NOTES ON THE MOLLISOLS OF THE SHENANDOAH VALLEY OF VIRGINIA AND WEST VIRGINIA

Because of low rainfall and extensive limestone bedrock, the Shenandoah Valley provides one of the most favorable environments for the formation of Mollisols in eastern North America. In recent years the number of soil series recognized as Mollisols in the Shenandoah Valley has increased substantially. During the 1970's and 1980's new county surveys recognized either no Mollisols or only 1 or 2 series. These were mapped almost exclusively along small streams draining large limestone springs and were characterized by very dark (10YR 3/1) mollic epipedons. Mollisols mapped later contain lighter-colored epipedons, which may have been overlooked in the earlier surveys. The 1991 survey of Shenandoah County, Virginia recognizes 6 series of Mollisols, 4 being new series. All 6 series occur in alluvium along streams draining predominantly limestone bedrock. Mollisols mapped to date in the Shenandoah Valley fall into two Subgroups; Fluventic Hapludolls and Fluvaquentic Hapludolls. Using pit excavations, samples were taken and detailed profile descriptions were prepared for two Fluventic Hapludolls, the Broadway and Nomberville series, and two Fluvaquentic Hapludolls, the Massanetta and Newmarc series. The Fluventic Hapludolls were found to have higher Munsell chromas and lacked mottling. The Fluvaquentic Hapludolls exhibited lower chromas and contained strong brown mottles. Texturally the soils fall into two distinct groups. The Broadway and Massanetta series classify as silt loams, and the Newmarc and Nomberville as loams. Calcium carbonate was much higher in the silt loams at 32.4% and 66.5%, whereas the loams contained 10.3% and 1.2%, respectively. Cation Exchange Capacities (CEC) and base saturation appear to be independent of texture and carbonate content. CEC showed a mean of 12.96 cmol/kg for the Broadway series and 8.76 cmol/kg to 8.96 cmol/kg for the remaining series. Base saturation values ranged from 67.60% for the Broadway series to 96.40% for the Massanetta series. All series met the appropriate taxonomic criteria for Fluventic Hapludolls and Fluvaquentic Hapludolls as mapped.