Both areas refer as their origin to the Tertiary Era, that is, from 65 to 1.8 million years ago. The Langhe, however, are older and have their origin in the Miocene period, or between 23 and 5.3 million years ago.
The Roero, on the other hand, is decidedly younger, as it emerged from the waters of the Padano Sea between 5.3 and 1.8 million years ago, in the Pliocene period.
This different geological origin, of course, is reflected in the characteristics of the soils and the products that arise from them: in the Langhe the soils are more compact, harder, made above all of limestone and clay.
In Roero, alongside the same basic structural components, we find frequent sandy presence which makes the soil less compact.