Pg. 1388, pl. 1 (geol. map). Andorno formation. Phyllite in massive and laminated units up to several 100 feet thick interbedded with persistent thin beds of quartzite, dolomitic quartzite, dolomite, and limestone. Total thickness 7,000 to 8,000 feet. Overlies Singas formation (new) with gradational contact; underlies Mullinix formation (new) with gradational contact. Fossils (deformed ammonoids, pelecypods, brachiopods). Age is Late Triassic (Norian; base of formation may be Karnian), based on fossils identified by S.W. Muller.
Type area: on high ridges that separate drainage of Andorno, Buffalo, Stone House, and Wash O'Neill [also spelled O'Neal] Creeks, southern Santa Rosa Range, Winnemucca region, Humboldt Co., north-central NV. Named from Andorno Creek, [notably in secs. 16 and 17, T. 41 N., R. 38 E., Five Fingers area, Paradise Valley 15-min quadrangle], Humboldt Co., north-central NV.

Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 97); GNU records (USGS DDS-6; Menlo GNULEX).

Pg. E3 (table 1), E6 (fig. 3), E8, E9. Andorno Formation of Auld Lang Syne Group. Andorno Formation of Compton, 1960 (GSA Bull., v. 71, no. 9, p. 1383-1416) included in Auld Lang Syne Group (new). Fossils. Deformed ammonites reported by Compton (1960) are too poorly preserved to warrant a tentative age assignment, but pelecypod MONOTIS cf. M. SUBCIRCULARIS and brachiopod HALORELLA sp. indicate a late Norian age for the Andorno. Age is considered Late Triassic (late Norian).
Type locality (=type area of Compton, 1960): in secs. 15, 16, and 17, T. 41 N., R. 38 E., Paradise Valley 15-min quadrangle, Humboldt Co., north-central NV.

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