Confusion Corner: Tuff, Tufa, Tuffeau

.

Tuff, tufa, tuffeau: welcome to confusion corner.

These “three t’s” are all types of stone and/or soil. Two—tuff and tuffeau—are of particular interest to viticulture, while tufa is the odd man out.

Let’s take a closer look:

Tuff: Tuff (pronounced tuhf like the English word tough) is a type of volcanic soil; however, it is sometimes classified as a sedimentary soil—so let’s just say it is formed via both volcanism and sedimentation.

Tuff is created when molten lava blasts out of a volcano, cools and fragments as it floats through the air, and eventually lands in a heap upon the ground. With time, the fragments (including volcanic ash as well as bits of igneous rock) settle, condense, and cement together into a soft, porous stone.

Tuff soils inside the crater of Mount Vesuvius (photo credit: Simona Cerrato via Wikimedia Commons)

Tuff-based soils are found in Napa (Howell Mountain), Lake County (California), Madeira, Hungary (Tokaj), Alto Piemonte (Gattinara, Ghemme), Campania (Mount Vesuvius) and large swaths of Yellowstone Park.

Tuffeau: Tuffeau (pronounced too’-foo) is a local type of limestone found in the Loire Valley. Tuffeau is fine-grained and very low density (about half the density of granite). Tuffeau is formed from the remnants of the sea floor (sediment, fossilized sea creatures, and sand) that covered the Loire Valley over 90 million years ago. Over the millennia, these particles became compressed to form a unique type of limestone due to the presence of foraminifera (creatures with multi-chambered shells), and the (previously) shallow water that stood between 2 and 20 meters deep—other forms of limestone were formed under deeper waters.

The fortified wall at the 8th-centure Château de Loches, showing tuffeau blocks of various ages (photo credit: Valerius Tygart via Wikimedia Commons)

Weathered tuffeau, combined with sand, flint, and clay—as found in the Central Loire regions of Anjou, Saumur, Touraine—is an excellent vineyard soil. Tuffeau is equally famous for being the building blocks of many of the gorgeous castles of the Loire, and may also be known as Turonian Limestone (after the city of Tours).

Tufa: The words “tufa” (pronounced too’-fah) and “tuff” and commonly confused, and that’s ok for people having casual conversations about the ground beneath their feet. However, for geologists and wine geeks, there’s a big difference between the two (and, to make matters worse, tufa and tuffeau have more in common than tuff and tufa). So here goes: tufa is a rare is a rare type of limestone created when calcium carbonate-saturated water releases carbon dioxide and precipitates a soft, caclium-carbonate rock. Tufa is specifically formed in ambient-temperature water.

The best-known examples of tufa (in the fascinating form of tufa towers) can be found at Mono Lake, California. Tufa is not—to the best of my knowledge—a factor in vineyard soils.

Tufa deposits originating from hot springs are known as travertine—and that’s a whole other corner story.

References/for more information:

The Bubbly Professor is “Miss Jane” Nickles of Austin, Texas… missjane@prodigy.net

About bubblyprof
Wine Writer and Educator...a 20-year journey from Bristol Hotels to Le Cordon Bleu Schools and the Society of Wine Educators

3 Responses to Confusion Corner: Tuff, Tufa, Tuffeau

  1. Paul Smith, DipWSET says:

    Thanks Miss Jane. A very useful clarification of terms which certainly tripped me up on many occasions. Is it worth mentioning a fourth ‘t’ word – travertine? Different from Tufa in that it forms in warm water (by the same precipitation process you describe for Tufa), but as water temperature increases so the volume of calcium carbonate that can be held in suspension increases leading to larger deposits of travertine. Unlike Tufa, travertine does factor in vineyard soils such as the Tuscan DOCs of Bianco di Pitigliano and Orcia.

    Ref: Maltman, Alex (2018) Vineyards, Rocks, & Soils. Oxford University Press.

  2. kristenvanhorn7471 says:

    I have requested the password for your site a few times with no response (or they went deep down into my spam folder, never to see the light of day). I would like to use the CSW practice quizzes & tests for studying.

    Could you help me?

    Thank you & Happy Thanksgiving!
    Kristen

    Sent from my iPhone

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: