DOCSLIB.ORG

Glaciogenic Reservoirs and Hydrocarbon Systems: an Introduction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Glaciogenic Reservoirs and Hydrocarbon Systems: an Introduction Downloaded from http://sp.lyellcollection.org/ by guest on September 28, 2021 Glaciogenic reservoirs and hydrocarbon systems: an introduction M. HUUSE1*, D. P. LE HERON2, R. DIXON3, J. REDFERN1, A. MOSCARIELLO4 & J. CRAIG5 1The University of Manchester, Manchester, UK 2Royal Holloway University of London, London, UK 3BP Exploration Operation Company Ltd, Sunbury on Thames, UK 4University of Geneva, Geneva, Switzerland 5Eni Exploration & Production, Milan, Italy *Corresponding author (e-mail: [email protected]) Abstract: Glaciogenic reservoirs host important hydrocarbon and groundwater resources across the globe. Their complexity and importance for exploration and palaeoclimate reconstruction have made glaciogenic successions popular subjects for study. In this paper we provide an over- view of the palaeoclimatic and tectonic setting for Earth glaciation and a chronological account of glaciogenic deposits since c. 750 Ma, with particular emphasis on their reservoir potential and associated hydrocarbon systems. Hydrocarbon accumulations within glaciogenic reservoirs occur principally in Palaeozoic (Late Ordovician and Permo-Carboniferous) sandstones in South America, Australia, North Africa and the Middle East, with relatively minor occurrences of shallow gas hosted in Pleistocene deposits in the North Sea and Canada. Groundwater reserves occur within glaciogenic sandstones across the northern European lowland and in North America. The main glaciogenic environments range from subglacial to glacier front to proglacial and deglacial. Rapidly changing environments, hydrodynamic regimes and glacier-front and sub- glacial deformation often result in very complex glaciogenic sequences with significant challenges for reconstruction of their origin and resource importance, which this volume seeks to address. Glaciogenic deposits constitute reservoirs for hydro- lake and continental shelf areas, as well as adjacent carbons in sedimentary basins across the globe, with continental slopes where large trough mouth fans reservoir ages ranging from Neoproterozoic to constitute volumetrically important deposits from Pleistocene (Fig. 1; Table 1). Onshore, Pleistocene Pleistocene glaciations (Sejrup et al. 2003; Ottesen glacial deposits are important reservoirs for ground- et al. 2012). In deep ocean settings, ice-rafted debris water in NW Europe and in North America, while provides the most important physical record of the offshore glacial deposits constitute potential drilling Pleistocene shelf glaciations (Hemming 2004). hazards and pose problems for deeper seismic The term ‘glaciogenic hydrocarbon systems’ can imaging due to their often anomalous infill litholo- be applied to any hydrocarbon system where at gies and pore fluids (in particular methane). Major least one part of that system is linked to glaciation. glaciations through Earth history appear on regular For example, we recognize glaciogenic reservoirs, 300–350 Myr cycles, with the Late Ordovician deglacial source rocks, glaciogenic seals, glacio- glaciation breaking this trend (Fig. 2; Page et al. genic deformation (glaciotectonics and glacial load- 2007). Important controls on glaciation include ing/unloading cycles), glacial sculpting of reservoir plate tectonic configuration (Fig. 3), ocean circula- rocks or cold climate conditions leading to gas tion and atmospheric CO2 pressure (Fig. 2; Craig hydrate formation. Source rock deposition linked et al. 2009). Growth of continental ice sheets leads with glaciation tends to be favoured by remnant topo- to global sea-level fall (Zachos et al. 2001; Miller graphic relief linked with glacial sculpting and et al. 2005), thus affecting depositional patterns transgressive and high sea-level stands causing con- worldwide, and also causes flexing of the litho- densed organic-rich sediment accumulation (Lu¨ning sphere within tens to a hundred kilometres from et al. 2000; Craig et al. 2009; Moreau 2011; Le the ice sheet margin and isostatic depression under Heron & Craig 2012). A common glaciogenic res- the ice sheet itself (e.g. Lambeck et al. 1998). ervoir and source rock system is deposited follow- Glaciogenic deposits are largely preserved in for- ing a glacial advance (lowstand), with subsequent merly glaciated lowland areas, including land, deposition of thick clastic reservoir systems during From:Huuse, M., Redfern, J., Le Heron, D. P., Dixon, R. J., Moscariello,A.&Craig, J. (eds) 2012. Glaciogenic Reservoirs and Hydrocarbon Systems. Geological Society, London, Special Publications, 368, http://dx.doi.org/10.1144/SP368.19 # The Geological Society of London 2012. Publishing disclaimer: www.geolsoc.org.uk/pub_ethics Downloaded from http://sp.lyellcollection.org/ by guest on September 28, 2021 M. HUUSE ET AL. Fig. 1. Global distribution of glaciogenic reservoir and hydrocarbon system case studies (this volume). Cryogenian (c. 690 Ma): 1, Le Heron & Craig (2012). Ordovician (c. 444 Ma): 2, Hirst (2012); 3, Lang et al. (2012a, b); 4, Girard et al. (2012); 5, Douillet et al. (2012). Permo–Carboniferous: 6, Bache et al. (2012); 7, Martin et al. (2012). Oligo-Miocene: 8, Fielding et al. (2012). Pleistocene: 9–18. Key to case study numbers provided in Table 1. the ice retreat phase. Later during the deglacial structures formed by high-velocity jet-like water transgression, the glaciogenic reservoirs are often flows, not commonly observed with deposition enhanced by transgressive reworking, and sub- under non-glacial hydrological conditions. In many sequently overlain by sealing mudrocks, which, dur- cases, associated larger-scale morphological fea- ing the later stages of glaciation may be organic-rich tures (observed at outcrop or in seismic data in the source rocks. When more than one glacial cycle subsurface), such as cross-shelf troughs, tunnel exists, intra-formational seals and possible source valleys, megascale glacial lineations (MSGLs), rock strata may also be found interbedded with the drumlins, iceberg scours, striations, moraines and reservoirs. The largest recorded transgression asso- glaciotectonics structures, allude to a likely glacio- ciated with rich post-glacial source rocks are found genic origin. in the early Silurian, following the Late Ordovician The specific origin of some glaciogenic features glacial interval (Fig. 2; Page et al. 2007). During the (e.g. cross shelf troughs, iceberg ploughmarks, drop- Pleistocene, numerous transgressive intervals are stones and moraines) is well documented, whereas recognized between glacial cycles (Zachos et al. others are being vigorously debated (e.g. tunnel val- 2001; Miller et al. 2005). leys, MSGLs, drumlins). Tunnel valleys, in particu- Glaciogenic sediments with reservoir potential lar, have been studied and debated for over a century may be deposited in a range of environments includ- (Ussing 1903; Ehlers et al. 1984; O’Cofaigh 1996; ing subaerial, subglacial, proglacial, lacustrine, shal- Huuse & Lykke-Andersen 2000a; van der Vegt low marine and deep offshore (Fig. 4). While some et al. 2012). Tunnel valleys can be hundreds of glaciogenic sediments may be difficult to distinguish metres deep, kilometres wide and many tens of kilo- from deposits not associated with glaciation, others metres long, incising lowland glacial and preglacial contain distinctive outsize clasts, large boulders substrates. They therefore represent huge reposi- and pebbles, sometimes striated, which are typical tories of glaciogenic (glacial, deglacial) and inter- of glacial environments. Glacial deposits are also glacial deposits in otherwise low-accommodation often associated with sandstone intrusions and other settings (e.g. Cummings et al. 2012). For this rea- soft-sediment deformation structures, produced son, an understanding of tunnel valley fill lithologies due to ice sheet loading, push or fluctuating water and facies variations would be a useful tool for reser- tables (Brodzikowski & van Loon 1991; Pedersen voir prediction. Unfortunately, to date, a consistent 2012). Glaciogenic sandstones often contain model linking tunnel valley formation and infill Table 1. Summary of studies in this volume Downloaded from Authors* Region Area Age Case study/review Data & methods Significance Andersen et al. (9) NW Europe Denmark (on- & Pleistocene Tunnel valley 2D & 3D Seismic & EM Groundwater reservoir offshore) morphometrics Bache et al. (6) South America Bolivia (onshore) Permo-Carboniferous Glaciogenic valleys and 2D Seismic & Wireline Hydrocarbon reservoir fills logs Buckley (10) NW Europe North Sea (UK) Pleistocene Grounded ice evidence 2D & 3D Seismic Hazards & chronology http://sp.lyellcollection.org/ Douillet et al. (5) North Africa Jordan (onshore) Ordovician Tunnel valley fill Outcrop Hydrocarbon reservoir properties GLACIOGENIC RESERVOIRS: INTRODUCTION Fielding et al. (8) Antarctica McMurdo Sound Oligo-Miocene Glaciogenic Reservoir Subsurface Reservoir properties (offshore) Properties Girard et al. (2) North Africa Tassili N’Ajjer Ordovician Outwash channels Outcrop Hydrocarbon reservoir (Algeria/Libya) Hirst (3) North Africa Illizi Basin (Algeria) Ordovician Facies succession and Outcrop & Subsurface Hydrocarbon reservoir origin Kristensen & Huuse NW Europe North Sea (DK) Pleistocene Tunnel valley fills 3D & 2D seismic Hazards/imaging (11) Lang et al. (4) North Africa Illizi Basin (Algeria) Ordovician Sequence stratigraphy Core & wireline logs Hydrocarbon reservoir and facies Le Heron & Craig (1) Australia Centralian Superbasin Neo-Proterozoic De-glacial source rocks Outcrop & well data Source
Load more

Recommended publications
  • Glacitectonic Deformation in the Chuos Formation of Northern Namibia Busfield, Marie E.; Le Heron, Daniel P
    Aberystwyth University Glacitectonic deformation in the Chuos Formation of northern Namibia Busfield, Marie E.; Le Heron, Daniel P. Published in: Proceedings of the Geologists' Association DOI: 10.1016/j.pgeola.2012.10.005 Publication date: 2013 Citation for published version (APA): Busfield, M. E., & Le Heron, D. P. (2013). Glacitectonic deformation in the Chuos Formation of northern Namibia: Implications for neoproterozoic ice dynamics. Proceedings of the Geologists' Association, 124(5), 778- 789. https://doi.org/10.1016/j.pgeola.2012.10.005 General rights Copyright and moral rights for the publications made accessible in the Aberystwyth Research Portal (the Institutional Repository) are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the Aberystwyth Research Portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the Aberystwyth Research Portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. tel: +44 1970 62 2400 email: [email protected] Download date: 26. Sep. 2021 Elsevier Editorial System(tm) for Proceedings of the Geologists' Association
    [Show full text]
  • The Onset of Widespread Marine Red Beds and the Evolution of Ferruginous Oceans
    ARTICLE DOI: 10.1038/s41467-017-00502-x OPEN The onset of widespread marine red beds and the evolution of ferruginous oceans Haijun Song 1, Ganqing Jiang 2, Simon W. Poulton3, Paul B. Wignall3, Jinnan Tong1, Huyue Song1, Zhihui An1, Daoliang Chu1, Li Tian1, Zhenbing She1 & Chengshan Wang4 Banded iron formations were a prevalent feature of marine sedimentation ~3.8–1.8 billion years ago and they provide key evidence for ferruginous oceans. The disappearance of banded iron formations at ~1.8 billion years ago was traditionally taken as evidence for the demise of ferruginous oceans, but recent geochemical studies show that ferruginous con- ditions persisted throughout the later Precambrian, and were even a feature of Phanerozoic ocean anoxic events. Here, to reconcile these observations, we track the evolution of oceanic Fe-concentrations by considering the temporal record of banded iron formations and marine red beds. We find that marine red beds are a prominent feature of the sedimentary record since the middle Ediacaran (~580 million years ago). Geochemical analyses and thermo- dynamic modelling reveal that marine red beds formed when deep-ocean Fe-concentrations were > 4 nM. By contrast, banded iron formations formed when Fe-concentrations were much higher (> 50 μM). Thus, the first widespread development of marine red beds con- strains the timing of deep-ocean oxygenation. 1 State Key Laboratory of Biogeology and Environmental Geology, School of Earth Science, China University of Geosciences, Wuhan 430074, China. 2 Department of Geoscience, University of Nevada, Las Vegas, NV 89154-4010, USA. 3 School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
    [Show full text]
  • Toward a Neoproterozoic Composite Carbon-Isotope Record
    Toward a Neoproterozoic composite carbon-isotope record Galen P. Halverson† Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138-2902, USA, and Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Building 54-1126, Cam- bridge, Massachusetts 02139, USA Paul F. Hoffman Daniel P. Schrag Adam C. Maloof‡ Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138-2902, USA A. Hugh N. Rice Department of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria ABSTRACT framework for a new, high-resolution model Various workers have compiled composite carbon-isotope record for the Neoproterozoic !13C records for the Neoproterozoic (e.g., Hayes Glacial deposits of Sturtian and Marinoan comprising new !13C (carbonate) data from et al., 1999; Jacobsen and Kaufman, 1999; Wal- age occur in the well-studied Neoproterozoic Svalbard (Akademikerbreen Group) and ter et al., 2000), but like attempts to construct successions of northern Namibia, South Aus- Namibia (Otavi Group) and data in the lit- 87Sr/86Sr records for this time period (Melezhik tralia, and northwestern Canada. In all three erature from Svalbard, Namibia, and Oman. et al., 2001), these compilations have suffered regions, the Marinoan glaciation is presaged A new U-Pb zircon age of 760 ± 1 Ma from from low sample density, limited availability by a large negative !13C anomaly, and the cap an ash bed in the Ombombo Subgroup in of chronostratigraphically well-constrained carbonates to both glacial units share a suite Namibia provides the oldest direct time-cali- data, and the consequent dependence on many of unique sedimentological, stratigraphic, bration point in the compilation, but the time tenuous correlations.
    [Show full text]
  • Reconafrica-Technical-Brief-V24.Pdf
    ReconAFRICA KAVANGO BASIN TECHNICAL BRIEF TSX-V: RECO OTC: RECAF FRANKFURT: 0XD www.reconafrica.com HIGHLIGHTS • ReconAfrica has discovered + licensed a new deep (30,000’) Permian Age rift sedimentary basin in northeast Namibia and northwest Botswana “Kavango Basin” • “All of the worlds basins of this depth produce commercial hydrocarbons” - Bill Cathey, CEO, Earthfi elds Technology, Houston • ReconAfrica TSX-V RECO holds rights to the entire sedimentary basin, 8.75 million acres • Same seaway or depositional environment as Shell’s 390 TCF Permian shale (top 10 shale plays worldwide) • Expecting up to 6,000’ Permian petroleum system supporting large-scale unconventional + conventional plays • ReconAfrica has acquired a 1,000 HP drilling rig shipping to Namibia for a Q4 2020 drilling campaign KAVANGO - NEW SEDIMENTARY BASIN Based on a previously drilled well (ST-1/1964) and the acquisition and interpretation of a high quality (200m spacing) aeromagnetic survey, ReconAfrica has discovered a deep, 30,000’, predominantly Permian aged, rift sedimentary basin in NE NamibiaKAVANGO and NW Botswana BASIN (FIG 01). All of the worlds basins of this depth produce commercial hydrocarbons. 190 MILES 1 2 1 3 Up to 30,000’ of Sedimentary Rock Basin Fill PPS* *Permian Petroleum System - up to 6000’ thick ReconAfrica’s Drilling Campaign begins 2020. The main objective is to confirm organic rich shales and conventional FIG 01: 8.75 millionopportunities acre license in Namibia (from surface and Botswana. to basement) ReconAfrica held by ReconAfrica. owns 2.5 million acres in Botswana, and 6.3 million acres in Namibia, for a total property of 8.8 million acres in the Kavango Basin.
    [Show full text]
  • Fjord Network in Namibia: a Snapshot Into the Dynamics of the Late Paleozoic Glaciation Pierre Dietrich1,2, Neil P
    https://doi.org/10.1130/G49067.1 Manuscript received 20 October 2020 Revised manuscript received 19 March 2021 Manuscript accepted 21 June 2021 © 2021 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license. Fjord network in Namibia: A snapshot into the dynamics of the late Paleozoic glaciation Pierre Dietrich1,2, Neil P. Griffis3,4, Daniel P. Le Heron5, Isabel P. Montañez3, Christoph Kettler5, Cécile Robin1 and François Guillocheau1 1 Géosciences Rennes, Université de Rennes, CNRS, UMR 6118, 35000 Rennes, France 2 Department of Geology, University of Johannesburg, Johannesburg 2006, South Africa 3 Department of Earth and Planetary Sciences, University of California, Davis, California 95616, USA 4 Berkeley Geochronology Center, Berkeley, California 94709, USA 5 Department für Geologie, Universität Wien, Althanstraße 14, 1190 Wien, Austria ABSTRACT infer the pace of ice-margin fluctuations and Fjords are glacially carved estuaries that profoundly influence ice-sheet stability by the paleo-ice thickness that once occupied draining and ablating ice. Although abundant on modern high-latitude continental shelves, these fjords. Furthermore, we estimate glacio- fjord-network morphologies have never been identified in Earth’s pre-Cenozoic glacial epochs, isostatic adjustment following deglaciation. hindering our ability to constrain ancient ice-sheet dynamics. We show that U-shaped valleys This work highlights the dynamic nature of in northwestern Namibia cut during the late Paleozoic ice age (LPIA, ca. 300 Ma), Earth’s the LPIA in southwestern Gondwana and the penultimate icehouse, represent intact fjord-network morphologies. This preserved glacial potential for an under-appreciated deep-time morphology and its sedimentary fill permit a reconstruction of paleo-ice thicknesses, glacial carbon and sediment sink that, if valid, would dynamics, and resulting glacio-isostatic adjustment.
    [Show full text]
  • Partners in Biodiversity
    AWF FOUR CORNERS TBNRM PROJECT : REVIEWS OF EXISTING BIODIVERSITY INFORMATION i Published for The African Wildlife Foundation's FOUR CORNERS TBNRM PROJECT by THE ZAMBEZI SOCIETY and THE BIODIVERSITY FOUNDATION FOR AFRICA 2004 PARTNERS IN BIODIVERSITY The Zambezi Society The Biodiversity Foundation for Africa P O Box HG774 P O Box FM730 Highlands Famona Harare Bulawayo Zimbabwe Zimbabwe Tel: +263 4 747002-5 E-mail: [email protected] E-mail: [email protected] Website: www.biodiversityfoundation.org Website : www.zamsoc.org The Zambezi Society and The Biodiversity Foundation for Africa are working as partners within the African Wildlife Foundation's Four Corners TBNRM project. The Biodiversity Foundation for Africa is responsible for acquiring technical information on the biodiversity of project area. The Zambezi Society will be interpreting this information into user-friendly formats for stakeholders in the Four Corners area, and then disseminating it to these stakeholders. THE BIODIVERSITY FOUNDATION FOR AFRICA (BFA is a non-profit making Trust, formed in Bulawayo in 1992 by a group of concerned scientists and environmentalists. Individual BFA members have expertise in biological groups including plants, vegetation, mammals, birds, reptiles, fish, insects, aquatic invertebrates and ecosystems. The major objective of the BFA is to undertake biological research into the biodiversity of sub-Saharan Africa, and to make the resulting information more accessible. Towards this end it provides technical, ecological and biosystematic expertise. THE ZAMBEZI SOCIETY was established in 1982. Its goals include the conservation of biological diversity and wilderness in the Zambezi Basin through the application of sustainable, scientifically sound natural resource management strategies.
    [Show full text]
  • The Development and Evolution of Etosha Pan, Namibia
    The Development and Evolution of Etosha Pan, Namibia Dissertation zur Erlangung des naturwissenschaftlichen Doktorgrades der Bayerischen Julius-Maximilians-Universität Würzburg Vorgelegt von Martin HT Hipondoka Würzburg 2005 To the demise of the Bantu Education System Table of Contents Table of Contents.................................................................................................................. ii List of Figures...................................................................................................................... iii List of Tables.........................................................................................................................iv Acknowledgments..................................................................................................................v Abstract .................................................................................................................................vi Ausführliche Zusammenfassung...................................................................................... vii 1. Introduction ................................................................................................ 1 1.1 Background..........................................................................................................1 1.2 Aims and Objectives of the Study......................................................................1 2. Methods and Techniques ............................................................................. 4 2.1 Remote Sensing (RS)
    [Show full text]
  • IN THIS ISSUE GSA TODAY May Vol
    Vol. 8, No. 5 May 1998 INSIDE • Upcoming Penrose Conference GSA TODAY p. 16 • Book Reviews, p. 19 A Publication of the Geological Society of America • Calls for Service, p. 3, 23, 26 Comings and Goings of Global Glaciations on a Neoproterozoic Tropical Platform in Namibia Paul F. Hoffman, Department of Earth & Planetary Sciences, Harvard University, Cambridge, MA 02138 Alan J. Kaufman, Department of Geology, University of Maryland, College Park, MD 20742 Galen P. Halverson, Department of Earth & Planetary Sciences, Harvard University, Cambridge, MA 02138 ABSTRACT many Neoproterozoic glacial deposits are Kennedy, 1996)—a climatological or geo- rich in carbonate debris and are directly chemical paradox, given that inorganic An enduring enigma of Neoprotero- overlain by carbonates containing struc- zoic Earth history is the intimate associ- tures indicative of sea-floor precipitates ation of glacial diamictites with typical (Fig. 1)(Roberts, 1976; Fairchild, 1993; Global Glaciations continued on p. 2 warm-water carbonates. Among the many hypothesized explanations for this paleoclimatic dichotomy are high orbital obliquity, true polar wander, reduced solar luminosity, snowball albedo, CO2 drawdown, stagnant ocean overturn, and reinterpretation of diamictites as mega-impact ejecta. The Otavi carbonate platform on the Congo craton in Namibia contains two discrete intervals of diamictite and associated glaciomarine deposits, sand- wiched by thick carbonates from which we have obtained detailed carbon-iso- topic records. From subsidence analysis,
    [Show full text]
  • Wanke Et Al Karoo Unconformities
    Communs geol. Surv. Namibia, 12 (2000), 291-301 Karoo unconformities in NW-Namibia and their tectonic implications A. Wanke1, H. Stollhofen1, I.G. Stanistreet2 and V. Lorenz1 1Institut für Geologie, Universität Wurzburg, Pleicherwall 1, 97070 Würzburg, Germany email: [email protected] 2Department of Earth Sciences, University of Liverpool, PO Box 147, Liverpool L69 3BX, United Kingdom The Karoo-Etendeka depositories in northwestern Namibia can be subdivided into (l) a Carboniferous-Permian, (2) a Triassic- Jurassic and (3) a Cretaceous megasequence, recording successive extensional periods, separated by time-stratigraphic gaps. Close to the present-day Atlantic coastline the Karoo Supergroup is only represented by the Permian succession in the Huab area. This is discon- formably overlain by the Lower Cretaceous Etendeka Group. Further east, the Karoo succession becomes successively’ more complete, but correlation with the main Karoo Basin in South Africa and the Brazilian Paraná Basin indicates major gaps in the sedimentary record. The gaps can be attributed to the combined effects ofthe long-lived South Atlantic rift evolution and orogenic pulses derived from the Samfrau active margin. Introduction roo Supergroup were indicated by Porada et al. (1996) and Miller (1997) and the most obvious gap between The Karoo Supergroup is widespread in various Up- Permian and Cretaceous strata in the Huab area has been per Carboniferous to Lower Jurassic depositories across used by Milner et al. (1994) as a basis for stratigraphic the Gondwana supercontinent. Of these depositories, separation of the Carboniferous-Jurassic Karoo Super- two major basin types are developed in southern Africa: group from the Cretaceous Etendeka Group.
    [Show full text]
  • Organization of African Intra-Plate Tectonics*
    Organization of African Intra-Plate Tectonics* James W. Granath¹ and William Dickson² Search and Discovery Article #30555 (2018)** Posted March 12, 2018 *Adapted from extended abstract prepared in conjunction with oral presentation given at AAPG/SEG 2017 International Conference and Exhibition, London, England, October 15-18, 2017 **Datapages © 2018 Serial rights given by author. For all other rights contact author directly. ¹Granath & Assoc. Consulting Geology, Highlands Ranch, CO, United States ([email protected]) ²Dickson International Geosciences Inc., Houston, TX, United States ([email protected]) Abstract Arrays of fault blocks loosely aligned in belts often comprise fields of extensional basins and/or compressional uplifts within continents, for example in the forelands of orogenic belts (e.g. the late Paleozoic Ancestral Rocky Mountains in the interior western North America) or as failed arms of plate triple junctions (as in the case of Central African Rift System). Transfer faults occur within and between individual elements of such systems (as intra- and inter-basinal faults): they are fundamental features and are necessary to facilitate the kinematic integrity of the system. At their extreme, these transfer fault systems may be localized into inter-basin/uplift, regional ‘mega-shear’ systems that exploit pre-existing defects in the crystalline basement, pre-existing lineaments and terrane boundaries for example. The Central African Shear Zone or the here-proposed Southern Africa Trans-Africa Rift and Shear System are examples of such systems that cross-cut the continent. These mimic wrench fault systems in many details of their geometry, but insofar as they only accommodate the net extension or compression of the overall system, they do not necessarily display a consistent sense of offset or accumulate much net strike-slip offset at the continental level.
    [Show full text]
  • Namibia: Africa’S Next Oil and Gas Frontier Awaits
    Namibia: Africa’s next oil and gas frontier awaits Featuring ReconAfrica Jenny Xenos, MBA, CFA Quester Advisors April 18, 2021 Quester Advisors | www.questeradvisors.com Table of Contents Executive summary ............................................................................................................................................ 2 Namibia: Africa’s next oil and gas frontier awaits .............................................................................................. 6 One of Africa’s newest countries .................................................................................................................... 6 Fragile economy and the need of foreign investment .................................................................................... 8 Attractive place to do business ....................................................................................................................... 9 A century of oil and gas exploration ............................................................................................................... 9 Promising geology ........................................................................................................................................ 15 Attractive fiscal regime and licensing system ............................................................................................... 25 Energy security and access to world markets .............................................................................................. 29 High hopes for oil and
    [Show full text]
  • De-Risking Oil and Gas Prospects
    Pioneer Oil & Gas Consulting NAMIBIA Namibia onshore Hydrocarbon Prospectivity Ansgar Wanke University of Namibia Petroleum Geology Purpose of Talk Pioneer Oil & Gas Consulting NAMIBIA 1. Overview of Namibian Onshore Basins 2. New encouraging insights 3. How and why to Explore Namibia 825 419 km2 Two groups of onshore basins: 1. Neoproterozoic- Early Cambrian rift- foreland basins 2. Karoo (rift) basins (Upper Carboniferous – Jurassic) Onshore basins cover some 350 000km2 > 40% of the country Map of Namibian Basins, adapted 12 onshore wells with TD from Bray & Lawrence (1998) between 600-2500m Neoproterozoic / Early Cambrian Basins 1: Owambo-Etosha Basin 2: Nama Basin Owambo – Etosha • Basins are bordered by early Cambrian Orogenic Belts • Rift, Platform and Molasse deposits • Foreland Basin architecture • Partly covered by Karoo Nama succession • Largely covered by a veneer of Cainozoic sediments Map of Namibian Basins, adapted from Bray & Lawrence (1998) Distribution of Pan- Extent of Cainozoic African Belts in Africa and Kalahari Cover adjoining parts of South excluding the Namib America Haddon & McCarthy Cahen & Snelling (1966) (2005) Martin & Porada (1977) Norton & Sclater (1979) Owambo Basin Vintage Exploration • Seismic campaigns 1969-1995 • 12 wells of which 5 HC exploration wells (1964-1986) Exploration from 2000 • Four aerial surveys (mag/gravity) (2004, 11, 13, 14) • Soil gas sampling (2012) • 120km 2D test lines (2017) • Airbus remote sensing study (2018) • Passive seismic (2018) Summary of exploration history in the Owambo
    [Show full text]