Virginia’s Physiographic Provinces
Area defined by geologic activity, rock type, and age
Provinces
12
3
4
5
1. Coastal Plain (flat)2. Piedmont (rolling hills)
3. Blue Ridge (mountains)
4. Valley and Ridge (mountains)
5. Appalachian Plateau (elevated flat land)
Fall line rapid change in elevation
1. Coastal Plain
Rock / Age Resources TopographySedimentary
1-140 myoClayOil and gas (offshore) Sand and gravel
Geologic Activity:CP = product of erosion of the Appalachian Mountains and oceanic sedimentary deposits.
1
•Flat (less than 50 m)• bordering the Chesapeake Bay and the Atlantic Ocean
2. Piedmont2
This area is the product of convergence
(plates moving together)
RockMetamorphicIgneousSedimentary
ResourcesSoapstone Slate GoldPyrite VermiculiteIron ZincCopper Coal
TopographyRolling hills
Geologic Activity•Folding•Faulting (earthquakes)•Intrusions (magma)
3. Blue Ridge 3
Rock / Age Resources Topography
MetamorphicIgneous1.2 byo
Copper Tin Iron GraniteTurquoiseQuartzite
The Blue Ridge is a high ridge separating the Piedmont and the Valley. It is a result of convergence.
Mountains
Ridges
Geologic Activity:•Folding•Faulting (earthquakes)•intrusions
4. Valley and Ridge 4
Rock and Age Resources Topography
Sedimentary300-550myo
Lime Zinc Gypsum Lead Iron Limestone
Mountains
*This area is the result of convergence between Africa and North America.
Geologic Activity:
•Folding
•Faulting (earthquakes)
•Karst
5. Appalachian Plateau
5
Rock and Age Resources Geologic Activity
Sedimentary280-320myo
Coal OilNatural gas
FoldingFaulting
(earthquakes)
*This area is the result of uplift from the convergence of plates. It is no longer a flat-topped area due to weathering and erosion.
Topography:
Used to be high, flat area, now hills
Watershed
Virginia has nine major river systems. •The New, Tennessee and Big Sandy empty (shed) into the Gulf of Mexico. •The Chowan and Roanoke empty (shed) into the Albemarle Sound. •The Potomac-Shenandoah, Rappahannock, York, and James empty (shed) into the Chesapeake Bay.
The area of land where all of the water that is under it or falls on it drains into the same place.
Chesapeake Bay Watershed
15 MILLION people live in this watershed!
Chesapeake Bay Watershed• Major Sources of Pollution
– Runoff (non point source!)• Fertilizers, pesticides, oil, other chemicals from
roadways, animal wastes
• The Solution?– Reduce chemical use– Natural filters
Consolidation and Water Quality
Virginia is underlain by igneous, metamorphic and sedimentary rocks. Throughout the five provinces sedimentary is the dominant rock type.
When the rock sediments have enough space for water and air to move through (porous), the water is naturally filtered. As the rock becomes more consolidated (less pore space for water movement), the water is not able to filter naturally.
Rock type and consolidation (how tightly packed the grains are within the sediment or bedrock), and age all contribute to the quality of groundwater.
As compaction increases water quality decreases.
Space No Space
As compaction increases,Water Quality decreases.
*Best*Worst