Reply To: Simple Outline of Lesson
Yes, I would classify crude oil as biological since it is derived from living organisms AND it would not be present without those organisms having lived. The same may be said for most of the natural gas, methane on Earth. However, methane is found to exist on other planets quite apart from life. Therefore, it might also be classified as a Natural Earth material. Recognize that the final breakdown products of biological materials, e.g., carbon dioxide and water, are natural earth materials. Methane seem to fall in the “crack” between.