GEOLEX

Summary of Citation: Signal

Publication:
Lucchitta, Ivo and Suneson, N.H., 1982, The Signal Granite
   (Precambrian), west-central Arizona, IN Stratigraphic notes,
   1980-1982: U.S. Geological Survey Bulletin, 1529-H, p.
   H87-H90

Usage in Publication:
Signal Granite*

Modifications:	Geologic Province:	Dominant Lithology:
Named	Southwestern Basin-and-Range region	Granite

Summary:
Named for town of Signal, Mohave Co, AZ in the Southwestern Basin-and-Range region. Type locality established in sec 9, T13N, R13W and sec 7, T12N, R13W, between town of Signal and Eagle Point in the Artillery Peak quad. Is a light-gray to medium-brown-gray, medium- to coarse-grained biotite granite or monzogranite pluton. Is cut by quartz, pegmatite and aplite veins, and diabase, porphyry and leucogranite dikes. The pluton is about 30 km in diameter and is best exposed in north part of Artillery Mountains. Northern contact is intrusive; eastern contact unknown (no mapping); western contact poorly exposed and structurally complex. Occurs along 113 degrees 50 min west in Casteneda Hills quad. Southern extent granite is sheared, altered, and mylonitized. Assigned to the Precambrian. Generalized areal extent map.

Summary of Citation: Signal

Publication:
Gray, Floyd, Miller, R.J., Pitkin, J.A., Bagby, W.C., Hassemer,
   J.R., McCarthy, J.H., Hanna, W.F., Conant Callas, M.L. and
   Lane, M.E., 1989, Mineral resources of the Arrastra
   Mountain/Peoples Canyon Wilderness Study Area, La Paz, Mohave,
   and Yavapai Counties, Arizona, IN Mineral resources of
   wilderness study areas; west-central Arizona and part of San
   Bernardino County, California: U.S. Geological Survey Bulletin,
   1701-E, p. E1-E28, (incl. geologic map, scale 1:62,500)

Usage in Publication:
Signal Granite*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified Isotopic dating	Basin-and-Range province

Summary:
Age is Middle Proterozoic based on U/Pb ages of 1409.6 +/-2.5 Ma and 1410 +/-3 Ma (J.L. Wooden, written commun., 1988) on samples from unit.

Summary of Citation: Signal

Publication:
Bryant, B.H., 1993, Geologic map of the Poachie Range, Mohave
   and Yavapai Counties, Arizona: U.S. Geological Survey
   Miscellaneous Investigations Series Map, I-2198, 1 sheet,
   scale 1:25,000, Supersedes U.S. Geological Survey Open-File
   Report OF-88-390.

Usage in Publication:
Signal Granite*

Modifications:	Geologic Province:	Dominant Lithology:
Isotopic dating	Southwestern Basin-and-Range region

Summary:
Isotopic ratios of U-Pb on zircons from two samples yielded an age of 1409.6 +/-2.5 Ma (Middle Proterozoic) (date provided by J. L. Wooden, USGS, 1987). Unit outcrops in western half of map, Mohave Co, AZ, Southwestern Basin-and-Range region.

Summary of Citation: Signal

Publication:
Lucchitta, Ivo and Suneson, N.H., 1994, Geologic map of the
   Artillery Peak northwest quadrangle, Mohave County, Arizona:
   U.S. Geological Survey Open-File Report, OF-85-277, 1 sheet,
   scale 1:24,000

Usage in Publication:
Signal Granite*

Modifications:	Geologic Province:	Dominant Lithology:
Overview	Southwestern Basin-and-Range region

Summary:
Mapped as a large body from Eagle Point north to Rupley Wash on the east side of the quad, Mohave Co, AZ, in the Southwestern Basin-and-Range region. Described in this report as a light- to medium-brownish-gray leucocratic to mesocratic, unfoliated to weakly foliated, typically massive, locally jointed and spheroidally-weathered, medium- to coarse-grained, porphyritic, biotite granite or monzogranite. Local zones of closely spaced subparallel joints in areas of crustal disturbance. Leucocratic and mesocratic phases form coherent bodies measuring hundreds of meters. Cut by numerous shear zones. Phenocrysts of twinned potassium feldspar usually 2-3 cm long. Has a coarse-grained equigranular phase locally. A gneiss, mapped as older than the Signal, may include a marginal facies of the Signal. Precambrian age.