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Phaseequilibriaconstraintsanddynamicsofmagmadifferentiationinsmalltolargemagmachambers

CONFERENCEPAPER·AUGUST2014

DOI:10.13140/RG.2.1.4231.7523

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5AUTHORS,INCLUDING:

AlexeyAriskin

LomonosovMoscowStateUniversity

136PUBLICATIONS970CITATIONS

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GalinaBarmina

RussianAcademyofSciences

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Availablefrom:AlexeyAriskin

Retrievedon:03February2016

Phase equilibria constraints and

dynamics of magma differentiation in small to large magma chambers

Alexey Ariskin1,

Galina Barmina1, Evgeny Koptev-Dvornikov2,

Egor Nikolaev1, Alexey Yaroshevsky2

1 Vernadsky Institute, Moscow, Russia2 Department of Geochemistry, Moscow

State University, Russia

Frenkel et al. (1988) Dynamics of intra-chamber differentiation of mafic magmas, 216 p.

Ariskin&Barmina(2000) Modeling phase equilibria at crystallization of basaltic magmas, 363 p.

1. Fundamentals of magma differentiation and

subordinate role of diffusive processes

2. Modeling solidification and crystal settling in

magma chambers

3. Significance of the buoyancy-driven convection

and crystal-rich suspension currents

4. The Convection-Accumulation Model

5. Development of COMAGMAT model and its

capabilty to calculate the structure of layered

intrusions

6. Main results for differentiated sills from the

Siberian platform

7. Examples for large layered intrusions

Plan of talk

Prehistory and methodology

Mike Frenkel

Alexey

Yaroshevsky

1978

Development of magma

differentiation models

Petrological and

geochemical studies of

mafic to ultramafic

layered intrusions

1. Genetic interpretation of

the natural obsertvations

vs. the modeling results

2. Updating the model

proposed

Tabular intrusions as an initial target

for the modeling

Country rocks

Country rocksHeat flux out

Magma (melt + suspended crystals)

Temperature or compositional convection?

In situ crystallization?

Crystal settling?

Mixed processes !?

Magmatic melt only?

Heat flux out

Fundamentals of the in situ crystallization

concept (Jackson, 1961)

Country rocks

Country rocks

Heat flux out

Bartlett’s temperature convection

Heat flux out

Heat flux out

Heat flux out

Boundary layer

Temperature convection

Temperature

dTliq /dP

Adiab

ate

Magmatic melt

Solid rock

The diffusive flows vs. the thermal flux

Magma body

Solid rock

Hot Cold

by Fourier’s low the thermal flux JQ=∂Q/∂t =-κρС (∂T/∂z)

Z

Transitional

zone

JQ > 0

Mg-rich melt Mg-depleted melt

Fe-depleted melt Fe-rich melt

by Fick’s low the diffusive flow Ii = -Di (∂Ci /∂z)

JQ> 0

Ii 0<>

Subordinate role of diffusion-driven processes

Ii = -Di (∂Ci /∂z), the diffusivity Di ∼∼∼∼10-10 – 10-15m2/s

JQ= ∂Q/∂t =-κρС (∂T/∂z), where C is the specific heat

and the thermal diffusivity κκκκ ∼∼∼∼10-6 – 10-7m2/s

Ii ∼∼∼∼ ki JQ , where ki ≈≈≈≈ 10-7 mole/cal !!!

Magma chambers are to cool and to crystallize

much faster than any significant effect of

diffusion can occur!

Subordinate role of diffusion

“On the relevant time scale, diffusion could be effective over distances no greater than a few centimeters”!

The Geological Society of America, Inc.

Memoir 132

1972

Heat and Mass Transport During

Crystallization of the Stillwater

Igneous Complex

G. B. Hess

The “Crystal-Settling Model” (1976-1979)

Boundary layer

JQU (t1)

JQL (t1)

Boundary layer

Solid rock

JQU (t2)

JQL (t2)

Time (t)

The main processes:

� Conductive cooling

� Crystallization in

boundary layers

� Formation of

chilled zones

� Heat transfer

through the magma

� Stokes’s crystal

settling

� Accumulation of

the crystals

� Cooling the

cumulate pile

� Motion of fronts of

solidification

A simplified phase diagram for basalts

This diagram was used at the development of the first “Crystal settling model”

After Bowen

The cornerstone of the proposed algorithm

Initial profile of

the temperature

Homoge-neous

Magma

Time t=t0

Country rocks

TMagma=1200oC

Tcr=25oC

200 m thick

Qin Olout Plout Pxout

Qout Olin Plin Pxin

Qin Olout Plout Pxout

Layer 1: ∆∆∆∆H, ToC, amounts

of melt & solid minerals

Layer 2: ∆∆∆∆H, ToC, amounts

of melt & solid minerals

Phase composition of the modelled “magma

layers” vs. their temperature distribution

Initial m

agma temperature

Homoge-neous

Magma

Country rocks

200 m thick

Solid

Solid

Current time t+∆∆∆∆t

Temp

Hetero-geneous

Magma

t=t0 t=t+∆t

The fundamental time-dependent structure:

Tabulating card to run

the program

BESM-6 at the Computer center of

the Russian Academy of Sciences

1977

Homogeneous magmatic melt

Height, m

Crystal-laden magma

(no stirring)Cumulate piles

Solidified rocks

Solidified rocks

Sandwich horizon !?

∼∼∼∼100 years ∼∼∼∼300 years The Crystal Settling

Model (CSM)

Distribution of minerals along the section of the

modeled intrusion: Crystal-Settling Model

Height, m

Mineral composition of modelled rocks, vol.%

The starting composition: 50 mole % Pl, 43% Px, 7% Ol;

the liquidus temperature is 1179°C;

the rates of crystal settling are: Pl 0.4 m/yr, Px 4.0 m/yr, Ol 7.6 m/yr

Anorthosite

Upper reversal

Lower reversal

Studies of differentiated sills

from the Siberian Platform

Anabar Shield

Aldan-Stanovoy

Shield

Podkanennaya Tunguska River

Lake Baikal

Siberian Craton

Norilsk

Province

Angara River

YeniseiRiver

Lena River

Vilyi River

Boating over rapids

of the Vilyi River

Podkamennaya Tunguska River

Siberian sills

49.4349.9249.4849.41SiO2

0.12

0.24

1.86

12.38

8.68

0.26

10.37

15.80

0.88

V304, 160 m

Vilyi River

0.13

0.35

2.12

11.77

7.86

0.28

11.00

15.85

1.16

Vavukan, 100 m

0.15

0.61

2.09

10.51

8.98

0.18

11.32

15.08

1.16

Kuzmovka, 90 m

Podkamennaya

Tunguska RiverLocation Average flood basalt

(Kutolin, 1972)Sill

TiO2 1.51

Al2O3 15.67

FeO 12.88MnO 0.19

MgO 6.31CaO 10.91

Na2O 2.22

K2O 0.75

P2O5 0.13

Comparison of results of the CSM modellingand the structure of the Siberian sills

1.0

0.5

0.0

Relative height

Olivine, %

10 20 30 10 20 30 10 20 30

Model B304 Vavukan KuzmovkaH=200 m 160 m 100 m 90 m

The origin of convective currents

in magma chambers

Heat loss

Bartlett’s temperature convection

Heat loss

Probable crystal distribution

near the solidification front

(Frenkel et al., 1976)

Boundary layer

Compositional convection in heterogeneous

magma

Solidified rocks

Cite (Hess, H., 1960. Stillwater Igneous Complex, Montana.

Geol. Soc. Amer. Memoir 80, 230 p.)

“… a layer of liquid might develop

below the roof which by loss of heat

and impregnation by crystals became

denser than the underlying liquid.

Although mechanically unstable it might develop

and remain in this position for a time”.

“Eventually overturn of the unstable mass of

liquid will occur. …some inhomogeneity in the

layer would cause it to get started at one point

first”.

“A downward bulge would form, the nose of

which would accelerate rapidly.

The velosity would be enormously greater

than the settling of crystals”.

“Light” magma

Hydrodynamic modelling of the buoyancy-driven

magma convection

(Trubitsyn, Kharybin, 1997)

A B

“Light” liquid “Light” liquid

Dense liquid Dense liquid

Assume isothermal process:

A High Vs-values at the

sedimentation Rayleigh

number Rs=10 < Ra (crit),

B Lower Vs-values at the

sedimentation Rayleigh

number Rs=1000 > Ra (crit),

Ra (crit) is the critical Rayleigh

number.

Z=h/ho is the relative height

where ho is the total thickness

of the layer of a “magmatic

melt”

Important issues from the scenario

1. The cooling-dependent structure of the boundary layers suggests time dependence, with the periods of the origin of the layers and their destruction.

Solidified rocks

2. Relatively short cycles of catastrophic sedimentation and convection should be repeated, probably becoming longer and dying out with time.

3. These processes promote a highly chaotic vigorous convection in the

chamber, including downward crystal-rich and upward crystal-

depleted convective currents.

4. The motions of the crystal-rich suspensions are the powerful mechanism of the large-scale transfer of the crystallized material

towards lower parts of the magma chamber.

Dynamics of the “Convection-Accumulation Model”

(CAM), the scheme from Frenkel et al. (1988)

Solidified rocks

Solidified rocks

Timet=0

Depth

z=0

Z

∂z /∂t = VStokes

Individual crystals

Country rocks

Sedimentation flows

∂z /∂t = VSed

VSed>> VStokes

Lines are the assumed trajectories of the settled/sedimentated crystals!

Uniform distribution of the magma composition

and its temperature assumed in the CAM model

Solid

Solid

Current time t1

Hetero-geneous

Magma

Ol +

melt

Solid

Solid Solid

Ol+Pl

+ melt

Solid

T2 <T1

Temp Temp

Time t2 = t1+∆∆∆∆t

T1

The fundamental time-dependent structure:

Height, m

Crystal-laden magma

The Convection-Accumulation Model

Cumulate piles

Solidified rocks

Solidified rocks

∼∼∼∼80 years ∼∼∼∼250 years

Crystal-laden magma

(assuming large –

scale stirring)

Homogeneous magmatic melt

Distribution of minerals along the section of

the modeled intrusion:

Height, m

Mineral composition of modelled rocks, vol.%Chilled Zone

The Convection-Accumulation Model (1976-1979)

Lower reversal

Chilled Zone

Upper reversal

Towards modeling the geochemical and

cumulate structure of differentiated sills:

1984–1989

Development of

the COMAGMAT model

simulating magma

crystallization processes

Construction of

the INTRUSION model

combining phase equilibria

calculations with those by the

Convection-Accumulation Model

Development of

the “Dynamics” algorithm

approximating the heat-mass

transfer in magma chambers

Mike Frenkel and Alexey Ariskin, Vernadsky institute, 1978

The empirical basis of the COMAGMAT model

1000 1100 1200 1300

1000

1100

1200

1300

T, °C

(exp)

1000 1100 1200 1300

(n=87) (n=95)

Ol-melt Pl-melt

r=0.970 r=0.937

1000 1100 1200 1300

T, °C (calc)

1000

1100

1200

1300

T, °C

(exp)

1000 1100 1200 1300

T, °C (calc)

Aug-melt Pig-melt(n=68) (n=17)

r=0.903 r=0.983

Mineral Comp Calibrated equations n Ref

Ol Fo ln K = 5543 / T - 2.32 + 0.210ln (Al/Si) 67 Ariskin et

Fa ln K = 6547 / T - 4.22 + 0.084ln (Al/Si) al., 1993

Pl An ln K = 10641 / T - 1.32 + 0.369ln R 58 Ariskin &

Ab ln K = 11683 / T – 6.16 - 0.119ln R Barmina,

1990

Aug En ln K = 8521 / T - 5.16 25 Ariskin et

Fs ln K = 13535 / T – 9.87 al., 1987

Wo ln K = 2408 / T – 1.24

Al01.5 D = 0.20

Pig En ln K = 8502 / T – 4.74 18 Ariskin et

Fs ln K = 5865 / T – 4.04 al., 1987

Wo ln K = 4371 / T – 4.02

AlO1.5 D = 0.10

Opx En ln K = 7208 / T – 3.71 39 [Bolikhov-

Fs ln K = 6386 / T – 4.39 skaya et

Wo ln K = 11950 / T – 10.40 al., 1996]

AlO1.5 D = 0.10

Notes. R = ln [(Na + K) Al / Si 2].

Mineral-melt geothermometers

calibrated in 1987-1996

Experimental vs. modelled

temperatures

Modelled vs. experimental data

Comments to the INTRUSION model

driven by difference in density between crystal-

enriched and crystal-depleted suspensions

(Trubitsyn, Kharybin, 1997)

The program calculates:

1. magma crystallization,

2. cooling of the magma body,

3. dynamics of downward transport of the near-roof crystallized material,

4. the motions of fronts of the in situ crystallization and crystal accumulation

5. original proportions of cumulate minerals and intercumuls melt,

6. bulk rock compositions for major and trace elements,

7. structure of upper and lower reversals responsible for the S-shaped profiles

Input parameters of the INTRUSION model

Oxygen fugacity (log fO2):

buffered or closed with respect to

oxygen system

Pressure (kbar):

isobaric or polybaric crystallization

Amount of intratelluric crystals

suspended in the parental magma,

wt%

Bulk composition of the parental

magma:

major+trace element contents, wt%

Thickness of the modelled

intrusion, meters

Properties of country rocks:

density, heat conduction, and heat

capacity

Magma properties:

density, heat conduction and heat

capacity (are variable)

The efficient rate of the convective

transport for each mineral, m/year :

Oliv, Plag, Augite, Pig/Opx, Ilm, Magn

Maximum fraction of accumulated

crystals (=minimum porosity):

both for upper and lower front

The boundary temperature:

as the initial thermal difference

between magma and country rocks

Comparisons of the modelled and observed

structure of the Siberian sillsFrenkel et al. (1988) Dynamics of intra-chamber differentiation of mafic magmas, 216 p.

Kuzmovka

VavukanB304

Structure of the Vavukan intrusion

Height, m

Poikilophitic

dolerite

Upper Zone

Lower inner-contact

Taxitophitic

dolerite

Gabbrodolerite

100

0

Ferro-gabbro

Cpx

Ol

OlMt

Pl

Cpx

Ol

Microdolerite

The modelled vs. observed structure of the

Vavukan intrusion (h=100 m, Vilyi River)

Ol – 20 m/year

Pl – 10 m/year

Cpx – 100 m/year

Velocities of sedimentation:

≤≤≤≤2.5%Intratelluric crystals

Ol+Pl at 1210oCParental magma

Original proportions of cumulate minerals

and amounts of crystals suspended in residual magmas

of the Vavukan chamber

0 10 20 30

Suspended crystals,%

0 10 20 30 40 50 60

Accumulated minerals, %

0

20

40

60

80

100

Height, meters

"Cumulate" rocks Residual magmas

Oliv Augite Plag SUM Ol Aug Plag SUM

Interpretation of WR geochemistry: Ni

OPTIMUM DYNAMIC MODEL

0 10 20 30

Cumulus Ol, %

0 100 200 300 400

Ni, ppm

WR modeledObserved

Ol+Pl, Lower

Reversal

Ol+Pl+Cpx±± ±±Mt

cumulates

100

80

60

40

20

0 m

Max fractionated

Oliv

Ni

Cum

Oliv

J

j

j

Ni

Cum

j

m

Nimelt

WR

Ni CfCfCfC ∑=

≈+=1

Upper Zone

Chilled rocks

Interpretation of WR geochemistry: Cr

Ol+Pl, Lower

Reversal

Ol+Pl+Cpx±± ±±Mt

cumulates

100

80

60

40

20

0 m

Max fractionated

OPTIMUM DYNAMIC MODEL

0 10 20 30

Cumulus Cpx, %

0 200 400 600 800

Cr, ppm

WR modeledObserved

Cpx

Cr

Cum

Cpx

J

j

j

Cr

Cum

j

m

Crmelt

WR

Cr CfCfCfC ∑=

≈+=1

Upper Zone

Chilled rocks

Interpretation of WR geochemistry: V

Ol+Pl, Lower

Reversal

Ol+Pl+Cpx±± ±±Mt

cumulates

100

80

60

40

20

0 m

Max fractionated

m

Vimelt

J

j

j

V

Cum

j

m

Vmelt

WR

V CfCfCfC ∑=

≈+=1

OPTIMUM DYNAMIC MODEL

40 60 80 100

Original porosity, %

100 200 300 400 500

V, ppm

WR modeledObserved

Chilled rocks

Upper Zone

Other attempts to develop a dynamic model

simulating the spatial structure of mafic intrusions

Criticism of the Convection-Accumulation Model

Geology, 2012, v. 40. p. 883-886.

Mode % (vol) MgO % (wt) Mg number % (mol) Ni (ppm) An content in Pl % (at)

Rims

Cores

Criticism of the Convection-Accumulation Model

MODELING: MgO(WR) Mg#(WR) Ni(WR)

An (intercum) An (liquidus)

An80

Microdolerite VV-138 from the chilled zone

1 mm

Modeling large layered intrusions:

The Kivakka intrusion (Karelia, Russia)

After Bychkova et al. (2007)

Olivinite

Norite

Gabbronorite

Pig-Gabbronorite

Interlayering

of norites and

bronzitites

H, m Ol Opx Pl Cpx Pig

Modeling large layered intrusions:

The Kivakka intrusion (Karelia, Russia)

Relative height

Lines – forward modeling by CAM

Normative composition, %

Whole-rock compositions, wt%

Small circles –observed

WR compositions

After Koptev-Dvornikov

(2012):

assumed pressure 2.6 kbar

Modeling large layered intrusions:

The Tsipringa intrusion (Karelia, Russia)Relative height

Normative composition, %

Whole-rock compositions, wt%

After Koptev-Dvornikov

(2012):

assumed pressure 5 kbar

SCSS

S in melt

Modeling the first sulfide-poor horizon

wt%

Lines – forward modeling by

CAM

Small circles– observed WR

compositions

BASIC CONCLUSIONS

1. The diffusion-driven processes can not result in any essential magma differentiation.

2. Only gravity-induced mechanisms can provoke an efficient transport of the crystallized material towards the lower parts of the magma chamber.

3. The role of in-situ crystallization is of two kinds. It is dominated at the earliest stages of solidification, whereas during the main course of solidification it is of a subordinate importance.

4. The S-shaped profiles are formed as a response of the crystallizing magma to the downward transport of solids, independently of the physical mechanism of their transfer.

5. The Convection-Accumulation theory describes quantitatively both the spatial structure and geochemistry of many layered intrusions, solidified as closed magma chambers.

CONCLUDING REMARKS

Our approach includes the contact crystallization

as an important component of phase equilibria

and thermal calculations.

1. Crystal settling vs. in situ crystallization

2. Other probable convection styles

The Convection-Accumulation Model does not

account for the compaction of cumulates, and the

compositional convection that could be induced

by pressing-out the intercumulus liquid upward

the cumulate pile.

CONCLUDING REMARKS

M.Ya. Frenkel(1943-1993)

M.Ya. Frenkel (1994)

THERMAL AND CHEMICAL DYNAMICS OF DIFFERENTIATION OF BASITE MAGMAS, 216 p.

“Whereas, the convective styles

themselves depend upon the

thermal field in which the intrusive

bodies began to solidify and

evolved”.

“The observed diversity of the structures of

layered intrusions is essentially the record

of an overprinting of several convection

styles occurred in the magma chambers”

Thermal fields as leading factor

Magma

“Cold” rocks(sediments)

T1

T2

∆T≈ 1200oC

(1) Siberian sills (2) Duluth, Dovyren (3) Sudbury IC?

MagmaMagma

∆T≈ 500oC

∆T ≈ 700-800oC “Warm” volcanics

Underlying “hot”intrusions

∆T < 0oC !

“Very hot” impact melt

“Cold” mafics of the Huron group ?

∆T≈ 1000oC

Sedimentation flows &

in situ crystallization →→→→implicit “orthocumulates”

Vigorous convection in chamber

and compositional convection in

cumultate pile →→→→ classic

orthocumulates and adcumulates

Mostly bottom in situ

crystallization →→→→implicit “orthocumulates”

Thank you for your attentionThank you for your attention

Podkamennaya Tunguska River. Podkamennaya Tunguska River.

Trap province of Eastern Siberia.Trap province of Eastern Siberia.

Geochemistry of CPX-oikocrysts in the rocks

from the Vavukan intrusionHeight, m

Poikilo-

phitic

dolerite

UZone

Gabbro-

dolerite

100

0After Koptev-Dvornikov et al. (1996): Evidence for the cumulate origin of clynopyroxene and for reequilibration of olivine in Vavukan-

Sill dolerites. Geochem. Intern., 33 (1), p. 81-102.

Contact

Taxitophi-

tic dolerite

Cr2O3, wt%

Cr2O3, wt%

Cr2O3, wt%

Fs, mole%

Fs, mole%

Fs, mole%

7.8 mm 7.8 mm

4.2 mm 4.2 mm

5.0 mm 5.0 mm

Cumulus Cpx

Intercumulus Cpx

Example of the CAM-theory: describe Ni

OPTIMUM DYNAMIC MODEL

0 10 20 30

Cumulus Ol, %

0 100 200 300 400

Ni, ppm

WR modeledObserved

)/1( SF

sed

Ol

magma

Ol

cum

Ol VVff −=

)/1( AF

sed

Ol

magma

Ol

cum

Ol VVff −=

)/(1

magma

m

j

crit

cum

sed

j

mag

jAF FFVfV ∑=

−=

Accumulation Front (AF):

Solidification Front (SF):

∑=

=m

j

magma

jmagma fF1

Suspended

phases

Lower crossover

VSF=Func (heat flux, JQ )Ol

Ni

cum

Ol

m

Nimelt

WR

Ni CfCfC +=

Cpx

Ni

cum

Cpx

Ol

Ni

cum

Ol

m

Nimelt

WR

Ni CfCfCfC ++=

Apparent absence of An80 in microdolerites?Ol+Pl

Ol+Pl+Cpx±± ±±Mt

Max fractionated

Chilled rocks

Upper Zone

Aspect ratio = Pl (WR) / Pl (cumulus)

40 50 60 70 801 10 1000 20 40 60

WR

Inter-

cumulus

Pl inmelt

Pl incumulus

WR

Pl mode (vol%) Aspect ratio An in Pl (mole%)

Pl-cum

Original proportions of cumulate minerals:

Forward vs. Inverse Modeling Results

0 10 20 30

Suspended crystals,%

0 10 20 30 40 50 60

Accumulated minerals, %

0

20

40

60

80

100

Height, meters

"Cumulate" rocks Residual magmas

Oliv Augite Plag SUM Ol Aug Plag SUM

Inverse COMAGMAT modeling

Cumulus minerals

/ Total (magma/cumulate)

S-shaped profile

due to the

“compositional

convection”?

FIG. 9. The “predictions” of the differentiation model are shown for the stratigraphic profiles of chemical compositions of the rocks:

(a) A refractory major element, (b) a highly incompatible trace element.

1. This is just a speculativescenario, proposed to describe the origin of the lower crossover

2. Note, in our model we did not try to describe the origin of the lower crossover. It was obtained automatically, as late as crystal settling was included in the dynamic calculations.

3. However, the proposed compositional convection and transport of fluids inside the cumulate pile is a valuable mechanism that can explain the formation of adcumulate rocks.

The “tear-droplike” magma suspension flows

Boundary layer

Сrystal accumulation

Solidified rocks

Heterogeneous magma

Cumulate pile

Recent modeling crystal

settling vs. convection

Figure 8. Typical (top) temperature and (middle) concentration profiles and the corresponding snapshots of a final state C regime. The particle-driven flow dominates the thermally driven flow. Most particles sink to the ground.

Figure 9. The packing of the particles in a Cregime isalmost a close packing of spheres.

The order isperturbed by upwelling hot plumes.

The C regime is characterized by particle-driven convection which leads to a segregation of the particles.

The bottom “sediment layer” is warm and mainly consists of all or most particles.

The top “suspension layer” is cold and has few or no particles in suspension.

Above the sediment layer there are someparticles which are still in the settling process.

New SCSS model and modeling sulfide immiscibility

in layered intrusions, see Koptev-Dvornikov et al. (2012)

Petrology, 2012, 20 (5), p. 450-466

ReferencesMonographs

Frenkel, M.Ya., Yaroshevsky, A. A., Ariskin, A.A., et al. (1988) Dynamics of in situ differentiation of

basic magmas, Moscow: Nauka, 216 p. (in Russian)

Ariskin, A.A. and Barmina, G.S. (2000)Modeling phase equilibria at crystallization of basalt magmas,

Moscow: Nauka, 363 p. (in Russian)

Papers

Ariskin, A.A. (1999) Phase equilibria modeling in igneous petrology: use of COMAGMAT model for

simulating fractionation of ferro-basaltic magmas and the genesis of high-alumina basalt, J. Volcanol.

Geotherm. Res., 90, 115-162.

Ariskin, A.A. (2003) The compositional evolution of differentiated liquids from the Skaergaard layered

series as determined by geochemical thermometry, Russian J. Earth Sci., 5 (1), 1-29.

Ariskin, A.A., and Barmina, G.S. (2004) COMAGMAT: Development of a magma crystallization model

and its petrologic applications: Geochem. Intern., 42 (Suppl.1), S1-S157.

Bychkova, Ya.V., Koptev-Dvornikov, E.V., Kononkova, N.N., and Kameneva, E.E. (2007) Composition

of rock-forming minerals in the Kivakka layered massif, northern Karelia, and systematic variations

in the chemistry of minerals in the rhythmic layering subzone: Geochem. Intern., 45 (2), 131-151.

Frenkel, M.Ya., Yaroshevsky, A. A., Ariskin, A.A., et al. (1989) Convective-cumulative model simulating

the formation process of stratified intrusions, in Magma-crust interactions and evolution, Bonin, B.,

Ed., Athens-Greece: Theophrastus Publ., pp. 3-88.

Koptev-Dvornikov, E.V., Aryaeva, N.S., and Bychkov, D.A. (2012) Equation of thermobarometer for

description of sulfide-silicate liquid immiscibility in basaltic systems: Petrology, 20, 450-466.

Trubitsyn, V.P. and Kharybin, E.V. (1997) Convection in magma chambers produced by inversion in

distribution of sinking crystals, Physics of the Solid Earth, 33, 382-386.

Variations of WR chemistry and Ol compositions

in the Camel sill (underneath the Yoko-Dovyren massif)

Fig 5.3 FeO*-MgO variation diagram. All unaltered WRanalyses lie on the olivine control line, illustrating the

compositional control by olivine (after Woolward, 2008).

Fig 4.2 Distribution of major element contents in the rocks throughout the Camel Sill section. The uniform and symmetrical patterns of patterns are consistent with the abundance of olivine (after Woolward, 2008).

Fo80

Fo82