Type Sections of the Madison Group (Mississippian) and its Subdivisions in Montana GEOLOGICAL SURVEY PROFESSIONAL PAPER 842 Type Sections of the Madison Group (Mississippian) and its Subdivisions in Montana By WILLIAM J. SANDO and J. T. DUTRO, JR. GEOLOGICAL SURVEY PROFESSIONAL PAPER 842 Descriptions of the type sections of theMadison Group, Mission Canyon Limestone, Lodgepole Limestone, and Paine and W oodhurst Members of the Lodgepole Limestone UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1974 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 7 4-600 112 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402- Price $1.70 (paper cover) Stock Number 2401-02528 CONTENTS Page Page 1\bstract ---------------------------------------- 1 Descriptions of type sections-Continued IntroductiQn ------------------------------------­ 1 Monarch-U.S. 89 section --------------------­ 8 History of nomenclature ------------------------­ 2 Dry Fork section ---------------------------­ 12 Descriptions of type sections ---------------------- 3 Mission Canyon section ----------------------­ 16 Field methods -------------------------------­ 3 Little Chief Canyon section ------------------- 17 Boundary criteria and nomenclature ----------- 4 1\ge and correlation -----------------------------­ 21 Logan section ------------------------------- 4 References cited --------------------------------- 21 ILLUSTRATIONS Page PLATE 1. Correlation of type and reference sections of Madison Group ----------------------------------In pocket FIGURE 1. Geologic sketch map of Logan section ------------------------------------------------------------ 5 2. Photographs showing Madison Group in Logan section ------------------------------------------- 6 3. Geologic sketch map of Monarch-U.S. 89 section ---------------------------------------------------- 9 4. Photographs showing Madison Group in Monarch-U.S. 89 section -------------------------------- 10 5. Geologic sketch map of Dry Fork section --------------------------------------------------------- 12 6. Photograph of cliffs at Currie Coulee on Dry Fork of Belt Creek, showing exposures of Lodgepole Limestone and basal beds of Mission Canyon Limestone ---------------------------------------- 13 7. Photograph of cliff face at Currie Coulee on Dry Fork of Belt Creek, showing uppermost beds of Jef- ferson Formation through basal beds of Woodhurst Member of Lodgepole Limestone -------------~- 13 8. Geologic sketch map of Mission Canyon section ---------------------------------------------------- 16 9. Photograph of cliffs on north side of Mission Canyon, showing contact between Mission Canyon Lime- stone and Lodgepole Limestone ----------------------------------------------------------------- 17 10. View down Mission Canyon, showing thick beds of lower 100 feet of Mission Canyon Limestone ____ 17 11. Geologic sketch map of Little Chief Canyon section ----------------------------------------------- 18 III TYPE SECTIONS OF THE MADISON GROUP (MISSISSIPPIAN) AND ITS SUBDIVISIONS IN MONTANA By WILLIAM J. SANDO and J. T. DuTRo, JR. ABSTRACT The purpose of the report is to designate and de­ This report presents descriptions of precisely located type scribe type sections for the Madison Group and its sections for the Madison Group and its principal subdivi­ principal subdivisions in Montana. Collections of fos­ sions in Montana. The type section of the Madison Group, sils from these sections, permanently housed at the originally p~roposed as a formation by A. C. Peale in 1893, U.S. National Museum in Washington, D.C., form is on the Gallatin River at Logan, southwest Montana. an important reference· set for any future biostrati­ Type sections for the· Lodgepol~ Limestone and Mission Canyon Limestone, originally proposed by A. J. Collier and graphic analyses of the type sections. These collec­ S. H. Cathcart in 1922, are located on ·the flank of the Little tions have already been used in several biostrati­ Rocky Mountains in north-central Montana. Inasmuch as graphic studies of the Madison Group (Sando, 1960; the Mission Canyon Limestone· is truncated by pre-Jurassic Sando and Dutro, 1960; Sando and others, 1969). erosion in its typ·e section, a complete, reference section just north of Monarch in the Little Belt Mountains is described This report deals with the type sections of the fol­ for the Mission Canyon. A section on the Dry Fork of Belt lowing stratigraphic units: Creek in the Little Belt Mountains is described as type Madison Group (Peale, 1893). section for the Paine and W oodhurst Members of the Lodge­ pole Limestone, units that were named by W. H. Weed in, Mission Canyon Limestone (Collier and Cath­ 1899. Collections of fossils from the type sections are used cart, 1922). for dating and corr·elation of the Madison strata and form Lodgepole Limestone (Collier and Cathcart, an important reference set for future biostratigraphic 1922). analyses. Woodhurst Member (Weed, 1899a). Paine Member (Weed, 1899a). INTRODUCTION A third subdivision of the Lodgepole Limestone, The Madison Group is one of the more widespread the Cottonwood~ Canyon Member (Sandberg and stratigraphic units in the western United States. Klapper, 1967), is recognized in two of the type sec­ This great mass of Mississippian carbonate rocks tions described herein. Inasmuch as its type section extends over most of Montana and parts of the is in Wyoming and has been described in detail by Dakotas, Idaho, Wyoming, and Utah. Limestone Sandberg and Klapper (1967, p. B16-B19), it is not units of equivalent age in California, Nevada, des·cribed in this report. Arizona, Utah, Wyoming, and Colorado, although The name Charles Formation has been applied to given different names, are part of a continuous sheet interbedded carbonate, terrigenous, and evaporitic of Madison-like carbonate sedimentary rocks. sedimentary rocks equivalent to the upper part of The Madison has been studied and mapped since the Mission Canyon Limestone in the subsurface the days of the earliest geological investigations of Williston basin of central and eastern Montana and the Western United States. From the standpoint of the western parts of the Dakotas. The Charles was stratigraphic nomenclature, ·the more important originally proposed by Seager (1942, p. 863, 864) for studies were made in Montana, where most of the beds between the Kibbey Formation of the Big subdivisions of the Madison were established. Al­ Snowy Group and the top of the Madison Group in though many stratigraphic studies have been made the Arro Oil and Refining Company and California since this stratigraphic unit was proposed in 1893, Company No. 4 well in sec. 21, T. 15 N., R. 30 E., type sections for most of the fundamental Montana Petroleum County, Mont. Although Seager originally subdivisions have never been described in detail. included the formation in the Big Snowy Group, 1 2 TYPE SECTIONS OF THE MADISON GROUP IN MONTANA Sloss (1952, p. 66-67) regarded the Charles as the HISTORY OF NOMENCLATURE uppermost unit of the Madison Group, and this usage Peale ( 1893, p. 32-39) proposed the name Madison has been followed in most subsequent stratigraphic formation for carbonate rocks of early Carbonifer­ work. ous age underlain by the Three Forks shales Perry and Sloss (1943, fig. 3) presented a graphic (Devonian) and overlain by the Quadrant formation log of the Charles in the well section originally de­ (upper Carboniferous) in the Three Forks area of scribed by Seager, and Nordquist (1953, p. 79) southwest Montana. Peale recognized three divisions referred to this section as the "type well" and rede­ of the Madison, in ascending order: Laminated lime­ fined the limits of the formation. Although some stones, Massive limestones, and Jaspery limestones. geologists have extended the term "Charles Forma­ Iddings and Weed ( 1894, p. 2) used the name Madi­ tion" to surface exposures of Madison rocks in parts son limestone for rocks of similar age, lithology, and of central and western Montana, it is defined on stratigraphic position near Livingston, Mont. Al­ criteria that are difficult to use with precision in out­ though Weed (in Hague and others, 1896, p. 4) stated crop areas. Moreover, it includes beds referred by that Peale's term was derived from the Madison most geologists to the Mission Canyon Limestone. Range, Sloss and Hamblin (1942, p. 313) suggested Pending further clarification of its exact relation­ that the name referred to the Madison River, which ships with the Mission Canyon Limestone of central joins with the Gallatin and Jefferson Rivers to form and southwestern Montana, we recommend that the the Missouri at Three Forks. Charles be restricted to the subsurface in the Willis­ Weed ( 1899a, p. 2 ; 1899b, p. 2) divided the Madi­ ton basin. son limestone of the Little Belt Mountains into Paine The Madison Limestone in the mountain ranges of shale, Woodhurst limestone, and Castle limestone, northwest Montana was divided by Deiss (1933, p. which evidently corresponded roughly to Peale's 45-48) into five members (in ascending order): Laminated limestones, Massive limestones, and Jas­ Silvertip Conglomerate, Saypo Limestone, Dean Lake pery limestones, respectively. In a later report, Weed Chert, Rooney Chert, and Monitor Mountain Lime­ (1900, p. 290-294) used the term "Madison group" stone. Later work by Deiss (1943, p. 228) in the Saw­ but does not seem to have