Slopes are less than 8 percent. The soils formed in residuum from basic rocks, most commonly gabbro, diabase and diorite. The climate is temperate and humid, with a mean annual temperature of 45 to 55 degrees F., and mean annual precipitation of 40 inches. These are the Aldino , Calvert , Chrome , Conowingo , Kelly , Legore , Montalto , Mount Lucas , and Neshaminy soils. Aldino soils are moderately well drained.
Calvert soils have a fragipan.
Chrome, Legore, Montalto, and Neshaminy soils are well drained. Conowingo and Mount Lucas soils are moderately well and somewhat poorly drained, Kelly soils are somewhat poorly drained. All of these soils except the Calvert soils are in slightly higher positions on the landscape than the Watchung soils. The Calvert soils occur in similar positions on the landscape to the Watchung soils. Runoff is slow to medium.