Late Paleozoic Stratigraphy of Central Cochise County Arizona GEOLOGICAL SURVEY PROFESSIONAL PAPER 266 Late Paleozoic Stratigraphy of Central Cochise County Arizona By JAMES GILLULY, JOHN R. COOPER, and JAMES STEELE WILLIAMS GEOLOGICAL SURVEY PROFESSIONAL PAPER 266 A report giving detailed descriptions of rocks of Mississippian^ Pennsylvanian, and Permian ages, with representative sections and fauna I lists of the formations concerned UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1954 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 45 cents (paper cover) CONTENTS Page Pennsylvanian and Permian rocks — Continued Abstract_ ____---_-_-____-_-____________________._ 1 Naco group— Continued Introduction. ______________________________________ 1 Colina limestone — Continued Priorwork_________________________________________ 1 Stratigraphy. ______ — _ ——— ___! — 23 Mississippian rocks_________________________________ 2 Epitaph dolomite. — _______________________ 25 Escabrosa limestone___________________________ 2 Name. __---_-__------------_------_-__ 25 Distribution and general character.___________ 2 Distribution and topographic expression. __ 25 Stratigraphy. ______________________________ 3 Stratigraphy __ ————————————————— 26 Thickness________________________________ 5 The problem of stratigraphic interpretation. 27 Representative sections____________________ 5 Thickness _______ __ _ __ — .__ — - 27 Fauna and correlation of the Escabrosa lime­ Conditions of deposition. ________________ 27 stone, by James Steele Williams. _________ __ Scherrer formation_________-----__---_--_-_- 27 Collections from Tombstone Hills_______ 9 Name_ ______________ _ ______ 27 Collections from Dragoon Mountains____ 10 Distribution and topographic expression. __ 28 Collections from Gunnison Hills __________ 10 Stratigraphy. __________________________ 28 Collections from other localities________ 10 Type section_____________-___-__-___-__ 28 Character and age of the fauna___________ 11 Thickness ______ __. — _ _ ——————— 29 Register of U. S. Geological Survey collec­ Concha limestone____---___-----__--_--_--_- 29 tions from localities not in stratigraphic Name. ___ _____________ _______ 29 sections described in this report_______ 13 Distribution and topographic expression. __ 29 Pre-Black Prince disconformity_________________ 13 Stratigraphy _________________ — __ — __ 29 Black Prince limestone________-_____-___________ 13 Type section__________-----__--_------- 29 Name.____________________________________ 13 Thickness ___ ____ _________ ___ 30 Distribution and topographic expression-______ 13 Age and correlation of the formations of the Stratigraphy- ______________________________ 13 Naco group, by James Steele Williams. _____ 30 Representative sections,_____________________ 14 General discussion. ____ — __ — —— _____ 30 Thickness________________________________ 14 Horquilla limestone. _ ________ — ______ 31 Fauna and correlation of the Black Prince lime­ Collections from Tombstone Hills_____ 31 stone, by James Steele Williams. _________ 14 Collections from Gunnison Hills ______ 33 Collections from Gunnison Hills. _________ 15 Collections from other localities —— ___ 33 Collections from Little Dragoon Mountains. 15 Character and age of the fauna. ______ 34 Character and age of the fauna.._________ 15 Earp formation________________-_---_--_ 35 Register of U. S. Geological Survey collec­ Collections from Earp Hill. __________ 35 tions from Black Prince localities not in Collections from Gunnison Hills. _____ 36 stratigraphic sections described in this Collections from other localities __ ___ 37 report.-..-.--_______________________ 15 Character and age of the fauna. ______ 37 Mississippian-Pennsylvanian disconformity___________ 15 Colina limestone...-- ___ __________ — _ 38 Pennsy 1 vanian and Permian rocks.___________________ 15 Collections from Tombstone Hills___- 38 Naco group._________________________________ 15 Collections from other localities. _ — __ 38 Name and subdivisions_-____________________ 15 Character and age of the fauna — —— 39 Horquilla limestone_________________________ 16 Epitaph dolomite__---_--______ —— _____ 41 Name.________________________________ 16 Collections from Tombstone Hills _ __ 41 Distribution and topographic expression___ 16 Collections from other localities —— ___ 41 . Stratigraphy ___________________________ 16 Character and age of the fauna. ______ 41 Earp formation___________________________ 18 Scherrer formation _ ________________ — 42 Name and type locality_______________ 18 Concha limestone.. _______ —— _ —— _____ 42 Distribution and topographic expression. __ 18 Collections from Scherrer Ridge ______ 42 Stratigraphy ___________________________ 18 Collections from other localities __ ___ 42 Representative sections__________________ 19 Character and age of the fauna. ______ 42 Thickness____________________________ 23 Register of U. S. Geological Survey localities of Conditions of deposition.________________ 23 collections from formations of the Naco group Colina limestone_________ T ________________ 23 that are not described in thisreport______ — __ 43 Name_____________________________ 23 Selected bibliography __ _________ — ___________ —— 44 Distribution and topographic expression. __ 23 Index. __ ______ ______________ _ _________ _ _ — 47 in ILLUSTRATIONS Page PLATE 1. Stratigraphic sections of the Naco group._____________________----______-_------_- _________________ In pocket FIGURE 1. Index map showing area within which Stratigraphic studies were made.___---________---.-___-______-----__-- 2 2. Map showing location of Stratigraphic sections in the Tombstone Hills____________________________________ 3 3. Map of Dragoon quadrangle showing the location of Stratigraphic sections- _____.-_________________---_---__ 4 4. Stratigraphic sections of formations of Mississippian age.------------------------------------------------- 6 IV LATE PALEOZOIC STRATIGRAPHY OF CENTRAL COCHISE COUNTY, ARIZONA By JAMES GILLULY, JOHN R. COOPER, and JAMES STEELE WILLIAMS ABSTRACT the gastropods, A. K. Miller of the University of Iowa In earlier work in central Cochise County, Ariz., the rocks for the cephalopods, J. Marvin Weller of the University above the Martin limestone (Devonian) were separated into two of Chicago for the trilobites, and Edwin Kirk of the formations: the Escabrosa limestone (lower Mississippian) and the Naco limestone (Pennsylvanian). Thirty miles to the east, Geological Survey for the crinoids. Lloyd G. Henbest in the Chiricahua Mountains, the Paradise formation of late of the Geological Survey has identified the fusulinids Mississippian age has been recognized. and supplied comments on their significance. Williams In the area here considered—the northern Mule Mountains, has assembled the paleontologic data and is responsible Tombstone Hills, Dragoon Mountains, and Little Dragoon for the age discussions and assignments here presented. Mountains—the Escabrosa limestone is well developed; a lime­ stone called the Black Prince limestone, probably referable to Throughout this report collections from representa­ the upper Mississippian, is present; and the rocks formerly tive stratigraphic sections described herein are given referred to the Naco limestone are subdivided into six formations. in order from top to bottom of formations. The fossils The Naco is a group that includes, from the base upward, the were identified in 1947, except for a few in 1948, and Horquilla limestone (Pennsylvanian), the Earp formation (late the terminology used is of that date. The various Pennsylvanian and possibly Permian), the Colina limestone (Permian? and Permian), and the Epitaph dolomite, the Scherrer classes of fossils listed were identified by the respective formation, and the Concha limestone (all three of Permian age). persons just mentioned, and Williams has identified Representative stratigraphic sections, faunal lists, and age the brachiopods and other forms not credited to others. discussions of these units are included. Collection numbers are those of the U. S. Geological INTRODUCTION Survey, and localities and zones at which these collec­ tions were made are shown in the stratigraphic sections The area of this investigation is shown in figure 1. or described in the registers of collections for the Esca­ Field work in the Pearce and Benson quadrangles was brosa limestone, the Black Prince limestone, and the begun by Gilluly in 1936, and continued for four field Naco group. Collection numbers preceded by this seasons. He was assisted at various times by Edgar symbol *fc (open star) are not from the measured Bowles, R. S. Cannon, Jr., J. H. Wiese., W. B. Myers, stratigraphic sections presented but are from areas so F. S. Simons, and S. C. Creasey. Williams visited the near that the collections can be fitted into the sections field in 1938 and spent several days assisting in inter­ with reasonable accuracy. preting the stratigraphic succession in this much-faulted The maps of figures 1, 2, and 3 are presented to show area. In 1944 Cooper began work in the Dragoon the general areal relations of the sections described. quadrangle just to the north and continued this work Their scale is inadequate to show all the geographic through 1949, assisted at various times by T. W. positions referred to in the text but these may all be Amsden, F. W. Farwell, Kuo