Lakes, Rivers, Streams, and Groundwater

Aquifers/ groundwater

Principal Watershed Components

Lakes Rivers/Streams

Swamps/WetlandsSoils

Hydrologic Connections

The Florida Example

Precambian 4.5 Bya to 500 Mya

Paleozoic 500 Mya to 248 Mya

Mesozoic 248 Mya to 65 Mya

Cenozoic 65 Mya to present

Geologic Time Line

(Earth formation, cooling, oceans, atmosphere, life, oxygen)

Approximately 250 million years ago

Rifting phase

- 250 Mya

Breakup of PangaeaLate Triassic, early Jurassic

Approximately 150 - 200 million years ago

Flooded, stable platformfor marine sedimentation

FL platform/plateau

For the next several million years the platform was dominated by carbonate deposition

Late Jurassic

High Sea Levels

Carbonate Deposition

Marine Calcium and Magnesium Carbonate

CaCO3

MgCO3

Florida platform was a flooded, submarineplateau dominated by carbonate deposition

FL platform

CaCO3

Between about 150 Mya and 25 Mya

Raised above earth’s crust

Dominated by carbonates

Formed over millions of years

Gently sloping

The Florida Platform

Cenozoic EraPaleocene Eocene Oligocene Miocene Pliocene Pliestocene

66-58 MYA 58-37 MYA 37-24 MYA 24-5.3 MYA 5.3-1.8 1.8 MY – 10KYA

carbonates

Before Miocene

Late Oligocene-Early MiocenePaleocene Eocene Oligocene Miocene Pliocene Pliestocene

66-58 MYA 58-37 MYA 37-24 MYA 24-5.3 MYA 5.3-1.8 1.8 MY – 10KYA

Suwannee Current

Georgia Channel

Late Oligocene-Early MiocenePaleocene Eocene Oligocene Miocene Pliocene Pliestocene

66-58 MYA 58-37 MYA 37-24 MYA 24-5.3 MYA 5.3-1.8 1.8 MY – 10KYA

Events:

•Lifting of the Florida Platform

•Lowering of Sea Levels, diversion of the Gulf Stream, interruption of Suwannee Current

•Rejuvenation of Appalachians, increased sediment load

•Filling of Georgia Channel

•Rising sea levels, lack of Suwannee Current

•Continental depositional influence on Fl. platform

Late Oligocene-Early MiocenePaleocene Eocene Oligocene Miocene Pliocene Pliestocene

66-58 MYA 58-37 MYA 37-24 MYA 24-5.3 MYA 5.3-1.8 1.8 MY – 10KYA

Suwannee Current

Georgia Channel

sediments

Siliciclastic Deposition

silici- refers to a chemical composition rich in silicate material

clastic- refers to the origin of the particles as clasts, products or fragments of silicate rocks.

Typical earth materialsSilicon-based sands, silts,

clays, rocks, rock fragments

Sands

Limestone

sands, silts, clays, rock 25 to 5 Mya

Miocene deposits are siliciclastic: sands, silts, clays, rocks

Megalodon #MG1Locality: Hawthorne Formation, South Carolina

Age:MioceneSize: 6 inches exactly

Virtually flawless museum grade specimen. Perfect serrations, black and gray mottlingPrice: $785.00 SOLD

Miocene sediments are marine sediments

In Gainesville, Miocene clays tend to be fairly thick and, in many cases, close to the surface

Alfred A. Ring Park

1801 NW 23rd Boulevard—parking at Elks Lodge

The thickness of and depth to Miocene sediments varies

Up to 40% phosphorus

0-500 ft thick in the North-central part of state

Also contains uranium

Thin or absent

30 – 200 ft sandy

30 – 200 ft clayey

> 200 ft thick

Alachua CountySediment Thickness

Thinning Miocene Sediments

Jurassic To

Miocene

Miocene

The thickness of the Miocene sediments hasA direct bearing on the formation of springs and sinkholes

Carbonate Dissolution

Acid (H+) dissolves calcium carbonate

Marine Carbonates

Miocene Siliciclastics

Limestone Cavities

Directly underlies Miocene deposits

Miocene Siliciclastics

Sinkholes

Solution (sinkhole) lakes

The most common origin of lake formation in Florida

Limestone bedrock is dissolved by acids

Land subsidence into dissolvedlimestone cavity createsdepressions filled with water

Sinkhole Lakes

Lakes are hydrologically connected to each otherAnd with the underlying aquifer system

Springs

Springs form best when the overlying clay layer is thin.

Calcareous streams

originate from springs

colder temperatures

clear water

rich in calcium and phosphorus

Santa FeIchetuckneeWeeki Wachee

Direct hydrologic connectionwith the carbonate aquifer

Hydrologic Connections