9a. 'Forward gravelly loam' soil
The earth of Napa Valley is a confluence of volcanic, alluvial, and oceanic geologies, lending the hillsides an extraordinary variety of soil types - over 60 are recorded in this valley of 300,000 acres. The type of soil pictured here, called forward gravelly loam, is highly respected by wine growers. Volcanic in origin, this soil is a fine host for cabernet, syrah, possibly zinfandel wine grapes.