Radiometric dating of interbedded flows gives it an age of 26.4 to 7 million yeawrs (Ma), corresponding to the late Oligocene to Miocene.

[1] The formation was severely deformed in the late Miocene or early Pliocene and some beds dip as much as 60 degrees.

[3] Deformation in the middle Miocene caused the area to subside at a rate that exceeded the sediment supply, forming a topographically closed basin in which the Popotosa Formation was deposited.

When tectonic activity finally slowed in the latest Miocene and early Pliocene, sedimentation exceeded accommodation.

The Socorro flora is notable for its impressions of juniper foliage, angiosperm leaflets, and floral parts.