Type

GR

DEN

RT

API

g/cm³

Ω∙m

Sandstone

50 - 82

2 - 2.25

2.5 - 25

Muddy interlayer

>80

2.2 - 2.35

<7

Physical interlayer

75 - 100

2.2 - 2.5

3 - 8