Virginia Geology and Chesapeake Bay

Estuary

Semi-enclosed body of water where fresh water from rivers meets and mixes with salt water from the ocean creating brackish water.

Often areas of high biologic productivity

Chesapeake Bay is the largest estuary in the United States

Watershed

Region of land where water from rain drains into a body of water

Chesapeake Bay watershed covers 64,299 mi2 and all or part of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia plus the District of Columbia.

Major Rivers

The largest rivers flowing into the bay, from north to south, are:

Susquehanna River - provides 50% of the fresh water

Patapsco River

Choptank River

Patuxent River

Potomac River

Rappahannock River

York River

James River

Fishing Industry

Blue crabs

Clams

Oysters

Rockfish (striped bass)

Eel

Bad situation

Btw 1940 & 2004 population grew from 3.7 M to 17 M

Bay receives waste from point and nonpoint sources from 9 large rivers & 141 smaller streams in parts of 6 states

Bay is a huge pollution sink because it is shallow & only 1% of the waste gets flushed into the Atlantic

Increased phosphate & nitrate levels

60% of phosphates come from point sources (sewage treatment plants & industrial plants)

60% of nitrates come from non-point sources (mostly runoff from urban, suburban, and agricultural lands & deposition from the atmosphere)

Environmental Problems

Large algal blooms, marine dead zones, and overharvesting

Large Algal Blooms

Due to runoff from farm and industrial waste

Block sunlight from reaching the bottom resulting in loss of marine vegetation

Marine Dead Zones

Areas without oxygen

Results in massive fish kills

Overharvesting

Taking more fish from bodies of water than can be afforded to take

Pollution is from

phosphates and nitrates

Commercial harvests of oysters, crabs, & fish have fallen sharply since 1960 due to:

Pollution

Overfishing

Disease

Chesapeake Bay Program was implemented in what year?

1983

What did the Chesapeake Bay Program integrate?

Coastal management

What did the Chesapeake Bay Program recommend?

Establishing land use regulation in watershed area

Banning phosphate detergents

Upgrading sewage treatment plants

Better monitoring of industrial discharge

Restoring wetlands

Replanting sea grasses

In what year did the phosphate levels drop 27% and nitrates drop to 16%

1985 and 2000

Major Rivers: Susquehanna river provides 50% of fresh water going into bay

Patapsco river, Choptank river, Patuxent river, Potomac river, Rappahannock river, York River, and James River

The bay report cards get

worse every year

THE COASTAL PLAIN

A region of sedimentary strata consisting of sands, muds, and gravels

Tidal waters occupy not only the Chesapeake Bay, but also lower portions of the James, York, Rappahannock and Potomac rivers

Extends inland for more than 100 miles and is monotonously flat

Willis Mountain

largest producer of kyanite in the world

THE PIEDMONT

Largest province extending from the Fall Line westward to the Blue Ridge Mountains

Comprised of a complex of metamorphic and igneous rocks, overlain in a few places by Triassic-age sedimentary beds

Important rocks and minerals include pegmatites, slate, kyanite, gold and pyrite

The state fossil is Chesapecten Jeffersanius in the Coastal Plain:

Mile wide asteroid struck near the mouth of the Chesapeake Bay 35 million years ago

The Chesapecten Jeffersanius is

A million years old

Amazonite

is an important type of feldspar from Amelia County

Unakite is found in the

Blue Ridge Mountains

Unakite is the largest producer of

rock in the world

The Valley and Ridge

Composed of folded and faulted 550 to 300 million-year-old sedimentary rocks ridges are held up by resistant sandstone, and most valleys are underlain by less resistant shale, limestone, and dolostone

Karst features, such as caves and sinkholes are common throughout this province

The Appalachian Plateau

Contains deep narrow valleys and steep, rugged mountain sides caused by downcutting by streams

Consists of 320 to 280 million-year-old sandstone and shale with coalbeds

Most of the rock layers are relatively flat-lying

Coal is Virginia’s most important mineral resource

Coal is in Buchanan County in

The Appalachian Plateu