Salisbury Embayment facts for kids
The Salisbury Embayment was like a giant, ancient arm of the Atlantic Ocean. It covered areas that are now Delaware, southern and eastern Maryland, the Virginia Peninsula, and parts of southern New Jersey. This happened a very long time ago, between about 65 million and 5 million years ago.
During this time, the sea level was much higher than it is today. As rivers carried dirt and sand from the land into this ocean arm, the weight of these sediments might have caused the ground underneath to slowly sink. This sinking created the "embayment," which is a fancy word for a large, curved indentation in the coastline. The edge of this ancient ocean was far inland, near what we now call the Fall Line.
Contents
What Was the Salisbury Embayment?
A Look at Ancient Times
The Salisbury Embayment existed during two long periods of Earth's history: the Paleogene and Neogene periods. These periods are part of the Cenozoic Era, which is sometimes called the "Age of Mammals."
For millions of years, as sea levels rose and fell, layers of sand, mud, and other materials built up on the bottom of the Salisbury Embayment. These layers formed different rock groups and formations. For example, during the Paleocene epoch, the Aquia and Brightseat Formations were created. Later, in the Eocene epoch, the Pamunkey Group formed. And during the Miocene epoch, the Chesapeake Group was laid down.
The Missing Layers: A Space Rock Mystery
Interestingly, there are no rock layers from the Oligocene epoch in the Salisbury Embayment. This is because the sea level dropped significantly during that time, so no new sediments were deposited.
However, something else very dramatic happened during the Oligocene! Scientists believe a huge meteorite or asteroid, about 2 to 3 miles wide, crashed into the area. This impact created a massive crater, about 50 miles across, which is now hidden deep beneath the southern Chesapeake Bay.
How Did It Become Land?
The Ice Ages and Falling Sea Levels
Millions of years later, during the Pleistocene ice ages, the Earth's climate became much colder. Huge sheets of ice, called glaciers, grew and covered large parts of the planet. As more and more water was locked up in these glaciers, global sea levels dropped dramatically.
When the sea level fell, the thousands of feet of sediment that had built up in the Salisbury Embayment were exposed. This is how the land we now know as the Coastal Plain in Delaware, Maryland, and eastern Virginia was formed. It's like the ocean floor became dry land!
