MARBLE TOMBSTONE WEATHERING RATES: A TRANSECT OF THE UNITED STATES

Abstract

Mean weathering rates measured on marble tombstones appear to vary linearly with mean annual rainfall at locations along the 10°C mean annual isotherm in the United States. Chemically-induced granular weathering is the dominant mechanism. Weathering is most rapid on upper portions of stone faces, which recede at about 1 mm/1,000 yrs where mean annual rainfall is 200 mm/yr, and 16 mm/1,000 yrs when rainfall is 1,000 mm/yr. These rates are about 50% greater than on central inscribed portions of vertical faces and on upward-facing horizontal slabs. Weathering rates of marble tombstones are perhaps one-quarter of those reported for limestone denudation in locations with similar climates and about one-half of the rates on marble tombstones in heavily polluted environments. Preliminary work in a high mountain environment with a mean annual temperature of 2°C indicates that marble weathering rates are an order of magnitude greater than at 10°C, possibly because of frost weathering. Where sprinkler irrigation is ...