Red beds have economic significance since many of them contain reservoirs of petroleum and natural gas.
Secondary red beds are linked to the uplift, erosion and surface weathering of previously deposited sediments and require conditions similar to primary red beds for their formation.
Formation
The formation of red beds has been much discussed. The basic chemical change which produces them is oxidation. At first it was thought they indicated desert conditions. Some do, and this can be proved if the strata show signs of dune formations. However:
"In modern times red beds are often found in low-latitudetropical climates, and they are always associated with oxidising conditions... the redbeds may be associated with rain forests or places where the rainfall is high but confined to monsoonal periods... A good model for red bed-producing conditions today is the Amazon basin.[2]"