Complex sentence: These shales though can have high yields close to 40 gallons per ton (166 l/t) of shale however due to their sporadic placement and thin bed nature they are thought to be unlikely candidates for commercial exploitation.
Split into simpler sentences: These shales though can have high yields close to 40 gallons per ton (166 l/t) of shale. However, due to their sporadic placement and thin bed nature they are thought to be unlikely candidates for commercial exploitation.