Description:
From the Abstract: "The study area, a classic metamorphic core
complex, actually shows the characteristic features of
such complexes only at the southern end of the range
and grades into other rock assemblages to the north.
The area thus affords the opportunity of analyzing the
definitive components of a core complex separately. It
measures about 48 by 11 km, traversing the central par t
of the Santa Catalina Mountains from the Tucson basin
to the San Pedro basin. The dimensions of study lend
themselves to a cross-sectional approach.
A supracrustal sequence 1.1 km thick consists of
Middle Proterozoic Apache Group and Paleozoic rocks
unconformably overlying mostly-granitic basement
rocks. Units of special interest include voluminous
pyroclastic rocks in the Pioneer Formation, glaciomarine
rocks of Upper Proterozoic age, and ?Devonian
fluvial deposits in a paleochannel on Mt. Lemmon.
Laramide intrusions of roughly granodioritic
composition are mostly concordant, typically inflate the
supracrustal sequence about 300 m, and define three
mutually exclusive large domains. The two domains
characterized by Leatherwood and San Manuel
intrusions show impressive heating and alteration
effects, whereas the central domain characterized by
Rice Peak intrusions show few such effects due apparently
to multiple small intrusions."