Transcript ~13.3 MB

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