Geology 104 - Spring 2007
Lecture #25

Everglades NP, Florida Keys and Biscayne NP

Everglades NP

Topography and History

• NP 1947
• Wide flat lowland
• Lake Okeechobee & other large shallow lakes; sawgrass flats, with hammocks
• Last large subtropical and tropical wilderness in NA
  • Sawgrass flats
  • Hammocks = higher ground with trees
  • Wildlife refute

Geology

1. Stratigraphy

Rock	Age
Peat	Quaternary (Holocene)
Miami Oolite	Quaternary (Pleistocene)
Tamiami Ls	Tertiary

2. Hydrology

• Formerly, L. Okeechobee overflowed often
  • Wide shallow "river"
  • Supplied fresh water to Everglades
• In 1900s, canals, ditches & dikes were built to "reclaim" the land for agriculture and habitation
• Results
  • many swamps drying up
  • water table dropping
  • saltwater intrusion
  • loss of soil
  • harm to Everglades species
• Comprehensive Everglades Restoration Plan
  • 2000
  • To "restore, protect, and preserve water resources of southern Florida"
  • Projected to take 30 yrs, cost ~$8 billion

Biscayne NP

Topography and History

• NM 1968, NP 1980
• Northern Keys, east of Miami
• Consists of shoreline, Biscayne Bay, reefs, keys

Geology

1. Rocks

2. Reefs

• Northernmost coral reefs in US
• Reefs constructed by corals - thrive in warm, shallow, nutrient-rich water
• Reefs are wave resistant structures
• Reefs worldwide currently under stress
  • Pollution
  • Overfishing
  • Global warming

Link to Coral Reefs web page

Florida Keys

• String of islands extending southwest from Miami (from Biscayne NP to Dry Tortugas NP)
• Pleistocene limestones (Miami Oolite & Key Largo Ls)
• Key Largo Ls was a coral reef, some still in growth position

Florida Bay = modern analog to Paleozoic seas on continent

• Raw materials: Ca, Mg, CO3
• Processes: evaporation, precipitation
• Provides clues to the environment in which ancient limestones were deposited

Everglades slides

Florida Keys slides

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