Medoc Glacial gravel outcroppings with sand and shale from the river, and clay in subsoil. Graves Very similar to Medoc, but further from the ocean with less clay subsoil, and higher elevations with some gently rolling hills. Sauternes Gravel gives way to more sandy soils and rolling hills. St. Emilion Limestone bluffs along north side of the sandy Dordogne valley floor. Vast area of generic wine produced from sandy, poorly drained sandy lowland, with best wines coming from bluffs.
Lower slopes have sandy topsoil, giving way to clay on upper slopes and terrace.
Small area of glacial gravel around Chateau Figeac on border of Pomerol. Cold soils not good for ripening Cabernet Sauvignon, therefore main varietals are Merlot and Cabernet Franc. As the land slopes gently away from the plateau, topsoil gives way to less favorable sand. System has never been revised, and many of the lesser growths do not conform to their given ranking. Sauternes and Barsac also included in 1855 Classification, later re-classified on their own system.