The only Cretaceous pluton exposed in the Lander County portion of the study area is a small outlier of biotite quartz monzonite just north of Iowa Canyon in the central Toiyabe Range. It is probably related to the only other Cretaceous pluton in Lander County, the Ravenswood stock some 15 miles to the northwest. This medium-grained porphyritic to equigranular quartz monzonite is composed of about 40 percent microcline, 30 percent quartz, 25 percent plagioclase and 5 percent biotite (Stewart and McKee, 1977).

Plutons scattered within the southern Dry Hills and central Cortez Mountains are dominantly Cretaceous granodiorite and quartz monzonite with small amounts of diorite, tonalite, and alaskite.

In the Ruby Mountains, small masses of two-mica granites are exposed in the eastern portion of the range within the lower plate or infrastructure of the metamorphic core complex. One of these plutons, the granite of Dawley Canyon is Cretaceous in age with Rb-Sr ages of 82 Ma (Howard and others, 1979; Snoke and Lush, 1984). In the Jiggs Quadrangle area of the Ruby Mountains, a small medium-grained muscovite-biotite granite with accessory garnet, and associated tabular pegmatite dikes has been mapped by Willden and Kistler (1969). Coats (1985) included this pluton as Cretaceous since the Dawley Canyon pluton just east of the Jiggs Quadrangle is Cretaceous.

Several small monzonite porphyry stocks, dikes and sills are present in the Ely-Ruth area and have been the source of the large porphyry copper bodies of the Robinson Mining District (Bauer and others, 1966; Brokaw and others, 1973; Brokaw, 1967; Hose and Blake, 1976). These intrusive bodies are light gray to brownish, hypidiomorphic-granular monzonite, and porphyritic quartz monzonite. Phenocrysts of orthoclase 5 to 10 mm in diameter, as well as smaller phenocrysts of plagioclase, and irregular grains of hornblende are contained in a fine-grained matrix of quartz and orthoclase. Accessory minerals include augite, magnetite, apatite, sphene, and zircon (Brokaw and others, 1973). The altered monzonites display sericitic, biotite-argillic, and prophylitic alteration. K-Ar determinations from several of these small bodies give ages in the 103 to 123 Ma range (Brokaw and others, 1973; Hose and Blake, 1976).

The Cretaceous Seligman and Monte Cristo stocks in the White Pine Range are medium-grained, biotite-hornblende granodiorites. The Monte Cristo stock has undergone intense hydrothermal alteration converting it to quartz, sericite, and clay minerals (Adair and Stringham, 1960; Humphrey, 1960). The Seligman stock is 90.4 Ma (Armstrong, 1970) and the Monte Cristo has not been dated as a result of its intense alteration.

A small circular Cretaceous pluton about 1 mile in diameter is exposed in the northern Pancake Range, in the center of T. 16 N., R. 55 E. This porphyritic granodiorite contains large anhedral quartz and plagioclase phenocrysts, and smaller biotite, hornblende, and augite in a quartz and feldspar rich matrix (Hose and Blake, 1976). K-Ar dates on biotite give an age of 108 Ma (Hose and Blake, 1976).

One of the largest plutons in the evaluation area is the Cretaceous Toquima or Round Mountain Pluton exposed in the southern Toquima Range in T. 9-10 N. R. 45 E., and an associated and separated body in T. 7-8 N., T. 44 E along the edge of the map area. This 76 to 78 Ma pluton is a medium-grained, hypidiomorphic to porphyritic, moderately foliated quartz monzonite to granodiorite, that shows a steep intrusive contact with Cambrian and Ordovician strata (Kleinhampl and Ziony, 1985).

The Belmont stock, exposed as the eastern portion of the plutonic mass, is intruded by the Round Mountain pluton, and is a medium-grained, porphyritic to massive, granite to quartz monzonite which is nearly concordant with surrounding metamorphosed Cambrian and Ordovician strata.

In the Dolly Varden, area the Melrose stock intrudes Permian sediments forming a 12 square mile plutonic mass. About 85 percent of the pluton is medium to coarse-grained, sill-like, hydrothermally altered quartz monzonite that is locally porphyritic, and 10 to 15 percent is augite monzonite, and fine-grained granite (Snow, 1964). The average intrusive contains about 10-27 percent quartz, 27-37 percent plagioclase, 20-40 percent potassium feldspar, 7-12 percent biotite, 1-6 percent hornblende and accessory magnetite, sphene, apatite, and epidote (Snow, 1964). Aplite, pegmatite, and porphyritic granitic dikes are associated with the stock, which is dated at 134 Ma (Armstrong and Hansen, 1966).

At Indian Spring in the Delano Mountains, a variably textured stock is dominantly composed of fine-grained and equigranular to porphyritic granodiorite to granite. It has a K-Ar age of about 136.0 +/- 2.0 Ma (Slack, 1974). In the Elk Mountains, a small stock of pink-gray, medium-grained and equigranular, biotite-hornblende granodiorite to quartz monzonite and associated aplite dikes were assigned a lead-alpha age 100 +/- 10 Ma (Fifer, 1960).

In the Mountain City Quadrangle, the large Cottonwood Creek and McDonald Creek (Hicks Mountain) plutons are both composed of biotite granodiorite and aplitic phases, and are partially overlapped by Tertiary volcanics. The northern stock, the Cottonwood Creek Pluton has given K-Ar ages 86.0 +/- 3 Ma and 89.2 +/- 3 Ma. The northern McDonald Creek pluton gives a K-Ar age of 88 +/- 4.4 Ma (Coats and McKee, 1972).

The Cretaceous Coffee Pot or Bruneau River stock is exposed along the western flank of the Copper Mountains ridge area in the Rowland Quadrangle and into the western Jarbidge Quadrangle. This stock is a very large, nearly circular mass of fine to medium-grained hornblende-biotite or biotite quartz monzonite, with a few smaller satellite bodies of granodioritic composition (Coats, 1964; Bushnell, 1967; Coats and others, 1977). Small mineable bodies of molybdenian scheelite are present in contact metamorphic haloes around the stock. This stock gives a lead alpha age of 120 +/- 10 Ma (Coats and McKee, 1977).

In the northern portion of the Rowland Quadrangle, the Deep Creek or Bearpaw Mountain stock is a relatively large granite to quartz monzonite stock with biotite, hornblende, orthoclase, quartz, plagioclase, and accessory magnetite and epidote (Bushnell, 1967). The K-Ar age of this Late Cretaceous stock is 73 +/- 3.7 Ma (Coats and others, 1965).

In the Owyhee and Bull Run Quadrangles several plutons are present including the Skull Creek pluton, and Mountain City pluton with its outlier mass, the Sikikareh Mountain pluton (Coats, 1971, 1985). These plutons are composed of hornblende-biotite granodiorite to quartz monzonite and are locally perthitic with orthoclase phenocrysts, and alaskite along contacts. K-Ar dates on biotite give an age of 81 +/- 4 Ma for the Skull Creek pluton, and 81 +/- 4 Ma and 90 +/- 4.5 Ma for the Mountain City pluton (Coats and others, 1965). The small Silver Creek pluton in the Bull Run Quadrangle is biotite granite dated at 92.1 +/- 3 Ma (in Coats, 1985).