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.
In order to extract natural gas from low permeability shale, fracturing fluids are pumped into a wellbore, a process which increases pressure underground, causes shale layers to crack, and allows the gas contained within the shale to escape.