to the complex diversity of geological lithology. In recent years, deep learning Citation: Liu, H.; Wu, K.; Xu, H.; Xu, has made great achievements in hyperspectral imagery classification feature extraction. It usually Y. Lithology Classification Using TASI captures abstract features through a multilayer network, especially convolutional neural networks Thermal Infrared Hyperspectral Data (CNNs), which have received more attention due to their unique advantages.
    [Show full text]
  • Petrography, Mineralogy and Crystallization Processes
    1177 The Canadian Mineralogist Vol. 47, pp. 000 (2009) DOI : 10.3749/canmin.47.6.000 THE PERALKALINE TIN-MINERALIZED MADEIRA CRYOLITE ALBITE-RICH GRANITE OF PITINGA, AMAZONIAN CRATON, BRAZIL: PETROGRAPHY, MINERALOGY AND CRYSTALLIZATION PROCESSES Hilton Tulio CoSti§ Museu Paraense Emílio Goeldi, Laboratório de Microscopia Eletrônica de Varredura and Instituto de Geociências, Universidade Federal do Pará, CP 8608, 66075–100, Belém, PA, Brazil RobeRto DAll’AGnol Instituto de Geociências, Universidade Federal do Pará, CP 8608, 66075–100, Belém, PA, Brazil MiCHel PiCHAVAnt Institut des Sciences de la Terre d’Orléans, UMR 6113 CNRS–Université d’Orléans, 1A, rue de la Férollerie, F–45071 Orléans, Cedex 02, France oSMo Tapani RÄMÖ Department of Geology, P.O. Box 64, FI-00014 University of Helsinki, Finland AbStRACt The 1.818 Ga magmatic, subsolvus, Madeira albite-rich granite of the Pitinga province, exploited at the Pitinga mine, in northern Brazil, crystallized from a F-rich melt, also enriched in Sn, Rb, and HFSE. It is composed of a peralkaline, cryolite- bearing core facies and a peraluminous to metaluminous, oxidized, fluorite-bearing border facies, generated by autometasomatic processes after the crystallization of the core facies. A metaluminous to peralkaline hypersolvus granite is comagmatic with the albite-rich granite. Petrographic studies indicate that quartz was the first phase to crystallize, at ~700°C; the quartz – K-feldspar cotectic was attained at around 650°C, and the ternary feldspar solvus and onset of albite crystallization down to the solidus, estimated at around 500°C. Massive cryolite and pegmatitic rocks found in the center of the stock were derived from the residual melt.
    [Show full text]