Press to Close

Table 7. Leg 152 dacites and comparisons.



Granophyre Gneiss Exp. melt Exp. melt Exp. melt



Unit 47*
Unit 55*
Rockall
Vøring
CL87-52E**
324721
1000ēC
0.1 GPa
1000ēC
0.3 GPa***
925ēC
0.3 GPa

SiO2
60.50
64.89
64.52
63.78
74.85
63.26
64.21
60.77
75.90

TiO2
0.99
0.74
0.90
1.38
0.34
0.78
0.28
1.53
0.32

Al2O3
14.86
13.32
16.08
16.85
12.30
17.25
16.46
14.07
13.04

FeO
7.07
5.19
6.03
5.21
1.96
2.11
5.56
9.58
1.27

MnO
0.14
0.14
0.14
0.06
0.03
0.06
0.22
0.37
0.03

MgO
2.67
3.04
1.53
0.62
0.59
1.60
2.13
3.08
0.37

CaO
4.78
4.42
2.22
4.64
1.07
3.30
3.99
6.35
0.64

Na2O
4.21
3.62
2.12
2.35
3.53
3.99
4.88
2.41
2.07

K2O
1.57
2.99
2.57
1.38
4.34
3.94
1.27
0.88
6.36

P2O5
0.27
0.07
0.16
0.61
0.07
0.30

0.96

Total
97.06
98.44
96.27
96.88
99.08
96.59
100.00
100.00
100.00

Notes: * = Site 917 dacite from Fitton et al. (1998b). Unit 47 = Sample 152-917A-32R-4, 76-60 cm. Unit 55 = Sample 152-917A-51R-1, 42-45 cm. = Dacite from the Rockall trough, well 163/6-1A (Morton et al.,1988, table 4, analysis C7.1). = Dacite from the lower series at Site 642 on the Vøring Plateau (Parson et al., 1989, table 1, analysis of flow F112). ** = Granophyre component in the hybridized zone of the saddle part of the Miki Fjord macrodike (Blichert-Toft et al., 1992). = Agmatitic gneiss from the late Archean Skjoldungen alkaline igneous province, SE Greenland (Blichert-Toft et al., 1995). = Experimental melt in dehydration melting of basalt at 0.1 GPa and 1000ēC (Beard and Lofgren, 1991). *** = Experimental melt in dehydration melting of basalt at 0.3 GPa and 1000ēC (Beard and Lofgren, 1991). = Experimental melt in dehydration melting of biotite gneiss at 0.3 GPa and 925 ēC (Patiņo Douce and Beard, 1995). Iron = total FeO. The experimental melts are calculated anhydrous to 100%.

Press to Close