Pg. 1-4. Frobisher-Alida beds (informal) of Madison group. Bounded above by Midale beds or Frobisher anhydrite and bounded below by Tilston beds (all informal). Boundary between Charles Formation and Mission Canyon Limestone may be at top of Frobisher-Alida beds. Embraces Mission Canyon Formation subunits M.C.3 to M.C.5 of Thomas (1954). Age is Mississippian.
Informally named from Frobisher and Alida oil fields, southeastern Saskatchewan, Canada. Complete section lies between 4,162 ft and 4,537 ft in the Imperial Workman no. 3-8 well, Lsd. 3, in sec. 8, T. 1, R. 32, West 1st Meridian, Saskatchewan, Canada.
[See also J.G.C.M. Fuller, 1956, Saskatchewan Dept. Min. Res. Rept., no. 19, 72 p.; G.E. Thomas, 1954, Mississippian of northeastern Williston basin, Can. Inst. Min. and Met. Trans., v. 57, p. 68-74.]

Source: Excerpted from North Dakota lexicon (North Dakota Geol. Survey Rept. Inv. 71, p. 41-42); supplemental information from GNU records (USGS DDS-6; Denver GNULEX).

Frobisher-Alida interval (informal) in Madison group. Defined by mechanical-log markers. Present in subsurface of the Williston basin, North Dakota. Revised to include Rivil subinterval in uppermost part (corresponds to lower part of Saskatchewan Geol. Soc., 1956, Midale beds). Overlain by Midale subinterval (informal) of Ratcliffe interval (informal) in Madison group (= Midale beds of Anderson and Carlson, 1958); underlying beds not shown here, but base of interval is same as that defined by Saskatchewan Geological Society (1956). Age is Mississippian. Electric- and radioactivity-log of the upper part of the interval shown for the Pan American, B. Staaleson No. 1 well, in NW/4 NE/4 sec. 6, T. 162 N., R. 91 W., Burke Co., ND, and in five mechanical-log cross sections in Burke Co., ND.

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

Frobisher-Alida interval (informal) in Madison group. Defined by mechanical-log markers. Present in subsurface of the Williston basin, North Dakota. Subdivided into (ascending): lower limestone unit, anhydrite unit, upper limestone unit, and Rivil subinterval. Underlies Ratcliffe interval (informal) in Madison group; overlies Tilston interval (informal) in Madison group. Age is Mississippian. Electric-log characteristics shown for the Carter-Phillips G. Blower No. 1 well, in SE/4 SW/4 sec. 20, T. 160 N., R. 83 W., Bottineau Co., ND, and on a detailed electric- and radioactivity-log correlation diagram extending from Renville Co., ND, southward to Sioux Co., ND. Report also includes isopach and structure maps of the lower two subdivisions, from Renville and Bottineau Cos. to Sioux and Emmons Cos., ND.

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

Frobisher-Alida interval (informal) in Madison Group. Defined by mechanical-log markers. Present in subsurface of the Williston basin, North Dakota. Compares usage of the term by some previous authors in North Dakota and southeastern Saskatchewan. Summarizes lithologic and stratigraphic relations. Age is late Early to early Late Mississippian (Osagean to early Meramecian), based on correlation with equivalent rocks in Canada. Electric-log characteristics shown for the Carter Oil Company, E.L. Semling No. 1 well, in sec. 18, T. 141 N., R. 81 W., Oliver Co., ND. Report also includes isopach map.

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