『Abstract
　Mineral weathering is the primary source of long-term buffering capacity in soils and is important for forest nutrient sustainability. Regional assessments of weathering rates in Canada and the U.S. have employed an empirical clay-based Soil Texture Approximation (STA) owing to limited data availability, although the STA is rarely calibrated before application to a study area. Soil weathering rates estimated with the STA at 75 sites in Canadian forests (6-367 eq ha^-1 year^-1) were on average seven times lower than estimates obtained using the PROFILE model and when mineralogy was not available, the Analysis to Mineralogy model and parameter estimation (143-2,119 eq ha^-1 year^-1). Comparison with a catchment mass balance at a subset of sites in Ontario (n=19) demonstrated the reliability of PROFILE weathering estimates. A revised (generalized) STA model for total base cation weathering was developed at the 75 study sites to incorporate soil silt content (％) and loss-on-ignition (LOI,％) (BCw = 1.734＋0.03・silt−0.06・LOI)・1,000・depth). The model performance (Radj²＝73％) and relative bias (−1％) suggested that the revised STA may have broad application to forest soils in Canada but may not necessarily be suited to all soil texture classes.

Keywords: Canada; Forest soil; Mineralogy; PROFILE; Soil texture; Weathering』

Introduction
Materials and methods
　Study area
　Data collection
　　Weathering rate estimation
　　PROFILE
　　Analysis to Mineralogy and parameter estimation
　　Soil Texture Approximation
　　Mass balance
　　Revised Soil Texture Approximation
Results
　Mineralogy estimation
　Soil Texture Approximation
　Mass balance
　Revised Soil Texture Approximation
Discussion
　Mineralogy estimation
　Evaluation of the Soil Texture Approximation
　Revised Soil Texture Approximation
　Further research and model improvement
Conclusions
Acknowledgments
References