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 a highly combustible odourless and colourless hydrocarbon gas largely composed of methane. Natural gas is created in roughly the same manner as oil, by processes that act upon organic matter over millions of years.