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.
Geological processes are natural processes that occur on the surface and subsurface of the Earth which help to shape the Earth, concentrate resources and so on. These processeâ¦s occurred millions of years ago, are occurring presently and will continue to occur.