DECIPHERING THE BUILDING STONES OF EVANSVILLE, INDIANA
Identification of some stone is particularly challenging. The oolitic Salem Limestone, produced in south-central Indiana, has been widely used in Evansville. But, another historically important stone in Evansville was the similar Gasper oolitic limestone (part of the Girkin Formation) quarried in the Bowling Green region of Kentucky. This stone could be shipped to Evansville by barge, and the Caden Company of Evansville owned one of the Kentucky quarries. However, the Caden Company also handled Salem Limestone. Salem Limestone and stone from the Girkin Formation are documented in newspaper accounts published at the time of dedication for the 1886 St. Paul's Episcopal Church. Distinguishing the two similar Mississippian oolites here and elsewhere requires attention to subtle color differences and differences in preservation of the rock matrix. The most economically important sandstone quarried in Indiana in the later 1800s was the Mansfield Formation, but brownstone from Illinois was used for prominent historic buildings (the 1879 Post Office and Custom House, and almost certainly for the 1885 Willard Library).
Most stone used for older structures have held up well, but thin-panel exterior cladding on more recent structures is more problematical: Fine-grained marble on the exterior of the 1969 Old National Bank Building exhibits warping and other degradation symptomatic of thin-slab marble construction.