We're looking at, I believe, Lookingglass Formation here. Soils in this area are quite thin, and the Giardet Winery basically creates its own. They break up the underlying sedimentary rock, as we see in the photo, and mix in some manure (I described it to Chris, on his visit, as "organic material," and was firmly corrected). I'm not sure if they let it age for a year or two, but it looks like the transition from grassy savannah to new grape vines is fairly swift; they may just plant immediately afterward. This transformation from bedrock (albeit it crumbly, weathered bedrock) to useable agricultural soil was new to me, and quite interesting. It might not work for many plants other than grapes, for which poor soils are beneficial.