Reassessing Foraminiferal Stable Isotope Geochemistry
495
-0.5
B
iIi' 4
0
22"CHL
iIi'
." .
0
n"Cl-!
0
1 70C HL
0
17"C1-l
Q
•
22"CDat
Q
Q.~ . . . . . .
•
22"CDJrk
~
•
17"CDo,k
~
'o ........... Q
•
1 7"C Dark
vi 2
•
vi
~
~
0
0
C
~
'ii
~ -2.5
Di 0
....
00 6
~u
- - dt=4.74.0.006[CO~-]
R1=O.9S .... ....
....,
-r.o
•
....
70
0
__ S'1>3.57-0.007[Ca;-j
R 1 =O,94
•
- - IrO=-L56-0.002tCO~·1
R 2 =O.89
-2
-3.5
0
100
200
300
400
500
600
700
800
0
100
200
300
400
500
600
700
800
[CO~l (~mol/kg)
[CO~l (~mol/kg)
-0.5
C
D
iIi' 4
iIi'
§
Q
Q
. . - Dark
~
~ -1.5 '~-i
vi 2
vi
~
~
~
~
0
.... .....
?)
~ 0
l ....
Jj -25
3
-
2 +' . . . . .
~o
o
......
~U
is
2·
2
........
(,0
- - 0' c ~ 4.29 - 0.006[C~ I R ~ 0.90 ... ....
- - O=-L60-0.002lC03 1
R =092
+ . . . .
__ 5'C ~ 3.30 - 0.006[C~-1
R 2 =O.92
•
r.o
__ SRO=_L31_0.002[CO~·1 R 2 =096
•
-2
-3.5
0
100
200
300
400
500
600
700
800
0
100
200
300
400
500
600
700
800
[CO~l (~mollkg)
[CO~l (~mollkg)
-0.5
iIi'
4
6J:'
§
Q
~
Q
. . - Dark
~
~ -1.5
vi 2
•
vi
f~- r -- g- - ~ - - - .
~
~
0
0
~
~
~
] 0
~ -2.5
~U~
- - dt=4.02-0.003[CO~·J
R 2 =O.70
P
- - &gO=-2.07-0.0004[CO~1
R2= 0.28
-r.o
__ aBC = 1.82 - O.OOO4[CO~-1
R 2 =O.92
-r.o
__ 6g0=-J.91-0.0003[CO~·1
R 2 =O.99
-2
-3.5
0
100
200
300
400
500
600
700
800
0
100
200
300
400
500
600
700
800
[CO~] (~mollkg)
[CO~l (~lmollkg)
Fig. 3. Effect ofC0 3 '- ion concentration on the 8 lJ C and 8 1 '0 values of Orbulina universa shell calcite under constant alkalinity (a and b), constant LC0 2 (c and d) and constant pH (e and f) conditions. Circles indicate specimens
grown at 22 DC and squares indicate specimens grown at 17 DC. Open symbols are mean values of specimens grown
under high light (HL), closed symbols are specimens grown in the dark. Plotted data are group mean values ± 1 sod;
most groups are composed of between 3 to 10 individual shell analyses_ Lines are linear regressions fitted to the
data.