recent geological history means a relatively short period of time
geological_age is not geological_time_period. geological_era is geological_time_period. geological_period is not geological_time_period. geological_age is geological_time_period. period is geological_time. geological_period is geological_time_period. geological_time_period is continuous_time_interval. geological_era is not geological_time_period. period is not geological_time. geological_time_period is not continuous_time_interval.