Chapter 2: The Everglades in Space and Time

What are the two keys to understanding the everglades?

climate and the underlying geology (limestone formations, hydrology, etc)

what was gondwanaland?

large land mass of africa and S. America, included Antarctica, Australia, and India

What was lapetus

the ocean between Gondwanaland and N. America

when did north america and gondwana collide

300 MYA

made appalachian mountains

what was geological continued upheaval

geologically speaking, 180 MYA north america began to lift from Pangaea

what happened by the late jurassic

crust had cooled enough that the southern part of the platform had subsided to become a shallow tropical marine environment.

what happened by the early cretaceous time

the entire platform had submerged with the southern part falling deeper and subsiding

what is the sunniland formation

135 MYA formed 11,000 feet below big cypress swamp

contains oil

what is significant about limestone

calcium carbonate forms and dissolves readily

many layers dissolved and look like a sponge.

highly permeable, voids and channels hold water, aquifers

what is the floridan aquifer

moves slowly from mid peninsula toward the coasts, including southward

water enters through rainfall, percolates through soils and permeable rock in N and central FL

what is an aquiclude

any geological formation that absorbs and holds water but doesnt transmit it at a sufficient rate to supply springs and wells

where is the floridan aquifer accessible

north of Lake O, not south of Lake O.

buried under newer impermeable layers and too salty to drink

what are two important uses of the floridan aquifer system in S. FL

aquifer storage and recovery

lower floridan aquifer called the boulder zone

what is the hawthorn formation

at the surface or in the shallow subsurface throughout, most of peninsular Florida. It is comprised pre- dominantly of early to middle Miocene lenses of limestone, dolomite, phosphatic quartz sand and clay (Pirkle, 1956).

why are glacial periods important in florida’s history

effect Florida platform.

past 2 mill years, 4 major episodes of glaciation occurred.

what happened in interglacial periods

high sea level, new sediments deposited, warm climate,

interglacial sediments made land surfaces we have today

tamiami formation

formed after hawthorn foundation

up to 150 feet thick on top of HF

exposed at surface in SW FL

forms upper bedrock in Big Cypress

Caloosahatchee formation

developed after tamiami formation

composed of sand and seashells

sangamon interglacial period

sea levels 25 feet higher

pamlico shoreline shaped

anastasia formation, Miami limestone, key largo limestone

Anastasia formation

primarily silica sand and seashells

deposited along E coast from Ft. Lauderdale

Biscayne aquifer

located at surface, rainfall and waters of interior enter it directly