Located among the Langhe hills, the Barolo zone is a collection of different mesoclimate, soil types, altitudes and expositions that can have a pronounced effect on the development of the nebbiolo grape and the resulting Barolo wine. Within the Barolo zone there are two major soil types separated by the Alba-Barolo road. Within the communes of Serralunga d'Alba and Monforte d'Alba is a compact, sandstone-based soil dating from the Helvetian epoch. In the Barolo and La Morra zone, the soils are similar to those found in the Barbaresco zone, dating from the Tortonian period, being composed of calcareous marl that is more compact and fertile. Throughout the Barolo zone there are clay deposits and soil with enough alkalinity to tame nebbiolo's naturally high acidity. In Jan 2007 Filippo Bartolotta indicated how a vertical tasting of Barolo, from 1985 to the present "showcased Barolo's longevity, intense aromatics, freshness, silk-and-cashmere tannins and also highlighted the considerable contrast between production zones".