Drillholes showing silicified facies within the Calcaire de Champigny in the central Brie Plateau, La Houssaye-en-Brie area (Seine-et-Marne). Tightly silicified layers occur above the basal marls. In the absence of distinct tightly silicified layers, silicification occurs in smaller patches randomly through the whole limestone unit. There is no obvious correlation of silicification with specific sedimentary horizons. Karst features are locally noted in the boreholes.