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- a mixture of gaseous hydrocarbons located under the surface of the earth, often near petroleum deposits; used as a fuel. Petroleum- liquid mixture of complex hyâ¦drocarbon compounds; used wisely as a fuel source. Oil and natural gas are formed from the remains of plants and animals.