Orthic Gray Brown Luvisolic Soils

Gray Brown Luvisolic soils are characterized by dark and granulated structure of the A horizon in addition to the presence of an illuvial Bt horizon The rapid incorporation of leaf litter and the mineral matter in these soils is due to high eart hworm activity and results to the formation of mull type of Ah horizon. These soils occur under decidous or mixed-forest vegetation with mild and humid climate. They occupy an area of about 46,780 km2 of the St. Lawrence Lowlands in Ontario and Quebec. 

Selected properties: 

2. Have an Ae horizon of which the upper 5 cm has chroma of 3 or less. The difference in the chroma between the upper and lower Ae is less than 1. 

3. Have a Bt horizon and lacks a Bf horizon. 

4. No evidence of distinct gleying within 50 cm and prominent gleying from 50-100 cm. 

Common horizon sequence: Ah, Ae, Bt, Ck