Igneous Rocks
                 of Southeastern Arizona

Cochise College
Arizona Geology
Geology of Southeastern Arizona

Geology Home Page

Roger Weller, geology instructor

last updated:  12/22/15

Texas Canyon Quartz Monzonite, Little Dragoons, Cochise County, Arizona

Data for these intrusive and extrusive rocks were taken from
Lexicon of Geologic Names of Southern Arizona,
by Larry Mayer, 1978,  Land of Cochise
New Mexico Geol. Soc. Guidebook, 29th Field Conference, p.143-155.




Johnny Lyon Granodiorite (Precambrian)

  location- Johnny Lyon Hills, Dragoon quadrangle

  description-medium to coarse-grained, gray to gray-green, hornblende-biotite granodiorite

  age-1660 mya


Tungsten King Granite (Precambrian)

  location- Dragoon quadrangle

  description-medium to coarse grain granite


Whetstone Granite (Precambrian)

  location-Whetstone Mountains

  description-nonfoliated granite

  age-intrudes Pinal Schist




Juniper Flat Granite (Triassic or Jurassic)

  location- Mule Mountains

  description-granite porphyry to porphyritic granite

  age-186 mya, 163 mya

  views of Juniper Flat Granite


Gleeson Quartz Monzonite (Triassic or Jurassic)

  location-Gleeson area, Dragoon Mountains

  description-coarse-grained, light-gray to greenish gray quartz monzonite

  age-173 mya


Canelo Hills Volcanics (Triassic or Jurassic)

  location- Canelo Hills-west of Huachuca Mountains

  description-volcanic sedimentary rocks, interlayered rhyolitic tuffs and lavas,
  rhyolitic lavas, and welded tuffs

  age-173 mya


Turquoise Granite (Triassic or Jurassic)

  location- near Courtland, Dragoon Mountains

  description-greenish-gray to pinkish-gray highly altered granite


Walnut Gap Volcanics (Triassic or Jurassic)

  location- Gunnison Hills

  description-andesitic and dacitic tuffs, pyroclastic breccias and conglomerates

  age-overlain by Glance Conglomerate


Huachuca Quartz Monzonite (Jurassic?)

  location- Huachuca Mountains

  description-medium to coarse-grained equigranular quartz monzonite

  age-164 mya; overlain by Glance Conglomerate


Bronco Volcanics (Upper Cretaceous or Lower Tertiary)

  location- Bronco Hill near Tombstone

  description- andesite flow breccia, fine-grained quartz latite tuff


Sugarloaf Quartz Latite (Upper Cretaceous or Lower Tertiary)

  location- Gleeson area, Dragoon Mountains

  description-light pinkish-gray quartz latite with phenocrysts of biotite, quartz
  and feldspar in an aphanitic groundmass; andesite flows


Schieffelin Granodiorite (Cretaceous)

  location- Tombstone area

  description-granodiorite to quartz monzonite

  age-72.2 mya


Uncle Sam Porphyry (Cretaceous)

  location- Tombstone area

  description-quartz latite porphyry to quartz monzonite porphyry

  age-71.9 mya




Texas Canyon Quartz Monzonite  (Tertiary)

  location- Little Dragoon Mountains

  description-biotite quartz monzonite

  age-50 mya


Chiricahua Rhyolite (Tertiary)

  location- Pedregosa Mountains


Bonita Park Formation (Cenozoic)

  location- Chiricahua National Monument

  description-red beds and tuff


Faraway Ranch Formation (Cenozoic)

  location- Chiricahua National Monument


  age-27.6 mya


Rhyolite Canyon Formation (Miocene)

  location- Chiricahua Mountains

  description-ash flows

  age-24.9 mya


Stronghold Granite (Tertiary)

  location- Chiricahua Mountains

  description-light-gray to light-pink biotite granite with porphyritic border facies

  age-22 mya