Pg. 25-26, pls. 3, 4. Schieffelin granodiorite. Has general appearance of a rather fine-grained light-gray granite and locally is referred to by that name. Slightly reddish tint in places and passes into various porphyritic modifications along its contact with the sedimentary rocks into which it is intrusive, including the Naco limestone and beds of the Bisbee group. May come from same body of magma as Uncle Sam porphyry (new). Age is Late Cretaceous or Tertiary. Report includes geologic maps.
Named from its typical occurrence in vicinity of Schieffelin's monument, about 1 mi northwest of Tombstone, western Cochise Co., southeastern AZ.

Source: US geologic names lexicon (USGS Bull. 1200, p. 3493); supplemental information from GNU records (USGS DDS-6; Denver GNULEX).

Schieffelin granodiorite. Age changed from Late Cretaceous or Tertiary --to-- probably early Tertiary. Intrudes Uncle Sam porphyry. Is older than the Pliocene Gila conglomerate. Mapped in Tombstone district, T. 19 and 20 S., R. 22 E., Cochise County, Arizona.

Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).

Pg. 102-104, pl. 5. Schieffelin granodiorite. Could also be called a quartz monzonite. Intrusive contacts found with all members of Naco group and with Bisbee formation, Bronco volcanics, and Uncle Sam porphyry. Occupies area of about 3 sq mi in Tombstone district and forms Bronco Hill in central Cochise County, southeastern Arizona. Unconformably underlies upper Pliocene valley fill. Age is probably middle Tertiary; not older than Late Cretaceous. Shown on geologic map with units of Eocene(?) to lower Pliocene(?).

Source: US geologic names lexicon (USGS Bull. 1200, p. 3492); supplemental information from GNU records (USGS DDS-6; Denver GNULEX).

K-Ar age 72 Ma.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Schieffelin Granodiorite. Sample from Tombstone area, Cochise County, Arizona. Recalculated K-Ar age is 76 +/-3 Ma [Late Cretaceous].

Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).

Pg. 6, geologic time scale (inside front cover). Schieffelin Granodiorite(?). Sample from granodiorite pluton, that may be a late-phase of the Schieffelin Granodiorite, in gully 250 m west of Lookout Lodge, in SE/4 sec. 2, T. 20 S., R. 22 E., Lat. 31 deg. 43 min. 18 sec. N., Long. 110 deg. 04 min. 27 sec. W., Tombstone 7.5-min quadrangle, Cochise County, Arizona, yielded a K-Ar age of 62.6 +/-2.8 Ma (hornblende). Age calculated using decay constants of Steiger and Jager, 1977 (Earth Planet. Sci. Letters, v. 36, p. 359-362). [Late Cretaceous to Paleocene; Cretaceous-Paleocene boundary 66 (66-63) Ma]

Source: Publication.