Mineralogy and Chemistry of Clay-Rich Sediments in the Contact

University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 1979 Mineralogy and chemistry of clay-rich sediments in the contact zone of the Bullion Creek and Sentinel Butte Formations (Paleocene), Billings County, North Dakota David W. Brekke University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Brekke, David W., "Mineralogy and chemistry of clay-rich sediments in the contact zone of the Bullion Creek and Sentinel Butte Formations (Paleocene), Billings County, North Dakota" (1979). Theses and Dissertations. 36. https://commons.und.edu/theses/36 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. MINERALOGY AND CHEMISTRY OF CLAY-RICH SEDIMENTS IN THE CONTACT ZONE OF THE BULLION CREEK AND SENTINEL BUTTE FORMATIONS (PALEOCENE), BILLINGS COUNTY, NORTH DAKOTA by David W, Brekke Bachelor of Science, North Dakota State University, 1973 I A Thesis Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Master of Arts Grand Forks, North Dakota May 1979 This thesis submitted by David W. Brekke in partial fulfillment, cf the requirements fer the Degree cf Master cf Arts from the University of North Dakota is hereby approved by the Faculty Advisory Committee under whom the work has been done. l I I I This thesis meets the standards for appearance and conforms to the style and format requirements of the Graduate Schoel cf the University of North Dakota, and is hereby approved. ! l ii 461955 Permission MINERALOGY AND CHEMISTRY OF CLAY-RICH SEDIMENTS IN THE CONTACT ZONE OF THE llULLION CREEK Al.'D SENTINEL BUTTE FORMATION Title (PALEOCENE), BILLINGS COUNTY, NORTH DAKOTA In presenting this thesis in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the Library of this University shall make it freely available for inspection, I further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my thesis work or, in his absence, by the Chairman of the Department or the Dean of the Graduate School. It is understood that any copying or publication or other use of this thesis or part thereof for financial gain shall not be allowed without my written per mission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any schol arly use which may be made of any material in my thesis • .,- ; Signature c:~~o.~~/ Date~~~,"",~"""'£~~:l~""""'~~,,/7".'.-"-~-"-'.7'~~ iii TABLE OF CONTENTS LIST OF ILLUSTRATIONS • vi LIST OF TABLES viii ACKNOWLEDGMENTS ix ABSTRACT X INTRODUCTION l General Statement Study Area Description of Contact MINERALOGY AND CHEMISTRY . .. .. 10 Previous Investigations Fieldwork and Methods Clay Mineralogy Distribution of Clay Minerals Clay Mineralogy of the "Blue Bed" X-ray Analysis of Selected Bulk Samples Chemistry of Clay-rich Sediments ORIGIN OF THE CLAY MINERALS . 55 Detrital Origin Diagenetic Origin Summary of Clay Mineral Relationships and Origins DISCUSSION 62 APPENDICES 65 APPENDIX A. Key to Abbreviations 66 APPENDIX B. Measured Stratigraphic Sections of the Sample Sites . 68 APPENDIX C. X-Ray Intensities of Clay-Fraction Minerals 75 APPENDIX D. Sample Correlation Coefficients 78 APPENDIX E. Sand-Silt-Clay Ratios 81 iv APPENDIX F. Separation of the Clay-Sized Fraction from a Bulk Sample for Preparation of X-ray Diffraction Mounts ••• 83 APPENDIX G. Preparation of Oriented Clay-Fraction Samples on Procelain Tiles 87 REFERENCES CITED 90 V LIST OF ILLUSTRATIONS Figure 1. Location Map of Billings County, North Dakota Showing Sample Sites and Major Topographic and Drainage Features ..•.•.. .. 4 2. Generalized Stratigraphic Section of the Tongue River and Sentinel Butte Formation . .......... 8 3. X-ray Diffractogram Traces of the Clay-Size Fraction of Sample Bc-TR-3 • • • • • • • 17 4. Scanning Electron Microscope Photograph of Bulk Sample Bc-SB-3 • • • • • • • • • • • • • • , . .. 22 s. Scanning Electron Microscope Photograph of a Replies of Bulk Sample SR-SB-2 •• , • , . .. 22 6. Scanning Electron Microscope Photograph of a Muscovite Flake in Sample Bc-SB-3 •• , 25 7. Scanning Electron Microscope Photograph of a Biotite Flake in Sample Bc-SB-3 , ••• . 25 8. Scanning Electron Microscope Photograph of a Possible Corroded Feldspar Crystal in Sample SR-SB-4 • ~ .•.•. ~ • 30 9. Scanning Electron Microscope Photograph of a Feldspar Crystal in Sample Bc-SB-3 ••• 30 10. Clay Mineralogy at Bear Creek, South Unit Theodore Roosevelt Park, and Blacktail Creek 32 11. Mineralogy of the Clay-Size Fraction at Bear Creek 34 12. Mineralogy of the Clay-Size Fraction at the South Unit Theodore Roosevelt Park •••••••••• 36 13, Mineralogy of the Clay-Size Fraction at Blacktail Creek • . • • • . • . 38 14. Mineralogy of the Clay-Size Fraction of the Sentinel Butte Formation "Blue Bed" Marker Unit . 43 vi 15. Bulk Sample Mineralogy at Bear Creek •••.• , , , , , , 46 16, Percent Total Iron, Expressed as Fe203, Plotted Against Percent Na20 for All Analyzed Samples , , •• , 51 17. Percent CO2 Plotted Against Percent CaO for All Analyzed Samples. • . • . • . .•.• 51 18. Percent K20 Plotted Against Integrated X-ray Diffraction Intensity of Mica Group Clay Minerals for All Analyzed Samples ••• . .. 53 19. Percent Total Iron, Expressed as Fe20, Plotted Against Integrated X-ray Diffraction Intensity of Clay-Size Chlorite ••••• 53 20. Triangular Plot of the Major Clay Minerals of the Bullion Creek and Sentinel Butte Formations at Bear Creek, South Unit Theodore Roosevelt Park, and Blacktail Creek • • • • • • • • • • • • • • . .. .. 61 vii LIST OF TABLES Table 1. Precision of the Analysis Technique •• , 14 2. Chemical Analysis of Bulk Sample Bc-SB-3 20 3. Chemical Analyses ................ ~. 47 4. X-Ray Intensities of Clay-Fraction Minerals 76 5. Sand-Silt-Clay Ratios ••••• 79 6. Sample Correlation Coefficients 82 viii ACKNOWLEDGMENTS I would like to acknowledge my committee chairman, Dr. Frank Karner, for his considerable time and constructive criticisms. I would also like t9 acknowledge the constructive criticisms of com mittee members Dr. Odin Christensen and Dr. Walter Moore, who also spent considerable time in restoring the x-ray equipment. Gratitude is extended to Dr. E, A. Noble, who served as an early committee member, and through the North Dakota State Geological Survey funded my field work and research, I would like to acknowledge the National Science Foundation and their Energy-Related Graduate Traineeship which supported part of my field wcrk and research. A special thank you is extended to Dr. Frank Low of the Anatomy Depart ment and Willis Beckering of the U.S. Department of Energy for use of the scanning electron microscopes and electron microprobe facilities. I would also like to thank Richard Pilatzke for his assistance with the computer analyses. ix ABSTRACT The Bullion Creek and Sentinel Butte Formations (Paleocene) form over 50 percent of the surface and near surface sediments in the North Dakota part of the Williston Basin. These rocks are composed of sand stones, siltstones, claystones, and numerous lignite beds. A distinct surface color change from light colors in the Bullion Creek Formation to dark colors in the Sentinel Butte Formation serves as a boundary marker and is widely exposed in the Little Missouri River badlands. The color boundary is a product of weathering and is not readily appar ent in the subsurface. The use of clay mineralogy was investigated as a possible criterion to distinguish between the two formations and provide an explanation of the coloring, Argillaceous units of both formations were sampled at three widely spaced sites along the Little Missouri River in Billings County, North Dakota. Samples were collected 32 km north of Medora, near Medora, and 25 km south of Medora. X-ray diffraction analysis of thirty-five samples established sodium montmorillonite with lesser amounts of mica-illite and iron chlorite as the major clay minerals. Minor amounts of kaolinite and the non-clay minerals quartz, calcite, dolomite, and feldspar are present in the clay-size fraction, The relative amounts and types of clay minerals are the same in both formations. Mica-illite and chlorite occur in about equal amounts and vary inversely with the amount of montmorillonite, The varia tion in clay mineral relationships within either formation is X greater than the variation between the formations. Any difference in clay mineralogy across the formational contact is localized, Chemical analyses of the clay-rich sediments showed a greater amount of iron and sodium in the Sentinel Butte Formation. The increase in iron, probably in disseminated form, i& suggested as the cause of the darker colors observed in outcrop. There appear to be two mechanisms of origin of the clay min erals in the Bullion Creek and Sentinel Butte Formations. Moat of the clays are detrital material from highly montmorillonitic Cretaceous shales to the west and northwest. Some of the montmorillonite may be diagenetic and derived from the breakdown of eolian volcanic ash from the west. xi INTRODUCTION General Statement Strata of the Paleocene Bullion Creek and overlying Sentinel Butte Formations compose over 50 percent of the surface and near sur face sediments of the Williston Basin in the northern Great Plains, Extensive outcrops are found in the unglaciated portion of North Dakota south and west of the Missouri River. There are excellent exposures in the Little Missouri River badlands, where the contact of the two forma tions is readily seen. A striking color change, from light to dark colors, at the contact provides a distinguishing feature for field mapping. However, this appears to be largely a weathering phenomenon and cannot easily be extended to the subsurface.

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