The Encyclopedia Americana (1920)/Cincinnati Anticline

CINCINNATI ANTICLINE. In the period of disturbance which marked the close of Ordovician time in North America, the limestones deposited during the Trenton Epoch in the interior sea that covered most of what is now the Mississippi Valley were forced up, on a line running through southern Ohio, Kentucky and Tennessee, in a low, broad arch. This arch is called the Cincinnati Anticline. It has been of much economic importance from its having contained great reservoirs of petroleum and natural gas, the latter now approaching exhaustion. See Ordovician System; Trenton Stage.