Typomorphgic characteristics of zircon as a criterion for subdivision and correlation of granitoids (on an example of the northern part of the Subpolar Urals)

Abstract

Ââåäåíèå Äëÿ öèðêîíîâ èç ãðàíèòîèäîâ õàðàêòåðíî áîëüøîå ðàçíîîáðàçèå ôîðì è âíóòðåííåãî ñòðîåíèÿ êðèñòàëëîâ, áîãàòàÿ öâåòîâàÿ ãàììà, íàëè÷èå ìèíåðàëüíûõ è ãàçîâî-aeèäêèõ âêëþ÷åíèé. Áëàãîäàðÿ ðàçíîîáðàçèþ ìîðôîëîãè÷åñêèõ îñîáåííîñòåé è óñòîé÷èâîñòè öèðêîíà ê íàëîaeåííûì ïðîöåññàì ïðåîáðàçîâàíèÿ ìàãìà-òè÷åñêèõ ïîðîä îí øèðîêî èñïîëüçóåòñÿ äëÿ ðàñ÷ëåíåíèÿ è êîððåëÿöèè ãðàíèòîèäîâ, äëÿ óñòàíîâëåíèÿ ôèçèêî-õèìè÷åñêèõ óñëîâèé èõ ôîðìèðîâàíèÿ è äëÿ îïðåäåëåíèÿ èçîòîïíîãî âîçðàñòà. Íàèáîëåå ïîëíûå ñâåäåíèÿ î ìîðôîëîãè÷åñêèõ îñîáåííîñòÿõ öèðêîíîâ èç ãðàíèòîâ è äðóãèõ èçâåðaeåííûõ ïîðîä Òèìàíà è ñåâåðà Óðàëà, è â òîì ÷èñëå Ïðèïîëÿðíîãî Óðàëà, ïðèâîäÿòñÿ â ìîíîãðàôèè Ì. Â. Ôèøìàíà è åãî êîëëåã [19]. Ïåðâàÿ ïîïûòêà èñïîëüçîâàòü òèïîìîðôíûå îñîáåííîñòè öèðêîíîâ äëÿ ðàçäåëåíèÿ ðàçíîâîçðàñòíûõ ãðàíèòîèäíûõ êîìïëåêñîâ áûëà ïðåäïðèíÿòà â íàøèõ ïðåäûäóùèõ ðàáîòàõ [5, 16 è äð.].  ïîñëåäíèå ãîäû ñîáðàí äîïîëíèòåëüíûé ìàòå

Th/U Ratio in Zircons of Metamorphic Rocks and Granitoids of the Urals as an Indicator of Their Genesis

“…Our studies show that accessory zircons from rocks of different granitoid complexes in the northern part of the Subpolar Urals, which occupy different geological positions and differ in isotopic age, differ in the set of morphotypes, their quantitative ratios, to some extent and geochemical features [10,15]. Recently, we have studied the morphological features of zircons from granites from Nikolaishor (PR1), Kozhim (PF3), Badiau (RF3-V) and Yarota (RF3-V) massifs [10] (Fig. 3).…”

“…They allow the mineral to be used in the reconstruction of specific metamorphic events and the interpretation of geochronological data [8, 9, etc.]. Recently, we also have obtained new results on the morphology and geochemistry of zircons from granitoids of the northern part of the Subpolar Urals [10]. Together this has made it possible to compare different morphological types of magmatic and metamorphic zircons.…”

Th/U Relations as an Indicator of the Genesis of Metamorphic Zircons (On the Example of the North of the Urals)

“…Our studies show that accessory zircons from rocks of different granitoid complexes in the northern part of the Subpolar Urals, which have different geological positions and isotopic age, differ in the set of morphotypes, their quantitative ratios and geochemical features (Pystina et al 2017). Recently we studied morphological features of zircons from the granites of Nikolayshor (PR1), Kozhim (PF2-3), Badyayu (RF3-V) and Yarota (RF3-V) Massifs.…”

“…

Having studied polymetamorphic complexes of the Urals, including its northern part, for many years we have collected material on the basis of which we attempted to make generalizations concerning both the morphology of zircons and their geochemical features, allowing the mineral to be used in the reconstruction of specific metamorphic events and the interpretation of geochronological data (Pystina et al 2017;Pystina and Pystin 2002). In recent years we also obtained new results on the morphology and geochemistry of zircons from granitoids in the northern part of the Subpolar Urals (Pystina and Pystin 2002).

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