The Lincoln Memorial is made of marble and was dedicated in 1922.
Under the roof overhang is one of the few places at the Lincoln Memorial where alteration crusts have developed on the marble.
Some columns at the Lincoln Memorial have flattened chalky areas where inclusions have weathered differently from the surrounding calcite.
The marble guttae on the roof overhang are crumbling and falling apart underneath blackened alteration crusts.
Buildings along 17th Street, NW
Some notable examples of stone deterioration are included in this part of our tour. We will begin this segment at the northeast corner of 17th Street and Constitution Avenue, with the Capitol Gatehouse. We will then cross 17th Street and examine several buildings along 17th Street as we walk north towards Pennsylvania Avenue. The total distance is about three-fourths of a kilometer (half a mile).