Dec. 12, 1913; Pg. 109, 113. Benson limestone. Descending: (1) hard, dark-blue, cherty, coralline limestone, 100 feet; (2) massive dark-blue limestone, 300 feet; (3) fossiliferous blue limestone, 3 feet; (4) thick-bedded blue limestone, 100 feet; (5) dark-blue cherty and brecciated limestone, 200 feet; (6) hard blue limestone, 100 feet; (7) dark porous limestone, very fossiliferous, 21 feet; (8) thick-bedded blue limestone, extensively bored, 120 feet; (9) thick-bedded light-blue limestone, 43 feet; (10) thin-bedded blue limestone, 46 feet; (11) limestone conglomerate at base, thin. Total thickness 1,032 feet. Underlies Reade formation without observed disconformity. Unconformably overlies Maxfleld formation (Ordovician).
Named from occurrence in Reade [Reed] and Benson Ridge, just above old mine workings of same name, Salt Lake Co., UT.

Source: US geologic names lexicon (USGS Bull. 1200, p. 163).

Benson limestone. Fossils collected from lower 500 feet of these rocks (by B.S. Butler in 1916 and 1917) have been identified by G.H. Girty as clearly of Madison ([Early] Mississippian) age. Whether upper 900 feet contains evidence indicating that any part of formation is post-Madison, and of Brazer age, remains to be determined, but probably some of it is of Brazer ([Late] Mississippian) age. [Girty informal USGS paleontological report dated March 2, 1917.]

Source: US geologic names lexicon (USGS Bull. 896, p. 163).