Thorite inclusions in zircon of the monzogranite, Lower Nubia, SW Egypt

• Autorzy: Hassan Kamaleldin M. , Brunarska Irena

Identyfikatory

DOI

10.2478/mipo-2023-0007

• Języki publikacji: EN

Abstrakty

EN

This report presents the results of a petrographical and mineralogical (optical microscopy, BSE-EDS image analysis) study of zircon in samples from the Lower Nubian monzogranite. The mineral occurs as smaller grains (< 80 µm) in a finegrained quartz-feldspar-matrix, coexisting with other accessory minerals including biotite, clinochlore, titanite, and britholite-(Ce). Zircon is also present within biotite and britholite-(Ce), suggesting that it started crystallization at about the same time as these two minerals. Two types of thorite inclusions within zircon are reported in this study. Type 1 is widely distributed throughout the zircon grain, forming crystallites of which each is typically < 1 µm in size. Type 2 is relatively larger (5-15 µm) and occurs only in one part of the grain. For the thorite inclusions, three possible origins are briefly discussed: (1) exsolution of thorite from zircon; (2) dissolution/reprecipitation of zircon; and (3) growth syngenetically with zircon. Of these potential hypotheses, the syngenetic growth model seems more favorable for zircon-thorite intergrowths than the other two hypotheses. Thorite inclusions and their host zircons seem to have grown from magma rather than hydrothermal or supercritical solutions. Here, they have primary textures and consistent chemical compositions that are consistent with whole-rock geochemistry.

Słowa kluczowe

EN

Zircon; thorite; syngenetic inclusions; accessory minerals; metaluminous granite; Nubian Desert

• Wydawca: Mineralogical Society of Poland
• Czasopismo: Mineralogia
• Rocznik: 2023
• Tom: Vol. 54, iss. 1
• Strony: 69--77
• Opis fizyczny: Bibliogr. [33] poz., rys., tab.

Twórcy

autor

Hassan Kamaleldin M.

• Nuclear Materials Authority, El Katameya, New Cairo 3, Cairo Governorate 4710030, Egypt

• https://orcid.org/0000-0001-5216-6756

autor

Brunarska Irena

• Institute of Geological Sciences, Jagiellonian University, Gronostajowa 3a, 30-387 Kraków, Poland

• https://orcid.org/0000-0002-3366-0633

Bibliografia

• Alekseev, V. I., Polyakova, E. V., Machevariani, M. M., & Marin, Yu. B. (2014). Evolution of zircons from postorogenic intrusive series with Li–F granites, Russian Far East. Geology of Ore Deposits, 56, 513–530. https://doi. org/10.1134/S1075701514070034.
• Corfu, F., Hanchar, J. M., Hoskin, P. W. O., & Kinny, P. (2003). Atlas of zircon textures. Reviews in Mineralogy and Geochemistry, 53, 469–500. DOI: 10.2113/0530469.
• Correia Neves, J. M., Lopes Nunes, J. E., & Sahama, T. G. (1974). High hafnian members of the zircon-hafnon series from the granite pegmatites of Zambézia, Mozambique. Contributions to Mineralogy and Petrology, 48, 73–80. DOI: 10.1007/BF00399111.
• Finch, R. J., Hanchar, J. M. (2003). Structure and Chemistry of zircon and zircon-group minerals. Reviews in Mineralogy and Geochemistry, 53, 1–25. DOI: 10.2113/0530001.
• Geisler, T., Pidgeon, R. T., Kurtz, R., van Bronswijk, W., & Schleicher, H. (2003). Experimental hydrothermal alteration of partially metamict zircon. American Mineralogist, 88, 1496–1543. DOI: 10.2138/am-2003- 1013.
• GSMA. (1981). Geological map of Egypt, scale 1:2,000,000. Geological Survey and Mining Authority, Abbasyia, Cairo, Egypt.
• Hassan, K. M. (1985). A study of the heavy minerals of some granitic plutons in the northern part of the Eastern Desert, Egypt as a guide to their petrogenesis. MS. Thesis. Azhar University, Cairo, Egypt.
• Hassan, K. M. (2007). Review ionizing radiation in the environments. Isotope and Radiation Research, 39, 743–662. https://inis.iaea.org/search/search. aspx?orig_q=RN:39022119.
• Hassan, K. M. (2008). Petrography, chemistry and radioactivity of granitoids at north Gebel Seri, South Western Desert, Egypt. Isotope and Radiation Research, 40, 615–629. https://inis.iaea.org/search/search. aspx?orig_q=RN:40047318.
• Hassan, K. M. (2018). Trace elements and REE enrichment at Seboah Hill, SW Egypt. Mineralogia, 49, 47–65. DOI: 10.2478/mipo-2018-0007.
• Hassan, K. M. (2023). Britholite-(Ce) from the metaluminous granite of SW Egypt. Mineralogia, 54, 11–17. DOI: 10.2478/mipo-2023-0002.
• Hassan, K. M., & Gunnlaugsson, H. P. (2013). Characterization of barren, granitic soils from the Nubian Desert (SW Egypt) by 57Fe Mössbauer spectroscopy. Mineralogia, 44, 39-51. DOI: 10.2478/mipo-2013-0004.
• Heaman, L., & Parrish, R. (1991). U-Pb geochronology of accessory minerals. In Short course handbook on applications of radiogenic isotope systems to problems in geology (Heaman, L., & Ludden, J. N. eds.). Mineralogical Association of Canada (59–102).
• Higazy, M., Abu El-Leil, I., & Mokhtar, K. (1986). Statistical study of zircon as a guide to the origin and type of granitic rocks, Northern Eastern Desert, Egypt. Annals of the Geological Survey of Egypt, 16, 309–314.
• Hoskin, P. W. O., Kinny, P. D., & Wyborn, D. (1998). Chemistry of hydrothermal zircon: investigating timing and nature of water-rock interaction. In Water-Rock Interaction, WRI-9 (Arehart,G. B., & Hulston, J. R. eds.). AA Balkema, Rotterdam (545–548).
• Jocelyn, J., & Pidgeon, R. T. (1974). Examples of twinning and parallel growth in zircons from some Precambrian granites and gneisses. Mineralogical Magazine, 39, 587–594.
• Kabesh, M. L., Refaat, A. M., & Abdallah, Z. M. (1976). The significance of zircon as a guide to the petrogenesis of granites from Ras Barud area, Eastern Desert, Egypt. Kuwait Journal of Science, 3, 207–216.
• Kaulina, T., Lyalina, L., Kamenetsky, V., Il’Chenko, V., Bocharov, V., & Gannibal, M. (2020). Composition and Structure of Zircon from Hydrothermal Uranium Occurrences of the Litsa Ore Area (Kola Region, Russia). Geosciences 10, 278. DOI: 10.3390/geosciences10080278.
• List, F. K., El-Gaby, S., & Tehrani, R. (1989). The basement rocks in the Eastern and Western Deserts and Sinai. In Stratigraphic lexicon and explanatory note to the geologic map of Egypt 1:500000 (Hermina, M., Klitzsch, E. & List, F. eds.). Egyptian General Petroleum Corporation, Cairo, Egypt (33–56).
• Mason, B. (1966). Principle of Geochemistry. Third edition. John Willey and Sons Inc., New York.
• Mumpton, F. A., & Roy, R. (1961). Hydrothermal stability studies of the zircon-thorite group. Geochimica et Cosmochimica Acta, 21, 217–238. https://doi. org/10.1016/S0016-7037(61)80056-2.
• Pointer, C. M., Ashworth, J. R., & Ixer, R. A. (1988). The zircon– thorite mineral group in metasomatized granite, Ririwai, Nigeria 2. Zoning, alteration and exsolution in zircon. Mineralogy and Petrology, 39, 21–37. https:// doi.org/10.1007/BF01226260.
• Rubin, J. N., Henry, C. D., & Price, G. (1989). Hydrothermal zircons and zircon overgrowths, Sierra Blanca Peaks, Texas. American Mineralogist, 74, 865–869. http:// www.minsocam.org/ammin/AM74/AM74_865.pdf.
• Sabet, A. H. (1972). On the stratigraphy of basement rocks of Egypt. Annals of the Geological Survey of Egypt, II, 79–102.
• Schmitt, A. K. (2006). Laacher See revisited: high-spatialresolution zircon dating indicates rapid formation of a zoned magma chamber. Geology, 34, 597–600. https://doi.org/10.1130/G22533.1.
• Sorokhtina, N. V., Kogarko, L. N., Shpachenko, A. K., & Senin, V. G. (2016). Composition and conditions of crystallization of zircon from the rare-metal ores of the Gremyakha–Vyrmes Massif, Kola Peninsula. Geochemistry International, 54, 1035–1048. https:// doi.org/10.1134/S0016702916120119.
• Spiridonov, E. M., Filimonov, S. V., Semikolennykh, E. S., Korotaevaa, N. N., & Krivitskaya, N. N. (2018). Zirconolite, baddeleyite, zircon, and thorite of island-arc quartz gabbronorite-dolerites of the Ayu-Dag Intrusive, Crimean Mountains. Moscow University Geology Bulletin, 73, 538–548. DOI: 10.3103/ S0145875218060121.
• Spotts, J. H. (1962). Zircon and other accessory minerals. Coast Range batholith, California. Geological Society of America Bulletin, 73, 1221–1240. https://doi.org/10.1130/0016- 7606(1962)73[1221:ZAOAMC]2.0.CO;2.
• Wang, X., Griffin, W., & Chen, J. (2010). Hf contents and Zr/ Hf ratios in granitic zircons. Geochemical Journal, 44, 65–72. https://doi.org/10.2343/geochemj.1.0043.
• Wedepohl, K. H. (1995). The composition of the continental crust. Geochimica et Cosmochimica Acta, 59, 1217–1232. http://dx.doi.org/10.1016/0016- 7037(95)00038-2.
• Xie, L., Wang, R., Chen, X., Qui, J., & Wang, D. (2005). Th-rich zircon from peralkaline A-type granite: mineralogical features and petrological implications. Chinese Science Bulletin, 50, 809–817. https://doi. org/10.1007/BF03183683.
• Xia, Q. X., Zheng, Y. F., & Hu, Z. C. (2010). Trace elements in zircon and coexisting minerals from low-T/UHP metagranite in the Dabie orogen: implications for action of supercritical fluid during continental subductionzone metamorphism. Lithos, 114, 385–412. https:// doi.org/10.1016/j.lithos.2009.09.013.
• Žáček, V., Škoda, R., & Sulovsky, P. (2009). U–Th-rich zircon, thorite and allanite-(Ce) as main carriers ofradioactivity in the highly radioactive ultrapotassic melasyenite porphyry from the Šumava Mts., Moldanubian Zone. Czech Republic Journal of Geosciences, 54, 343– 354. DOI: 10.3190/jgeosci.053.