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Fault Segmentation, Paleostress and Paleoseismic Investigation in the Dodoma Area, Tanzania: Implications for Seismic Hazard Evaluation

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Fault Segmentation, Paleostress and Paleoseismic Investigation in the Dodoma Area, Tanzania: Implications for Seismic Hazard Evaluation FACULTEIT WETENSCHAPPEN Vakgroep Geologie-Bodemkunde Onderzoekseenheid Renard Centre of Marine Geology Fault Segmentation, Paleostress and Paleoseismic Investigation in the Dodoma Area, Tanzania: Implications for Seismic Hazard Evaluation Athanas Simon MACHEYEKI Academiejaar 2007-2008 Frontpage figures: Top left = fault segments in the study area, as determined in this study (Chapter 5) Top right = conjugate fault system observed on the Hombolo fault. The principal stresses σ1, σ2 and σ3 are also shown (Chapter 6) Bottom = The Magungu trench along the Gonga segment of the Bubu fault (Chapter 7). Fault Segmentation, Paleostress and Paleoseismic Investigation in the Dodoma Area, Tanzania: Implications for Seismic Hazard Evaluation Athanas Simon MACHEYEKI Student registration number: 20045573 A thesis submitted in fulfillment of the requirements for the degree of Doctor of Science in Geology Universiteit Gent Academiejaar 2007-2008 Promotor: Prof. Dr. Marc De Batist, Universiteit Gent, Belgium Co-Promotors: Prof. Dr. Abdulkarim Mruma, University of Dar Es Salaam, Tanzania. Dr. Damien Delvaux, Royal Museum for Central Africa, Belgium Key words: Central Tanzania, Eastern branch, Active Faults, Fault segments, Paleostress, Slip Tendecy Analysis, Thermal springs, Paleoseismic investigations, Manyara-Dodoma rift segment, Chenene surface fractures, Seismic Hazard Evaluation. A.S. Macheyeki Declaration Declaration I, Athanas Simon Macheyeki (37 yr), hereby declare that this Ph.D. thesis, titled “Fault Segmentation, Paleostress and Paleoseismic Investigation in the Dodoma Area, Tanzania: Implications for Seismic Hazard Evaluation”, contains data and results of my own work and has never been submitted in any other University in the world for similar award, and that all sources that I have used or quoted throughout the thesis have been indicated and acknowledged by complete references at the end of the thesis. ------------------------------------------------ -------------------------------- Signature of Candidate Date ------------------------------------------------ -------------------------------- Signature of Promoter Date i A.S. Macheyeki Declaration ii A.S. Macheyeki Dedication and Acknowledgements Dedication To the memory of my lovely mother Lusiya Sayi Petro Sambusa Matula Hima (1950- 1995) and to my father, Malimi Simon Macheyeki Shija Magengeledi Shidūka Makūngū (1936-) for bringing me up and sending me to school. Acknowledgements I foremost mention the most forgotten name in science – “the Creator, Jehovah, God” for His marvelous mercy in this work. Through Him, though I was alone most of the time, I never felt lonely. I deeply thank Him in all dimensions for without Him my work would be dimensionless. My thesis supervisor, Professor Marc De Batist, has been giving me guidance to my work and has been available for me at any time. Through him, I have gained a tremendous confidence in my field! His input in my work (design, comments and suggestions) was so great that I regard him as one of my greatest teachers of science! Professor De Batist has been so kind, keeping on encouraging me. As if that is not enough, when my laptop collapsed, he bought a new one for me instantly – thank you so much, Marc. I am indebted to Professor Abdul Mruma, my Professor at the University of Dar Es Salaam and currently the Chief Executive Officer of the Geological Survey of Tanzania. His role as a Tanzania-based supervisor cannot go unnoticed. Professor Mruma assisted me to get all geological data I needed from the Survey and he was an important link between the Universiteit Gent, my sponsors and my employer – thank you so much, Abdul. Dr. Damien Delvaux, my co-supervisor, worked tirelessly with me. He is a person who shared a lot of good times with me. He provided me with a lot of logistics and technical assistance both in the field (Tanzania) and in the office, particularly at the Royal Museum for Central Africa (RMCA). Damien has worked extensively in Tanzania and I feel honored to have known and worked with him. Let me say, I appreciate your enormous iii A.S. Macheyeki Dedication and Acknowledgements contribution to my career. Thank you, Damien, and thanks to your family for their hospitality! I am also indebted to Dr. Kris Vanneste of the Royal Observatory of Belgium (ROB) for his great technical and scientific input in this thesis, particularly for Chapter 7. Dear Kris, I count on your contribution. The Kingdom of Belgium, through the Belgian Technical Cooperation (BTC), and the Government of the United Republic of Tanzania, through the Ministry of Energy and Minerals (MEM), are both highly appreciated for their financial supports. I mention Daphnée Windey, Victor Ndiyezeye, Sylvia Kimpe, Joachim Defraye, Liesbet Vastenavondt and Janet Lindoya from BTC, and Mrs. Lukindo, Mr. A.L. Msigwa and S.A.S. Msambachi from MEM for their dedicated cooperation at their capacity before and during my studies. Lieven Naudts, Marc Faure Didelle, Wim Versteeg, Dr. Jeffrey Poort, Prof. Jean-Pierre Henriet, Jeroen Vercruysse, Koen De Rycker, Els Verfaillie, Kristien Schelfhaut, Hans Pirlet, Dr. David Van Rooij and my fellow students from the Renard Centre of Marine Geology, Universiteit Gent. Also Prof. E. Mbede of the University of Dar Es Salaam, currently working for the Ministry of Education, are collectively thanked very much for their technical cooperation and their encouragements. I am giving a special “thank you” to all Tanzanian students in Belgium for their moral support throughout my studies. Thanks also go to all students who were staying with me at Ontmoeting Buitenlandse Studenten Gent (OBSG) for their general support. I am indebted to Dr. François Kervyn who took a lot of time teaching me how to process various data using various softwares, which in turn enabled me to work independently – I would be very unfair if I do not say to him “nashukuru sana”. This chapter, however, remains far unclosed if I do not mention Dr. Luc Tack and Dr. Karel Theunissen from RMCA for their useful comments on the geological setting of Tanzania. I must also thank Dr. Max Fernandez Alonso for his technical and social support in RMCA. Similarly, I thank Christelle Wauthier and Benoît Smets. Christelle and Benoît worked with me for a month in northern Tanzania following the July 2007 seismic crisis. From RMCA, I also mention Suzane for her kindness and preparedness to help throughout my stay in the laboratories of the RMCA at Tervuren. As I cannot mention all people from the RMCA, let me just thank all of them in the African language: “asanteni”. Others in this list are Koen Verbeeck and Toon Petermans from the Royal Observatory of Belgium, who are highly thanked for their constructive comments. Dr. Shukrani Manya from the University of Dar Es Salaam, who provided me with the information about a project that was related to this study, is thanked as well. I also thank Prof. Sospeter Muhongo, the Regional Director of ICSU-Regional Office for Africa, and Dr. Ibrahim Chikira, Dr. Martin Kimanya, Ms. Annelies De Craene and Mr. Charles Bakundukize iv A.S. Macheyeki Dedication and Acknowledgements from the Universiteit Gent for their encouragements. My students at Madini (Mineral Resources) Institute and my work mates Mr. Placid Kabyemera, Mrs. Halima Kikoti, Mr. Florian Asenga, Mr. E.B. Temu, Mr. Faustin Petro Nyanda, Mr. Sadiki Kipaya, Mr. Alphonce Bushi, Mr. Charles Baasha, Mr. Gumbo, Bi Suzy Kiweru and others are similarly thanked for their moral support and readiness to support me. My immediate boss, Mr. Kandidus P. Lupindu is thanked in the similar accord. I thank all public leaders in Dodoma and Singida regions (Hombolo, Kwamtoro, Chenene, Bahi, Sanzawa, Fufu, Gonga, Kilimatinde, Mponde, Musuhaa and Saranda) for their support during my field work. I also thank Mr. J.S. Rweyemamu of Bukoba Tanzania for his moral support – thank you. A special thank goes to Mr. Linus Salamba of Geita Gold Mine. He freely accepted to assist me twice in the field and rejected any payments from me for his assistance! I also thank his entire family in Dodoma for accommodating me for weeks during the difficult task of drafting this thesis – thank you for food, drinks and moral support. Equally so are the families of Mr. Joseph Manhyakenda and Jerenimo Mhande in Dar es Salaam for their supports. I dedicatedly thank my lovely wife Paulina Awasi, our dear children Juliana, Mathias, Faith, and their nurse Aifa, for their tireless prayers and good wishes to my success and dedicated support. Similarly, I must mention Mr. David Kitundu, Philbert Christopher, Mr. Mdongo’s family of Shinyanga Tanzania and Rehema Kalawa of Iringa Tanzania for intervening with my family during my absence. I love you all. I would not be fair if I did not mention my lovely father Mr. Simon Malimi Macheyeki and the whole dear extended family for their prayers at all times of my studies and for the encouragements that “usichoke mwanetu (i.e. our son, never give up)”. As I close these pages, I would like to thank all people who, from ages, took the lead in making sure that I am who I am now. This is a long list beginning with my lovely late mother, “Ng’wana Sambusa”, my dear standard one teachers at Igunya Primary School, fellow pupils and students at all levels through which I have passed, to many others whose names requires a separate volume to list in full. Please, wherever you are, and in whichever form you are, kindly accept my words that I deeply recognize your role and contributions towards this special dream of my life – “mkabejano”! Finally, I thank all members of the Jury for their constructive comments. Your comments have shaped my final work, thank you all, and thank you so much. v A.S. Macheyeki Dedication and Acknowledgements vi A.S. Macheyeki Table of Contents Table of Contents Declaration i Dedication iii Acknowledgements iii Table of contents vii English Abstract 1 Nederlandse samenvattting 3 Chapter 1 – General Introduction 7 1.1.
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