The paper summarizes results of work on the geochronological confirmation of the age of metamorphic structures occurring at the base of the Precambrian of the north of the Urals and the age of overlying Upper Precambrian basal sediments. It is shown that the occurrences of early stages of metamorphism of rocks of metamorphic (polymetamorphic) complexes date back to about 2.1 Ga. Their substrate is unambiguously related to the Lower Precambrian. We determined that Mesoproterozoic strata are absent Upper Precambrian sections of the north of the Urals, in contrast to more southern regions of the Urals. The basal strata in the Lyapin and Kharbey-Marunkeu anticlinoria, according to the data obtained, are dated to the Middle Neoproterozoic (cryogenian). The established fact of the absence of deposits of a huge age interval (Mesoproterozoic — at least 600 Ma) in the north of the Urals can be explained by a high standing of the territory of the northeast (in modern coordinates) of the Baltic craton, a fragment of which at that time was the Timan-Northern Ural lithospheric segment, and the location in the interiors of the Columbia (Nuna) supercontinent.

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

Early Precambrian rock units in the Urals are present in several polymetamorphic complexes, which are exposed in the Urals in the form of small (<1500 km 2 ) tectonic blocks. Their ages are Archaean (as old as 3.5 Ga) and Palaeoproterozoic. During the formation of these complexes in the early Precambrian, two stages of ultra-high-temperature (granulite) metamorphism occurred. The maximum age of the early Neoarchaean stage of metamorphism is 2.79 Ga. Evidence of this metamorphic event includes the dating of the Taratash gneiss-granulite complex of the South Urals. Gneiss-migmatite complexes, which dominate the lower Precambrian section of the Urals, were formed in the Palaeoproterozoic during the sequential appearance of granulite facies metamorphism followed by amphibolite facies metamorphism and accompanying granitization. The maximum age of the Palaeoproterozoic stage of granulite metamorphism in the Alexandrov gneissmigmatite complex, the most well-studied complex in the South Urals, is 2.08 Ga.

The first results of U-Pb LA-SF-ICP-MS-dating of detrital zircons from terrigenous deposits of the Miniseishor suite of the Nyarovei series of the Harbei anticlinorium of the Polar Urals are presented. The series has a presumably Middle Riphean age and lies at the base of the section of the Polar Ural Upper Precambrian. The data obtained give grounds to limit the lower age interval for the formation of sediments of the Minisejshor suite abroad 660 million years ago. Allotment the Nyarovei series as a Middle Riphean straton is erroneous. Formation of the whole cut the Nyarovei series occurred in a relatively narrow age range at the end of the late Riphean. The dominant role in the formation of deposits of the entire series belonged to the products of erosion close arrays of deeply metamorphosed rocks.

Приведены новые геохронологические данные по нижне-и верхнепротерозойским комплексам Приполярного Урала, где обнажающийся на поверхности разрез докембрия в Ляпинском антиклинории является стратотипическим для всего Тимано-Североуральского региона. Предложен авторский вариант схемы стратиграфии допалеозойских образований рассматриваемого района. Показано, что в отличие от Башкирского антиклинория на Южном Урале, где известен полный разрез верхнего протерозоя, здесь отсутствуют нижне-и среднерифейские отложения. С учетом новых данных по изотопному возрасту цирконов из докембрийских образований различных районов Тимано-Североуральского региона обосновывается представление о том, что в течение всего раннего рифея и большей части или всего среднего рифея северо-восточная окраина Балтики была вне зоны морского осадконакопления. То есть время заложения Тиманской континентальной окраины близко к рубежу среднего и верхнего рифея. К л ю ч е в ы е с л о в а: Приполярный Урал; нижний и верхний протерозой; комплекс; свита; изотопный возраст. a. m. Pystin, yu. i. Pystina. The PrecamBrian in The suB-Polar urals: The chronosTraTiGraPhic asPecT 1 -Nyartin metamorphic complex (PR 1, ), 2 -Manhobeyu suite (RF 1 ?), 3 -Schekurya suite (RF 1 ?); 4 -Puiva suite (RF 2 ?); 5 -Upper Riphean-Vendian deposits (RF 3 -V), undissected; 6 -Paleozoic deposits (Є 3 -O), undissected; 7 -granite-gneiss; 8 -granites; 9 -undissected magmatic complexes of the Main Uralian Fault; 10 -smooth boundary between Nyartin complex and Manhobeyu suite; 11 -geological boundaries: а -boundaries of stratigraphic and intrusive units, б -faults. The black circles with figures show the numbers of samples and places of their taking

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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). Together, this made it possible to compare different morphological types of magmatic and metamorphic zircons. Geochemistry of zircons 2 Results and DiscussionDetritic zircons (type 1) determine the metamorphic affiliation to one or another source formation. Zircons of the "soccer ball" type or, as is customary in the Urals, after Krasnobayev (1986), call them "granulitic" (type 2), and also "migmatite" (type 4) fix several age levels of occurrences of high-temperature rock transformations. Zircon of irregular shape like "cauliflower" (type 3) is typical for rocks metamorphosed under

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