It is characterized by its abundant clusters of small shield dome structures located throughout the unit and lack of pervasive tectonic deformation.
The formation region tends to occur as equidimensional patches several tens to hundreds of kilometers across.
[2] These shields typically found in close proximity with each other and will form groups of structures.
Along with the volcanic shields, slight deformation is present evidenced by wrinkle ridges and a few fractures and grabens.
This system defines and maps rock units based on the description of the observable characteristics at the surface due to lacking other information.