The Winemaker’s Dance: Exploring Terroir in the Napa Valley, California

David Howell, US Geological Survey ― October 30, 2004

The text below is reprinted from the trip announcement
Photographs from the event provided by NCGS members

Most people, when they think about the geology of California, focus first on earthquakes. Indeed, as the mountains and valleys of California have been shaped, earthquakes have been the pounding of the carpenter’s hammer, a resounding echo from Earth forming processes. Thus, even though most of us are horrified by the prospect of another devastating earthquake, the great beauty and abundant resources in California are a direct consequence of the very events that trigger these periodic Earth shaking temblors.

Geology plays an important role in controlling the quality and nuances of California’s wine. It affects the soils — their chemistry and texture, the topography — mountain slopes versus valley floors, and the climate — humidity, sun angle, and temperature. The three S’s — soil, slope, and sun — help us understand the principal factors that control wine quality. How the vintner manipulates these controls determines the specific attributes of each bottle of wine.

Understanding the geology of different California regions, and how it relates to wine growing, can be broken down into three basic categories:  how the bedrock formed, evolution of the landscape, and relating these two factors to soil development and micro climatic conditions. These elements will be explored during a field trip as well as the wine that does indeed convey a 100 million years of earth history.

The Winemaker’s Dance: Exploring Terroir in the Napa Valley, by Jonathan Swinchatt and David Howell, had just been published. In the book, the authors use the geology of the Napa Valley to provide a physical context for terroir and examine in this context how winegrowers and winemakers relate to this notion through their daily work. The book is based on investigations over many years by the US Geological Survey, and interviews with some 80 winegrowers and winemakers. The book is illustrated with 3D maps that provide views of the valley never before seen, created through a cooperative project with the US Geological Survey.

If you would like to read more about the book click here.

The NCGS sincerely appreciates the outstanding efforts of David Howell in taking the time in helping organize this wonderful and educational field trip.