Geology Reference
In-Depth Information
0.708
(a)
(b)
0.5134
0.707
0.5132
FOZO
0.706
0.5130
0.705
0.5128
C
0.704
C
0.5126
0.703
0.5124
FOZO
0.702
0.5122
16
18
20
22
0.9
1.0
1.1
1.2
206
Pb /
204
Pb
208
Pb* /
206
Pb*
0.5134
(c)
FOZO
0.5132
C
PAC. MORB
ATLAN. MORB
INDIAN MORB
FOZO, C
HIMU
EM-1
EM-2
OTHER OIB
0.5130
0.5128
0.5126
PRIMA
0.5124
0.5122
0.702
0.704
0.706
0.708
87
Sr /
86
Sr
Figure 10.2. Isotopic data from oceanic mantle-derived rocks. Each ratio is of a
radiogenic isotope over a non-radiogenic reference isotope. EM2 is another class
of OIB. FOZO and C are proposed mean compositions. PRIMA is estimated
primitive mantle.
208
Pb
∗
and
206
Pb
∗
refer to just the radiogenic components of
these isotopes. After Hofmann [176]. Reprinted from
Nature
with permission.
Copyright Macmillan Magazines Ltd.
15.9
(a)
(b)
41
15.8
UCC
40
15.7
FOZO, C
39
15.6
UCC
LCC
38
15.5
FOZO, C
15.4
37
LCC
15.3
36
16
17
18
19
20
21
22
16
17
18
19
20
21
22
206
Pb /
204
Pb
206
Pb /
204
Pb
Figure 10.3. Lead isotopic data for oceanic mantle-derived rocks.
207
Pb is the
radiogenic daughter of
235
U,
206
Pb is from
238
U, and
208
Pb is from
232
Th. UCC
and LCC refer to the upper and lower continental crust. The
geochron
is a 4.5 Ga
isochron tied to an iron meteorite. After Hofmann [176]. Reprinted from
Nature
with permission. Copyright Macmillan Magazines Ltd.
