2009
Studie zirkonu z alkalického syenitu od Naloučan, moldanubikum
ŠKODA, Radek; Mariana KLEMENTOVÁ a Renata ČOPJAKOVÁZákladní údaje
Originální název
Studie zirkonu z alkalického syenitu od Naloučan, moldanubikum
Název česky
Studie zirkonu z alkalického syenitu od Naloučan, moldanubikum
Název anglicky
Study of zircon from alkali syenite near Naloučany, Moldanubicum, Czech Republic
Autoři
ŠKODA, Radek; Mariana KLEMENTOVÁ a Renata ČOPJAKOVÁ
Vydání
Acta Mus. Moraviae, Sci.geol. Brno, Moravské zemské muzeum, 2009, 1211-8796
Další údaje
Jazyk
čeština
Typ výsledku
Článek v odborném periodiku
Obor
10500 1.5. Earth and related environmental sciences
Stát vydavatele
Česká republika
Utajení
není předmětem státního či obchodního tajemství
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/09:00028621
Organizační jednotka
Přírodovědecká fakulta
Klíčová slova anglicky
zircon; typology; radiation damage; metamictization; fluid interaction
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 8. 4. 2010 13:59, doc. Mgr. Radek Škoda, Ph.D.
V originále
The fine-grained part of alkali-feldspar syenite near Naloučany is extremely enriched in Zr, Th and U. In these parts the zircon content reach 5 percent. The zircon forms euhedral crystals 100 do 350 micrometers in size with uniform typology. Among crystal faces dominate prism (100) and pyramid (101). The prism (110) and pyramids (301), (211), and (121) are less evolved. According Pupins classification studied zircons fall into S24-S25 indicated crystallization temperature about 850 oC and confirmed high alkalinity. In the BSE four different parts of zircon were observed: i) central part with inclusions of thorite, ii) dark parts propagating along fractures, iii) homogeneous rim, and iv) bright zones between central part and rim. The dark parts contain higher concentrations of Ca, Fe, Al and Ti. Based on the U and Th content the radiation damage was calculated. The highest degree of radiation damage shows bright parts (0.38-0.66 dpa) and the lowest was recorded in the rim (0.07-0.31 dpa). The dark parts exhibit lower damage (0.11-0.38 dpa) than central parts (0.17-0.46 dpa). Metamict state was confirmed by HRTEM. The first percolation point was reached about 0.11 dpa. Low calculated radiation damage in the most altered dark parts suggest loss of U > Th during mineral-fluid interaction.
Anglicky
The fine-grained part of alkali-feldspar syenite near Naloučany is extremely enriched in Zr, Th and U. In these parts the zircon content reach 5 percent. The zircon forms euhedral crystals 100 do 350 micrometers in size with uniform typology. Among crystal faces dominate prism (100) and pyramid (101). The prism (110) and pyramids (301), (211), and (121) are less evolved. According Pupins classification studied zircons fall into S24-S25 indicated crystallization temperature about 850 oC and confirmed high alkalinity. In the BSE four different parts of zircon were observed: i) central part with inclusions of thorite, ii) dark parts propagating along fractures, iii) homogeneous rim, and iv) bright zones between central part and rim. The dark parts contain higher concentrations of Ca, Fe, Al and Ti. Based on the U and Th content the radiation damage was calculated. The highest degree of radiation damage shows bright parts (0.38-0.66 dpa) and the lowest was recorded in the rim (0.07-0.31 dpa). The dark parts exhibit lower damage (0.11-0.38 dpa) than central parts (0.17-0.46 dpa). Metamict state was confirmed by HRTEM. The first percolation point was reached about 0.11 dpa. Low calculated radiation damage in the most altered dark parts suggest loss of U > Th during mineral-fluid interaction.
Návaznosti
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