fossil fuels / fossils forming occurs over a period of 300000000 years which is considered a very long time to a human
geological_age is not geological_time_period. fossil is remains. fossil_fuel_generation is geologic_process. geological_era is geological_time_period. petroleum is fossil_fuel. geological_age is geological_time_period. period is geological_time. geological_period is geological_time_period. fossil_fuel_generation is not geologic_process.