Record Display for the EPA National Library Catalog

RECORD NUMBER: 241 OF 382

OLS Field Name OLS Field Data
Main Title Mineral Weathering Rates from Small-Plot Experiments, WMP Site, Bear Brooks, Maine, U.S.A.
Author Drever, J. I. ; Swoboda-Colberg, N. G. ;
CORP Author Wyoming Univ., Laramie. Dept. of Geology and Geophysics.;Corvallis Environmental Research Lab., OR.
Publisher 1993
Year Published 1993
Report Number EPA/600/A-93/246;
Stock Number PB94-107992
Additional Subjects Minerals ; Weathering ; Silicates ; Soil analysis ; Dissolving ; Acidification ; pH ; Kinetics ; Air pollution ; Field tests ; Cation exchanging ; Experimental design ; Deposition ; Water pollution ; Maine ; Reprints ; Bear Brooks(Maine) ; Bear Brooks Watershed Manipulation Project
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB94-107992 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 02/27/1994
Collation 5p
Abstract
The pH-dependence of silicate mineral weathering rates was measured in small-plot experiments at the Bear Brooks Watershed Manipulation Project site in Maine, USA. Six 2 sq m plots were acidified with solutions of HCl in deionized water at pH values of 2, 2.5, and 3. Acid application was at the rate of 3 cm/week for approximately 26 weeks per year for 2 years. Soil solutions were collected by tension lysimeters at 25 and 50 cm depths. The composition of the soil solutions, together with the grain-size distribution and mineralogy of the soil, were used to calculate mineral weathering rates. In the lab experiments, the dependence or base cation release rates on pH varied from cation to cation, reflecting the different behavior of different minerals. Dissolution rates observed in the field, normalized on the basis of geometrical mineral surface area, were smaller than laboratory rates by a factor of about 200. Laboratory dissolution experiments can be used to predict the pH-dependence of mineral weathering in the field, but not absolute rates.