Published 07/31/2015 by Energy Institute
Shale gas is natural gas formed and held within shale formations. It is a fossil fuel originating from plant, algal or other remains, and composed primarily of methane (CH4). Generally, shale formations are composed of fine-grained (less than 0.0039 mm in diameter) laminated sedimentary rocks made up of clay minerals (at least 30%), quartz, and small quantities of fossils, organic matter, carbonates, feldspars and other minerals. Gas shale formations are normally black due to the high organic matter content, although other colours can occur depending on their mineralogical composition.