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Record of the Angola Portion of the Congo Craton: Newly Dated Magmatic Events at 1500 and 1110 Ma and Implications for Nuna (Columbia) Supercontinent Reconstructions
NOTICE: This is the author’s version of a work that was accepted for publication in Precambrian Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Precambrian Research, Vol. 230 (2013). doi: 10.1016/j.precamres.2013.01.010 Accepted Manuscript Title: Mesoproterozoic intraplate magmatic ‘barcode’ record of the Angola portion of the Congo craton: newly dated magmatic events at 1500 and 1110 Ma and implications for Nuna (Columbia) supercontinent reconstructions Authors: Richard E. Ernst, Eurico Pereira, Michael A. Hamilton, Sergei A. Pisarevsky, Jose´ Rodriques, Colombo C.G. Tassinari, Wilson Teixeira, Vitoria´ Van-Dunem PII: S0301-9268(13)00011-9 DOI: doi:10.1016/j.precamres.2013.01.010 Reference: PRECAM 3703 To appear in: Precambrian Research Received date: 24-7-2012 Revised date: 26-11-2012 Accepted date: 3-1-2013 Please cite this article as: Ernst, R.E., Pereira, E., Pisarevsky, S.A., Rodriques, J., Tassinari, C.C.G., Teixeira, W., Van-Dunem, V., Mesoproterozoic intraplate magmatic ‘barcode’ record of the Angola portion of the Congo craton: newly dated magmatic events at 1500 and 1110 Ma and implications for Nuna (Columbia) supercontinent reconstructions, Precambrian Research (2010), doi:10.1016/j.precamres.2013.01.010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. -
The Long-Term Evolution of the Congo Deep-Sea Fan: a Basin-Wide View of the Interaction Between a Giant Submarine Fan and a Mature Passive Margin (Zaiango Project)
The Congo deep-sea fan: how far and for how long? A basin-wide view of the interaction between a giant submarine fan and a mature passive margin Zahie Anka 1,*, Michel Séranne 2,**, Michel Lopez 2, Magdalena Scheck-Wenderoth 1, Bruno Savoye 3,†. 1. GFZ German Research Centre for Geosciences. Telegrafenberg, 14473 Potsdam, Germany. 2. CNRS-Université Montpellier II. cc 060, Geosciences Montpellier. 34095 Montpellier, France. 3. IFREMER, Geosciences Marines, BP 70 — 29280 Plouzané, France. (*) [email protected] (**) [email protected] (†) deceased 1.- Introduction The Congo deep-sea fan is one of the largest submarine fan systems in the world and one of the most important depocentre in the eastern south Atlantic. The present-day fan extends over 1000 km offshore the Congo-Angola continental margin and it is sourced by the Congo River, whose continental drainage area is the second largest in the world (3.7 106 km²) (Droz et al., 1996) (Fig.1). There is a direct connexion between the river’s drainage basin and the deep basin through an impressive submarine canyon, which cuts down about 950 m at the shelf-break and more than 1300 m at 100 km offshore the coastline (Babonneau et al., 2002). Hence, the direct transfer of terrigenous material onto the abyssal plain takes place through the canyon, by-passing the shelf and upper slope. The submarine fan covers a surface of about 300,000 km² and contains at least 0.7 Mkm³ of Tertiary sediments (Anka and Séranne, 2004; Droz et al., 2003; Savoye et al., 2000). -
Tracing the Central African Rift and Shear Systems Offshore Onto
Tracing the West and Central African Rift and Shear Systems offshore onto oceanic crust: a ‘rolling’ triple junction William Dickson (DIGs), and James W. Granath, PhD, (Granath & Associates) Abstract Compared to the understood kinematics of its continental margins and adjacent ocean basins, the African continent is unevenly or even poorly known. Consequently, the connections from onshore fault systems into offshore spreading centers and ridges are inaccurately positioned and inadequately understood. This work considers a set of triple junctions and the related oceanic fracture systems within the Gulf of Guinea from Nigeria to Liberia. Our effort redefines the greater Benue Trough, onshore Nigeria, and reframes WCARS (West and Central African Rift and Shear Systems) as it traces beneath the onshore Niger Delta and across the Cameroon Volcanic Line (CVL), Figure 1. We thus join onshore architecture to oceanic fracture systems, forming a kinematically sound whole. This required updating basin outlines and relocating mis- positioned features, marrying illustrations from the literature to imagery suitable for basin to sub- basin mapping. The resulting application of systems structural geology explains intraplate deformation in terms of known structural styles and interplay of their elements. Across the Benue Trough and along WCARS, we infer variations in both structural setting and thermal controls that require further interpretation of their petroleum systems. Introduction Excellent work has defined Africa's onshore geology and the evolution and driving mechanisms of the adjacent (particularly the circum-Atlantic) ocean basins. However, understanding of the oceanic realm has outpaced that of the continent of Africa. This paper briefly reviews onshore work. We then discuss theoretical geometry of tectonic boundaries (including triple junctions) and our data (sources and compilation methods). -
The Mesozoic to Early Cenozoic Magmatism of the Benue Trough (Nigeria); Geochemical Evidence for the Involvement of the St Helen
JOURNAL OF PETROLOGY VOLUME 37 NUMBER 6 PAGES 1341-1358 1996 C. COULON1*, P. VIDAL2, C. DUPUY3, P. BAUDIN1, M. POPOFF*, H. MALUSKI5 AND D. HERMITTE1 'PETROLOGIE MAGMATIQUE, URA 1277, CEREGE, BP 80, 15545 AIX EN PROVENCE CEDEX 4, FRANCE 'CENTRE DE RECHERCHES VOLCANOLOGIQUES, URA 10, 63038 CLERMONT FERRAND CEDEX, FRANCE 'CENTRE GEOLOGIO.UE ET GEOPHYSIO.UE, CNRS, PLACE BATAILLON, J4095 MONTPELLIER CEDEX, FRANCE *INSTITUT DE GEODYNAMIQ.UE, URA 1279, UNIVERSITE DE NICE—SOPHIA ANTIPOLIS, AVENUE EINSTEIN, 06560 VALBONNE, FRANCE JLABORATOIRE DE GEOCHRONOLOGIE—GEOCHIMIE, URA 176J, PLACE BATAILLON, 34095 MONTPELLIER CEDEX, FRANCE The Mesozoic to Early Cenozoic Downloaded from https://academic.oup.com/petrology/article/37/6/1341/1406521 by guest on 28 September 2021 Magmatism of the Benue Trough (Nigeria); Geochemical Evidence for the Involvement of the St Helena Plume The Benue Trough is a continental rift related to the opening of Equatorial Atlantic. Moreover, the geochemical similarity the equatorial domain of the South Atlantic which was initi- between the alkaline magmatism of the Benue Trough and that ated in Late Jurassic-Early Cretaceous times. Highly diversi- of the Cameroon Line suggests that both magmatic provinces fied and volumetrically restricted Mesozoic to Cenozoic were related to the St Helena plume. Finally, the temporal magmatic products are scattered throughout the rift. Three per- change of the mantle sources observed in the Benue Trough can iods of magmatic activity have been recognized on the basis of be accounted for by the recent models of plume dynamics, in the *°Ar-39Ar ages: 147-106 Ma, 97-81 Ma and 68-49 Ma. -
Durham Research Online
Durham Research Online Deposited in DRO: 13 April 2015 Version of attached le: Published Version Peer-review status of attached le: Peer-reviewed Citation for published item: Kaislaniemi, L. and van Hunen, J. (2014) 'Dynamics of lithospheric thinning and mantle melting by edge-driven convection : application to Moroccan Atlas mountains.', Geochemistry, geophysics, geosystems., 15 (8). pp. 3175-3189. Further information on publisher's website: http://dx.doi.org/10.1002/2014GC005414 Publisher's copyright statement: c 2014. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modications or adaptations are made. Additional information: Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom Tel : +44 (0)191 334 3042 | Fax : +44 (0)191 334 2971 https://dro.dur.ac.uk PUBLICATIONS Geochemistry, -
Continental Complexities: a Multidisciplinary Introduction to Africa
Continental Complexities A Multidisciplinary Introduction to Africa By Dr. Ibigbolade Simon Aderibigbe and Dr. Akinloye Ojo Included in this preview: • Table of Contents • Chapter 1 & 2 For additional information on adopting this book for your class, please contact us at 800.200.3908 x501 or via e-mail at [email protected] Dpoujofoubm!Dpnqmfyjujft A MULTIDISCIPLINARY INTRODUCTION TO AFRICA Revised Edition Edited by Ibigbolade Aderibigbe and Akinloye Ojo University of Georgia Bassim Hamadeh, CEO and Publisher Christopher Foster, General Vice President Michael Simpson, Vice President of Acquisitions Jessica Knott, Managing Editor Kevin Fahey, Cognella Marketing Manager Jess Busch, Senior Graphic Designer Zina Craft , Acquisitions Editor Jamie Giganti, Project Editor Brian Fahey, Licensing Associate Copyright © 2013 by Cognella, Inc. All rights reserved. No part of this publication may be reprinted, reproduced, transmitted, or utilized in any form or by any electronic, mechanical, or other means, now known or hereaft er invented, including photocopying, microfi lming, and recording, or in any information retrieval system without the written permission of Cognella, Inc. First published in the United States of America in 2013 by Cognella, Inc. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identifi cation and explanation without intent to infringe. Printed in the United States of America ISBN: 978-1-62131-133-1 (pbk) Contents The Study of Africa: An Introduction 1 Ibigbolade Aderibigbe -
SÉRANNE, M., and ANKA, Z., 2005
ARTICLE IN PRESS Journal of African Earth Sciences xxx (2005) xxx–xxx www.elsevier.com/locate/jafrearsci South Atlantic continental margins of Africa: A comparison of the tectonic vs climate interplay on the evolution of equatorial west Africa and SW Africa margins Michel Se´ranne *, Zahie Anka UMR 5573 Dynamique de la Lithosphe`re, CNRS/Universite´ Montpellier 2, 34095 Montpellier cedex 05, France Received 5 February 2005; accepted 18 July 2005 Abstract Africa displays a variety of continental margin structures, tectonic styles and sedimentary records. The comparative review of two representative segments: the equatorial western Africa and the SW Africa margins, helps in analysing the main controlling factors on the development of these margins. Early Cretaceous active rifting south of the Walvis Ridge resulted in the formation of the SW Africa volcanic margin that displays thick and wide intermediate igneous crust, adjacent to a thick unstretched continental crust. The non-vol- canic mode of rifting north of the Walvis ridge, led to the formation of the equatorial western Africa margin, characterised by a wide zone of crustal stretching and thinning, and thick, extensive, syn-rift basins. Contrasting lithologies of the early post-rift (salt vs shale) determined the style of gravitational deformation, whilst periods of activity of the decollements were controlled by sedimentation rates. Regressive erosion across the prominent shoulder uplift of SW Africa accounts for high clastic sedimentation rate during Late Creta- ceous to Eocene, while dominant carbonate production on equatorial western Africa shelf suggests very little erosion of a low hinterland. The early Oligocene long-term climate change had contrasted response in both margins. -
Sea Experience in Developing Countries
Chapter 6 SEA EXPERIENCE IN DEVELOPING COUNTRIES Increasingly, developing countries are experimenting with SEA and some have SEA-type approaches and elements in place already. There is also considerable experience with using a variety of strategic planning processes that display many of the characteristics of SEA (para SEA). We focus first on SEA in southern Africa where a dedicated regional workshop on SEA was organised to feed into this review (SAIEA 2003a), followed by sections covering francophone Africa, the rest of sub-Saharan Africa, Latin America, Asia and elsewhere. But our survey of this field represents no more than a preliminary reconnaissance. Selected examples of SEA and para SEA illustrate some of the indigenous approaches that have been adopted. These are less common than SEAs promoted and funded by development assistance agencies (which are reviewed in Chapter 4). In most cases where formal SEA has been undertaken in developing countries, the basic aim and approach has mirrored that in the north – namely to identify the environmental consequences (and associated social and economic effects) of existing, new or revised policies, plans and programmes. These represent only a small number of the broad family of SEA approaches. But they are a highly visible sub-set of the large suite of informal or para-SEAs which form part of development policy-making, land use planning or resource management. No strict boundaries can be drawn for this latter area of application. Only the more evident SEA type elements and approaches are introduced in this chapter. Nevertheless, they indicate the scope and diversity of the extended SEA family in developing countries, where political and economic realities constrain what can be done. -
Hafnium and Neodymium Isotopes in Surface Waters of the Eastern Atlantic Ocean: Implications for Sources and Inputs of Trace Metals to the Ocean
Available online at www.sciencedirect.com Geochimica et Cosmochimica Acta 74 (2010) 540–557 www.elsevier.com/locate/gca Hafnium and neodymium isotopes in surface waters of the eastern Atlantic Ocean: Implications for sources and inputs of trace metals to the ocean J. Rickli a,*, M. Frank b, A.R. Baker c, S. Aciego a, G. de Souza a, R.B. Georg d, A.N. Halliday d a ETH Zurich, Institute for Isotope Geochemistry and Mineral Resources, Clausiusstrasse 25, CH-8092 Zurich, Switzerland b IFM-GEOMAR, Leibniz Institute of Marine Sciences, 24148 Kiel, Germany c School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK d Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK Received 14 January 2009; accepted in revised form 30 September 2009; available online 7 October 2009 Abstract We present hafnium (Hf) and neodymium (Nd) isotopic compositions and concentrations in surface waters of the eastern Atlantic Ocean between the coast of Spain and South-Africa. These data are complemented by Hf and Nd isotopic and con- centration data, as well as rare earth element (REE) concentrations, in Saharan dust. Hafnium concentrations range between a maximum of 0.52 pmol/kg in the area of the Canary Islands and a minimum value of 0.08 pmol/kg in the southern Angola Basin. Neodymium concentrations also show a local maximum in the area of the Canary Islands (26 pmol/kg) but are even higher between ~20°N and ~4°N reaching maximum concentrations of 35 pmol/kg. These elevated concentrations provide evidence of inputs from weathering of the Canary Islands and from the partial dissolution of dust from the Sahara/Sahel region. -
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). -
Evidence of a Permian Remagnetization in the Neoproterozoic- Cambrian Adoudounian Formation (Anti-Atlas, Morocco)
Bulletin de l’Institut Scientifique, Rabat, section Sciences de la Terre, 2012, n° 34, p. 15-28. Evidence of a Permian remagnetization in the Neoproterozoic- Cambrian Adoudounian Formation (Anti-Atlas, Morocco) Florent BOUDZOUMOU1,2, Didier VANDAMME2, Pascal AFFATON2 Jérôme GATTACCECA2, Hassane OUAZZANI3, Lakhlifi BADRA3 3 & Elmahjoub MAHJOUBI 1. Université Marien Ngouabi, Faculté des Sciences, Département de Géologie, B.P. 69, Brazzaville, Congo. e-mail : [email protected] 2. CEREGE, Université d’Aix-Marseille, CNRS, B.P. 80, Europôle Méditerranéen de l’Arbois, 13545 Aix-en-Provence Cedex 04, France. 3. Université Moulay Ismail, Faculté des Sciences, Département de Géologie, B.P. 11201 Zaitoune, Meknès, Maroc. Abstract. A paleomagnetic study was undertaken on samples collected from seven sites of the exhumed and eroded Ait-Abdallah and Kerdous antiforms in the Moroccan Anti-Atlas of the West African craton. These sites are located in the Adoudounian Formation considered as of Neoproterozoic–Cambrian age. The magnetic mineralogy is represented essentially by magnetite and titanohematite. Magnetization is carried by three components respectively of high-temperature (500-670°C), medium-temperature (350-470°C) and low- temperature (NRM-300°C). Plotted in Gondwana Apparent Polar Wander Path, the high and medium temperature components close to the Permian pole and determine Permian overprint directions. The low temperature component closes to the present day field and corresponds to the present overprint day. This study shows that Permian overprint largely affect the Anti-Atlas area. Key words: Paleomagnetism, Anti-Atlas, West-African craton, Adoudounian Formation, Neoproterozoic, Cambrian. Mise en évidence d’une ré-aimantation permienne dans la Formation Adoudounienne, d’âge Néoprotérozoïque-Cambrien (Anti- Atlas, Maroc) Résumé. -
Deep Sea Drilling Project Initial Reports Volume 40
28. LEG 40 RESULTS IN RELATION TO CONTINENTAL SHELF AND ONSHORE GEOLOGY William G. Siesser, Department of Geology, University of Cape Town, Rondebosch, South Africa INTRODUCTION tion of basins; instead a sediment wedge has prograded seaward in a deltaic fashion (Scrutton and Dingle, This study compares and contrasts the sedimentary 1974). However, there is some suggestion that history of the onshore coastal region and the continen- marginal-fracture zones striking perpendicular to the tal shelf along the west coast of South Africa, South coast have acted as lines of differential subsidence, thus West Africa, and Angola with that of the outer con- exercising some control over the movement of tinental margin of those countries (Figure 1), as shown sediments parallel to the coast (Scrutton and Dingle, by Leg 40 drilling. 1974). This situation is in contrast to the Cuanza Basin of Geologic Setting: Mesozoic and Tertiary Sedimentation Angola, where sedimentation has been controlled by a Southern Africa underwent its last orogenic phase marginal basement plateau, a number of basement during the Triassic, raising up the Cape Fold Belt. highs, and salt structures (Scrutton and Dingle, 1974). Although no further orogenies occurred, southern Africa remained a high continental mass throughout Onshore the Mesozoic and Cenozoic owing to repeated epeiro- Only two Cretaceous exposures have been reported genic uplift. Epeirogenesis had a characteristic and between Cape Agulhas and the Kunene River. The repeated pattern: maximum uplift occurred in a zone southernmost is a deposit of nonmarine clayey sands near the coastal margin (somewhat seaward of what is (with calcareous concretions) containing bones of the now the Great Escarpment), resulting in a steep dinosaur Kangnasaurus coetzeei, calcified and silicified seaward tilting on the outer side and a gentler inland wood, and streaks of lignite (Rogers, 1915).