The geologic origin of the Adrianna vineyard dates back to the Eocene period, over 50 million years ago when the Andes Mountains were formed and volcanoes and earthquakes ruled the land. Adrianna’s canto rodado (round boulder) subsoil made of volcanic (igneous rocks solidified on the surface) and plutonic rocks (igneous rocks solidified below the surface) was laid down and then covered by marine fossils that dispersed as the mountains rose over millions of years. During the subsequent ice ages, the melting glaciers carried down stones and pebbles which were deposited on top of the volcanic subsoil. This volcanic subsoil holds one of the secrets of Adrianna: it’s phenomenal drainage. No matter how hard it rains, it is impossible to get very high yields or botrytis rot at Adrianna, because the water seeps so quickly down through the large boulders in the subsoil.
The geologic events that explain the particularly heterogeneous topsoil of Adrianna, so rich in limestone and gravel,
are more recent. Most of the differences throughout Adrianna lie in the topsoil, which is predominantly of alluvial (formed by the passage
of rivers and glaciers) and eolic (formed by wind) origin. When we first started studying Adrianna’s geology, we couldn’t understand why
there were so many parcels dating to different geological times, yet all with the structure of a dried river bed. What we found was that
during the formation of the Jaboncillo and Peral hills to the North, the river that went through Adrianna had been forced by seismic activity
to gradually move down South, creating a series of terraces where as the river dried, limestone deposits formed.
And depending on the speed and violence of the earthquakes that formed the hills,
the river would move its flow in different directions and leave behind the white stones and limestone
deposits that we find all over the vineyard today. Because of the constant movement down the river,
the stones became rounded and smooth.
But as the rivers dried out, the calcium carbonate (main component in limestone) would make the stones turn white and form layers of limestone and chalk throughout. Limestone soils are ubiquitous in many parts of France, including Bordeaux, Burgundy and the Jura, and many people think that they hold the secret to the elegant flavors of French wine. Yet, in Bordeaux for example, great wines are also made in areas that have gravel and clay rather than limestone, so I have always been somewhat skeptical of the “limestone cult.” What we do find particular about these limestone soils is that they have two seemingly contradictory properties: they have excellent drainage but they also retain water for a longer time than gravel, but less than clay. This structural property makes them ideal for certain vine stress situations where intense sun and heat follow rains, and vines that have access to small amounts of water fair better during droughts. Also, vines from limestone soils tend to have lower brix (and eventually lower alcohol) but very high acidities, and that is often what we winemakers are looking for.
When we started studying the soils of Adrianna over a decade ago, we were making 5 soil pits per hectare. Today, with 70 soil pits per hectare, we have a much deeper understanding of the vineyard. We vinify between 200 and 300 separate lots at Adrianna and usually keep them completely separate in barrel, so that they can each run their natural fermentations. The Adrianna vineyard, because of its particular location surrounded by hills and near the Las Tunas River, is covered by a light mist in the mornings, which makes it particularly rich in native yeasts. These native yeasts and their interaction with their various parcels of origin are part of the native flavor of Adrianna.
Biologist & Fourth Generation Vinter