A rift system can be seen as a string of connected triple junctions or connected hot spots. The rifting process continues on two of the three arms. Third arm becomes a failed rift called an aulacogen. As the crust breaks due to the uplift and extension, blocks fall down along the normal faults creating a rift valley. Progressive spreading forms a wide, rift graben.
Typical sediments are coarse immature alluvial debris and fluvial deposits.
Small lakes with lacustrine shales, limestones and evaporites may form in the middle of the structure. Vulcanism is alkaline and peralkaline. Carbonatites sometimes occur . Ore deposits in this setting provide important elements, phosphorus, niobium, rare earths, copper, uranium, thorium and zircon. Magnetite, fluorite, barite, strontianite and vermiculite, copper-nickel deposits and hydrothermal copper deposits are formed.