Discover the geological history of our Costières de Nîmes appellation with a stroll through of our vineyards
In 2012, I had the pleasure of showing James Molesworth of Wine Spectator around our appellation and in showing him the different terroirs in Costières de Nîmes. At the time I wrote an article about my understanding of the particularities of what I then categorized as two types. Today I’d like to develop on my previous reflections.
The terroir of the Costières de Nîmes is sedimentary, a “layer cake” created through the ages by the Mediterranean Sea, wind, the Rhône and Durance rivers, and constantly eroded by the elements.
Huge variability of the contents of this “millefeuille” exists, not only from one zone to another, not only between vineyards, but sometimes even from one vine to another. To simplify the overall pattern, today we see two broad geological types in our vineyards, each one with significant nuances.
Vineyards in northern Costières de Nîmes :
Here the commonality is « Grès », rolled pebbles from the Rhône, over red iron-rich clay. It’s a terroir that is warm and earlier-ripening due to its stones’ ability to radiate the solar heat. The stones are also great for their drainage capacity. Below, the iron-rich clay stores the rainfall, nourishing the vine during hot, dry summers with water and minerals. This soil type dates back to the Quaternary period (1 million years ago), and ages of rainfall have dissolved the calcium in the soil giving it a neutral to slightly acidic pH. This soil type is especially suitable for red varieties, it gives powerful red wines with aromas of very ripe red fruits and garrigue scents and soft spices. Fully mature tannins give longevity to these beautiful wines.
Slightly further south, and higher in elevation, this same topsoil has been covered with a loess layer (10 to 60 cm), wind sediment from erosion of the Massif Central by glaciers. This “glacial flour” of limestone modifies the mineral composition and pH of the soil and serves as a “cover” for water regulation. Young vineyards tend to suffer until theirs vines’ roots penetrate the hard cap. Once they do, the terroir provides regular access to water and an interesting freshness to their wines. Very suitable for white varieties, it gives great results in Syrah as well.
Vineyards on southern Costières de Nîmes :
Facing the Rhone delta marshes of the Camargue, our southern vineyard is located on what geologists call “the flexure of Vauvert.” sedimentary layers from as far back as 23 million years ago were lifted upward. The commonality of our three types of terroir here is a “layer cake” base that alternates between chalk (fine “flour textured” powder made from ancient seashells) and “safres” (fine yellow sands).
On the highest-elevation vineyards this base sits below a layer of red sandstone (iron-rich clay and sand) that is topped by up to 60cm of “cailloutis” (pebbles from the ancient Durance River). Here, the vineyards are rarely thirsty and they give focused and racy reds, with aromas of fresh red fruit, with beautiful concentration. However, the vineyards here require time to deliver their best.
A bit farther down the slope, the stone layer thins out completely and the base layer of chalk and “safres” is closer to the surface. Here the surface of the vineyards is a relatively infertile loam whose texture varies considerably from zones with have a higher percentage of sand and others with higher percentage of clay. A terroir with exceptional drainage and yet important water retention deep down, it is also rich in calcium. Here the soil has a very high pH (8-8.4) and offers up wines with freshness, dynamism and a certain salinity in the finish.
At the lowest point of our vineyards, the alluvium matter that sits above our chalk and “safres” bed is sandy clay. Richer, and with more limestone, here is where we planted our white varietals. With surprising minerality and freshness, the terroir here reinforces the maritime microclimate and gives our Rhone grapes a very original mark.