It is known for its phosphate rock resources, and for its rich assemblages of Neogene vertebrate fossils.

The Hawthorn group has complex bedding, primarily consisting of clay, silt and sand.

It is predominantly siliciclastic, consisting primarily of fine-to medium-grained quartz sand.

Other common components of Hawthorn units include phosphate, palygorskite, sepiolite, chert, and dolomite or dolostone.

The Hawthorn is also present below undifferentiated sediments (TQu) as well as the Tamiami Formation from Polk County south through Highlands, Glades, Hendry, Dade, Collier, and Monroe County at depths ranging from mean sea level near Polk to below 600 meters in Monroe Co.[8] The Hawthorn overlies Ocala Limestone[9] The Alachua Formation may have resulted from the weathering of Hawthorn Group sediments, intermixed with Pliocene deposits.