Châteauneuf-du-Pape is located in the northwest part of the Vaucluse, a French department created in the late 18th century. It is named after the narrow valley where the River Sorgue rises (Vallis Clausa in Latin).
The Châteauneuf-du-Pape appellation is bordered on the west by the Rhône River, and the famous Mont Ventoux is located 40 km to the east. The town of Châteauneuf is on a hillside, and features the ancient castle at 110m altitudes. The surrounding vineyards are on rolling land and a large plateau that starts west of Mont-Redon (119 m), going eastward to its highest point in Pied Long (128 m) and finishing southward in the lieu-dit La Crau
In the Tertiary Period, 60 million years ago a shallow primeval sea, a continuation of the Mediterranean, flooded the Rhône Valley. When this receded, it left behind sedimentary rock (bedrock), especially safre, an aggregate of sandy sediment, and banks of clay and limestone. When the Alps were formed during the late Tertiary and early Quaternary ice ages, followed by a warm period causing the glaciers to melt, the hollowing out of sedimentary rock created the Rhône Valley. As a result, many tons of pebbles and quartzite were swept down from the Alps along hundreds of kilometers, rubbed smooth and round, and deposited in layers on top of the bedrock. A series of 4 ice ages, punctuated by warm interglacial periods, accounts for the terraces in Châteauneuf-du-Pape.
The lowest terraces, which you can see when approaching Châteauneuf-du-Pape from Sorgues, were formed during the Würmian Period (100,000 years ago). The soil is very heterogeneous here, consisting of varying combinations of clay, sand, limestone and marl. The surface is covered with alternating large and small pebbles, or even stoneless in some places.
Soil and subsoil can be very different. To generalize, one can say there is limestone soil in the (rocky) western part of Châteauneuf-du-Pape; sand and clay soil covered with large stones on the plateaus; mixed sand, red and grey clay, and limestone in the northern part of the appellation; less stony soil alternating with marl in the east; and shallow sand and clay soil on a well-drained layer of gravel in the south. The large pebbles contribute to the quality of the vines and grapes by storing heat during the day and holding water.
Limestone Pebbles Sandstone-Clay Sands