DOCSLIB.ORG

Morpho-Tectonic Analysis of the East African Rift System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Morpho-Tectonic Analysis of the East African Rift System MORPHO-TECTONIC ANALYSIS OF THE EAST AFRICAN RIFT SYSTEM By LIANG XUE Bachelor of Engineer in Geological Engineering Central South University Changsha, China 2011 Master of Science in Geology Missouri University of Science and Technology Rolla, Missouri 2014 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY July, 2018 MORPHO-TECTONIC ANALYSIS OF THE EAST AFRICAN RIFT SYSTEM Dissertation Approved: Dr. Mohamed Abdelsalam Dissertation Adviser Dr. Estella Atekwana Dr. Danial Lao Davila Dr. Amy Frazier Dr. Javier Vilcaez Perez ii ACKNOWLEDGEMENTS This research could never have been completed without the support of my mentors, colleagues, friends, and family. I would thank my advisor, Dr. Mohamed Abdelsalam, who has introduced me to the geology of the East African Rift System. I was given so much trust, encouragement, patience, and freedom to explore anything that interests me in geoscience, including tectonic/fluvial geomorphology, unmanned aerial system/multi-special remote sensing, and numerical modeling. I thank my other members of my committee, Drs. Estella Atekwana, Daniel Lao Davila, Amy Frazier, and Javier Vilcaez Perez for their guidance in this work, as well as for their help and suggestion on my academic career. Their writing and teaching have always inspired me during my time at Oklahoma State University. The understanding, encouragement from my committee members have provided a good basis for the present dissertation. Also, I thank Dr. Nahid Gani, of Western Kentucky University for her contribution to editing and refining my three manuscripts constituting this dissertation. It has been four years since I came to Oklahoma State University for my PhD program. I have greatly benefited over that time from interaction with my teachers and colleagues. The professors in Geology and Geography departments prepared me to be a much more balanced researcher. I also wish to express my appreciation to the Boone Pickens School of Geology, for providing the Graduate Teaching Assistant, and fellowships that made my study possible. Further, I would like to thank several communities. This work is partially supported by American Association of Petroleum Geologists’ Grant-in-Aid fund and Geological Society of America’s Graduate Research Funding. I also thank the members of American Geophysical Union Gilbert Club and Community Surface Dynamics Modeling System for sharing their data, code, and helping me with methodologies of this work. To my colleagues and treasured friends in the PhD office (NRC 412) and in the Geodynamic and Geospatial Science lab (NRC 303), Tadesse Alemu, Mercy Achang, Sahar Mohammadi, Jingyao Meng, Pouyan Ebrahimi, Ibukun Bode Omoleye, Zelalem Demissie, Folarin Kolawole, and Andrew Katumwehe, Babak Shabani, Luel Emishaw, I cannot give enough thanks for their supports, encourage, friendship, and good moments. A sincere thank is also due to all members of the Tectonic Group for their intellectual discussions, as well as for collaboration with Steven Johnson and Ines Barrios Galindez in their research projects. Finally, I am grateful to my parents, grandma, and Shaoyi, who supported my efforts throughout this long journey. During my four years in the PhD program, I have only been back home once, so I would also like to thank my family and friends in China who have tolerated my long absence. iii Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. Name: LIANG XUE Date of Degree: JULY, 2018 Title of Study: MORPHO-TECTONIC ANALYSIS OF THE DRAINAGE SYSTEMS IN THE EAST AFRICAN RIFT SYSTEM Major Field: GEOLOGY Abstract: Tectonic uplift of mountain ranges and plateaus have a significant impact on the geological record by influencing drainage systems and sediment supply, and on climate and on biogeography. Recent geomorphological, geochronological and geophysical studies have provided some understanding of time constraints and uplift rate distribution patterns, especially in convergent plate margins. Nevertheless, fewer studies took a comprehensive view over the topographic patterns, rates and changes in rates of tectonic uplift in continental rift systems. We do not know the how ground’s vertical motion is localized along the axis of rift and the relative roles of upwelling of magma and rift extensional processes play in tectonic uplift history. The East African Rift System (EARS) has long served as the ideal example of a continental rift to explore the distribution patterns, rates, and timing of tectonic uplift in the evolution of geomorphology. This work addresses fundamental questions of tectonic uplift and its footprint on the topography associated with rift systems. Specifically, three distinct segments along the EARS, the Rwenzori Mountains in the Western Branch, the southeastern Ethiopian Plateau in the Northern Branch and the Kenyan Rift in the Eastern Branch are investigated. The first chapter evaluated geomorphic proxies in the Rwenzori Mountains. We found that the linear geomorphic proxies (normalized steepness and chi integral) have strong positive correlation with the erosion rates. Additionally, our geomorphic proxy results suggest that the north and south sectors of the Rwenzori Mountains are in relative tectonic quiescence but that the central sector is experiencing higher levels of erosion and rock uplift. The second chapter used morphotectonic analysis to study the tectonic uplift history of the southeastern Ethiopian Plateau (SEEP). We find an increase in tectonic uplift rates from the southeastern escarpments of the Afar Depression in the northeast to that of the Main Ethiopian Rift to the southwest. We identify three regional tectonic uplift events at ~11.7, ~6.5, and ~4.5 Ma recorded by the development of regionally distributed knickpoints. This is in good agreement with ages of tectonic uplift events reported from the Northwestern Ethiopian Plateau. The third chapter examined the tectonic uplift history of the Kenya Rift. This work found that the spatial and temporal pattern of the tectonic uplift inferred from the drainage incision is well-correlated with known phases of magmatic activities. Also, this work found that the rapid increase in drainage incision since ~4.5 Ma correlated well with a major change in vegetation from grassland to woodland. This suggests that the tectonic uplift coupled with Pliocene magmatic activities have caused a major shift in the ecosystem in the region. iv PUBLICATION DISSERTATION OPTION This dissertation has been structured in two sections. The first section (Chapter 1) gives a brief introduction of the dissertation and introduces the scientific questions investigated in this research. The second section (Chapters 2, 3, and 4) also presents three manuscripts including two that have been published and one in preparation for publication. Paper 1: Xue, Liang, Nahid D. Gani, and Mohamed G. Abdelsalam. "Geomorphologic proxies for bedrock rivers: A case study from the Rwenzori Mountains, East African Rift system." Geomorphology 285 (2017): 374-398. Paper 2: Xue, Liang, Alemu, Tadesse, Nahid D. Gani, and Mohamed G. Abdelsalam. "Spatial and temporal variation of tectonic uplift in the southeastern Ethiopian Plateau from morphotectonic analysis." Geomorphology 309 (2018): 98-111. Paper 3: Xue, Liang, Nahid D. Gani, and Mohamed G. Abdelsalam. (Submitted) “Drainage incision, tectonic uplift, and magmatism of the Kenya rift, East African Rift System: a morpho-tectonic analysis approach.” JGR-Earth Surface. v TABLE OF CONTENTS CHAPTER I ............................................................................................................................... 1 INTRODUCTION ...................................................................................................................... 1 1.0. Project Motivation ................................................................................................................ 1 1.1. Objectives ............................................................................................................................ 2 1.2. Significance ......................................................................................................................... 3 1.3. References ........................................................................................................................... 6 CHAPTER II .............................................................................................................................. 8 GEOMORPHOLOGIC PROXIES FOR BEDROCK RIVERS: A CASE STUDY FROM THE RWENZORI MOUNTAINS, EAST AFRICAN RIFT SYSTEM................................................. 8 2.0. Abstract ............................................................................................................................... 8 2.1. Introduction ....................................................................................................................... 10 2.2. Geologic setting ................................................................................................................. 12 2.2.1. The East African Rift system (EARS) .......................................................................... 12 2.2.2. The Rwenzori Mountains ............................................................................................. 14 2.2.2.1. Lithology .............................................................................................................
Load more

Recommended publications
  • PROFILES of ATTRACTION SITES-ELGEYO MARAKWET. Tourist Attractions in Elgeyo Marakwet County Include Sports Tourism, Rivers, a Na
    PROFILES OF ATTRACTION SITES-ELGEYO MARAKWET. Tourist attractions in Elgeyo Marakwet County include Sports Tourism, Rivers, A national reserve, waterfalls and the hills and escarpments. Rimoi National Reserve The National Reserve is a protected area in the kerio valley along the escarpment of the Great Rift Valley. The 66 square kilometers (25sq mi) reserve was created in 1983 and is managed by the Kenya Wildlife Service. The isolated Kerio Valley lies between the Cherangani Hills and the Tugen Hills with the Elgeyo Escarpment rising more than 1,830 meters (6,000ft) above the valley in places. The valley is 4,000 feet (1,200m) deep. It has semi-tropical vegetation on the slopes, while the floor of the valley is covered by dry thorn bush. The most comfortable time of the year is in July and August when the rains have ended and the temperatures are not excessive. The reserve is on the west side of the Kerio River, while the Lake Kamnarok National Reserve is on the east side. The reserve has beautiful scenery, prolific birdlife and camping site in the bush beside Lake Kamnarok. Gazzement of the conservation area was done to protect wildlife from rampant poaching which was going on at the time. A fence was also put up to address human wildlife conflicts. It provides unique geological scenery & biodiversity and is one of the few protected areas within the spectacular Kerio Valley. The main attraction is the groups of elephants, Culture and scenery of the Kerio valley. The Reserve has earth and gravel road network which make for an adventurous outing.
    [Show full text]
  • African Mountains: Water Towers in Need of Attention Policy Brief
    African Mountains: Water Towers in need of Attention Policy brief majority of water to the entire sub-region. Hydropower is the Introduction main source of clean energy in most mountainous areas of Africa. The consistent flow of water from mountains is Mountains cover 25% of the world’s land surface, and are essential for this clean energy. In a continent highly home to about 10% of its population, most of whom depend dependent on traditional energy sources and badly affected on mountain resources for their livelihoods. A key link by rising oil prices, mountains can thus significantly between the actions of mountain and wider populations is contribute to energy security. The conditions in mountain that most of the world’s major rivers rise in mountain areas: regions allow for higher and better quality yields, significantly mountains are the world’s ‘water towers’, and the contributing to regional and lowland food security. sustainable management of their watersheds is vital for the Mountains house many ecosystems such as forests, provision of high-quality water to billions of people, as well as grasslands, drylands, rivers and wetlands. The Fynbos Biome for ensuring that the risks of natural hazards, such as floods in South Africa is home to 6,200 endemic plant species, and and landslides, are minimized. Mt. Mlanje, the Rwenzori Mountains, Mt. Cameroon, the Fouta Djallon and the Ethiopian highlands all have high levels During the World Summit on Sustainable Development in of endemic species. Over 50% of African birds, 39% of Johannesburg (2002), a Type-II Partnership “The International mammals, 19% of amphibians and 14% of reptiles are found Partnership for Sustainable Development in Mountain in the Albertine Rift region.
    [Show full text]
  • Application of Scripting Cartographic Methods to Geophysical Mapping and Seismicity in Rwenzori Mountains and Albertine Graben, Uganda Polina Lemenkova
    Application of scripting cartographic methods to geophysical mapping and seismicity in Rwenzori mountains and Albertine Graben, Uganda Polina Lemenkova To cite this version: Polina Lemenkova. Application of scripting cartographic methods to geophysical mapping and seis- micity in Rwenzori mountains and Albertine Graben, Uganda. Makerere University Journal of Agri- cultural and Environmental Sciences, 2021, 10 (1), pp.1-21. 10.5281/zenodo.5082861. hal-03282142 HAL Id: hal-03282142 https://hal.archives-ouvertes.fr/hal-03282142 Submitted on 8 Jul 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Lemenkova, P. Makerere University Journal of Agricultural and Environmental Sciences Vol. 10 (1). pp. 1 - 21, 2021 Printed in Uganda. All rights reserved © Makerere University 2021 ISSN 1563-3721 Application of scripting cartographic methods to geophysical mapping and seismicity in Rwenzori mountains and Albertine Graben, Uganda Lemenkova, P.1 1Schmidt Institute of Physics of the
    [Show full text]
  • 1843 KMS Kenya Past and Present Issue 43
    Kenya Past and Present Issue 43 Kenya Past and Present Editor Peta Meyer Editorial Board Marla Stone Patricia Jentz Kathy Vaughan Kenya Past and Present is a publication of the Kenya Museum Society, a not-for-profit organisation founded in 1971 to support and raise funds for the National Museums of Kenya. Correspondence should be addressed to: Kenya Museum Society, PO Box 40658, Nairobi 00100, Kenya. Email: [email protected] Website: www.KenyaMuseumSociety.org Statements of fact and opinion appearing in Kenya Past and Present are made on the responsibility of the author alone and do not imply the endorsement of the editor or publishers. Reproduction of the contents is permitted with acknowledgement given to its source. We encourage the contribution of articles, which may be sent to the editor at [email protected]. No category exists for subscription to Kenya Past and Present; it is a benefit of membership in the Kenya Museum Society. Available back issues are for sale at the Society’s offices in the Nairobi National Museum. Any organisation wishing to exchange journals should write to the Resource Centre Manager, National Museums of Kenya, PO Box 40658, Nairobi 00100, Kenya, or send an email to [email protected] Designed by Tara Consultants Ltd ©Kenya Museum Society Nairobi, April 2016 Kenya Past and Present Issue 43, 2016 Contents KMS highlights 2015 ..................................................................................... 3 Patricia Jentz To conserve Kenya’s natural and cultural heritage ........................................ 9 Marla Stone Museum highlights 2015 ............................................................................. 11 Juliana Jebet and Hellen Njagi Beauty and the bead: Ostrich eggshell beads through prehistory .................................................. 17 Angela W.
    [Show full text]
  • 2009 Trip Report KENYA
    KENYA and TANZANIA TRIP REPORT Sept 25-Oct 23, 2009 PART 1 - Classic Kenya text and photos by Adrian Binns Sept 25 / Day 1: Blue Post Thika; Castle Forest We began the morning with an unexpected Little Sparrowhawk followed by a Great Sparrowhawk, both in the skies across the main road from the Blue Post Hotel in Thika. The lush grounds of the Blue Post are bordered by the twin waterfalls of the Chania and Thika, both rivers originating from the nearby Aberdare Mountain Range. It is a good place to get aquatinted with some of the more common birds, especially as most can be seen in close proximity and very well. Eastern Black-headed Oriole, Cinnamon-chested Bee- eater, Little Bee-eater, White-eyed Slaty Flycatcher, Collared Sunbird, Bronzed Mannikin, Speckled Mousebird and Yellow-rumped Tinkerbird were easily found. Looking down along the river course and around the thundering waterfall we found a pair of Giant Kingfishers as well as Great Cormorant, Grey Heron and Common Sandpiper, and two Nile Monitors slipped behind large boulders. A fruiting tree provided a feast for Yellow-rumped Seedeaters, Violet-backed Starlings, Spot-flanked Barbet (right), White-headed Barbet as a Grey-headed Kingfisher, an open woodland bird, made sorties from a nearby perch. www.wildsidenaturetours.com www.eastafricanwildlifesafaris.com © Adrian Binns Page 1 It was a gorgeous afternoon at the Castle Forest Lodge set deep in forested foothills of the southern slope of Mt. Kenya. While having lunch on the verandah, overlooking a fabulous valley below, we had circling Long-crested Eagle (above right), a distant Mountain Buzzard and African Harrier Hawk.
    [Show full text]
  • The East African Rift System in the Light of KRISP 90
    ELSEVIER Tectonophysics 236 (1994) 465-483 The East African rift system in the light of KRISP 90 G.R. Keller a, C. Prodehl b, J. Mechie b,l, K. Fuchs b, M.A. Khan ‘, P.K.H. Maguire ‘, W.D. Mooney d, U. Achauer e, P.M. Davis f, R.P. Meyer g, L.W. Braile h, 1.0. Nyambok i, G.A. Thompson J a Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968-0555, USA b Geophysikalisches Institut, Universitdt Karlwuhe, Hertzstrasse 16, D-76187Karlsruhe, Germany ’ Department of Geology, University of Leicester, University Road, Leicester LEl 7RH, UK d U.S. Geological Survey, Office of Earthquake Research, 345 Middlefield Road, Menlo Park, CA 94025, USA ’ Institut de Physique du Globe, Universite’ de Strasbourg, 5 Rue Ret& Descartes, F-67084 Strasbourg, France ‘Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90024, USA ’ Department of Geology and Geophysics, University of Wuconsin at Madison, Madison, WI 53706, USA h Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN 47907, USA i Department of Geology, University of Nairobi, P.O. Box 14576, Nairobi, Kenya ’ Department of Geophysics, Stanford University, Stanford, CA 94305, USA Received 21 September 1992; accepted 8 November 1993 Abstract On the basis of a test experiment in 1985 (KRISP 85) an integrated seismic-refraction/ teleseismic survey (KRISP 90) was undertaken to study the deep structure beneath the Kenya rift down to depths of NO-150 km. This paper summarizes the highlights of KRISP 90 as reported in this volume and discusses their broad implications as well as the structure of the Kenya rift in the general framework of other continental rifts.
    [Show full text]
  • The Rwenzori Mountains, a Landslide- Prone Region?
    The Rwenzori Mountains, a landslide- prone region? Liesbet Jacobs, Olivier Dewitte, Jean Poesen, Damien Delvaux, Wim Thiery & Matthieu Kervyn Landslides Journal of the International Consortium on Landslides ISSN 1612-510X Landslides DOI 10.1007/s10346-015-0582-5 1 23 Your article is protected by copyright and all rights are held exclusively by Springer- Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy Original Paper Landslides Liesbet Jacobs I Olivier Dewitte I Jean Poesen I Damien Delvaux I Wim Thiery I Matthieu Kervyn DOI 10.1007/s10346-015-0582-5 Received: 17 July 2014 Accepted: 7 April 2015 The Rwenzori Mountains, a landslide-prone region? © Springer-Verlag Berlin Heidelberg 2015 Abstract With its exceptionally steep topography, wet climate, Rwenzori Mountains while Bauer et al. (2010) state that landslides and active faulting, landslides can be expected to occur in the play a significant role in erosion processes in the region. However, Rwenzori Mountains. Whether or not this region is prone to except for a brief description of a landslide damming the Bujuku landsliding and more generally whether global landslide invento- River (Eggermont et al.
    [Show full text]
  • The Position of Madagascar Within Gondwana and Its Movements During Gondwana Dispersal ⇑ Colin Reeves
    Journal of African Earth Sciences xxx (2013) xxx–xxx Contents lists available at ScienceDirect Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci The position of Madagascar within Gondwana and its movements during Gondwana dispersal ⇑ Colin Reeves Earthworks BV, Achterom 41A, 2611 PL Delft, The Netherlands article info abstract Article history: A reassembly of the Precambrian fragments of central Gondwana is presented that is a refinement of a Available online xxxx tight reassembly published earlier. Fragments are matched with conjugate sides parallel as far as possible and at a distance of 60–120 km from each other. With this amount of Precambrian crust now stretched Keywords: into rifts and passive margins, a fit for all the pieces neighbouring Madagascar – East Africa, Somalia, the Madagascar Seychelles, India, Sri Lanka and Mozambique – may be made without inelegant overlap or underlap. This Gondwana works less well for wider de-stretched margins on such small fragments. A model of Gondwana dispersal Aeromagnetics is also developed, working backwards in time from the present day, confining the relative movements of Indian Ocean the major fragments – Africa, Antarctica and India – such that ocean fracture zones collapse back into Dykes themselves until each ridge-reorganisation is encountered. The movements of Antarctica with respect to Africa and of India with respect to Antarctica are defined in this way by a limited number of interval poles to achieve the Gondwana ‘fit’ situation described above. The ‘fit’ offers persuasive alignments of structural and lithologic features from Madagascar to its neighbours. The dispersal model helps describe the evolution of Madagascar’s passive margins and the role of the Madagascar Rise as a microplate in the India–Africa–Antarctica triple junction.
    [Show full text]
  • Pan-African Orogeny 1
    Encyclopedia 0f Geology (2004), vol. 1, Elsevier, Amsterdam AFRICA/Pan-African Orogeny 1 Contents Pan-African Orogeny North African Phanerozoic Rift Valley Within the Pan-African domains, two broad types of Pan-African Orogeny orogenic or mobile belts can be distinguished. One type consists predominantly of Neoproterozoic supracrustal and magmatic assemblages, many of juvenile (mantle- A Kröner, Universität Mainz, Mainz, Germany R J Stern, University of Texas-Dallas, Richardson derived) origin, with structural and metamorphic his- TX, USA tories that are similar to those in Phanerozoic collision and accretion belts. These belts expose upper to middle O 2005, Elsevier Ltd. All Rights Reserved. crustal levels and contain diagnostic features such as ophiolites, subduction- or collision-related granitoids, lntroduction island-arc or passive continental margin assemblages as well as exotic terranes that permit reconstruction of The term 'Pan-African' was coined by WQ Kennedy in their evolution in Phanerozoic-style plate tectonic scen- 1964 on the basis of an assessment of available Rb-Sr arios. Such belts include the Arabian-Nubian shield of and K-Ar ages in Africa. The Pan-African was inter- Arabia and north-east Africa (Figure 2), the Damara- preted as a tectono-thermal event, some 500 Ma ago, Kaoko-Gariep Belt and Lufilian Arc of south-central during which a number of mobile belts formed, sur- and south-western Africa, the West Congo Belt of rounding older cratons. The concept was then extended Angola and Congo Republic, the Trans-Sahara Belt of to the Gondwana continents (Figure 1) although West Africa, and the Rokelide and Mauretanian belts regional names were proposed such as Brasiliano along the western Part of the West African Craton for South America, Adelaidean for Australia, and (Figure 1).
    [Show full text]
  • REGIONAL GEOGRAPHY of AFRICA. Uganda Certificate of Education
    REGIONAL GEOGRAPHY OF AFRICA. Uganda Certificate of Education. GEOGRAPHY Code: 273/2, Paper 2 2 hours 30 minutes PART I : THE REST OF AFRICA. INSTRUCTIONS TO CANDIDATES: This paper consists of two sections: Part I Rest of Africa. Answer two questions from part I @ question carry 25marks. Any additional question (s) answered will not be marked. Four questions are set and a candidate is required to answer only two questions. This region covers 50% of paper 273/2. 1) Download and print out a hard copy then copy this notes in a fresh book for Rest of Africa paper2. 2) If You need a copy of this work organized by the teacher for Rest of Africa. Call 0775 534057 for a book of Africa and it will be delivered. Emihen – Utec 1 SIZE, SHAPE AND POSITION. POSITION OF AFRICA. Africa is one of the largest continents of the world. It’s the second to the largest landmass combined of Eurasia i.e. Europe and Asia continents. LOCATION: Africa lies between latitudes 37.51’N just West of Cape Blanc in Tunisia to Cape Aghulhas at Latitude 34.51’S a distance of 8,000kms. Africa also lies between Cape Ras Hagun 51.50’E and Cape Verde 17.32’W. SIZE: Africa covers land area of about 30,300,300km2. THE SHAPE: Africa’s shape is unbalanced; with her northern part being bulky and wide, while the southern part being thinner and narrower in appearance. Emihen-Utec 2 The Latitude EQUATOR divides the continent into TWO HALVES, there being approximately; 3800kms between the Cape Agulhas in the south and Equator while between Tunisia and Equator in the North is 4,100kms.
    [Show full text]
  • The Phanerozoic Thermo-Tectonic Evolution of Northern Mozambique Constrained by Ar, Fission Track and (U-Th)/He Analyses
    THE PHANEROZOIC THERMO-TECTONIC EVOLUTION OF NORTHERN MOZAMBIQUE 40 39 CONSTRAINED BY AR/ AR, FISSION TRACK AND (U-TH)/HE ANALYSES Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften am Fachbereich Geowissenschaften der Universität Bremen Vorgelegt von Matthias Ch. Daßinnies Bremen, 2006 Tag des Kolloquiums: 22.12.2006 Gutachter: Prof. Dr. J. Jacobs Prof. Dr. W. Bach Prüfer: Prof. Dr. T. Mörz Prof. A. Kopf Contents CONTENTS ACKNOWLEDGEMENTS ...................................................................................................... v SUMMARY........................................................................................................................ vii ZUSAMMENFASSUNG ......................................................................................................... x CHAPTER 1 INTRODUCTION .................................................................................................................. 1 1.1 Scope of thesis.................................................................................................. 1 1.2 Research objectives and methods..................................................................... 3 1.3 Outline of thesis ............................................................................................... 4 CHAPTER 2 THERMOCHRONOLOGICAL METHODS AND ANALYTICS ...................................................... 6 2.1 40Ar/39Ar dating method................................................................................... 6 2.1.1 Argon isotope measurements
    [Show full text]
  • Ocean Drilling Program Initial Reports Volume
    Backman, J., Duncan, R. A., et al., 1988 Proceedings of the Ocean Drilling Program, Initial Reports, Vol. 115 1. INTRODUCTION1 Shipboard Scientific Party2 Leg 115 is the first of a nine-leg program of exploration of these volcanic islands and submarine (presumed volcanic) ridges the Indian Ocean. Previous drilling by the Deep Sea Drilling is consistent with northward motion of the Indian plate, fol- Program (DSDP), Legs 22 through 29 (1972-73), resulted in the lowed by northeastward motion of the African plate, over a first detailed information about the geologic and Oceanographic fixed melting anomaly at the location of Reunion during Ter- history of this major region of the oceans. Compared with the tiary time (Morgan, 1981; Duncan, 1981). In addition, this vol- Atlantic and Pacific Ocean Basins, however, the Indian Ocean is canic trail is parallel with the Ninetyeast Ridge, another subma- still relatively unexplored. During this multifaceted investiga- rine lineament linked to hotspot activity (now centered near the tion, we hoped to examine many fundamental questions. The Kerguelen Islands, Antarctic plate), and the two may record the scientific objectives of this leg fell into two main subject areas: northward motion of India during the opening of the Indian hotspot volcanism and paleoceanography. Ocean. Until Leg 115, however, the only accessible sampling loca- HOTSPOTS AND PLATE TECTONICS tions along the proposed Reunion hotspot track were the young An extraordinary feature of the Indian Ocean is the large volcanic islands at the southern end and the Deccan flood ba- number of elevated plateaus and ridges scattered throughout the salts at the northern end.
    [Show full text]