pre-Boreal The first Flandrian (Holocene, or post-glacial) stage, a time of rapid forest spread, from about 10300–9600bp. Pre-Boreal refers to climatic conditions and in vegetational terms is equivalent to Pollen Zone IV of the standard British and European post-glacial pollen chronology. See pollen zone.

pre-Boreal The first Flandrian (Holocene, or post-glacial) stage, a time of rapid forest spread, from about 10300–9600 BP. Pre-Boreal refers to climatic conditions and in vegetational terms is equivalent to Pollen Zone IV of the standard British and European post-glacial pollen chronology.