Physiographic Provinces of Virginia
Coastal Plain:
Flat, wide flood plain. Low elevation of 0-20 feet. Dendritic drainage. Youngest province of Virginia formed in the Cenozoic Era. Marine Sedimentary rocks. Land dips towards the Atlantic Ocean.
Piedmont:
Rolling hills, wide flood plain. Low elevation of 280 – 1000 feet. Dendritic drainage. Fall line. Many terranes. Land developed during the Paleozoic and Mesozoic Eras. Igneous, sedimentary, and metamorphic rocks are present. Triassic basins and normal faults.
Blue Ridge:
Two mountain ranges (NE and SW). West side is steeper than the eastern side. Higher elevation ranging between 446 and 2268 feet. Dendritic drainage. Mostly metamorphic rock, some sedimentary. Oldest rock in Virginia (1.1 to 1.8 billion years old) Precambrian Era. Grenville basement rock. Faults.
Valley and Ridge:
Valleys in the center separated by parallel mountains. Trellis drainage. High elevations between 480 – 2392 feet. Sedimentary rock. Paleozoic Era rock. Plunging anticlines and synclines and thrust faults.
Appalachian Plateau:
High elevations with flat peaks (dissected plateaus – low relief with deep valley cuts) 1028 – 2497 feet. Dendritic drainage. Sedimentary rock. Coal and natural gas. Late Paleozoic Era rock. Thrust faults on east, remaining province is flat.
VIRGINIA’S SIMPLIFIED GEOLOGIC HISTORY
Virginia is a unique state in that you could drive from the mountains, across the hills and valley, to the foothills and lastly to the sandy beaches of Tidewater. It is a state of exciting contrasts.
The geologic history of Virginia can be overwhelming. Geologic time scales can be obtained from James Madison University at One, two, and sixteen page histories are available. Other sites are from the College of William & Mary at and Radford University at
Below is a very simplified version of Virginia history based on time. It has been adapted from information provided by the Virginia Living Museum and the university websites listed above.
1 BILLION YEARS AGO
If you go back 1 billion years, Virginia was a little chain of volcanoes in an ocean where the Blue Ridge Mountains are today. Everything else was under water. If you go to the Blue Ridge Mountains, you can find an igneous rock called greenstone. Greenstone forms as hot lava flows into ocean water. Pumice (lava that is shot into the air and is full of gas bubbles) is also found in the Blue Ridge Mountain region. These rock clues show that lava poured out and shot out of volcanoes and into the ocean in the Blue Ridge region.
500 MILLION YEARS AGO
At this time, most of Virginia was under water and still a chain of volcanoes in the ocean. The coastline of the North American continent was where Virginia’s Valley and Ridge region is today. Virginia was south of the equator, and the climate was tropical. The crustal plates were moving due to plate tectonics. Thick layers of sediment began to be deposited over western Virginia. There were sand bars and sand beaches and warm shallow inland seas. These seas were teeming with life. Trilobites, horn corals, and crinoids were abundant. Shells and coral were deposited in thick layers on the bottom. Over time, these particles cemented together to form limestone, a sedimentary rock. Limestone is found in the mountains of the Appalachian Region (this include the Valley and Ridge and the Appalachian Plateau regions) west of the Blue Ridge.
225 MILLION YEARS AGO
Africa collided with North America. The impact lasted thousands of years and pushed hard enough to wrinkle up the curst under the inland sea west of the Blue Ridge. These huge wrinkles formed the ancient Appalachian Mountains. These mountains towered between 15,000 and 20,000 feet and were the largest mountains in the United States. The force of the collision produced incredible heat and pressure and changed some of the sedimentary limestone into marble, a metamorphic rock. Most of the organisms that lived in the inland sea became extinct.
190 million years ago the Africa plate started to pull away and the Atlantic Ocean opened. Parts of Virginia’s coast were pulled away with it and parts of Africa were left behind. This pulling caused the land west of Richmond to stretch and crack. Millions of years of erosion caused these rift valleys to fill with mud and clay. Coelophysis (Cee-lo-FY-sis) footprints are found in the sedimentary rock called mudstone in the Piedmont Region.
Coelophysis lived between 248 and 213 million years ago during the Triassic Period. This small dinosaur, about 10 feet long became extinct before Africa completely pulled away from Virginia.
140 to 70 MILLION YEARS AGO
After rifting, the continental margin sinks below sea level and sediment form the eroding Appalachian Mountains gets carried across the Piedmont Region by streams and rivers and washes into the Atlantic Ocean. The Virginia coast used to be where Richmond is today. Over millions of years, these sediments continued to build up to form the Coastal Plain Region. If you dig a hole in the Tidewater region, you will dig through hundreds of feet of sand made from the same rocks found in the Appalachian Mountains. When you walk on the beach you are walking on the mountains.
ICE AGE to 1.8 MILLION YEARS AGO
During this time, climates kept cooling and the ice kept piling up in Canada and northern areas in the United States. Great ice sheets (or glaciers) covered large areas of North America and Europe. The ice never made its way to Virginia. However, because so much water evaporated, the level of the ocean was more than 450 feet lower than it is today. Virginia’s coastline was 60 miles farther to the East than it is today. As the glaciers melted, sea level rapidly rose. About 18,000 years ago the Chesapeake Bay started to “drown” its ancestral river basin of the Susquehanna River. This continued till 6,000 to 7,000 years ago