structural controls on the primary distribution of mafic ... · basalt trap sedimentary rocks...
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Structural controls on the primary distribution of mafic-ultramafic intrusions containing Ni-Cu-Co-(PGE) sulfide mineralizationPeter C Lightfoot and Dawn Evans-Lamswood, Vale Base Metals
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Process Controls on Formation of Nickel Sulfides
Craton Margin
Crust
Plume
Mantle
Strike-slipfault zone
2 Sub-ContinentalLithospheric Mantle
30 -
40km
Basalt Lavas
Disseminated Sulphide
Sulphide-richLayers
Mid-CrustalMetamorphic Rocks
Deep Crustal Granitesand Gneisses
Upper CrustalSediments
Generate ultramafic magma from metalendowed source
Ascent of magma
Fractionation and contamination
Emplacement
Sulphide saturation and metal endowment
Sulphide segregation
Syn-tectonic and post-tectonic modification
Key Process Controls
Tetonic Setting Crustal Architecture
1
2
3
4567
1
2
1
765432
After: Lightfoot (2007) and Naldrett (2010)
Begg et al (2011)
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PLAN B - Dyke Configuration
PLAN A - Pipe Configuration
PLAN C - Chamber
extensionalbend
contractionalbend
obliquethrust
obliquenormal fault
right-stepping left-stepping
View Along Plane of Stike-SlipShear Zone Plan View
Magma Conduits (pipes, dykes, chambers)at different crustral levels
Kinematics : dextral strike-slip fault zone
Mantle
Chamber
Conduit
Chamber
Chamber
PLAN A
PLAN B
PLAN C
MeltAccumulation
RigidDuctile?
Melting
Heat Source
Cru
st
Surface
Dyke
Magma Conduits
Extensional spaces in transform fault systems act as “magma highways” from mantle to surface and control many small differentiated intrusions with nickel sulfide deposits
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Key Points To Take Away• Widespread importance of strike-slip structures on emplacement of small
differentiated intrusions with transported sulphide: Vertical champagne glass-shaped chonoliths (e.g. Huangshan,
Huangshandong, Jingbulake, Limahe, Hong Qi Ling…) Accumulations within sub-horizontal chonoliths (e.g. Noril’sk-
Talnakh, Karatungk, Nkomati, Babel-Nebo…)• A common model for nickel sulfide formation in the roots of large igneous
provinces in craton-margin structures• Case studies of Chinese deposits, Norli’sk and Voisey’s Bay • Chamber geometry, ore distribution, and transport of magmatic sulfide
controlled by dilational space created in a right-lateral fault zone
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Distribution and scale of Ni sulfide deposits in China
1000 Km
80°E 90°E 100°E 110°E 120°E 130°E
Hongqiling
Huangshan,Huangshandong
40°N
50°N
30°N
20°N
Jinchuan
Kalatongke
Jingbulake
Limahe
Qingquanshan
Large >1000kt Ni
Medium >100-1000kt Ni
Small >10-100kt Ni
Central Asian Orogenic BeltCentral Orogenic BeltNorth China CratonYangtze CratonTarim CratonCathaysian BlockHimalayan Orogen
Jinbaosan
Ban Phuc
Baimazhai
Yangliuping
Xiarihamu
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Distribution of nickel deposits in Western China
40°N
45°N
Pobei
Korla
Jingbulake
Urumqi
Karatungk
Hami
Hulu Tula’ergenHuangshandong
Huangshan
Jinchuan
Lashuisha
JunggarBasin
TarimBasin
Hami Basin
90°E85°E 95°E 100°E
Mesozoic-Cenozoic Basins Cover
Mesozoic fold-thrust belt
Paleozoic
Precambrian
Border
Nickel Sulfide DepositFaults (strike-slip with thrusting)Town / City
Underlain by Shield
After: Mao et al. (2008), Cunningham (2007)
Xinjiang Gansu
Qinghai
Mongolia
Xiarihamu
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Restraining bends and pull-apart basins along the Gobi-Tien Shan fault system in Eastern Xinjiang, China
HuangshanHuangshandong
200km
15km
BogdaShan
Aj Bogd
Barkol Tagh
Turpan Basin
XinjiangAfter: Mann, (2007)
Lightfoot, Evans-Lambswood, (2007)
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Geology of the Huangshandong Intrusion and the location of Cu-Ni Sulfide mineralization
A’
A 1km
A’162° 325°A
200m
Gabbro DioriteDiorite
Gabbronorite
Peridotite Country rocks
Ni-Cu sulphidemineralization
FaultsSynformAntiformBoreholes
Gabbro to olivine gabbro
Huangshandong 15km
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Xinjiang: Hami Belt – shaft on Huangshandong
Photograph: Peter Lightfoot, 2001
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Xinjiang: Hami Belt – exploration under Chairman Mao’s 5 Year Plans
Photograph: Peter Lightfoot, 2001
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Geology of the Huangshan Intrusion and the location of Cu-Ni Sulfide mineralization
X U
V Y Z
500m
500m
500(m)
0U V
ZYX 50° 90°0
500(m)
Fault
Basalt and trachyteConglomerate and sandstoneSiltstoneLimestone
Hornblende peridotite
Dunite
PeridotiteWebsterite
GabbroDiorite
Gabbronorite
Disseminated Ni - Cusulfide mineralization
A
BC
Plan View
Long Section View
CrossSection
View
HuangshanIntrusion
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Jingbulake Intrusions, Xinjiang Province
Yang et al., 2012
Sulu
Changawuzi
Jingbulake
81°00 E 81°30 E
42°25 N
42°40 N
40km
Carboniferous BlueschistCarboniferous GreenschistCarboniferous EclogiteEarly-Middle Paleozoic GraniteMafic IntrusionMarbleCarboniferous Volcanicsedimentary rocksProterozoic ComplexFault
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Karatungk #1,2 and 3 Intrusions, Xinjiang Province, China: North-facing long section
1000
500(m)
040 111103958779716359514335271911312162024283236 4
0 500m
#1 #2 #3
Wang et al., 1991
1000Km
F3
F18
F4
F6 F5
F7F21
F20
F9
150m
Biotite-pyroxene diorite
Biotite-hornblende norite andBiotite-hornblende gabbronoriteBiotite-hornblende olivinegabbronoriteBiotite-hornblende diabase gabbro
Disseminated sulphideHeavy disseminated sulphideCu-rich massive sulphideNi-rich massive sulphide
Karatungk
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Karatungk #1,2 and 3 Intrusions, Xinjiang Province, China: West-facing long section#2 Deposit
#3 Intrusion Country rockOlivine gabbronoriteGabbronoriteDioriteQuartz monozoniteOutline ofmineralizationBorehole trace
200m
Wang et al., 1991
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Location Map of the Jinchuan Intrusion, Proterozoic Longshushan Belt, Gansu Province, China
Yongchang
Jinchuan
Qingshijing
ZhangbutaiShandan
1000 Km
39°00’
38°40’
38° 20’
101°00’ 101°30’ 102°00’ 102°30’
10 km Cenozoic
Cretaceous
Devonian-Jurassic
Cambrian-Silurian
Proterozoic
Paleozoic granite
Proterozoic mafic-ultramafic intrusion
FaultMagmatic sulfide mineralization
After Song et al., 2008
Jinchuan Intrusion
Jinchuan
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Geological Map and Sections of the JinchuanIntrusion
Tang Zongli (1993)
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Mine area #2 – no trace of sulfide or country rock xenoliths inside the intrusion at surface
Photograph: Peter Lightfoot, 2000
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Jinchuan Model
Sequential Emplacement of Sulfide-bearing silicate melts
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Hongqiling – Geology, Structure and Mineral Occurrences
1000 Km
Hulan Group Gneiss (older)Hulan Group Gneiss (younger)
Granitoid rocksMafic-ultramafic Intrusions
Mesozoic sedimentary rocks
Fault0 5
km
Hongqiling
Jilin #1Deposit
Jilin #7Deposit
After Zhou et al., 2000
Hongqiling
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Hongqiling: Jilin Province
A’
100m100m
200
100
-100
-200(m)
0
A A’
Number 7Deposit
A
C D
Othopyroxenite andhybrid zone
Massive sulphideConglomerate
Disseminated and massiveSulphide in orthopyroxenite
SchistMarbleGneissOutline of open pit
UnconformityFaults and shear zones
WesternIntrusion
200
-200
-400
-600
0
Shaft
EasternIntrusion
250m 150m
A GabbroPyroxeniteOlivine PyroxeniteDisseminated sulfidein olivine pyroxeniteWeakly mineralizedperidotiteAmphiboliteGneissFaultPit outline
B
Plan View
Plan View Section View
Section View
Number 7Deposit
EasternIntrusion
WesternIntrusion(projected toSurface)
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Intrusions controlled by structures beneath the ~260 Ma Emeishan Flood Basalt, SW China
1000km
200km
Chengdu
SICHUAN
YUNNAN
Kunming
Yangliuping
Qingquanshan
Limahe
Pan
xi“R
ift”
Baimazhai
Jinbaosan
Yangtze cratonHimalayan orogenEmeishan flood basaltUnderlain by manysmall intrusionsFault zoneNickel and PGE sulphidedepositsProvincial boundary
A
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Geology of the Limahe and Qingquanshan Cu-Ni Sulfide Deposits (Sichuan Province)
50m
A'A
200m
A A’
50m
1700
1800
(m)
1600
70o
B C D E
Mined-outHekou formationGabbroPeridotite
OverburdenDiorite and gabbroPyroxenite and peridotiteMassive and disseminatedNi - Cu sulfide
Section View Section ViewSection ViewPlanView
Huili group quartziteHuili group limestoneFault
High grade massive sulfideDissemintated sulfideDiabaseFault
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Noril’skPanoramic view from Bear’s Brook towards north
Photograph: Peter Lightfoot, 2002
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Distribution of Siberian Trap Basalts
Crustally-contaminated andNi-Cu-PGE-depletedbasalts
Stratigraphic equivalent ofLow Talnakh Type Intrusions
Stratigraphic equivalentof Talnakh Type Intrusions
~3500m
Ivakinsky
Syverminsky
GudchikhinskyKhakhanchansky
Tuklonsky
NadezhdinskyNd3
Nd2
Nd1
Morongovsky
Mokulaevsky
Kharaelakhsky
Kumginsky
Samoedsky Tholeiitic basaltsPicrictic basaltsAlkalic and sub-alkalic basalts
KHARAELAKHINTRUSION
TALNAKHINTRUSION
50km
Basalt trapSedimentary rocks
Isopach map thickness ofNadezhdinsky Formationbasalts (in meters)
Economically mineralizedintrusions projected tosurface
Naldrett et al (1995)
OmskNovosibirsk
Kara Sea
MongoliaKazakhstan
Russia
Noril’sk
Margin ofSiberianShield
West SiberianLowlands
Siberian Trap basaltWest Siberian basalts
www.largeigneousprovinces.org/LOM.html
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Stratigraphy of the Noril’sk Region
Ivakinsky suiteP ivUpper
Permian
Mid
dle
Car
boni
fero
us-Lo
wer
Per
mia
n
UpperDevonian
MiddleDevonian
LowerDevonian
UpperSilurian
96 - 105
50 - 100
30 - 90
110 - 140
62 - 85
110 - 150
110 - 210
12 - 40
2 - 80
140 - 180
280 - 330
80 - 140m2
D kl3
D nk3
D jk2
C -P2 2Tungusskaya series
Kalargonskyformation
Nakokhozskyformation
Yuktinsky formation
Manturovskyformation
Razvedochninskyformation
Kureysky formation
Zubovsky formation
Khrebtovsky formation
Yampakhtinskyformation
Postichny formation
D mt1-2
D rz1
D kr1
D zb1
D hr1
D jm1
S ps2
Noril’skIntrusion
KharaelakhIntrusion
TalnakhIntrusion
Low
Taln
akh
Intr
usio
nLo
w N
oril
’sk
Intr
usio
n
Period and Unit Basalt Formationor Series
Thickness(m)
RockTypes Stratigraphic Position of Intrusion
CoalConglomerateSandstoneSiltstoneArgilliteMarl
LimestoneDolomitic marlDolomiteAnhydriteSalt (NaCl) & Breccia
Low Noril’skIntrusion
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Morphology of the Talnakh and Kharaelakhchonoliths
1000
500
0
(m)
0 1km
SkalistyMine
GlubokyMine
TaimyrskMine
OktyabryskMine
EW
Kharaelakh Intrusion
Noril’sk-KharaelakhFault
TalnakhIntrusion
Siberian Trap basalt
Permian sedimentary rocksDevonian sedimentary rocks(including evaporites and shales)Kharaelakh and TalnakhIntrusions and their apophyses
Massive sulphide
Low Talnakh Intrusion
Faults
1 km
E
W
KHARAELAKHINTRUSION
TALNAKHINTRUSIONNE BRANCH
TALNAKHINTRUSION
SW BRANCH
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Skalisty and Gluboky Mines, Talnakh and Kharaelakh Intrusion: North-facing Section
Intrusion
Noril’skKharaelakhFault zone
GlubokyDeposit
KharaelakhIntrusion
Surface
SkalistyDeposit1500 m
0 m
250m
Talnakh
West EastSiberian Trap basaltCarboniferous and Permiansedimentary rocksDevonian sedimentary rocksIntrusionsNi-rich sulphideFault zone
Lightfoot and Evans-Lamswood (2014)
TalnakhIntrusion
NE Branch
KharaelakhIntrusion
SectionLine
TalnakhIntrusion
SW Branch1
km
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Morphology of the Low Talnakh chonolith
2.5 km
<40m
Thickness of the Low Talnakh Intrusion
40 - <80m
80 - <120m
< = 120m
Anticline, syncline
Projected position ofKharaelakh Intrusion
Central graben structure
Noril’sk – Kharaelakh fault
A
29
Morphology of the Kharaelakh chonolith
2km
25 100 150 250m
Contact betweenKharaelakh Intrusion andLowTalnakh Intrusion
2km
Thickness of massivesulfide orebodies nearlower contact
0 20m 40m
Contact betweenKharaelakh Intrusionand lowTalnakh Intrusion
B C
Thickness of Kharaelakhintrusion
Lower Talnakh intrusionthickness >40 m
Margin of the Intrusionwhere thickness <50m
Noril’sk – Kharaelakh fault
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Geology of the Voisey’s Bay Deposit
Voisey’s Bay2 km
AshleyIntrusion
WesternDeeps
Chamber
Reid BrookDyke
Eastern DeepsChamber
Ovoid
568000E556000E544000E62
3700
0N62
4500
0N
Makhavinekh Lake GraniteSuiteVoisey’s Bay Granite SuiteAnorthosite SuitesMushuau IntrusionOutcrop of VBISubsurface extent of VBIChurchill ParagneissEnderbite OrthogneissArchean GneissRegional FaultsSection LineOre deposits
Y
X
100km
GREENLANDLABRADOR
Voisey’s Bay
Nain Plutonic SuiteGardar IntrusionsOrthogneissParagneiss
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Geology of the Voisey’s Bay Deposit
Makhavinekh Lake GraniteSuiteVoisey’s Bay Granite SuiteAnorthosite SuitesMushuau IntrusionVoisey’s Bay IntrusionSubsurface extent of VBI
400m
200
0
-200
-400
-600
-800
3400
N
3600
N
3800
N
4000
N
4200
N
4400
N
4600
N
4800
N
5000
N
5200
N
5400
N
North ofEastern Deeps
Zone
EasternDeepsDeposit
FeederConduitGneiss
Lip
Depth(m)
VB95-266 VB95-194 Weakly - mineralized VTTHeavily - mineralized VTTSemi-massive sulfideMassive sulfide
A B
Section View
GneissWall
EasternDeeps
Churchill ParagneissEnderbite OrthogneissArchean GneissRegional FaultsSection LineOre deposits
Y
Eastern Deeps Intrusion
Western DeepsIntrusion
0m
500m
1000m
1000m
X
Reid BrookZone
EasternDeeps
Ovoid
Southeast Extension ZoneOvoid DepositDiscovery Hill ZoneReid Brook Zone
DykeEastern Deeps IntrusionNorth Eastern Deeps ZoneEastern Deeps Deposit
Long Section ViewFrom Lightfoot & Evans Lamswood (2012)
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Voisey’s Bay: Drill rig on Eastern Deeps, 1997
Photograph: Peter Lightfoot, 1997
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Geological relationships in the OvoidC
Northing(m)
OvoidDeposit
Line55985E
SoutheasternExtensionDeposit Southeastern
ExtensionDyke
Ovoid
5000
4800
VB95-010 VB95-014
Northing(m)
Ovoid DepositVB95-013
Line55945E
OvoidDyke
SoutheasternExtensionDyke
4800
4200
Northing(m)
SoutheasternExtensionZone
EasternDeepsChamber
Easternendof OvoidDeposit
OvoidDyke
Line56044E
EasternDeepsDyke
Elev
(m)
4250
0
4300
0
4280
0
4330
0
Elev
(m)
5000
4800
Elev
(m)
4250
0
4300
0
A
B
Lightfoot et al (2011)
0 1000
Threewest-facing sections
ABC D
Massive SulphideEnderbitic Orthogneiss
OverburdenDyke Mafic RocksDisseminated Sulphide
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Ovoid Deposit
35
Geology of the Reid Brook Zone
Contactdip 45°
20° to 50°
45° plungeof mineral zone
Mini-Ovoid
Ovoid
Mafic EnderbiteFelsic EnderbiteChurchill paragneiss
Leopard troctoliteMassive sulfide
Troctolite
Variable troctolite with heavydisseminated sulfide
FaultsPlunge of mineral zone
Ferrogabbro
500 m
Granite
Tasiuyak Gneiss
W E
Evidence for syn-magmaticdextral transtension1. Displaced contacts2. Magnetic fabric3. Morphology of intrusion4. Shear zones with granite5. Fabric of gneiss rotated into
north wall of Eastern DeepsFrom Lightfoot & Evans Lamswood (2012)
53700 E
Line
of s
ectio
n
36
Reid Brook Zone: 53700E Section – Looking West
2.43, 1.1933
VB-12-941B
Western DeepsIntrusion
VB-05-653VB-07-8272.64, 1.11
35 2.76, 1.0626
0 m
100 m
200 m
300 m
400 m
500 m
600 m
700 m
Rapakivi Granite
Massive SulphideSulphide
Troctolite
Host Rock
Overburden
Garnetiferous ParagneissParagneiss / Quartz Paragneiss
FaultHistoric Drilling
Troctolite
Amphibolite
Breccia
Mineralized Troctolite
Granite / Pegmatitic
Leopard Textured Troctolite
Troctolite Chamber
% Ni, % Cucore meters
Reid BrookDyke
Section prepared byDanny Mulrooneyand Sheldon Pittman
100 m
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Leapfrog model showing Ni grade distribution in the Reid Brook Zone projected onto W-E long section
Model prepared byLisa Gibson
Discovery Hill zone
Mini-Ovoid
Reid Brook zone
Mineralization in paragneisscontrolled by structureplunging ~10° East.
Mineralization in dykecontrolled by chonolithplunging ~45° East.
Top of WesternDeeps Chamber
Isosurface Ni>0.5wt%Isosurface Ni>1wt%Isosurface Ni>1.5wt%Isosurface Ni>2wt%Trend of mineral system
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Kinematics: Summary for Voisey’s Bay
From Lightfoot & Evans Lamswood (2012)
3D model:rotational movementon a “scissor” fault
3D modelnegative flower structureon dextral strike-slip fault withrotational movement to createspace for Eastern Deeps chamber
Offset
Offset
Pivot OffsetPosition ofReid BrookDyke
Position of Eastern DeepsChamber
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A Model for Voisey’s Bay: Compressed into a single N-S section
Floating blocksof Gneiss
WesternDeeps
SulphidicParagneiss
Red Dog
EasternDeeps
Mini-Ovoid
Disco Hill
LowerReidBrookZone
NED
Ovoid
UpperReidBrookZone
Lightfoot et al (2011)
Massive Sulphide and BrecciaAssemblage Sulphides
Tasiuyak Gneiss
Variable Troctolite with Sulphide
Troctolite Olivine Gabbro
Churchill Enderbitic OrthogneissSulphidic Paragneiss
Nain OrthogneissFaults with direction ofdisplacement
Detailed area shown in inset
Direction of emplacement
Known (above);proposed model (below)
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Summary• Magmatic Ni-Cu-(PGE) sulphide ore bodies: often not the product of
simple in-situ gravity settling within a magma chamber. • Sulphide-laden magma ascended through a sub-vertical conduit
system in a structural zone from a parental source/chamber at depth.• Common theme now recognised in a spectrum of Ni sulphide ore
deposits that underpin process models for their formation– Funnel-shaped intrusions– Chonoliths– Dykes
• Conduit morphology is controlled through the intersection of regional structures that create space, and are localized by dilations and traps created by transtension in strike-slip fault zones:
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Global Examples of magma conduits (red – this talk):
• FUNNEL MORPHOLOGY: Jinchuan, Hong Qi Ling #1, Jingbulake, Huangshan, Huangshandong, Limahe, Qingquanshan, Lengshuiqing, Zhubu, Ban Phuc, Ovoid, Discovery Hill, Eastern Deeps, Eagle, Double Eagle, Aguablanca, Maksut, Santa Rita, Suwar, Savanah, South Raglan
• PIPE (CHONOLITH) MORPHOLOGY: Baimazhai, Tongdongzi, Talnakh, Kharaelakh, Noril’sk I, Karatungk, Noril’sk II, Chernagorsk, Maslovskoe, Tamarack, Current Lake, Babel-Nebo, Nkomati, Limoeiro, Chibasong, Wellgreen, Voronezh, Zhouan, Xiarihamu
• DYKE MORPHOLOGY: Reid Brook, NED, Worthington (Sudbury), Copper Cliff (Sudbury), Hong Qi Ling #7, Tong Dong Zi
Controls on emplacement and morphology of komatiites (Yilgarn, Thompson, Pechenga, and Raglan) may also share primary structural controls.
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Thank You:Graphic design: Alex Gagnon
Dawn-Evans LamswoodRogerio MonteiroIan FieldhouseLisa Gibson
Danny MulrooneySheldon PittmanVivian FengIgor Zotov