Structure and stratigraphy of the Hagan embayment--A new look
— Bruce A. Black

In the Hagan embayment and the Sandia Mountains block, the full stratigraphic section of this area of central New Mexico is exposed. This area gives us a unique opportunity to study early Tertiary normal faulting which apparently was active prior to the late Tertiary easterly rotation of the Sandia and Hagan basin area.

The Cretaceous rocks exposed in this area help document the Cretaceous facies relationships on the east side of the Rio Grande rift and allow projection of certain Cretaceous facies across the alluvial-covered rift system.