New Mexico Bureau of Mines & Mineral Resources A DIVISION OF NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Facies, diagenesis, and mineralogy of the Jurassic Todilto Limestone Member, Grants uranium district, New Mexico Augustus K. Armstrong U.S. Geological Survey, c/o New Mexico Bureau of Mines & Mineral Resources, Socorro, New Mexico 87801 Geotechnical Information Center SOCORRO 1995 11 NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Daniel H. Lopez, President NEW MEXICO BUREAU OF MINES & MINERAL RESOURCES Charles E. Chapin, Director and State Geologist BOARD OF REGENTS Ex Officio Gary Johnson, Governor of New Mexico Alan Morgan, Superintendent of Public Instruction Appointed J. Michael Kelly, President, 1992-1997, Roswell Steve Torres, Secretary/Treasurer, 1991-1997, Albuquerque Charles Zimmerly, 1991-1997, Socorro Diane D. Denish, 1992-1997, Albuquerque Delilah A. Vega, Student Member, 1995-1997, Socorro BUREAU STAFF ORIN J. ANDERSON, Senior Geologist KATHRYN G. GLESENER, Manager, Cartography Section Virgil LUETH, Mineralogist/Economic Geologist RUBEN ARCHULETA, Metallurgical Lab. Tech. DEBBIE GOERING, Staff Secretary FANG LuO, Research Associate/Petroleum Engineer GEORGE S. AUSTIN, Senior Industrial Minerals Geologist IBRAHIM GUNDILER, Senior Metallurgist DAVID MCCRAW, Cartographer II ALBERT BACA, Maintenance Carpenter II WILLIAM C. HANEBERG, Assistant Director, WILLIAM McIntosh, Volcanologist/Geochronologist JAMES M. BARKER, Assistant Director, Engineering Geologist CHRISTOPHER G. McKEE, X-ray Facility Manager Senior Industrial Minerals Geologist, BRUCE HART, Petroleum Geologist VIRGINIA T MCLEMORE, Senior Economic Geologist Supervisor, Cartography Section JOHN W. HAWLEY, Senior Environmental Geologist, NORMA J. MEEKS, Director of Publications Office PAUL W. BAUER, Field Economic Geologist Manager, Albuquerque Office LISA PETERS, Lab Technician LYNN A. BRANDVOLD, Senior Chemist LYNN HEIZLER, Assistant Curator BARBARA R. POPP, Biotechnologist RON BROADHEAD, Assistant Director, Man HEIZLER, Geochronologist MARSHALL A. REITER, Senior Geophysicist Senior Petroleum Geologist, LYNNE HEMENWAY, Computer Pub./Graphics Spec. CINDIE A. SALISBURY, Cartographer II Head, Petroleum Section CAROL A. HJELLMING, Associate Editor SANDRA SWARTZ, Chemical Lab. Technician RITA CASE, Administrative Secretary (Alb. Office) GRETCHEN K. HOFFMAN, Senior Coal Geologist TERRY TELLES, Technical Secretary STEVEN M. CATHER, Field Economic Geologist GLEN JONES, Manager, Digital Cartography Laboratory REBECCA J. Titus, Senior Cartographer RICHARD CHAMBERLIN, Field Economic Geologist PHILIP KYLE, Geochemist/Petrologist JUDY M. VAIZA, Business Serv. Coordinator RICHARD R. CHAVEZ, Assistant Head, Petroleum Section ANN LANNING, Executive Secretary MANUEL J. VASQUEZ, Mechanic II RUBEN A. CRESPIN, Garage Supervisor ANNABELLE LOPEZ, Petroleum Records Clerk SUSAN J. WELCH, Manager, Geologic Extension Service NELIA DUNBAR, Analytical Geochemist THERESA L. LOPEZ, Receptionist/Staff Secretary MICHAEL WHITWORTH, Chemical Hydrogeologist ROBERT W. EVELETH, Senior Mining Engineer DAVID W. Love, Senior Environmental Geologist MAUREEN Wilks, Bibliographer NANCY S. GILSON, Assistant Editor JANE A. CALVERT LOVE, Editor JIRI ZIDEK, Chief Editor/Senior Geologist ROBERT A. BIEBERMAN, Emeritus Sr. Petroleum Geologist SAMUEL THOMPSON III, Emeritus Sr. Petroleum Geologist FRANK E. KOTTLOWSKI, Emeritus Director/State Geologist ROBERT H. WEBER, Emeritus Senior Geologist JACQUES R. RENAULT, Emeritus Senior Geologist Research Associates WILLIAM L. CHENOWETH, Grand Junction, CO BARRY S. KUES, UNM GLENN R. OSBURN, Washington Univ. CHARLES A. FERGUSON, Univ. Alberta, CAN MICHAEL J. KUNK, USGS ALLAN R. SANFORD, NMT JOHN W. GEISSMAN, UNM TIMOTHY F. LAWTON, NMSU JOHN H. SCHILLING, Reno, NV LELAND H. GILE, Las Cruces DAVID V. LEMONS, UTEP WILLIAM R. SEAGER, NMSU CAROL A. HILL, Albuquerque SPENCER G. LUCAS, NMMNH&S EDWARD W Slams, Tesuque BOB JULYAN, Albuquerque GREG H. MACK, NMSU JOHN F SUTTER, USGS SHARI A. KELLEY, SMU NANCY J. MCMILLAN, NMSU RICHARD H. TEDFORD, Amer. Mus. Nat. Hist. WILLIAM E. KING, NMSU HOWARD B. NICKELSON, Carlsbad TOMMY B. THOMPSON, CS U Graduate Students ROBERT APPELT RICHARD ESSER TINA ORTIZ ULVI CETIN JOHN GILLENTINE DAVID J. SIVILS DAVID ENNIS MICHIEL HEYNEKAMP JOE STROUD Plus about 30 undergraduate assistants Original Printing Published by Authority of State of New Mexico, NMSA 1953 Sec. 63-1-4 Printed by University of New Mexico Printing Services, December 1995 Available from New Mexico Bureau of Mines & Mineral Resources, Socorro, NM 87801 Published as public domain, therefore reproducible without permission. Source credit requested. 111 Contents ABSTRACT 5 ACICULAR-CALCITE CEMENT 21 INTRODUCTION 5 DRUSY DOGTOOTH CEMENT 21 ACKNOWLEDGMENTS 5 EQUANT-SPAR CALCITE CEMENT 21 PREVIOUS STUDIES 6 DIAGENETIC MINERALS 21 DOLOMITE ENVIRONMENTS OF DEPOSITION 6 21 LACUSTRINE DEPOSITION 6 HEMATITE 22 MARINE DEPOSITION BARITE 23 7 DETRITAL GRAINS 23 AGE 7 CLAYS 23 REGIONAL PALEOLATITUDE DETRITAL-QUARTZ AND FELDSPAR GRAINS 23 AND PALEOCLIMATES 7 CHERT 23 STRATIGRAPHY 8 X-RAY STUDIES BY CHRISTOPHER MCKEE 23 MEASURED SECTIONS 10 CARBONATE DEPOSITIONAL STRUCTURES 23 LAYERING: Coolidge section 88J-4 10 ORIGINS AND DEPOSITIONAL ENVIRONMENTS OF Continental Divide section 90J-3 11 TODILTO LAMINATIONS 23 Billy the Kid mine section 88J-3 11 INTRAFORMATIONAL FOLDS IN THE TODILTO LIMESTONE Haystack Mountain section 90J-1 12 MEMBER 25 Section Four and Nine mines 92J-1 12 Faulting associated with intraformational folds 27 Zia/La Jara mine section 90J-2 13 Todilto paleokarst 28 CARBONATE PARTICLES 13 Intraformational folds: Previous concepts 29 ORIGINS OF TODILTO LIME MUD 14 Tepee structures 30 CALCAREOUS MICROBIALITES 14 Origin of Todilto intraformational folds 31 NEOMORPHIC PROCESSES Sedimentary features of tepees absent in 14 Todilto folds 32 SKELETAL GRAINS 18 Evidence from this study 32 DASYCLADACEAN ALGAE URANIUM DEPOSITS IN THE TODILTO LIMESTONE 18 MEMBER 33 OSTRACODES 19 CONCLUSIONS 38 COMPOUND GRAINS 19 REFERENCES 38 Figures 1—Distribution of the Todilto Limestone Member in 19—Photomicrographs of sedimentary structures from New Mexico 6 the middle crinkly and upper massive zones 26 2—Jurassic nomenclature for southern San Juan Basin and 20—Diagrammatic illustration of the diagenetic history Gallup and Acoma sags (after Condon, 1989) 7 of typical Todilto ooids 27 3—Middle-Late Jurassic (middle Callovian-middle 21—Calcite pseudomorph of an anhydrite diapir bed on Oxfordian) paleogeography 8 the flank of an intraformational fold 28 4—Regional stratigraphy and correlation, lithology, and 22—Calcite pseudomorphs of diapir beds and laterally facies chart for the Todilto Limestone Member, Grants associated intraformational conglomerate beneath an uranium district, New Mexico 9 intraformational fold 28 5—Outcrop north of Coolidge section 88J-4 10 23—Intraformational fold in the middle crinkly zone, La 6—Highest beds at the Coolidge section 10 Jara mines 29 7—Continental Divide section 90J-3 11 24—Internal structures of the fold shown in Figure 23 8—Sedimentary structures in the Continental Divide sec- 29 tion 90J-3 11 25—Diapiric enterolithic structures in the middle 9—Desiccated microbial mats, Continental Divide crinkly zone 29 section 11 26—Desiccation features and a small intraformational 10—Outcrop on the highwall of Billy the Kid mine sec- fold 30 tion 88J-3 12 27—Desiccation features and flat lime-mudstone 11—Well-developed intraformational fold on the south- pebbles 30 west side of Haystack Mountain 13 28—Intraformational folds, Haystack Mountain 31 12—SEM photomicrographs of Todilto carbonates 15 29—Intraformational folds, Haystack Mountain 31 13—SEM photomicrographs of Todilto carbonates 16 30—Small intraformational fold, La Jara mines 32 14—Photomicrographs of dasycladacean algae and 31—Intraformational fold in a natural exposure, Zia/La ostracodes from the upper limestone beds of the Jara mines area 33 Coolidge section 88J-4 17 32—Penecontemporaneous, soft-sediment deformation, 15—Photomicrographs of Todilto ostracodes 18 flank of intraformational fold, Bunny mine 33 16—Photomicrographs of Todilto fossils and textures 20 33—"Massive" intraformational fold in a natural outcrop, 17—Photomicrographs of Todilto ooids 22 middle crinkly and upper massive zones, La Jara 18—Naturally weathered outcrop of the Todilto Lime- claim number 9 33 stone Member 25 34—Intraformational fold developed over an Entrada iv Sandstone paleohigh 34 38—Open pit and intraformational fold illustrating the com- 35—Open pit and tunnel into intraformational folds and plex relationship between the Todilto and Beclabito associated small fault, Bunny mine, Section Four Members, Section Nine, unnamed mine 35 area 34 39—High wall of open pit, south face, showing limestone 36—Open pit and tunnel into intraformational fold, facies relationships, karst surface, sinkholes, and Bunny mine 35 breccias, Section Nine, unnamed mine 36 37—Open pit and tunnel into intraformational fold with 40—Solution cavities and breccia, Section Nine, sinkhole, Bunny mine 35 unnamed mine 37 Table 1—X-ray diffraction analysis of mineralogy 24 5 Abstract—The Todilto Limestone Member, the basal member of the Wanakah Formation of the Grants uranium district, is 1-30 ft (0.3-9.1 m) thick and records the change in depositional environment from a restricted marine embayment with an ephemeral connection to the Curtis-Summerville Sea to a completely enclosed salina/playa and shrinking body of gypsifer- ous water. The salina measured 300 mi (483