A compound is a substance that contains two or more elements close elementA pure substance that is made from only one type ... shale, and sandstone are all examples of sedimentary rocks.

Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils ... Throughout the earth's history, each of the three rock types has been continuously formed and recycled ...

Shale is a type of sedimentary rock that contains significant amounts of organic material. Shale gas extraction involves a combination of horizontal drilling and hydraulic fracturing, commonly ...