CULTURAL GEOLOGY OF THE CARNEGIE LIBRARY AND CARNEGIE NATURAL HISTORY AND ART MUSEUMS OF PITTSBURGH

The Carnegie Library, Museum of Natural History, and Museum of Art buildings in Pittsburgh, Pennsylvania together are a National Historic Landmark. They were built in 1895, 1907, and 1974, respectively, and have an intriguing geologic story to tell. They were constructed of 16 different building stones that were quarried on four different continents. The interiors and exteriors are made up of igneous, metamorphic, and sedimentary rocks that span all geologic eras. Some of these rocks can tell us about ancient climates, others document mountain building episodes, while others give us glimpses of the bottom of ancient sea floors.

Exterior building stone from the Late Devonian Berea Sandstone of eastern Ohio represents deposits of an ancient river system that flowed from the craton at a time when the sea level dropped as a result of polar glacier growth. The Ordovician, Holston Limestone of Tennessee represents facies of an ancient reef tract, and was used for the interior of the library and the floor of dinosaur hall. High columns of the Lower Cretaceous, Hauteville Limestone of France decorates the Museum of Natural History entrance and walls of the Music Hall. The unusually warm Eocene global climates are indicated by nummulite foraminifera of the Nummulitic Limestone from Algeria that was used for the President's office. Mountain building episodes are recorded by the anorthosite and serpentine that distinguish the Museum of Art and the Music Hall foyer. Another outstanding example is the Pentellic marble seen in the Hall of Sculpture.