The Tertiary geological history of Germany was mainly characterized by basin deposition in restricted tectonic settings, either as graben structures or as the molasse-filled foreland foredeep of the Alps. The most prominent basin structure of the Tertiary is the N-S trending Upper Rhine Graben that represents one of the most striking geomorphological elements of southern Germany today. Other graben structures are the Lower Rhine Valley, the Eger Graben and some smaller grabens such as the Hessian Depression. During this time, thick Tertiary lignite deposits formed in coastal environments in the areas of basinal sedimentation. Another major type of Tertiary deposit is the molasse. These clastic sediments represent alternations of marine and freshwater deposits that were derived from the uplifting Alpine mountain chain that lay to the south. These sediments accumulated in a foreland basin area of down flexure and subsidence that lay in front of the advancing fold-and-thrust belt.