Geology of the Willcox north Quadrangle and the southeastern-most Greasewood Mountain Quadrangle, Arizona

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Author
Erickson, R.C.
Issue Date
1988
Keywords
Arizona Geological Survey - Miscellaneous Maps
Proterozoic
cretaceous
Tertiary
Quaternary
Basin and Range Province
Cochise County
Spike E Hills
Campomocho Draw
Circle I Hills

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Citation
Erickson, R., 1988, Geology of the Willcox north Quadrangle and the southeastern-most Greasewood Mountain Quadrangle, Arizona. Arizona Bureau of Geology and Mineral Technology, Miscellaneous Map MM-88-B.
Publisher
Arizona Geological Survey (Tucson, AZ)
Description
A 1:24,000 scale geologic map of the Willcox north Quadrangle and the southeastern-most Greasewood Mountain Quadrangle, Arizona. sandy sediments of unknown age were deformed and metamorphosed to greenschist facies conditions at ca. 1690 ma (Erickson, 1981) to form the Pinal Schist. The Sommer stock and a large number of mafic bodies were intruded toward the end of this episode and share metamorphic mineralogy and foliation but not lineation with the Pinal units. Garnets in the Pinal in two locations in the Circle I Hills indicate an unusually high metamorphic grade. Probably at some time in the Precambrian the Apache Pass fault formed, causing major lateral offset between the Precambrian terrains of the northern and southern Dos Cabezas mountains (Erickson, 1969). In this quadrangle the faul t is presumed to lie close to the southwestern border of the Dos Cabezas and to pass between the Spike E and Circle I Hills, since the quartzites of the Spike E Hills are like those of the southern Dos Cabezas and the metasediments and metavolcanics of the Circle I Hills are like those of the northern Dos Cabezas. Intrusion of a small breccia stock in the Circle I Hills occurred in latest Cretaceous time correlative with the intrusion of the similar much larger mass in the Dos Cabezas mountains at about 63 ma (Erickson, 1981). The volcanic sequence of Campomocho Draw was erupted in the Tertiary and faulted. The Circle I stock was intruded at 28 rna; intrusion of albite porphyry dikes in the southern Circle I Hills may be related. Hornblende andesite porphyry dikes were intruded into the western Dos Cabezas 35 ma ago, closely followed by intrusion of numerous quartz dikes and POds (Erickson, 1981). In the last 20 ma Basin and Range faulting has blocked out the present ranges.
URI
http://hdl.handle.net/10150/630731
Additional Links
https://library.azgs.arizona.edu/item/AGMM-1552428322453-767
Language
en
Series/Report no.
MM-88-B
Rights
Arizona Geological Survey. All rights reserved.
Collection Information
Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu.
North Bounding Coordinate
32.38
South Bounding Coordinate
32.25
West Bounding Coordinate
-109.885
East Bounding Coordinate
-109.75
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