The Jeffersonville Formation

This project examined fossils from the Devonian Period, and more specifically the Jeffersonville Limestone. This formation is easily visible on Geological Quadrangle map GQ-1211 and on the surrounding Anchorage, Jeffersontown, and Louisville East Maps. Throughout most of the map area, the Jeffersonville Limestone (colored purple and marked Dsj) and is boarded by Quaternary accumulations and deposits, and lies disconformably over Silurian Louisville Limestone (colored blue and marked Slv). Also, the Sellersburg Limestone is included in the same map area as the Jeffersonville although it is locally missing at unconformity near US 42 and the Watterson Expressway, where some of my fossils were collected.

The Limestone features a range of colors and has been classified on the Kentucky side as having six different zones which feature, in ascending order: Aemulophyllum exiguum (Zone A), Prismatophyllum prisma (Zone B). stromatopoids (Zone C), Brevispirifer gregarius (Zone D), stropheodontids (Zone E), and Paraspirifer acuminatus (Zone F). It should be kept in mind that the fossils at the Falls of the Ohio have been classified into different zones.

As seen on the geological map, driving along U.S 42 in Eastern Louisville provides the opportunity to observe both the Louisville and Jeffersonville Limestones. Both contain similar fossils that include brachiopods and corals. The index fossil coral Halysites, which is found only in the lower Silurian rocks, may help distinguish between the two formations.

The Jeffersonville Limestone is in both the Emsian and Eifelian Ages.