In general, irregular periods are very common during the perimenopause. The most common early menstrual irregularity noticed in the perimenopause is a shortening of cycle length.
Abiogenic petroleum origin. Abiogenic petroleum origin is a term used to describe a number of different hypotheses which propose that petroleum and natural gas are formed by inorganic means rather than by the decomposition of organisms.
Natural gas is made up of just two elements - carbon and hydrogen. It is part of a family of chemicals known as hydrocarbons, which also includes oil and gasoline. As its name suggests, natural gas comes out of the ground as a gas; oil, gasoline and other hydrocarbons are recovered mixed together in a liquid called crude oil.