|• Total||64.08 km2 (24.74 sq mi)|
Flo parish is the namesake for the Floian stage, which is the second stage of the Lower Ordovician. The base of the Floian is defined at the Diabasbrottet quarry type section (GSSP) 5 km to the northwest of Flo. The base is defined in the quarry as the lowest stratigraphic occurrence of the graptolite species Tetragraptus approximatus.
- "GSSP Table - Paleozoic Era". Geologic TimeScale Foundation. Retrieved 24 November 2012.
- Bergström, Stig M.; Anita Löfgren; Jörg Maletz (2004). "The GSSP of the Second (Upper) Stage of the Lower Ordovician Series: Diabasbrottet at Hunneberg, Province of Västergötland, Southwestern Sweden" (PDF). Episodes. 27 (4): 265–272. Retrieved 20 September 2012.