Geology & Fossils
If you visited the southern border of Virginia, tunneled deep into the earth, then looked north across Virginia with X-ray vision, you might see something like the geological cross-section below. On your left are the three highland regions of the Appalachian Mountains — the Appalachian Plateau, Valley & Ridge and Blue Ridge Mountains. To the right (east) is the Piedmont. East of the Piedmont, the Coastal Plain slopes gently eastward to the Atlantic Ocean.
(Courtesy College of William & Mary)
If you had X-ray vision and flew high above Virginia in an aircraft, it might look something like the map below.
(Courtesy College of William & Mary)
Most of the rocks in the Piedmont and Blue Ridge Mountains of central Virginia are metamorphic (created by enormous pressure) or igneous (hardened magma or lava or volcanic ash). These contain few fossils.
Fossils occur in sedimentary rocks in the Valley and Ridge region of western Virginia. These are mostly fossils of animals lived during the Paleozoic Era, before dinosaurs evolved. They include both marine invertebrates and coal and associated fossils. Coal mining is an important industry in western and southwestern Virginia. Limestone and marble (formed in ancient seas) are also quarried in Virginia.
Fossils are also found in sedimentary rocks along the Coastal Plain. Most fossils found here represent marine animals that lived during the Cenozoic Era, or Age of Mammals. Fossils of Pleistocene, or Ice Age, animals lie scattered across Virginia at or just below the surface.
The Appalachian Mountains were formed towards the end of the Paleozoic Era, when continents were crashing together (very slowly!). During the following Mesozoic Era, North America began to split away from Africa and Europe. As Earth’s crust stretched thin, great cracks, or basins appeared along the Atlantic Coast. Today, these Mesozoic basins produce fossils of animals that lived during the Triassic and Jurassic periods. In Virginia, these basins have yielded the remains of Tanytrachelos, a bizarre reptile with an extremely long neck.
Virginia Geologic Map
Courtesy College of William & MaryTo see the map, click here.
The silver or gray area at center is the Piedmont. The slender green areas inside it are the Triassic-Jurassic basins which may occur fossils of dinosaurs. Fossils of a strange reptile called Tanytrachelos have been found in these basins. It had an extraordinarily long neck.
The chart below indicates the ages of rocks in the regions that may contain fossils. The rocks in the Blue Ridge Mountains and Piedmont are even older than the Cambrian Period — more than half a billion years old!
| Coal and fossils associated with it are likely to be found in rocks dating to the Mississippian and Pennsylvanian periods. In regions that were underwater, these rocks would instead have fossils of marine invertebrates, as would older Devonian, Silurian, Ordovician and Cambrian rocks. | The Coastal Plain begins north of Virginia and stretches south to Florida, then west into Texas and beyond. Coastal Plain rocks mostly represent the Cenozoic Era, or Age of Mammals. In some areas, rocks dating to the Cretaceous Period, when dinosaurs still lived are found. |
Learn more about Virginia’s geologic regions from the College of William & Mary. (#1 are articles written for teachers and students. #2 are more complex articles written for geologists.)
1) Appalachian Plateau | Valley & Ridge | Blue Ridge | Piedmont | Coastal Plain
2) Appalachian Plateau | Valley & Ridge | Blue Ridge | Piedmont | Coastal Plain
Or go to the Geology Home Page for even more information, including a Virginia Geological Time Chart
The Shock Doctrine: The Rise of Disaster Capitalism - 
