The crest of the Bückeberg consists of a hard, light sandstone, known as Obernkirchen sandstone, which is one of the best in Europe and, because of its transshipment through Bremen, is known internationally as Bremen Sandstone. The western Bückeberg contains clay and anthracite that used to be mined here. In the eastern section there are Jurassic limestones with halite (rock salt) deposits. It is here near Soldorf that the brine springs emerge which extend to the spa town of Bad Nenndorf, where they are used for bathing.