Magmatic belts of NE Russia Vyacheslav Akinin and Paul Layer Index map showing major geologic units on surrounding margins (modified from Nokleberg et al., 1998; using Worrall et al., 1996). Index map Subduction and Collison Subduction Belts 1000 South Anyui Suture lt r n Be a e h t r No - 13 0 M 123 Main Belt > 140 Ma to ~160 Ma Rb (ppm) Shalaurova 113 Ma Collisional B elts Subduction Gr anitoids syn-collisional 72 oN 10 0 Yana River volcanic arc 10 10 Nb + Y (ppm) withinplate 90 Ag e Uncertain 68 oN 1000 Collisional granitoids Sarychev Range ? ? ? ? Rb (ppm) ? Ma in B Indigirka River elt 1 38 - 14 3M a 64oN 10 0 South Verkhoyansk 122 Ma 132 oE 10 10 Nb + Y (ppm) 70 Layer et al., 2000 144oE Extension N orthern Belt 1 20 - 124 Ma 1000 Older extensional granitoids Rb (ppm) Older Extensional Belts Svyatoi Nos 105-106 Ma 10 0 Kul ar Ra nge 103 Ma D eputatsky ~100 Ma, K-Ar 10 Lampr ophere Dike > 120 Ma Bezimyanni Pluton Derbek e-Nel'gese 131- 137 Ma Tarin Subvolcano 134-138 Ma 30 Nb + Y (ppm)10 0 1000 Younger extensional granitoids Rb (ppm) Endibal >124 Ma Younger E xtensional Be lts Bol'shoi Lyakhov vv v v Sievernyi v 103 Ma v v vv Endiba l 95-97 Ma 10 0 Sou th Verkhoyansk 92 - 107 Ma 10 30 Nb + Y (ppm) 10 0 Layer et al., 2000 Relative “magmatic productivity” through time in the NE Russia 70 50 40 30 20 10 PR PZ1 D-C P T J1-J2 J3 J3-K1 K1 K2 Pg N 0 Q Area, % 60 Volcanic rock s in sediment Intrusions unit 0 Pre Cabmbrian Lower Paleozoic Devonian Permian Triassic EMidJurassic Late Jurassic TithonianHauteriv. CretaceousEarly CretaceousLate Paleogene Neogene Pleistocene 2 Area (Km ) Intrusions Area vs. Time scale for North East of Russia (Yakutia, Magadan, Chukotka, Kamchatka) 120000 100000 80000 60000 40000 20000 Example of attribute file in GEONE GIS containing K-Ar and Ar-Ar dating results ArcView project Mesozoic Continental Margin Tectonism 230 240 250 260 Early Laramide Boulder Sevier Sierra Nevada Omineca-Coast Range Tonsina-Chicagof / Gravina-Nutsotin Interior Alaska Koyukuk Brookian Thrusting Quiescence Ladinian Anisian Scythian Continental/ marine volcanic arc sequences Norian "Age of Marine Island Arcs" Quesnellia & Stikine Arcs Hettangian Rhaetian Talkeetna Arc Sinemurian Island Intrusives Ini tial thrusting of Angayucham Bajocian Aalenian Toarcian Pliensbachian Mafic alkalic to calc-alkaline plutons Calc-alkaline batholiths Bathonian Carnian Mi ddle uplift Callovian QUIESCENCE ? Early Middle Late QUIESCENCE Khetachan 220 Oxfordian Alazeya Arc 210 rmian Triassic 200 Late 190 Late 180 ly 170 Jurassic 160 Berriasian (Volgian) Tithonian Kimmeridgian Canada Basin LEGEND Rift-related basalts Collision granites (Magmatic Lull) Kolyma-Verkhoyansk belt New U-Pb data Oloi Arc Hauterivian Extensional basins Uyandina-Ya sach naya South Anyui Suture Barremian Verkhoyansk Thr usting ? Aptian Valanginian 140 150 ? ? Cenomanian Ch ukotka granites+ core complexes Co ni acian Turonian Albian U.S. OCVB, New U-Pb data ? OCVB Late Santonian Ma in Belt No rthern Belt Kolyma Granites 130 Extensional basins Koni-Murgal 120 Campanian ? 110 ? Koni-Murgal 100 Maastrichtian Ma gadan Batholith 90 Early 80 Cretaceous 70 Canada Alaska Calc-alkaline mafic-intermediate volcanics Small magnitude shortening Sierra Nevada NE Russia 60 Large magnitude shortening Unconformity Conglomerates Quiescence Ma rin e No nMa rin e Din kum Ch ukotka Sills "Age of Rifting" Karmutsen-Nicolai W. Nevada Tatarian Kazanian Ufimian Kungurian Artinskian Miller et al., 2003 Distribution of Andean-style magmatic arcs (OkhotskChukotka volcanic belt and its sectors and Sikhote-Alin belt) and associated forearc and accretionary-prism units. 1000 Parental basaltic magma 900 800 CCF Closed - system Crystal Fractionation 600 500 400 AFC 300 200 100 Assimilation Fractional crystallization Bulk Assimilation 0 0 50 100 150 200 250 300 Rb, ppm Norn -Thompson, R.N., 1982 1000 Upper basalts OCVB Lower andesites Rock/Chondrites K/Rb 700 100 Pre OCVB basalts 10 1 BaRbTh K Nb Ta La Ce Sr Nd P SmZr Hf Ti Tb Y TmYb Okhotsk –Chukotka geochemistry of volcanism and plutonism 1000 1000 Collisional m m ppm Rb 100 m 10 oo m oooo o ca. 70o 85 Ma m m mm mm m m m m ppm Rb m Syn-Collisional Withinplate m 9 9 100 9 9 99 99 9 9 99 9 9 9 9 99 9 9 9 9 9 85-100 Ma ca 85-100 Ma Volcanic Arc 1 10 9 9 9 75-85Ma 99 9 ocean ridge 100 ppm Nb + Y 8 88 8 88 8 8 8 8 8 8 8 88 888 8 8 8 8 8 Withinplate Volcanic Arc 10 10 100 ppm Nb + Y 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). Summary of chronostratigraphic data for Okhotsk-Chukotka volcanic belt (Okhotsk sector) Mineral Deposit and Metallogenisis (Adapted from Nokleberg et. al., 1996) Epithermal gold deposits 1000 t * s EPITHERMAL DEPOSITS, MAGADAN REGION * ss s 100 s=silver, t=tin *=Ag-Sn extensional magmatism s Kar 10 Ny arc magmatism Kh Oi 1 65 75 85 95 Age, Ma 105 115 125 Coarse isoferroplatinum nuggets from Galmoenansky District, Koryak-Kamchatka Peninsula Source KGD/PRGCI Information Brochure, 2004 Tectonostratigraphic Terranes of Kamchatka (Adapted from Nokleburg et. al. 1994) Kuveralog Prospect, Kamchatka Kamchatka ages Kvinum Sill Kortlandite Sill Aleneya Pyroxenite Sill Shanoch Norite Sill Geology of Galmoenonsky Massif Koryak-Kamchatka Peninsula Ar/Ar Sample Site Ar/Ar Sample Site Data source; KGD/PDAC Toronto Convention, 2004 Hornblende and Biotite 40Ar/39Ar Ages from Galmoenansky intrusive area, Koryakia, Russian Far East South Anyui Magnetic anomaly map Middle Jurassic-Early Cretaceous greenschists of the South Anyui Suture: The Bistrianka complex Quaternary volcanism Bilibina Anyui historic Zhokhov Is. 1.2 Ma ? ? Djaktardakh 100 Ma Alyuchin ~500 ka ? Upper Anadyr River Balagan Tas 266 ka ? Levyi Taryn 35 Ma ? Quaternary? Volcanism from Whitford-Stark, 1987 Balagan Tas Geological studies and geophysical prospecting throughout the 2-DV reference profile (Koni Peninsula -Wrangel Island), North-East Russia (Surkov et al., 2003, 2004) 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 ?). 1. 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. 2. 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? Societal impacts • Understanding of paleoclimates • Economic development of mineral resources