Friday, February 23, 2007

Back to the Cretaceous

After being covered with ice and snow for more than two months, the recent warm weather has turned the plains of western Kansas into vast, meltwater lakes. Country roads are flooded, the winter wheat crop is threatened and cattle are marooned near the barns. For a region that is semiarid and must irrigate its fields with water from the dwindling Ogallala Aquifer, the current flooding might be considered a godsend; unfortunately, the deeper soil remains frozen and any long term benefit seems unlikely.

Looking out on this flooded landscape, one might wonder if the Cretaceous Sea is making a comeback. During that Period, some 80 million years ago, a broad, shallow seaway stretched from the Gulf of Mexico to the Arctic Ocean, covering much of what is now the High Plains. Pierre shale, deposited in that Cretaceous sea, underlies the region and remnant towers of marine limestone still dot Kansas, eastern Colorado and western Nebraska. As one might expect, fossils of ancient sea turtles, squid, sharks, marine reptiles and aquatic dinosaurs have been found in these deposits.

The current flooding will likely get worse before it gets better. There is still plenty of snow cover and, adding insult to injury, a major Pacific storm is forecast for this weekend. Heavy rains and thunderstorms will preceed the front while high winds and "backside snow" will follow.
It's just too much of a good thing at the wrong time!