Index to the Geologic Names of North America By DRUID WILSON, GRACE C. KEROHER, and BLANCHE E. HANSEN GEOLOGIC NAMES OF NORTH AMERICA GEOLOGICAL SURVEY BULLETIN 10S6-B Geologic names arranged by age and by area containing type locality. Includes names in Greenland, the West Indies, the Pacific Island possessions of the United States, and the Trust Territory of the Pacific Islands UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1959 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.G. - Price 60 cents (paper cover) CONTENTS Page Major stratigraphic and time divisions in use by the U.S. Geological Survey._ iv Introduction______________________________________ 407 Acknowledgments. _--__ _______ _________________________________ 410 Bibliography________________________________________________ 410 Symbols___________________________________ 413 Geologic time and time-stratigraphic (time-rock) units________________ 415 Time terms of nongeographic origin_______________________-______ 415 Cenozoic_________________________________________________ 415 Pleistocene (glacial)______________________________________ 415 Cenozoic (marine)_______________________________________ 418 Eastern North America_______________________________ 418 Western North America__-__-_____----------__-----____ 419 Cenozoic (continental)___________________________________ 421 Mesozoic________________________________________________ 421 Cretaceous______________________________________________ 422 Jurassic__ ______________________________________________ 422 Triassic ____________________________________ 422 Paleozoic.________________________________________________ 422 Permian___________________._______________ 423 Pennsylvanian__________________________________________ 423 Mississippian____________________________________________ 424 Devonian_______________________________________________ 425 Silurian________________________________________________ 425 Ordovician______________________________________________ 426 Cambrian_______________________________________________ 426 Precambrian-_____________________________________________ 427 Rock Units ..__________________________________ 429 United States....._____________.________________ 429 Canada...________________________________.__ 576 St. Pierre and Miquelon________________________________________ 603 Mexico.___________________________________._ 603 Central America_____________________________________________ 607 Greenland.....___._____________________.____...__ 609 Bermuda__________________________________________________ 611 West Indies.._________________________________ 612 Pacific Islands_______________________________________________ 618 Additions and corrections...-_________-____.-____________-------- 621 ni Major stratigraphic and time divisions in use by the U.S. Geological Survey Estimated ages of tune Era System or Period Series or Epoch boundaries in millions of years ' Recent Quaternary Pleistocene 1_ Pliocene Cenozoic 10 Miocene ocr Tertiary Oligocene 40 Eocene £ff\ Paleocene Cretaceous 2 Upper (Late) Lower (Early) 10K Upper (Late) Mesozoic Jurassic Middle (Middle) Lower (Early) i^n Upper (Late) Triassic Middle (Middle) Lower (Early) 1 9ft Permian 2 OAR Upper (Late) g § | Pennsylvanian 2 Middle (Middle) f2.2 Lower (Early) Q-^ 5? Mississippian 2 Upper (Late) Lower (Early) oec Upper (Late) Paleozoic Devonian Middle (Middle) Lower (Early) 01 C Upper (Late) Silurian 2 Middle (Middle) Lower (Early) OCA Upper (Late) Ordovician 2 Middle (Middle) Lower (Early) IOA Upper (Late) Cambrian 2 Middle (Middle) Lower (Early) Kin Informal subdivisions such as upper, middle, Precambrian 2 and lower, or upper and lower, or younger and older may be used locally. Terms designating time are La parentheses. Informal time terms early, middle, and late may be used for eras, periods, and epochs where there is no formal subdivision into Early, Middle, and Late. Informal rock terms lower, middle, and upper may be used where there is no formal subdivision of a system or of a series. 1 Age values given are the Holmes "B" time scale points (Holmes, 1947, p. 145). pates are rounded to the nearest 5 million years. The errors are unknown, but more recent age determinations by various phys­ ical methods are in partial agreement with these values. For a recent compilation of radiogenic dates see selection of Adolph Knopf in Longwell's "Geologic column and scale of time" (1958, AGI 5). 8 Provincial series accepted for use in U.S. Geological Survey reports are listed under both the time and the rock units. IV GEOLOGIC NAMES OF NORTH AMERICA INDEX TO THE GEOLOGIC NAMES OF NORTH AMERICA By DRUID WILSON, GRACE C. KEROHER, and BLANCHE E. HANSEN INTRODUCTION Beginning in 1902, the U.S. Geological Survey has published five compilations treating the names of geologic formations and strati- graphic classification and nomenclature: "North American Geologic Formation Names," by F. B. Weeks (Bull. 191, 1902). "The Geologic Time Classification of the United States Geo­ logical Survey Compared with Other Classifications, Accompanied by the Original Definitions of Era, Period, and Epoch Terms," by M. Grace Wilmarth (Bull. 769, 1925). "Names and Definitions of the Geologic Units of California," by M. Grace Wilmarth (Bull. 826, 1931). "Lexicon of Geologic Names of the United States (including Alaska)," by M. Grace Wilmarth (Bull. 896, 1938; reprinted 1951, 1957). "Geologic Names of North America Introduced in 1936-1955," by Druid Wilson, W. J. Sando, R. W. Kopf, and others (Bull. 1056-A, 1957). The demand for compilations of geologic names is well attested by the circumstance surrounding the completion of the first Survey compilation by F. B. Weeks. In 1899, after it became apparent that the task was too great for one compiler, Survey geologists were asked to help, and were apportioned parts of the geologic literature to review. In this way the compilation was completed and published in 1902. The following geologists participated: M. R. Campbell, N. H. Darton, J. S. Diller, G. H. Girty, C. W. Hayes, F. H. Knowlton, F. L. Ransome, G. 0. Smith, A. C. Spencer, T. W. Stanton, J. A. Taff, T. W. Vaughan, and David White. Wilmarth's compilation of terms used in geologic-tune classification was published in 1925 and is still invaluable for quotations of the original definitions and descriptions of the standard and other strati- 407 408 GEOLOGIC NAMES OF NORTH AMERICA graphic and tune divisions from widely scattered and sometimes un­ available sources. The California names and their annotations pub­ lished in 1931 were repeated without change in Wilmarth's lexicon of the United States names in 1938. The reprinting of Wilmarth's lexicon in 1951 and 1957 confirms its place in the field of geologic publications. Brevity of format in "Geologic Names of North America Introduced in 1936-1955" made it possible to bring out quickly a compilation intended to be superseded by the first supplement to Wilmarth's lexicon, now in preparation. In the present report the geologic names of North America, including Greenland, the West Indies, the Pacific Island possessions of the United States, and the Trust Territory of the Pacific Islands, that were published before 1956 are arranged to form a nonalphabetic index to Wilmarth's lexicon and to the "Geologic Names of North America Introduced in 1936-1955." This grouping of the names on the basis of the age and politico-geographic divisions containing the type locality is an easily used key not available elsewhere. The age of each formation (that is, rock unit) named from an area is shown, but not its complete geographic extent. The geologic-tune and time- stratigraphic units are grouped together under the major time divisions. Some names entered in Wilmarth's lexicon have been omitted. They include (a) all paleontologic and descriptive terms, (b) all names of economic units, such as miner's terms, trade names, and subsurface names identical with the names of formal rock units, (c) the names of moraines and other units of which physiography is an essential part of the definition, and (d) the names of orogenies. The American Commission on Stratigraphic Nomenclature (1955, p. 2008) has recommended that the names of moraines and other physiographic units be considered informal and not subject to the rules that apply to stratigraphic names. The names of the rock units are listed once only in the geographic area that contains or is assumed to contain the type area or locality. Thus, the Grenville series, a geologic name commonly used in the State of New York, is listed under the Canadian province of Ontario, where its type locality occurs; and the Colorado group or shale, used widely in Canada, is under the State of Colorado. Not all geologic formations end at political boundaries. In the period of more than 20 years since the compilation if Wil­ marth's lexicon, many names have been revised and many names not then accepted for use by the U.S. Geological Survey have been adopted. Adoption of names for use by the U.S. Geological Survey is based on the published and unpublished reports of Federal Survey geologists on areas of the United States and its possessions or trust INDEX TO THE GEOLOGIC NAMES OF NORTH AMERICA 409 territories. The U.S. Geological Survey has had occasion to consider for acceptance or rejection considerably less than one-half of the names of geologic units