The intricate role of organic matter (OM) for structure formation is unraveled. A multitude of pathogenic processes already operates during early stages of weathering. OM strongly slows down the dissolution kinetics of carbonate host rock. OM provokes a rapid and pronounced evolution of microstructure and topography. Weathering is a very important process because it breaks down rocks and minerals, which helps to create soil. Soil is necessary for the growth of plants, which provide food and oxygen for animals and humans. Weathering also creates landforms such as mountains, valleys, canyons, and plateaus.