1. A primary depositional lamination in sedimentary rocks that may be preserved, though possibly with different properties, in metamorphic rocks. These laminations may be clearly visible where lithologies change or where depositional cycles were completed/initiated, or they may be effectively invisible to the naked eye, marking subtle changes in depositional conditions. Most bedding planes were originally horizontal or very slightly inclined, but more steeply inclined bedding planes developed in rocks deposited in deltaic or sand dune environments or in marine reefs. When rocks are folded the bedding planes provide an indication of the degree of deformation. Bedding planes play a crucial role in the inception and ongoing development of most caves and many surface karst features [3]. 2. A plane that separates two strata of differing characteristics [10]. See also parting.