Average annual precipitation ranges from 40 to 48 inches, average annual air temperature from 50 to 55 degrees F. and average frost-free season from 160 to 190 days. These are the better drained Abbottstown , Readington and Chalfont soils which are on the more sloping areas adjacent to the Croton soils on level areas or depressions. Drainage is poor. Runoff is slow and permeability is slow in the fragipan. Excess water is perched above the fragipan in late winter and early spring but this has been used or has evaporated by summer.
Wild vegetation is forest of pin oak, white oak, ash, beech and red maple.
Cleared areas are used mostly as pasture, hayland or are idle. A small part is used for growing corn. In the Triassic shale and sandstone belt in New Jersey, Pennsylvania and Maryland. The series is extensive, more than 100,000 acres. Hunterdon County, New Jersey, 1917.