One of the fuels commonly used today is natural gas. Natural gas can be harvested through hydro-fracturing or fracking shale, a type of sedimentary rock. The natural gas is harvested by drilling wells deep into the shale and releasing the natural gas trapped inside. Natural gas has become increasingly important recently and as a result there has been an increased focus on attaining the natural gas through fracking. However, there has been an increasing amount of backlash about the effects that fracking has on water supplies, livestock (including animals used for food) public concerns and safety. There are documented incidents where fracking has polluted water supplies, contaminated animals and sickened people. There is a conflict between the producers and consumers of the natural gas, and the people it is affecting. Natural gas is a commodity that we are fast exploiting, and we are only beginning to see the consequences of our actions.
Hydro-fracking for natural gas begins with shale. Shale is the most abundant of sedimentary rocks (Tarbuck, Lutgens, Tasa, 2012). Due to being a sedimentary rock, shale begins with sediments. Shale has very fine-grained sediments, similar to sandstone and siltstone and dissimilar to breccia and conglomerate. Sediments this fine settle out of water in calmer areas like lakes and other bodies of water; they collect on the bottom to create mud. This mud is then heated and compressed until its layers create sedimentary rock (Tarbuck, et. al, 2012). This is how sedimentary rocks like shale, sandstone and siltstone are formed.
The Marcellus shale in particular, which ranges from central New York to northern Tennessee, began between 300 million and 400 million years ago as mud at the bottom of an inland sea.
The sediments in the mud, which included decaying organic material, were compressed over time and formed shale (Wilber, 2012). This material was compressed over many years and when the inland sea was no more, there was the Marcellus shale. The sea disappeared because of plate tectonics driving the Taconic and Acadian orogenies. Between 400-450 million years ago, the Taconic orogeny occurred. It deformed the continental shelf and welded it to the North American plate. Remnants of the continental shelf can be found in the Piedmont region of the Appalachian Mountains. About 400 million years ago, the Acadian orogeny occurred. This brought about the collision of an island arc with North America. Evidence for this mountain-building event is found in the slate belt of the eastern Piedmont. About 250-300 million years ago, the Alleghenian orogeny occurred. This is when historical Africa and North America collided. This convergence left sandstones, limestones and shales as far inland as central Pennsylvania, and in combination with the disappearance of the ancestral sea, provided the formation process for the Marcellus shale. This rock was then buried by other materials including other rocks and soils. (Tarbuck, 2012)....