I am an amateur lichenologist that is helping the wildlife biologist for the Red Rock Ranger District, Coconino National Forest in doing a lichen survey.  

The specimen I collected was found on a North facing slope growing on detritus, soil, and moss.  I believe it is Micarea, but the lichen key for this area (Lichen Flora of the Greater Sonoran Desert Region) has led to a dead end.  Key characteristics are a brownish hymenium,  simple hyaline ellipsoid spores (8-10 x 4-6 microns), with all spot tests negative with the exception of the epihymenium being N+ violet.  Further the thalli have cephalodia containing Nostoc.

Any suggestions would be appreciated.

Garry, you might check Bryobilimbia hypnorum or Mycobilimbia berengeriana. Not sure what to make of what you are calling cephalodia, since those would not be expected in these species. Perhaps they are freeliving cyanobacteria?

On p.344 of Vol.2 of the Microlichens of the PNW there is a multi-genus key to species like this growing on soil, detritus, and moss. Most of these species look rather like your photos.