65.5 Ma to Present

Paleogene: 65.5 to 55.8 Ma

Eocene: 55.8 to 33.9 Ma

Oligocene- 33.9 to 23.0 Ma

Miocene- 23.0 to 5.3 Ma

Pliocene- 5.3 to 2.6 Ma

Pleistocene: 2.6 to .001 Ma

Holocene: .001 to present

Continued opening of the Atlantic Ocean

Rapid northward movement of India towards Eurasia (Himalayan Orogeny)

Collision of Africa with Southern Europe (Alpine Orogeny)

Mountain building in the western United States (Laramide Orogeny)

Rifting in the western United States (Basin and Range and Rio Grande Rift)

Isolation of Antarctica and establishment of the Southern Ocean

Uplift of Florida (yes, I did type uplift) due to karstification

Florida’s surficial deposits are all Cenozoic in age (though older deposits lie below the surface.

Florida was left behind during the rifting of Pangea.

Florida was largely submerged during the bulk of the Cenozoic

Karstification of the limestone has resulted in uplift of Florida due to unloading the crust.

*Limestone, limestone everywhere

Geological Map of Florida available on website. Useful to download.

No rocks older than middle Eocene outcrop at the surface.

Middle Eocene < 50 Ma

Payne’s Prarie

Cedar Keys Formation-dolostone and evaporites (gypsum and anhydrite) with minor limestone; forms the base of the Floridan Cenozoic rocks over most on the State except NW Florida where the Oldsmar Formation (Eocene) forms the base.

(1) Lower to Middle Eocene Claiborne Group of NW Florida-glauconitic to clayey sand; usually about 100m below the surface with a thickness of 100m; unconformably overlain by the Ocala Limestone.

Glauconite- bluish green sandstone or mudstone typical of continental shelf deposits

(2) Oldsmar Formation-Lower to Middle Eocene in South and Peninsular Fla.; limestone with vuggy dolostone; bottom of the Floridan in some areas.

Oldest Unit is the Avon Park Limestone

The Avon Park Formation is composed of cream to light-brown or tan fossiliferous marine limestone interbedded with dolostone.

In a few areas of west-central Florida, evaporites may be present in the dolostone.

The Avon Park Formation occurs throughout the Florida peninsula and the eastern panhandle. It comprises the oldest rock cropping out in Florida.

These sediments are locally exposed in sinks and quarries near the crest of the Ocala Platform in Citrus and Levy Counties.

Avon Park fossils include mollusks, foraminifera, echinoids, algae, and carbonized plant remains.

The Ocala two units differing textures (lower unit granular; upper muddy limestone); major component of Floridan aquifer; characteristic North American biota; surface and thickness highly irregular due to karst development.

(1) The limestone is remarkable in that it is composed of almost pure calcium carbonate: shells of sea creatures and very tiny chalky particles.

(2) Ocala Limestone underlies almost all of Florida, but it is found at the surface of the land only in a small portion of the state.

(3) It is mined for use as roadbase and cement where it is close to the surface in west-central Florida and the northwestern peninsula.

(4) Fossils present in the Ocala Limestone include abundant large and smaller foraminifers, echinoids, bryozoans, mollusks and rare vertebrates.

Rocks are more clastic than earlier limestones due to Appalachian uplift; Ocala Platform active; first land vertebrates occur.

Suwanee Limestone-in Peninsular and part of the Panhandle, interbedded dolostone and limestone; absent in northern and central Peninsula due to erosion; scattered outliers; part of the Floridan where present.

Bucatunna Clay- Limited distribution in western Panhandle

Marianna Limestone-Lateral equivalent of the Suwanee Ls (western and central panhandle

Chickasawhay Formation- Limited to western Panhandle (maybe Miocene in age.

Miocene of Florida (23-5.3 Ma)Mostly Clastics- Missing in the Ocala Platform area.

(1) Chattahoochee Formation-lower silty and sandy dolostone; occurs in central Panhandle; laterally gradational

(2) St Marks Formation-Limestone; occurs in Apalachicola Embayment

(3) Hawthorn(e) Group-Middle Miocene sand, silt, and clay; irregular karstic and erosional surface; aquitard for Upper Floridan; much more later

(4) Bruce Creek Limestone-Middle Miocene; occurs in the Apalachicola Embayment of west Fla.

(5) Alum Bluff Group-west of the Apalachicola River, Hawthorn replaced by Alum Bluff; clays, sands, and shell beds; locally in the intermediate aquifer

(6) Pensacola Clay-silty, sandy clays with plant remains

(7) Intracoastal Formation-sandy with abundant microfossils; Middle Miocene at the base to Late Pliocene at the top (Panhandle)

a. "Coarse Clastics"-sands and gravels that occur in a variety of locations

b. Tamiami Formation-widespread in south Fla.; complex depositional history; part of the surficial aquifer

c. Citronelle Formation-fine to very coarse clastics; covers much of central and western Panhandle

d. Miccosukee Formation-grades laterally from Citronelle Fm; clayey unit occurring from Gadsden to Madison Counties

e. Cypresshead Formation-siliciclastic clayey sands; occurs in the Central Highlands to Highlands County; surficial aquifer in many places

f. Nashua Formation-calcareous to clayey sand; extent not well known; grades laterally to Cypresshead Fm; local aquifer

g. Caloosahatchee Formation-quartz sand and interbedded, freshwater ls; occurs along the west coast from Tampa to Lee County, then north along the east coast; undifferentiated from Ft Thompson as an aquifer

h. Fort Thompson-marine and freshwater limestone and shell beds

i. Key Largo Limestone-coralline limestone occurs from Miami to low Keys; grades laterally to Miami Ls

j. Miami Limestone-oolitic-bryozoan Ls; covers Dade and parts of Broward and Monroe Counties; grades laterally to Key Largo and Anastasia Fms; part of the Biscayne aquifer

k. Anastasia Formation-interbedded sands and coquinoid Ls; forms that Atlantic Coastal Ridge; outcrops from St Augustine to Boca Raton

Undifferentiated Pleistocene-Holocene Sediments-dunes, fluvial deposits. Aeolian deposits, carbonates, peats; locally important components of shallow aquifers

•Background

•Miocene

•Pliocene

•Pleistocene

• During the break up of Pangea, Florida left Africa and joined N. America

• Dinosaurs were roaming the Earth, but sadly, Florida was underwater

• During this time, mammals were also roaming the Earth (tiny little things who spent most of their time trying not to be crushed under sauropod feet)

• After the dinosaurs meet their untimely demise, those pesky mammals flourish

The Paleogene includes the first three epochs of the Cenozoic (Paleocene, Eocene, Oligocene)

The Paleogene was a watery time for Florida

During of the middle of the last epoch of the Paleogene (the Oligocene), roughly 35 Mya, Florida began to emerge

There are some terrestrial fossils, but they are few and far between

Made up of the remaining epochs of the Cenozoic –Miocene, Pliocene, Pleistocene and Holocene

Mammals have diversified greatly in the post-dino world. By the Neogene they come in all makes and models.

The Horse Can see the transition from browsing (O-Late M) to

grazing (Late M-present)

Can also see transition from three toes to one toe (aka –a hoof)

This lineage has been historically important to the study of evolution, and is still widely stude

http://www.flmnh.ufl.edu/fhc/

Mesohippus

23 – 5.33 Mya

This is a time when grazing animals diversified, and by the end of the epoch had reached their heydey –exploiting expanding grasslands

This is really good for paleontologists – animals that tend to live in large groups also have a habit of dying together in large groups

Why do we care about lots of specimens of one species?

• Thomas Farm Site▫ One of the richest terrestrial fossil sites in the state

▫ It is a prehistoric sinkhole (what else did you expect in FL?)

▫ http://www.flmnh.ufl.edu/vertpaleo/fall_2009.htm

• The Hawthorne Formation▫ If you have ever taken a lab in geology at UF, chances are

that at some point you were required to stand in creek

▫ The fossils you found (assuming you did) are from this formation

Fossil Tapirs

Tapirs Known from Early Miocene in Hernando County

Very abundant in FL, perhaps more abundant here than anywhere else

Browsers (I know, I said

Miocene was heydey of

grazers….) – as evidenced

by the teeth

Rhino (Menoceras barbouri and Floridaceras whitei)

(Thomas Farm Site)

Rhino Agate Springs, NE = famous site for them

Browsers – I know, again, not a grazer

Lightly built

Two bumps, side by side, on upper snout – thought to be a male-only characteristic

Two tusks on lower jaw that oppose small upper teeth –looks like they have severe under bites

Thought to look something like the brontotheres (think “He ate the last dandelion of the season”

Jefferson’s Ground Sloth

Jefferson’s Sloth Named for President Thomas Jefferson – renowned

naturalist

Specimen in the FL Museum

And, yes, they were browsers

How did they get here?

“Hell Pig” (Entelodonts)

Likely a scavenger – bone crushing jaws

More abundant in northern midwest (think SD)

As number and size of grazers grew, so did the number and size of hell pigs – well, to a point

5.3 to 2.5 Mya

Getting colder and drier, but not quite the Ice Age

Time of the Great American Interchange Volcanic activity gives rise to isthmus of Panama

Lots of animals cross it – although immigration is a bit lopsided (more NA going to SA than vice versa)

• Haile Quarry▫ Yet another sinkhole, also in the Ocala Limestone

▫ Actually, it’s several sinkholes and several quarries – all of which have unique identifying numbers

▫ Ages actually range from Miocene to Pleistocene

▫ Good area in which to find articulated skeletons

▫ It is privately owned and mining operations continue (For instance, you may have gone here on a field trip. That site was closed down as it was not producing enough fossils anymore and is now being mined)

Terror Birds

Terror Birds (Titanis waleri) I know, not mammals, but terrestrial and very cool

ft tall, +300 lbs, could run (maybe 65 mph) = really, really scary

Gifts from SA across the isthmus (found in TX - marks a trail from SA to FL across land, terrorizing as it goes)

No surprise, these survive into the Pleistocene

Glyptodonts (and other Giant Armadillos)

Glyptodonts (and other Giant Armadillos) Glyptodonts were the size of a VW Beetle that were

grazers and hung out around streams. Unlike modern Armadillos (but a lot like Stegosaurs) it had a spiky tail

Giant Armadillos (Dasypus bellus, Holmesina) are a lot like extant armadillos, only, well, bigger – think, 6 ft long and 500 lbs in some species. They ate ants, grubs, etc. (can tell by teeth) and have teeth that grow continually and never wear out

2.5 Mya to 12,000 yrs. ago

Welcome to the Ice Age

a.k.a. Time of the Megafauna

Very well represented in FL (including the Haile site mentioned earlier)

Scimitar Cat (Xenosmilus hodsonae)

• Scimitar Cat (Xenosmilus hodsonae) ▫ Lived 1.5 Mya to 10,000 yrs ago

▫ Relatives of Sabre Toothed cats, but smaller – about the size of a modern lion

▫ Might have hunted like a modern Cheetah – short bursts of speed

▫ Cave paintings in France show a cat of similar size; the cat is depicted as spotted with a light colored underside

▫ Found at Haile Quarry

▫ They traveled to SA – fair trade for a terror bird?

Giant Short Faced Bear

Giant Short Faced Bear (Arctodus simus) Lived 800,000 to 12,000 years ago

At shoulders: 5.5 feet; on hind legs: 11.5 feet tall

Despite the huge incisors and slashing claws, it was probably an omnivore (although there is some debate about this)

Thought to be related to the Cave Bear – their DNA has been recovered (well, 21 or so genes – still pretty good)

Mammoths vs. Mastodons

Mammoths and Mastodons Mammoths can to FL in the late Pliocene

Mastodons came in the early Pleistocene

And there is evidence that the coexisted with another ice age mammal….

What happened to all of the megafauna? Humans

Climate Change

Disease (esp. because many genetically isolated populations)

Meteor, Gamma Ray Burst, etc. (aka – the usual extinction suspects)