Stop 3: Bank of America Building - 10 Light Street

Walk north on the west (left) side of Light Street and continue across Redwood Street. The Bank of America Building, on the northwest corner of Light and Redwood Streets, shows an outstanding example of Indiana Limestone. This stone, which is quarried in central Indiana, is called Indiana Limestone in the quarrying and building trade, but is known as Salem Limestone by geologists. Indiana Limestone formed over 300 million years ago during the Mississippian geological time period.

Indiana Limestone is a sedimentary rock formed by the cementation of broken shells and hard skeletal fragments of ancient marine organisms (Figure 3). Notice that some of the smaller fragments appear to have “weathered” away leaving behind the larger fossils. The cementing material also appears to have weathered faster, owing to its lesser durability.

This limestone is a popular building stone with high durability and ease of cutting and etching. Indiana Limestone was used in the National Cathedral in Washington D.C. More examples of Indiana Limestone can be seen in this walking tour at Stops 7 and 8