Open-File Report 98-755 Online version 1.0 In the mid 1980s, the
National Acid Precipitation Assessment Program (NAPAP), in
cooperation with the National Park Service (NPS) and the U.S.
Geological Survey (USGS), initiated a Materials Research Program
(MRP) that included a series of field and laboratory studies
with the broad objective of providing scientific information on
acid rain effects on calcareous building stone. Among the
several effects investigated, the chemical dissolution of
limestone and marble by rainfall was given particular attention
because of the pervasive appearance of erosion effects on
cultural materials situated outdoors. In order to track the
chemical erosion of stone objects in the field and in the
laboratory, the Ca 2+ ion concentration was monitored in the
runoff solution from a variety of test objects located both
outdoors and under more controlled conditions in the laboratory.
This report provides a graphical and statistical overview of the
Ca 2+ chemistry in the runoff solutions f