ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES THE POSSIBLE CAUSES OF THERMAL VARIATIONS OF COALS IN DILBI-MOYE BASIN ADDISU GELETA JULY 2009 ADDIS ABABA ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES THE POSSIBLE CAUSES OF THERMAL VARIATIONS OF COALS IN DILBI-MOYE BASIN, JIMMA ZONE, OROMIA NATIONAL REGIONAL STATE, SOUTHWESTERN ETHIOPIA A THESIS PRESENTED TO THE SCHOOL OF GRADUATE STUDIES ADDIS ABABA UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE MASTER OF SCIENCE IN PETROLEUM AND COAL GEOLOGY BY ADDISU GELETA JULY 2009 ADDIS ABABA ii ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES THE POSSIBLE CAUSES OF THERMAL VARIATIONS OF COALS IN DILBI-MOYE BASIN, JIMMA ZONE, OROMIA NATIONAL REGIONAL STATE, SOUTHWESTERN ETHIOPIA BY ADDISU GELETA DEPARTMENT OF EARTH SCIENCES Approved by: Dr. Balemwal Atnafu ____________________________ Chairperson Dr. Wolela Ahmed _____________________________ Advisor Dr. Worash Getaneh ______________________________ Examiner Ato Kibrie Tadesse _____________________________ Examiner iii Praise the Lord, O my soul. O Lord my God, you are very great; you are clothed with splendor and majesty. Psalm 104:1 iv ACKNOWLEDGMENTS I, the author, wish to express my sincere gratitude to my advisor, Dr. Wolela Ahmed Mohammed, for his critical manuscript correction, invaluable suggestions and discussions through out the whole work. I also thank my co- advisor Dr. Balemwal Atnafu, for his constructive advice, practical guidance and comfortable communication. I wish to extend my appreciation to the Oromia Mineral and Energy Resources Development Agency, exempting me from any activities that could make me busy during all my studies. I also thank my brother in Jesus Christ, Ato Yonas Bekele, who has digitized all the maps in this manuscript. At most, but not least, I thank Obbo Kebede Chala for the AutoCAD drawings in this thesis. My brothers Obbo Ebba Geleta and Obbo Endalew Yando are greatly indebted for their encouragement and financial support. I extend my gratitude to the Geological Survey of Ethiopia, as a whole, and some of the management members who allow me to get the Dilbi-Moye Basin core coal samples and to use the secondary data of their library, library and laboratory workers particularly, for their cooperation. My gratitude is also due to the Derba-East Africa Coal Mining PLC that allows me to use their chemical analyses results and borehole data. I also extend my appreciation to the Ethio-Pak Coal Mining PLC for their good hospitality and help in transportation facility in the field. Finally, I thank my wife Aadde Marame Belina and children Hella Asefa, Beshatu Merga, Duretti Addisu, Jalal Addisu and Samuel Addisu for their all sacrifications, love, patience and inspiration during my study. v TABLE OF CONTENTS PAGE 1. INTRODUCTION ........................................................................ 1 1.1 GENERAL ............................................................................................................... 1 1.2 LOCATION AND ACCESSIBILITY ..................................................................... 2 1.3 PHYSIOGRAPHY AND DRAINAGE ................................................................... 5 1.4 CLIMATE AND VEGITATION ............................................................................ 5 1.5 PREVIOUS WORK ................................................................................................. 6 1.6 OBJECTIVE .......................................................................................................... 11 2. METHODOLOGY ..................................................................... 12 3. GEOLOGY ............................................................................... 17 3.1 REGIONAL GEOLOGICAL SETTING .............................................................. 17 3.2 GEOLOGY OF DILBI-MOYE BASIN ................................................................ 19 3.2.1 Volcanic Rocks ............................................................................................ 20 3.2.2 Tertiary Sediments ..................................................................................... 28 3.2.3 Facies and Depositional Environments ................................................. 34 3.3 COAL GEOLOGY ............................................................................................... 36 3.3.1 Dilbi Coals .................................................................................................... 36 3.3.2 Moye Coals ................................................................................................... 37 4. RESULT OF THE STUDY ............................................................ 38 4.1 DISTRIBUTION OF COALS OF DILBI-MOYE BASIN ..................................... 38 4.2 PHYSICAL CHARACTERISTICS OF COALS OF DILBI-MOYE BASIN ....... 39 vi 4.3 LABORATORY ANALYSES RESULTS ............................................................... 41 4.3.1 Petrographic Description .......................................................................... 41 4.3.2 Chemical Analysis of the Coals ............................................................... 42 5. THERMAL CHARACTERISTICS OF DILBI-MOYE COALS .......... 50 5.1 VERTICAL THERMAL VARIATIONS ................................................................ 50 5.2 LATERAL THERMAL VARIATIONS .................................................................. 53 5.3 THE POSSIBLE CAUSES OF THERMAL VARIATIONS OF THE BASIN ...... 74 6. DISCUSSION AND INTERPRETATION ....................................... 77 7. CONCLUSION .......................................................................... 86 REFERENCES................................................................................ 88 APPENDICES ................................................................................ 93 vii LIST OF FIGURES FIGURE PAGE 1-1 Location map of Dilbi-Moye Basin ---------------------------------------------- 4 1-2 Borehole location map of Dilbi-Moye Basin --------------------------------- 10 3-1 Geological map of Dilbi-Moye Basin ----------------------------------------- 22 3-2 Geological map of Dilbi Sub-Basin -------------------------------------------- 23 3-2A Geological cross sections along boreholes in Dilbi Sub-Basin --------- 24 3-3 Geological map of Moye Sub-Basin ------------------------------------------- 25 3-3A Geological cross sections along boreholes in Moye Sub-Basin -------- 26 3-4 Generalized stratigraphic column of Dilbi-Moye area -------------------- 27 3-5 Typical basin fill at Dilbi Sub-Basin ------------------------------------------- 30 3-6 Typical basin fill at Moye Sub-Basin ------------------------------------------ 31 3-7 Geological cross-sections along BH 6, 2 and 1 and along BH 11 and 1, Dilbi area ----------------------------------------------------------- 32 3-8 Geological cross-sections along BH 21, 18 and 19, Moye area --------- 33 3-9 Facies distribution and depositional environment in Dilbi-Moye Basin ------------------------------------------------------------------ 35 5-1A Interrelation of ash content vs calorific value within the basin ---------- 57 5-1B Borehole-coal seam and ash content vs calorific value across the basin (from NE to SW) ------------------------------------------------------- 58 5-2A Interrelation of fixed carbon content vs calorific value within the basin ---------------------------------------------------------------------------- 60 viii 5-2B Borehole-coal seam and fixed carbon vs calorific value across the basin (from NE to SW) ------------------------------------------------------- 61 5-3A Interrelation of volatile matter vs calorific value within the basin ------ 63 5-3B Borehole-coal seam and volatile matter vs calorific value across the basin (from NE to SW) ------------------------------------------------------- 64 5-4A Interrelation of ash content vs fixed carbon within the basin ----------- 66 5-4B Borehole-coal seam and ash content vs fixed carbon content across the basin (from NE to SW) ------------------------------------------------------- 67 5-5A Interrelation of ash content vs volatile matter content within the basin 69 5-5B Borehole-coal seam and ash content vs volatile matter across the basin (from NE to SW) ------------------------------------------------------- 70 5-6A Moisture content vs calorific value within the basin ----------------------- 72 5-6B Borehole-coal seam and moisture content vs calorific value across the basin (from NE to SW) ------------------------------------------------------- 73 6-1 Sulfur content vs calorific value within the basin --------------------------- 83 6-2 Borehole-coal seam and sulfur content vs calorific value across the basin (from NE to SW ) ------------------------------------------------------ 84 6-3 Borehole-coal seam vs sulfur content across the basin, from NE to SW 85 ix LIST OF TABLES TABLE PAGE 1-1 The x, y, z coordinates of boreholes drilled by Geological Surveys of Ethiopia and Derba-East Africa Coal Mining PLC ------------- 8 4-1A Chemical analyses result of Dilbi coals by Geological Survey of Ethiopia (previous) -------------------------------------------------- 44 4-1B Chemical analyses result of Dilbi coals by the authors (recent) -------- 44 4-2A Chemical analyses result of Moye coals by Geological Survey of Ethiopia (previous) -------------------------------------------------- 45 4-2B Chemical analyses result of Moye coals by the author (recent) -------- 46 5-1 Ash content and calorific value of Dilbi-Moye