Group · Neogene
Hawthorn Group
Miocene unit, Florida · Georgia · South Carolina
The Hawthorn Group is the Miocene phosphatic shelf sequence of Florida, Georgia and the Carolinas that parents the Bone Valley and Peace River deposits and the shark-tooth beds of the Cooper River. For collectors it is the source label for most southeastern US megalodon, mako, Hemipristis and tiger shark teeth, dugong bone and whale material. Colour and preservation vary by river and county, so record the specific site.
| Country | United States |
|---|---|
| Region | Florida, Georgia, South Carolina |
| Age | Miocene |
| Age range | ~25–5 Ma |
| Group | Hawthorn Group |
| Macrostrat rank | Gp· Macrostrat |
| Macrostrat age | 17.7–16.5 Ma· Macrostrat |
| Lithology | sand, siliciclastic, phosphorite, clay· Macrostrat |
| Environment | marine, deltaic indet., coastal indet., fluvial indet.· Macrostrat |
| Macrostrat columns | 4 column(s) sampled from 8 unit(s)· Macrostrat |
| Members (Macrostrat) | Bone Valley, Ebenezer, Screven· Macrostrat |
| PBDB collections | 110 collections, 1235 occurrences· Paleobiology Database |
Collecting and legality
Hawthorn exposures are creek beds and quarries; Florida's vertebrate permit applies on state lands and waters, and quarries require owner permission. Georgia and South Carolina river sites have their own rules (South Carolina requires a hobby licence for diving).
Lithology and setting
Phosphatic clays, sands, dolostones and limestones of a Miocene shelf across the southeastern coastal plain; the Bone Valley and Peace River formations are its upper members in Florida.
Commonly recorded taxa (PBDB)
Genera most often recorded from this unit in the Paleobiology Database (first 200 occurrences): Calippus (13), Cormohipparion (13), Nannippus (11), Neohipparion (10), Borophagus (9), Pomatodelphis (9), Pseudhipparion (8), Ostrea (7), Dinohippus (5), Enhydritherium (5), Desmathyus (4), Hexameryx (4), Mammut (4), Abertella (3), Camelidae (3).
Source: Paleobiology Database
Elsewhere
- Macrostrat: 7303
- macrostratConcept: 2013
- PBDB: strata:Hawthorn
- Wikidata: Q5685491
- Macrostrat stratigraphic name
- PBDB occurrences for this unit
- Wikipedia: Hawthorn Group
- Mindat: Hawthorn Group
Cite this article
Stratum Study. "Hawthorn Group" (Formation). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/formations/hawthorn-group. Accessed 2026-09-20.
@misc{stratum-hawthorn-group,
title = {Hawthorn Group},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/formations/hawthorn-group}},
year = {2026},
note = {Formation article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, macrostrat, pbdb, wikidata, commons. Accessed 2026-09-20.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.