by letter code
| example: Gd
|
| -
|
145Gd
|
< 1 day
|
| V
|
146Gd
|
1–10 days
|
| I
|
149Gd
|
10–100 days
|
| B
|
153Gd
|
100 days–10 a
|
| G
|
148Gd
|
10–10,000 a
|
| Y
|
150Gd
|
10 ka–103 Ma
|
| O
|
152Gd
|
> 700 Ma
|
| R
|
158Gd
|
Stable
|
| Used in:
|
|
by number code
| 0
|
|
1–10 years
|
| 1
|
|
10–100 years
|
| 2
|
|
100–1k years
|
| 3
|
|
1k–10k years
|
| 4
|
|
10k–100k years
|
| 5
|
|
100k–1M years
|
| 6
|
|
1M–10M years
|
| 7
|
|
10M–103M years
|
| 8
|
|
103M–700M years
|
| 9
|
|
700M–14G years
|
| Used in:
|
|