July 8, 2008
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The Niobrara Sea
Eighty five million years ago, long before The Great Ice Age came and locked away vast amounts of water at the poles, the earth was much warmer, and the great Niobrara Sea, also known as The Western Interior Seaway, covered Middle America. Stretching from Utah to Iowa, during the Cretaceous period, this inland sea allowed water travel from the North Pole all the way to the equator, right through the very center of what is now North America. During the age of the dinosaurs, for millions of years, the entire state of Kansas, and most of the surrounding states, lay submerged as the floor of a vast inland sea.
Palm trees, cottonwoods, cedars, giant ferns, and flowering trees lined the fertile coasts and dotted the sporadic rocky islands. In the sky, Pteranodons, hairy winged lizards that resembled giant bats with long pointy beaks and wing-spans as large as two cars, soared above the teeming waters hunting for fish. The Niobrara Sea was full of life. Colonies of Crinoids and Nautiloids swam in pulsating motions among vast shoals of fish. Herds of crab ranged among the swaying reef-building coral, pointy sea urchins, and the thick beds of bottom dwelling clams, some of which grew as big as three foot wide. Giant squid swam and fed in the waters of the Niobrara Sea, among other true sea monsters, like the snake-necked Plesiosaur that grew up to 40 ft long, and the terrifying piranha-jawed Xiphactinus, the largest of all bony fish , that grew up to 20 foot long, and had eyes the size of dinner plates, and the truly terrifying 50 foot long crocodile with fins, called a Mososaur.
‘Cretaceous’ means ‘abounding in chalk’ and while huge dinosaurs walked about on the dry lands of the Cretaceous period, there were also clouds of billions of tiny one-celled golden brown algae, known as ‘calcareous’ algae, with delicate calcium carbonate shells, that floated in the warm wet Niobrara Sea. As these microscopic plants died, their protective shells slowly drifted down like an invisible snow that slowly built up on the sea floor. In parts of Kansas, the Niobrara Sea left chalk deposits 600 feet thick, similar to the more famous white cliffs of Dover, in England. In places where there was more heat and the crushing weight of the deep sea, hundreds of feet of limestone deposits were formed. In other places there are deposits of sandstone, formed from the Cretaceous-era beaches of the great Niobrara Sea. As the Rocky Mountains rose up on the western shores, the Niobrara Sea receded, and eventually disappeared into the Great Plains of the American Midwest.
