hard shale formation

burgess shale shale

oil shale and oil shale residue

Member 4 of Quantou Formation -Yaojia Formation

Abnormally Pressured Shale

active soft shale

Agrillaceous shale

Albert shale

alkali leach liquor of carbonaceous shale containi

alum shale

alumina shale

aluminous shale

angular shale

areaceous shale

arenaceous shale

asphaltic hyrobituminous shale

asphaltic shale

Athens shale

balck shale

Barnett shale