IGNEOUS INTRUSIONS AND THERMAL EVOLUTION IN THE RATON BASIN, CO-NM: CONTACT METAMORPHISM AND COAL-BED METHANE GENERATION A Thesis presented to the Faculty of the Graduate School University of Missouri-Columbia ____________________________________ In Partial Fulfillment Of the Requirements for the Degree Masters of Science _________________________________ by JENNIFER REBECCA COOPER Dr. Alan Whittington, Thesis Supervisor MAY 2006 The undersigned, appointed by the Dean of the Graduate School, have examined the thesis entitled: IGNEOUS INTRUSIONS AND THERMAL EVOLUTION IN THE RATON BASIN, CO-NM: CONTACT METAMORPHISM AND COAL- BED METHANE GENERATION Presented by Jennifer Rebecca Cooper A candidate for the degree of Master of Science A hereby certify that in their opinion it is worthy of acceptance. _____________________________ Alan Whittington _____________________________ Peter Nabelek _____________________________ Steven Keller ACKNOWLEDGEMENTS So many people have helped with this project by providing laboratory assistance, instruction and encouragement. These include William Huggett and Dr. Jack Crelling of Southern Illinois University and Dr. Sue Rimmer of the University of Kentucky-Lexington. Access to these laboratories was essential to this project. AAPG’s Energy-Minerals graduate student research grant and GSA’s Coal Division Annette Medlin Award provided funding for this research. Thanks to a GSA Graduate Student Research grant that provided funding for investigation of xenolith dissolution. Thanks to the MU Research Council and the University of Missouri Research Board for funding. Thank you to Gus Holmes and Rich Larsen at the Vermejo Park. Both were helpful in providing land access and information about the geology of the park. Thanks to the NRA for land access. Thank you to Brad Joliff and Gretchen Benedix at Washington University for assistance with the electron microprobe. Thanks to Bob Poli and Bruce Fegley for access to the Experimental Petrology laboratory at Washington University. Thanks to everyone at the University of Missouri-Columbia who assisted with this project. Thanks to my thesis committee members, Dr. Peter Nabelek and Dr. Steven Keller. Thanks to Lou Ross for assistance with the SEM, Damon Bassett for assistance with the mass spectrometer and Amanda Hassler for field work assistance. Thanks to Fred Davis for help with experiments and discussions about the results. Thanks to Paula Lee for input, suggestions and encouragement. Thanks to my advisor, Dr. Alan Whittington for guidance and encouragement throughout this project. ii TABLE OF CONTENTS AKNOWLEDGEMENTS…………………………………………………………….ii LIST OF ILLUSTRATIONS………………………………………………………..vi LIST OF TABLES………………………………………………………………….xiii ABSTRACT………………………………………………………………………. .xiv CHAPTER 1: INTRODUCTION 1.1 Overview……………………………………………………………………….….1 1.2 Geological Setting of the Raton Basin…….……….……………………...………5 1.3 Maturation History of the Coal-bearing Strata…….……..…………………...…12 1.4 History of Igneous Activity in the Raton Basin…………………………..……..16 1.5 Carbon Isotope Fractionation During Coalification…….……………...………..18 1.6 Coal Metamorphism by Igneous Intrusion……………………...……………….23 1.7 Coal-bed Methane and Igneous Activity in the Raton Basin and other Locations ……………………………………………..28 1.8 Xenolith Dissolution in Nature and Experiments ……………..…………………34 1.9 Summary…………………………………………………………………………38 CHAPTER 2: CONTACT METAMORPHISM OF COAL 2.1 Introduction………………………………………………………………………40 2.2 Methods…………………………………………………………………………..42 2.3 Sample Locations and Outcrop Descriptions…………………………………….46 2.4 Thermal Profiles across Sills and Dikes……………………………...………….54 2.5 Paleotemperatures………………………………………………...……………...60 2.6 Coke Petrography………………………………………………………...………68 2.7 Carbon Isotope Results………….……………………………………………….71 iii 2.8 Total Organic Carbon Results……………….…………………………………...74 2.9 Discussion ……………………….……………………………………………….78 2.9 A. Reflectance Values, Intrusion Thickness and Intrusion Geometry …………………………….………………..………………8 2.9 B. Carbon Isotopes as an Indicator of Rank………….………………………….87 2.9 C. Depositional Heterogeneity of Coal and its Influence on Isotopic Signature ……………………………………….…..……………...….91 2.9 D. Carbon Isotopic Patterns Across Dikes and Sills………………...….…….….95 2.9 E. Volatile Generation and the Formation of Pyrolytic Carbon….……………...99 2.9 F. Implications for coal-bed methane generation in the Raton Basin…….….…101 2.9 G. Sill Isotopic Pattern as a Result of Difference in Isotopic Fractionation…,,.104 2.9H. Cumulative Effects of Multiple Intrusions and Their Significance in Methane Generation…………………………………………………………..105 2.10 Summary…….……………………………………………….………………110 CHAPTER 3: XENOLITH DISSOLUTION IN ALKALI BASALTS AND IMPLICATIONS FOR DURATION OF MAGMA EMPLACEMENT 3.1 Introduction……………………….……………………………………………113 3.2 Natural Xenolith Examples from the Raton Basin……………………………..117 3.2A Outcrop Descriptions………………………………………………..………..118 3.2B Petrographic Description……………………………………..………………124 3.3 Experimental Procedure………………………………………………………..139 3.4 Results…………….……………………………………………………………144 3.4 A. Quartz Dissolution in the Raton Basin Alkali Basalt (RB Basalt)………….144 3.4 B. Quartz Dissolution in the Synthetic Iron-Free Basalt ………………………151 3.4 C. Quartz Dissolution in the CMAS Raton Basin Basalt Analog …….…..…….157 iv 3.5 Discussion of Dissolution Rates………………………………………………163 3.6 Comparison of Dissolution Rates Obtained in this study with other studies….175 3.7 Experimental Dissolution Rates in Comparison to Natural Xenolith Samples.178 3.8 Summary………………………………………………………………………181 CHAPTER 4: INTRUSIONS AND ORGANIC MATURATION WITHIN THE RATON BASIN AND IMPLICATIONS FOR OTHER BASINS 4.1 Introduction……………………………………………………………………183 4.2 Overview………………………………………………………………………184 4.3 The effects of Intrusions on Coal based on Vitrinite Reflectance, Carbon Isotopes and Coke Petrography………......………….………………………..189 4.4 Xenoliths, xenocrysts and their implications for duration of magma emplacement within the Raton Basin………………………………………….192 4.5 The Effects of Intrusions on Elevating Coal Rank in the Raton Basin……….196 4.6 Applications of this stud to locations beyond the Raton Basin………………..196 4.7 Summary of Conclusions……………………………………………………...198 REFERENCES………………………………………………..……………………200 APPENDIX 1: QUARTZ DISSOLUTION EXPERIMENTS BY OTHERS……...206 APPENDIX 2: VITRINITE REFLECTANCE DATA……..………………………210 APPENDIX 3: FIELD STOP LOCATIONS………………………….……………246 APPENDIX 4: SUMMARY OF ALL COAL DATA…..………..………………...248 v LIST OF ILLUSTRATIONS Figure Page 1.1 Raton Basin Location Map………………….……………...…………………7 1.2 Raton Basin and the Interior Cretaceous Seaway……………...….…………..8 1.3 Raton Basin Stratigraphic Column………………………...………………….9 1.4 Raton Basin Stratigraphic Column Outcrop Units…………………………...10 1.5 Raton Basin Structural Cross Sections……………...……………………….10 1.6 Raton Basin Intrusion Map…………………………………………………..11 1.7 Raton Basin and the Rio Grande Rift……………...………………………...12 1.8 Raton Basin Coked Coal Distribution Map………...………………………..15 1.9 Raton Basin Intrusion Ages………………...………………………………..16 1.10 Raton-Clayton Field Photo……………………………………...…………...17 1.11 Sills Preferentially Intruding Coal……………...……………………………18 1.12 Southern Raton Basin Subsurface…………………………………...……….19 1.13 Carbon isotopic values for organic matter……………………………...……21 1.14 Carbon isotopic fractionation during coalification……...…………………...22 1.15 Van Krevelen Diagram…………………………...………………………….25 1.16 Coal behavior during coking……………………..………………………….26 1.17 Coal dike cutting sill in the Raton Basin………………..…………………...27 1.18 Coked Coal fracture pattern……………………………………...…………..28 1.19 Coal fields of the United States………………………………..…………….29 1.20 Sill in the Purgatoire Valley, Raton Basin………………………..………….31 1.21 Correlation between aureole thickness and coal rank……………..…………33 vi Figure Page 2.1 The effect of multiple intrusions on coal rank…………………………...…41 2.2 Raton Basin location map…………………………………………………..43 2.3 Location of JCRB 18……………………………………………………….47 2.4 Outcrop photo of JCRB 18…………………………………………………47 2.5 Outcrop sketch with sample locations of JCRB18…………………………48 2.6 Coal seam sampled at JCRB18……………………………………………..49 2.7 Location of JCRB 19……………………………………………………….49 2.8 Outcrop photo of JCRB 19…………………………………………………50 2.9 Outcrop sketch with sample locations of JCRB 19………………………...50 2.10 Location of JCRB 25……………………………………………………….51 2.11 Outcrop photo of JCRB 25…………………………………………………51 2.12 Outcrop sketch with sample locations of JCRB25……………………........52 2.13 Location of JCRB65………………………………………………………..53 2.14 Outcrop photo of JCRB 65…………………………………………………53 2.15 Outcrop sketch with sample locations of JCRB 65………………………...54 2.16 Vitrinite reflectance profile for JCRB18……………………………………55 2.17 Vitrinite reflectance profile for JCRB 19…………………………………...56 2.18 Vitrinite reflectance profile for JCRB25……………………………………56 2.19 Vitrinite reflectance profile for JCRB65……………………………………57 2.20 Dike reflectance as a function of intrusion width…………………………..58 2.21 Sill reflectance as a function of intrusion width……………………………59 2.22 Bostick and Pawlewicz (1984) paleothermometer…………………………62 vii Figure Page 2.23 Peak temperature for JCRB19……………………………………………...63 2.24 Peak temperature for JCRB18……………………………………………..64 2.25 Peak temperature for JCRB25………….………………………………..…64 2.26 Peak temperature for JCRB65…………………………….………………..65 2.27 Peak temperature for dikes as a function of intrusion thickness.…………..65 2.28 Peak temperature for sills as a function of intrusion thickness….…………66 2.29 Mean contact reflectance versus intrusion thickness………………………68