The following is a map unit description from the "Soil Survey of Norfolk and Suffolk Counties, Massachusetts (Peragallo, 1989)"
HrC-Hollis-Rock outcrop-Charlton complex, 3 to 15 percent slopes. This map unit consists of gently sloping and strongly sloping soils and areas of exposed bedrock on hills and ridges where the relief is affected by the underlying bedrock (fig. 7). The shallow, somewhat excessively drained Hollis soil is on the tops of ridges or is near rock outcrops. The very deep, well drained Charlton soil is in low pockets and saddles. Stones and boulders 10 inches to 10 feet in diameter cover 0 to 15 percent of the surface. A typical map unit is about 30 percent Hollis soil, 30 percent Rock outcrop, 25 percent Charlton soil, and 15 percent other soils. These soils and areas of exposed bedrock are intermingled so closely that it was not practical to separate them at the scale used for mapping. Areas of the map unit are irregular in shape and range from 6 to 250 acres.
Typically, the surface layer of the Hollis soil is black fine sandy loam about 3 inches thick. The subsoil is dark yellowish brown fine sandy loam about 11 inches thick. Bedrock is at a depth of 14 inches. In some areas the substratum is pale yellow fine sandy loam. The bedrock is granite, basalt, diorite, or conglomerate.
Typically, the surface layer of the Charlton soil is black fine sandy loam about 1 inch thick. The subsurface layer is dark brown fine sandy loam about 5 inches thick. The subsoil is yellowish brown fine sandy loam about 30 inches thick. The substratum is light brownish gray sandy loam to a depth of 60 inches or more. In some areas the surface layer is very fine sandy loam. In some areas the subsoil is redder.
Included with this complex in mapping are small areas of moderately deep soils and Canton soils in saddles and on side slopes. Also included are small areas of Scituate soils in depressions. Also included are small areas of seeps or wet pockets. In some areas stones and boulders cover 1 to 15 percent of the surface. Included areas make up about 10 percent of the map unit.
Permeability: Moderate or moderately rapid throughout in both Hollis and Charlton soils.
Available water capacity: Hollis soil-low; Charlton soil-moderate.
Soil reaction: Very strongly acid to moderately acid in both Hollis and Charlton soils.
Depth to bedrock: Hollis soil-10 to 20inches; Charlton soil-more than 60 inches.
Depth to the seasonal high water table: More than 6 feet in both the Hollis and Charlton soils.
Hydrologic group: Hollis-C/D; Charlton-B.
Most of the soils in this complex are woodland. A few areas are used as individual homesites.
These soils are fairly suited to pasture, but exposed bedrock, stones, and boulders on the surface nearly prohibit pasture maintenance and renovation with conventional farm equipment. These soils are poorly suited to cultivated crops.
Potential productivity for northern red oak on this soil is moderate. The shallow depth to bedrock and low available water capacity on the Hollis soil are management concerns. Rock outcrops generally limit the use of equipment. Some areas are suitable for hand-planting of trees.
Slope is the main limitation to use of these soils as building sites. On the Hollis soil, shallow depth to bedrock is also a limitation. Extensive land shaping and blasting of bedrock are generally needed. Constructing roads on the contour, if possible, and planting roadbanks to well adapted grasses help to control erosion. In some areas the underlying bedrock limits road construction. The underlying bedrock and slope are the main limitations to use of the soils as sites for septic tank absorption fields, Installing the distribution lines across the slope is generally needed for proper operation. In many areas the bedrock limits installation operations. It is difficult to find suitable sites for septic tank absorption fields unless building lots on these soils are more than 2 acres in size.
The very deep Charlton soil in this map unit is well suited to lawns, landscaping. and gardens.
The Hollis and Charlton soils are in capability subclass VIIs.