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Magmatic belts of NE Russia Vyacheslav Akinin and Paul Layer

Magmatic belts of NE Russia Vyacheslav Akinin and Paul Layer. Index map. Index map showing major geologic units on surrounding margins (modified from Nokleberg et al., 1998; using Worrall et al., 1996). Subduction and Collison. Layer et al., 2000. Extension. Layer et al., 2000.

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Magmatic belts of NE Russia Vyacheslav Akinin and Paul Layer

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  1. Magmatic belts of NE Russia Vyacheslav Akinin and Paul Layer

  2. Index map Index map showing major geologic units on surroundingmargins (modified from Nokleberg et al., 1998; using Worrall et al., 1996).

  3. Subduction and Collison Layer et al., 2000

  4. Extension Layer et al., 2000

  5. Relative “magmatic productivity” through time in the NE Russia

  6. Example of attribute file in GEONE GIS containing K-Ar and Ar-Ar dating results ArcView project

  7. OCVB, New U-Pb data Collision granites Kolyma-Verkhoyansk belt New U-Pb data Miller et al., 2003

  8. Distribution of Andean-style magmaticarcs (Okhotsk-Chukotka volcanic belt and its sectors and Sikhote-Alin belt) and associated forearc and accretionary-prism units.

  9. Okhotsk –Chukotkageochemistry of volcanism and plutonism

  10. Okhotsk-Chukotka volcanic belt (OCVB) • Eruption of about 1.2 million km3 of calc-alkaline volcanic rocks over a 500,000 km2 area. • It is generally accepted in the literature (based on phytostratigraphic, K-Ar and Rb-Sr whole-rock dating) that OCVB volcanism encompasses a wide interval of time from the middle Albian to the Early Campanian (Belyi, 1994; Kotlyar et al., 2000) or up to Maastrichtian (Filatova, 1988). • New 40Ar/39Ar ages indicate that the majority of the volcanic sequence inner zone of OCVB was emplaced in Coniacian-Santonian between 89 Ma and 82 Ma (Kelley et al.,1999; Akinin et al., 2000; Ispolatov et al.,2000;Hourigan and Akinin, 2004). • Capping basalts were emplaced between 77.5 ±0.8 Ma and 73.6 ± 0.7 Ma and exhibit a within-plate geochemical signature, which we attribute to a temporally and geochemically distinct extension-related phase of magmatism (Filatova, 1988; Hourigan and Akinin, 2004). Coeval alkaline granitoids with intra-plate geochemical signatures have formed due to subduction slab fracturing as a result of major tectonic blocks merging the continental edge (Goryachev and Khanchuk, 2002).

  11. Summary of chronostratigraphic data for Okhotsk-Chukotka volcanic belt (Okhotsk sector)

  12. Mineral Deposit and Metallogenisis (Adapted from Nokleberg et. al., 1996)

  13. Epithermal gold deposits

  14. Coarse isoferroplatinum nuggets fromGalmoenansky District, Koryak-Kamchatka Peninsula Source KGD/PRGCI Information Brochure, 2004

  15. Tectonostratigraphic Terranes of Kamchatka (Adapted from Nokleburg et. al. 1994)

  16. Kuveralog Prospect, Kamchatka

  17. Kamchatka ages Kvinum Sill Aleneya Pyroxenite Sill Kortlandite Sill Shanoch Norite Sill

  18. Geology of Galmoenonsky MassifKoryak-Kamchatka Peninsula Ar/Ar Sample Site Ar/Ar Sample Site Data source; KGD/PDAC Toronto Convention, 2004

  19. Hornblende and Biotite 40Ar/39Ar Ages from Galmoenansky intrusive area, Koryakia, Russian Far East

  20. South Anyui

  21. Magnetic anomaly map

  22. Middle Jurassic-Early Cretaceous greenschists of the South Anyui Suture: The Bistrianka complex

  23. Quaternary volcanism

  24. Balagan Tas

  25. Geological studies and geophysical prospecting throughout the 2-DV reference profile(Koni Peninsula -Wrangel Island), North-East Russia (Surkov et al., 2003, 2004)

  26. Magmatic belts in NE of Russia Un-answered questions and proposed research projects • Call for the detailed revision of current chronostratigraphy of Okhotsk-Chukotka volcanic belt (OCVB): high-resolution geochronometry of key units including paleoflora- bearing sediments. • Relation of tectonic and volcanic episodes to biologic crises, climate change and mineralization. • Trace elements and isotopic signatures recorded by calc-alkaline magmas of OCVB: role of subduction and extension. Was this transition synchronous along the belt? • Pre-Mesozoic history of the terranes of NE Russia. e.g., isotopic dating of pre-OCVB magmatic events (Uda-Murgal arc beginning from Permian ?). • U-Pb, Ar-Ar, FT dating of granitic belts (Ar-Ar age 144–134 Ma after Layer and others, 1995, 2000) for reconstruction of ENTIRE geologic history. • Development of GEOCHRON database. We need to assess older dates and geochemistry (what do ages and compositions represent?) Can we get to a common data set and have access to data?

  27. Societal impacts • Understanding of paleoclimates • Economic development of mineral resources

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