...Gary E. Guthrie ABSTRACT Isopachs and lithofacies of the Big Snowy Group in the Bridger Range of southwestern Montana reflect subtle shifting of tectonic elements along an ancient structural lineament. The group comprises a transgressive series informally divided into the Kibbey Formation (with two...

... to show the lateral extent, thickness, and lithologic character of the Jurassic Ellis formation, the lower Pennsylvanian Amsden formation, the upper to middle Mississippian Big Snowy group. The Big Snowy group, which is divided into the Heath, Otter, Kibbey and Charles formations in descending order...

.... The Mississippian Big Snowy group-Pennsylvanian have been divided as follows. The Big Snowy group has been subdivided into the Kibbey, Otter, and Heath formations. The Kibbey formation contains a lower, middle and upper member. The Pennsylvanian sediments comprisethe Tyler and Minnelusa-Amsden formations. ...

...: Kibbey, Otter, and Heath, and the group reaches an aggregate thickness of approximately 1,000 feet. Seager (1942) included the Charles formation in the Big Snowy group, but this interpretation has not found wide acceptance, and the Charles formation is generally considered to be lithologically...

... the now mainly buried shelf-edges of this irregular basin. As a name for the entire intergrading sequence, the Big Snowy group of Scott is expanded and redefined to include, in ascending order, not only the Kibbey sandstone, Otter formation, and Heath formation of his original report, but also three...

... favor including in the Heath the beds at 6,762–6,766 feet containing scolecodonts, but consider the decision somewhat arbitrary. As to the boundary between the Otter and Kibbey formations in the N.P. well No. 1 and the Porcupine well, we suggest that a satisfactory basis for a decision is lacking...

... to reconstruct the geometry of the trough in Chesterian time has been destroyed, especially the evidence that could have been determined from the sedimentary facies within the Big Snowy Group. The Big Snowy Group, comprised from base to top of the Kibbey, Otter, and Heath Formations ( Figure 2 ), probably...

... formation of central Montana has been designated the Big Snowy group, because of its extensive distribution and excellent exposures in the Big Snowy Mountains. Scott divided the group into three formations which, in descending order, are: Heath, Otter, and Kibbey. The names, Kibbey and Otter, had...

... Kinderhookian to lower Meramecian (Mississippian) carbonate rocks as well as Upper Devonian rocks. The floor thrust of this imbricate stack appears to lie within the Upper Devonian Three Forks Formation; the roof thrust lies within the middle Meramecian Kibbey Sandstone. The upper duplex involves Upper...

... formation (Pennsylvanian) at Herrick Dome in the Laramie Basin, Wyoming, opened another producing zone in this area that had heretofore been considered doubtful. Production of oil from the Kibbey sand (upper Mississippian) at Ragged Point, Montana, can be classed as a new producing zone in that state...

...Figure 12. Isopach map (in feet) of the base of the Kibbey Formation to top Bakken Formation. Four discrete structural zones are present within the Red Wing Creek structure: (1) outer rim, (2) annular trough and the central uplift complex composed of a raised inner rim, and (3) central core...

... (Charles, Mission Canyon, and Lodgepole) isopachous map. The Big Snowy group of Chester, Upper Mississippian age includes the Kibbey, Otter, and Heath formations ( Perry and Sloss, 1943 ). The Kibbey formation consists of limestone and sand, and unconformably overlies the Charles. An erosional...

... of dolomite; Orbiculoidea sp. and conodonts 4,830–4,935 Otter formation—red, purple, orange, yellow, green, buff, and gray shale; small amounts of anhydrite 4,935–5,050 Kibbey formation—varicolored shale, like Otter; considerable fine gray argillaceous sandstone, increasing near base 5,050–5,603 Charles...

... is included in a stratigraphically distinct unit which should be recognized as a new formation. The Kibbey formation is characterized by sandstone, siltstone, reddish brown shale, dolomitic limestone, and variable amounts of anhydrite. Various workers have suggested several possible source areas...

... Section 1 is in the Big Snowy Mountains, Sec. 6, T. 12 N., R. 20 E., as measured by Scott. 5 It illustrates the Big Snowy group at the type locality, beneath the Amsden, including the three formations in ascending order, Kibbey, Otter, and Heath. Scott emphasizes the occurrence of black shales...

...Frank W. Foster ABSTRACT The strata discussed in this paper belong to the shale and lenticular sandstone sequence which has been called the Heath formation of Mississippian age in the Williston Basin. This unit is of economic importance as a source of oil in southwestern North Dakota. Information...