Rufus Ward: Sharks in your backyard

Posted: 09/05/2011 in all marine news

Cdispatch –

Many young people — and old ones too — enjoy collecting fossil shark’s teeth. The Tombigee River Valley is full of chalk and sand outcroppings that contain many different kinds of fossils. In the Golden Triangle area, these deposits are mostly from the Cretaceous Period of geologic history and range from about 70 to 82 million years old. Throughout the area are found the teeth of sharks, giant fish, sea going reptiles and even an occasional dinosaur.

During the Cretaceous Period (some times called the “Age of Dinosaurs”) a great sea covered much of the South Central United States. The chalk and sands of our region date to the end of that period. The southern end of the then already ancient Appalachian Mountains was eroding and filling rivers with sand and gravel. These rivers were emptying into the forerunner of the Gulf of Mexico in northwest Alabama and the northeast corner of Mississippi.

When the Aberdeen, Columbus, Starkville and West Point area was covered by the inland sea, what is now Jackson and the part of the Delta around southern Humphreys County, were volcanic islands. The Delta volcano is known as the Midnight Volcano for the sleepy community of Midnight under which it lies. The Jackson Volcano was actually a 420-square-mile volcanic island on which Jackson now sits. The remains of the Jackson Volcano’s main vent still exist a half a mile beneath the city whose name it bares.

The large amounts of ash from these volcanoes reacting with the sea water created the bentonite deposits that are found around Aberdeen. Fortunately it has probably been 75 million years since there has been a major eruption and the two volcanoes are now considered extinct.

The variety of fossils that can be found in the Cretaceous deposits is amazing. One can find everything from amber to coral, shells, crabs, sand dollars, bones, plant remains and even coprolites (fossilized animal waste). It is teeth, however, that most seem to capture people’s imagination.

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