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.
âFrackingâ â or hydraulic fracturing is the process in which oil and gas companies drill into the ground to extract natural gas from the shale rock that lays thousands of feet under the ground.