impermeable [Adjective] + rock [Noun]

Strength Strength Dispersion
A:
6
CHISQ:
368.97
AWT:
21,862,280
TTEST:
2.41
G2:
46.85
FAWT:
2.49
MI:
5.99
LOGLOG:
15.47
JD:
0.29
MI3:
11.16
DICE:
0.13
RANGE: