Investor Presentaiton
Ore chr-spinels from the podiform chromite on the discriminatory diagrams are divided into three groups and localized in the fields MORB-type (I group), supra-subduction zone
(boninites) peridotites (I, II groups), Alaskan type (III group) (a-c). Graphic plots of calculated Al2O3 composition of melts in equilibrium with Ulan-Sar'dag chromitites,
compared with spinel melt relationship for MORB (a) and Arc lavas and chromitites Alaskan type (b).
100
Fe/Fe (Crsp)
Chromites Ulan-Sardag massive
■Grl Grill Grill
Literature data from different
geodynamic setting
Cr# (Crsp)
b
1.0
☆
Boninites
☆ 4 ★ 5
* 6
0.8
II
* 7
✰ 8 * 9
10
10
11
A 12
*
13
A 14 A 15
0,6
⭑
0,4
MORB
0,2
Alaskan
type
10 TiO2 ms% (Crsp)
LIP
***
OIB A
MORB
**
Bon
0,1
ARC
IAT
ALO3 ms% (Crsp)
Mg# (Crsp)
Al2O3 ms% (Crsp)
0,0
0,1
T
0.01
0
5
10
15
20
25
30
35
40
45
50
1.0
0.8
0,6
0,4
0.2
0.0
10
20
30
40
50
dTiO, (ms%) melt
e
Al2O3 ms% (melt)
f ALO, (ms%) melt
14
1,4-
1.2.
y=4,873(lnx)-0,948
R²=0,998
20
MORB ES; Al# (21-60), Cr# (36-74), Mg# (59-84)
g (TiO2)melt
Boninite ES; Al# (14-23), Cr# (74-81), Mg# (46-63)
Alyskyn type ES; Al#13-20), Cr# (67-81), Mg# (42-50)
Literature data
MORB from Mid oceanic ridge basalt; Cr#<0,7
Back-arc basalt; Cr#<0,7
Oceanic-island basalt; Cr<0,7
Island arc, high K and calc-alcalain basalt; Cr#>0,7
lisland arc boninite and tholeite basalt; Cr>0,7
Large igneous province: Flood Basalt; Cr#>0,7
Spinel in abissal peridotites
Chromite in ophiolitic mantle high Al#
Chromite in ophiolitic mantle high Cr#
Chromitite in subcontinental mantle
Chromitite in continental layered intrusion
Chromitite in Alaskan-type complexes
2-
12
1,0-
0,8-
y-0,48(lnx)+0,42
10
R²=0.987
0,6-
0,4-
0.2
0,0-
TiO2 (ms%)sp
T
T
T
T
T
0,0
0.2
0.4
0.6
0,8
1.0
1.2
1.4
1,6
y=3,354(lnx)+2,522
R²=0,994
6
10
y-6,426(Inx)-5,513
15
R²=0,998
1.5-
Troodos boninites
MORB
Thetford boninites
0,5
ALO (ms%) sp
Boninites
Al2O3 ms% (sp)
10
20
15
20
25
30
35
40
45
50
8
(Al2O3)melt
☆
16
18
20
The chr-spinels composition of podiform chromitites, in terms of their FeO, MgO, Al2O3, TiO2 contents, is considered to function of the parental melt composition. We
estimated the Al2O3, TiO2 contents and FeO/MgO of the parental melt composition in equilibrium with the podiform chromite (table above). The chr-spineles of group I
correspond to trend (Al2O3) sp - (Al2O3) melt for MORB setting (d). The chr-spineles of group II and III correspond to trend Island arc boninites (8) Alaskan type chromitites
(15) (e). The calculated abundance TiO2 in melt is very low and do not reach (arrive) the field of MORB type. Despite the low TiO2 content, the trend of (TiO2)s
- (TiO2)melt
corresponds to this trend for MORB spinel's. It is remarkable that the ratios of (TiO2) sp/(TiO2)melt are similar to this ratio in chr-spinels from abyssal peridotites (f). Based on
calculated of abundance TiO2 and Al2O3 in melt chr-spineles of massive Ulan-Sar´dag lie in Boninitic field (g).
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