% Illile in Illite / Smecfite
o
20 /.o
60
BO Ioo
o
3
(U
Q
&
|
I
i
-,'o
-~
-,'o
6 D ( % . ) sMow
-'io
vm
Fig. 6.8. 8D and percent illite as a function of depth. (Yeh 1980)
E ~- 3
te~
A <0.1
b
:.
4
~....~
i
l
g
!
,d
>
C("" Whole rock
d
f /
.p
i
t
i
.
i
i
l
l
J
|
9
,
9
i
i
0
20
40
6O
J0
100 120 lz~
Age (Ma)
20
8O
Illile (%)
6 Isotope Geochemistry of Clay Minerals 165
Fig. 6.9. Depth dependence of K-Ar ages. (Aronson and Hower 1976)