Skip

Rock Soils

Soil Map Unit Description from the RI Soil Survey Report

Rk—Rock outcrop.

This unit consists of level to very steep areas of exposed bedrock along the shore of Narragansett Bay and Block Island Sound. The areas are long and narrow and range mostly from 5 to 25 acres. Slopes range from 0 to 50 percent. The areas are unprotected from the ocean. During storms they are subject to strong wave action.

Included with this unit in mapping are small areas of well drained Newport soils, poorly drained Matunuck soils, and Beaches. In places in the intertidal zone the rock is sparsely covered with aquatic plants. Small tidal pools are common. Included areas make up about 20 percent of this map unit.

Rock outcrop is suitable for summer recreation activities, including surf fishing, sunbathing, and hiking. Capability subclass and woodland group not assigned.

Soil Map Unit Description from the RI Soil Survey Report

Rp—Rock outcrop-Canton complex.

This complex consists of bare, hard rock and well drained soils on glacial upland hills and ridges. Stones and boulders cover 2 to 10 percent of the surface of the complex. Slopes range from 0 to 35 percent. Areas are irregular in shape and range mostly from S to 100 acres. The complex is about 50 percent rock outcrop, 25 percent Canton soils, and 25 percent other soils. The soils and rock are so intermingled that it was not practical to map them separately.

Typically the Canton soils have a surface layer of very dark grayish brown fine sandy loam about 3 inches thick. The subsoil is dark yellowish brown, yellowish brown, and light olive brown fine sandy loam 19 inches thick. The substratum is olive gray and light olive gray gravelly loamy sand to a depth of 60 inches or more.

Included with this complex in mapping are small areas of somewhat excessively drained Lippitt soils, well drained Charlton and Narragansett soils, moderately well drained Sutton and Woodbridge soils, and poorly drained Leicester soils.

The permeability of Canton soils is moderately rapid in the surface layer and subsoil and rapid in the substratum. Available water capacity is moderate, and runoff is medium. The soil is extremely acid through medium acid.

The areas of rock, the stones and boulders on the surface, and the steep slopes make this complex poorly suited to community development. Onsite septic systems need special design and installation. The use of straw bale sediment barriers and temporary diversions and quickly establishing plant cover help to control erosion during construction.

This complex is poorly suited to trees and cultivated crops, but most areas are wooded. The main limitations are the rock outcrops and stones and boulders on the surface.

This complex is poorly suited to woodland wildlife habitat and is not suited to openland wildlife habitat or wetland wildlife habitat. Capability subclass VIIIs; Rock outcrop not assigned to a woodland group, Canton part in woodland group 5r.

< Back to RI Soil Map Unit Legend Page