Middle Proterozoic granitic rocks (AZYg;0)

Middle Proterozoic granitic rocks

Mostly porphyritic biotite granite with large microcline phenocrysts, with local fine-grained border phases and aplite. Associated pegmatite and quartz veins are rare. This unit forms large plutons, including the Oracle Granite, Ruin Granite, granite in the Pinnacle Peak - Carefree area northeast of Phoenix, and several bodies west of Prescott. (1400-1450 Ma)

State	Arizona
Name	Middle Proterozoic granitic rocks
Geologic age	Middle Proterozoic
Lithologic constituents	Major Igneous > Plutonic > Granitic > Granite (Pluton) Minor Igneous > Plutonic > Granitic > Leucocratic-granitic > Aplitelocal fine-grained border phases and aplite Incidental Igneous > Plutonic > Granitic > Leucocratic-granitic > Pegmatite (Dike or sill)associated pegmatite and quartz veins are rare
Comments	~ 1.4 Ga
Stratigraphic units	Oracle Granite, Ruin Granite
References	Richard, S.M., Reynolds, S.J., Spencer, J.E., and Pearthree, P.A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000. Anderson, J.L., 1989, Proterozoic anorogenic granites of the southwestern United States, in Jenney, J.P., and Reynolds, S.J., editors, Geologic evolution of Arizona: Arizona Geological Society Digest 17, p. 211-238.
NGMDB product	NGMDB product page for 34746
Counties	Cochise - Gila - Graham - La Paz - Maricopa - Mohave - Pima - Pinal - Santa Cruz - Yavapai - Yuma

Middle Proterozoic granitic rocks

Richard, S.M., Reynolds, S.J., Spencer, J.E., and Pearthree, P.A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000.

Anderson, J.L., 1989, Proterozoic anorogenic granites of the southwestern United States, in Jenney, J.P., and Reynolds, S.J., editors, Geologic evolution of Arizona: Arizona Geological Society Digest 17, p. 211-238.