Youthful volcanic field; the McCartys lava flow is one of the youngest and longest lava flows on the continent.
Alkali basalt, hawaiite, tholeiite cones, craters, and fissures.
Zuni Bandera tube
Several basaltic centers erupted relatively long lava flows within a broad valley between the east end of the Zuni Mountains and Cebolleta Mesa.
The youngest flow, the McCartys lava flow, is the youngest eruption in New Mexico. This lava is a classic pahoe hoe lava flow and is about 40 km long. The extreme northern distal end of the lava flow lies within the Rio San Jose Valley at modern day I-40. Another young lava flow of aa type lava characteristics, erupted from a small basaltic cone within the Zuni Mountains flowed north through a canyon and out onto the valley of the Rio San Jose near modern day Grants and I-40.