Geoscience Reference
In-Depth Information
Table 4.5
Lu-Hf isotopic data for basalts from
Burkina Faso
176
Lu/
177
Hf
176
Hf/
177
Hf
Sample
B44
0.0325
0.282976
B47B
0.0331
0.282992
B46
0.0209
0.282461
BN75
0.0224
0.282515
BN11A
0.0352
0.283011
BN208A
0.0667
0.284325
BN209A
0.0848
0.285037
BN263A
0.0469
0.283458
BN280B
0.0652
0.284246
Table 4.6
K-Ca isotopic data for Pikes Peak sample
PP 76-2 (Marshall and DePaolo,
1982
)
40
K/
42
Ca
40
Ca/
42
Ca
Whole-rock
0.1224
151.109
Plagioclase
0.0123
151.040
K-feldspar
0.800
151.577
Biotite
1.294
151.941
Table 4.7
U-Th activity ratios of minerals in a basaltic
andesite from the Soufrière St. Vincent in the Antilles
238
U
232
Th
230
Th
232
Th
Whole-rock
1.253
1.496
Olivine
1.089
1.183
Clinopyroxene
1.145
1.259
Plagioclase
1.136
1.244
Groundmass
1.244
1.450
Magnetic
1.230
1.458
10. Determination of the growth rate of a ferromanganese nodule from the excess of
230
Th
in different layers below the nodule surface. Plot the excesses listed in
Table 4.8
in a
semi-log diagram. Find the growth rate from the slope of the alignment.
11. Dating the oldest terrestrial zircons (Wilde
et al.
,
2001
)
.
Table 4.9
lists the
206
Pb/
238
U
and
207
Pb/
235
U ratios of four zircons from the Jack Hills conglomerate (Australia).