DOCSLIB.ORG

Back Matter (PDF)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Back Matter (PDF) Index Aaiun-Tarfaya Basin, Cretaceous 399-401 Aptian, Early Abaco see Great Abaco Formation carbon accumulation 305 Abathomphalus sp. 68, 76 plankton 316 Abyssal plains Aptian, Site 534 Gambia 121 black shales 349 Madeira 131-42 Archaeocretacea zone 427, 439, 440 Porcupine 88 Archaeoglobigerina sp. 72, 73, 75, 76 Sierra Leone 120-1 Arctica islandica, amino acid analysis 146-7 Africa Arsenic, sea water 449-54 External Continental Margin 423 see also Rif Mountains Bacteria North-west Margin site 608 microbe biomass, hydrogen content 380 hiatuses 84-5 remineralization, organic matter 370-1,373-5 African plate, position 423-5 Baffin Bay, meltwater discharge rates 176-7 Agadir Basin, coastal, sediments 442 Bahloul Formation, Tunisia 404-6 Cretaceous 399-401 Bajocian, evolutionary event 315 Alabamina sp. 195 globigerinids 316 Albian, Ireland, continental margin 17, 20 Baltimore Albian, late Canyon Trough, Site 612 45, 48 carbon accumulation 305 Late succession 75 globigerinids 316 'Banc du Large' Formation 390 nannofossils, palaeowater depth and Barium upwelling 301, 303 diagenesis 454-6 preservation 302 sea water 449-54 Site 364 309 and Sulphur-34 456 Site 400 306 Barremian coccoliths 44 Site 466 310 Barremian, Ireland, continental margin 17 Albian, Site 547, organofacies types 380 Barremian, Late, Site 367, nannofossils, relative Albian, Site 603, black shale, analysis 335, 341 abundance 308, 316 Albian, Upper, Mauretanian, compositional Barremian, Site 603, organofacies 384-5 change 427-9 Bascocantabric Basin, Spain 398 Alboran Block 401-403 Bathonian, spread ofproto Atlantic 259 mid-Cretaceous 425, 427 Bay of Biscay margin model 441 Pataeocene-Eocene 27 Algae, evidence for 355, 359 Sites 400, 401 83-4 Alkanes 349-59 Beni Ider nappe 401 analysis 336-41 Benthic foraminifera see Foraminifera, benthic Alkanol, chainlength 336-41 Bering Sea, meltwater discharge 179 Allerod Interstadial 151 Bermuda Ridge 87 Aluminium Bermuda Rise Formation 256-9 diatomaceous sediments 452, 455 lithology 41 ratios V/A1, Mo/AI, S/A1 455-456 Site 534, Organic Carbon 382 sea water, ratios 452-4 Berriasian-Barremian, pelagic limestones 426 Ammonites Berriasian Site 603, organofacies 384-5 Mesozoic facies 314, 317 Berriasian Wealden, North-west Germany 364 Tethys/Atlantic/Pacific 286 Bigenerina sp. 214 Amino acid analysis, foraminifera 146-7 Biscutum sp. (map) 300-2, 306-10 Anglo Basin 361-71 Bismuth, sea water 450-54 site 530 342 Black Mesa, Arizona 391,414-16 summary section 368 Black shales Anomaline 214 basinal deposition 371-75 Anoxic events, late Cretaceous 67-76 Blake-Bahama Basin Site 534 347-56 see also Oxygen Blake-Bahama/Hatteras Formation Site 603 333- Antarctic Bottom Water 219-29 43 Antarctic Ice cap, expansion 29 Callovian Site 534 283-5 Appennines, Cenomanian-Turonian sediments 442 accumulation 290 Aptian-Albian, Cretaceous sedimentation 426 origins 294-6 Aptian-Barremian, East and West sub basins, Cenomanian-Turonian Boundary Event 389-422 Atlantic 14 Cretaceous, Angola Basin Site 530 361-71 Aptian, coccolith index 44 distal fan turbidites 361 463 464 Index Cretaceous (cont.) Jurassic 312-18 Ghana, offshore 361-71 minimum abundance plots 303 Hatteras Formation Site 603 361-71 Neogene, correlations, with diatoms 247 metals 369 preservation, water mass structure 302-5 Wealden, North-west Germany 361-71 stratigraphy, Sites 610, 611 92 'Cretaceous warming' 325 Triassic 312-15 Hatteras Formation 256-9, 411-12 zonation, Miocene 210-11 Hatteras Rise, Site 603 347, 353-9 Calcispheres 442-3 major depositions 299 Carbonate Compensation Depth marine vs terrestrial organic matter 294 Calcium compensation Zone 304 metal enrichment, origins 458-60 Callovian 296 Toarcian 315 carbon and calcite cycles 272-3 Unit 7, West Atlantic 255, 257-9, 268 Cretaceous, North Atlantic 304 Blake-Bahama Basin Gibraltar Arch 443 black shales, Site 534 347-59 lowering, increased aridity 278 Callovian, Site 534 283-93 magnetic anomaly reversals 262, 267-8 organic carbon data, Site 534, Cretaceous 381 Mesozoic facies 304, 314 Jurassic 381 sea-level, correlation 268, 272 redeposited siliciclastics 279 variation with time 141 Blake-Bahama Formation Calcium carbonate, mass spectrometer analysis 334 carbon-rich/carbon-poor 259 see also Carbonates geology 255-6, 258 California, Gulf of Outer Ridge formation 257 diatomaceous sediments 452~i0 physiography 256 productivity 447 seismic reflection profile 258 sea water, plankton chemistry 448-9 Site 603, black shales 333-43 upwelling sediments, samples 448-452 lithology 41 Callovian slump folds 43 North Atlantic, circulation 288 Blake-Bahama Outer Ridge 87 block diagram 289 Blake Plateau, Core V26-125 palaeogeography 259 biostratigraphy 237 Site 534, accumulation rates 285 comparison, DSDP, Site 552 237-40 black shales 294-5, 349, 353-6 Pliocene 237-40 calcite compensation depth 290 Blake Spur geological setting 283-4 damming effect 288 organofacies 381 interruption, seismic profiles 285 Oxfordian transition 295-6 magnetic anomaly 259 sediment, drifts 291-4 age 261 sources 288-90 Jurassic quiet zone 260 succession 285 Bolivina spp. 208, 212-14, 216 theoretical circulation 286-8 Boiling chronozone 150-1 Calpionellids 316 Bonarelli Horizon, Umbria 322, 408 Campanian Bonarelli 'Livello' layer, Umbrian Apennines 407 nannofossil distribution 300 BOUMA sequences 43,432, 435, 443 ocean ventilation 311 Broinsonia sp. 302 Canary Basin DSDP sites 132 Brunhes event 159, 162 Cape Hatteras see Hatteras Formation Bulimena sp. 196, 214 Cape Verde Basin, Site 367 342, 390-97, 456-60 Bulk sediment see Sediments Cape Verde Islands, Maio, Jurassic and Bunker Hill, Kansas 391,414-16 Cretaceous 390 Cape Verde Rise, regional setting 132 Cadmium, sea water 449-54 Carbon Calcareous nannofossils C/N ratios, Site 603 334-6 biogeography 299-302 continental margins 373, 374 Atlantic circulation 307-12 see also Black shales carbon shift 312-15 Carbon cycle 317-18 cyclic fluctuations 305-9 variations 269-70 discussion 315-18 Carbon dioxide evolutionary rates 299, 312-15 correlation, nannofossils 317 sea floor spreading rates 314 early Cretaceous 323-30 Callovian, black shales 290, 292 Carbon- 13 correlation of hiatuses 79-85 analysis, method 334 Cretaceous 312-18 fractionation, air-water interface 324, 327-9 Discoaster accumulation, Pliocene 231-41 fluxes, effect on ocean 329 dominant macerals 378 photosynthetic preference 326 Index 465 Carbonate Chalk see Carbonate Compensation Depth mid Mesozoic shift 312 Charlie-Gibbs Fracture Zone 88, 91-2 preservation, bioturbation, cessation 290-1 CHN analyser, Hewlett Packard 334 production, Cretaceous 324-30 Chondrites Site 534, bioturbation 285 dissolution, sediments 305 Chouamat Nappe 427 nannofossils 299 Chromium, sea water 449-54 see also Calcite Compensation Depth Cibicides sp. 147 Carbonate platform, development 270-1 Cibicidoides sp. 194--7, 208-11,213-16, 220 Caribbean Cicarinella sp., diversification 72 and Gulf of Mexico 178 Classopollis pollen, Callorian 295 open connection, Pacific 310 Claystones, carbonaceous Mesozoic 377-85 Carlo-Erba Mega Gas chromatograph 347-9 CLIMAP project 181, 188 Casamance Cretaceous Site 369 Climate, Jurassic/Cretaceous sediments 277-80 Maritime Wells 390-97 Coal deposits, middle Cretaceous 310 Cassidulina sp. 220 Coal sources, 'low sea-level' origins 268 Cat Gap Formation Cobalt (black shales) 367, 370-72 Site 534, organic carbon 38 sea water 449-54 west North Atlantic 255-9 Coniacian Site 603, organofacies 384-5 Celtic Margin see Ireland Coniacian-Santonian, foraminiferal diversity 67 Cenomanian Conifers, evidence, Site 534, geolipids 355 Black Band 311 Continental margin density stratification 311 non-turbidite conditions 372 foraminiferal diversity 67 turbidite conditions 374 Site 534, organofacies 383 Continental reconstruction Site 547, organofacies types 380 Callovian 259 Site 603, black shales 333-43, 349 Oxfordian 260 organofacies 385 Contourites Cenomanian-Turonian Boundary Event definition 292 and Anomaly 34 evidence 295 correlations, north-west Europe 70 Cordillera-Nevada orogeny 271 Gibraltar Arch, biostratigraphy 436-9 Core analysis, method 334-5 Continental margin 426-7 Core locations, CLIMAP database, core-top correlations 439-40 samples 188 deep sea fans and basin plains 427-32 Cretaceous External Rif 425-6 absence of polar ice caps 322 geology 423-5 Ireland, continental margin 18-21 maps 405, 424, 425 nannofossils 312-18 microfossils 436-9 CO2peak 317 on shore deposits, faunistic characteristics 442 sea-level rises 324 palaeoenvironment 425 Cretaceous, Early reconstruction 430 carbon supply 323-4, 328-30 sedimentation 432-40 stable isotopes 326 summary 440--43 storage 324-30 Ireland, continental margin 21-4 circulation 322-3 map, North Atlantic and West Europe 24 East and West sub basins, Atlantic 14 North Atlantic and Tethys, African (Casamance) productivity 322-3 margin 390-96 temperature 322-3 Hatteras formation 411-14 Cretaceous, Late location map 391 cooling, nutrient recycling 311 Moroccan margin 396-401 East and West sub basins, Atlantic 14 North-East Atlantic 407-9 Cretaceous, Middle Rif Mountains 401-4 black shale cycles 312 summary 416-18 CCD 304 Tethys 404-7 coal deposits 310 Western Interior Basin 414-16 deep and intermediate circulation 304, 307-12 North Sea and England 67-71 increased carbon accumulation 305, 307 Cenozoic nannofossils 300, 302 sediment flux, North Atlantic 3-15 sea floor spreading 415 unconformities, North-east Atlantic and Greenland 'stagnation event' 311 Sea 79-85 surface currents 310 Central America see also Cenomanian-Turonian
Load more

Recommended publications
  • Impact of Large-Scale Natural Physical Disturbance on the Diversity of Deep-Sea North Atlantic Nematodes
    MARINE ECOLOGY PROGRESS SERIES Vol. 214: 121–126, 2001 Published April 26 Mar Ecol Prog Ser Impact of large-scale natural physical disturbance on the diversity of deep-sea North Atlantic nematodes P. J. D. Lambshead1,*, J. Tietjen2, A. Glover1, T. Ferrero1, D. Thistle3, A. J. Gooday4 1Department of Zoology, The Natural History Museum, London SW7 5BD, United Kindom 2Department of Biology, City College of New York, New York, New York 10031 & Division of Invertebrates, American Museum of Natural History, New York, New York 10024, USA 3Department of Oceanography, Florida State University, Tallahassee, Florida 32306-3048, USA 4Southampton Oceanography Centre, George Deacon Division for Ocean Processes, Empress Dock, Southampton SO14 3ZH, United Kindom ABSTRACT: Nematode alpha diversity from 3 physically disturbed sites in the deep North Atlantic was compared with reference sites. Nematode diversity at the HEBBLE benthic storm site was statis- tically, and significantly, lower than at reference sites. Nematode diversity at the Madeira Abyssal Plain site, which was subject to a turbidite dated at 930 BP, also showed a significantly lower diver- sity than reference sites. However, limited data suggest that diversity was not low at a Venezuela Basin turbidite site. The difference in nematode diversity between the 2 turbidite sites is ascribed to a long term change in sediment conditions at the Madeira site. The Venezuela Basin turbidite site has a sedimentation rate greater than the Maderia site by 1 to 2 orders of magnitude, and this was reflected in the sediment profiles. Another possibility is that the Venezuela Basin turbidite is consid- erably older, by at least 1000 yr, than the Madeira turbidite, allowing more time for recolonisation.
    [Show full text]
  • 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).
    [Show full text]
  • 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.
    [Show full text]
  • Provenance and Pathways of Late Quaternary Turbidites in the Deep-Water Agadir Basin, Northwest African Margin
    Int J Earth Sci (Geol Rundsch) (2009) 98:721–733 DOI 10.1007/s00531-008-0313-4 ORIGINAL PAPER Provenance and pathways of late Quaternary turbidites in the deep-water Agadir Basin, northwest African margin Michael Frenz Æ Russell B. Wynn Æ Aggeliki Georgiopoulou Æ Vera B. Bender Æ Gayle Hough Æ Douglas G. Masson Æ Peter J. Talling Æ Bryan T. Cronin Received: 29 January 2007 / Accepted: 11 March 2008 / Published online: 28 March 2008 Ó Springer-Verlag 2008 Abstract A series of individual turbidites, correlated volume volcaniclastic turbidites are attributed to a Canary over distances[100 km, are present in the recent fill of the Islands landslide source, while several small mud-domi- Agadir Basin, offshore northwest Africa. The aim here is to nated turbidites are interpreted to be locally sourced from unravel multiple turbidite source areas and flow pathways, hemipelagic-draped seamounts (e.g. Turbidite AB10). and show how turbidite provenance studies contribute to Finally, Turbidite AB1 (*1 ka) is only present in the interpretation of flow processes. Agadir Basin turbidites are western Agadir Basin, and is linked to recent ‘‘re-activa- sourced from four main areas, with the majority originating tion’’ of the Sahara Slide headwall. The muddy suspension from the siliciclastic Morocco Shelf; their sand-mud dis- clouds of three large-volume flows, all linked to large-scale tribution is strongly controlled by flow sediment volume, landslides, have covered huge areas of seafloor and flowed with relatively low-volume flows dying out within the along or even slightly upslope for long distances. It is Agadir Basin and large-volume flows bypassing significant proposed that northeastwards-flowing bottom currents have sediment volumes to basins further downslope.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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).
    [Show full text]
  • Deep Sea Drilling Project Initial Reports Volume 47 Part 2
    INDEX Acaeniotyle umbilicata Zone, 668 Background and objectives, Site 398, 26 Acoustic Bacterial, sulfate reduction, 733 anisotropy, 59, 585 activity, 44 basement, 86, 639 Base-of-slope province, 374 impedance, computation of, 625, Site 398, 63 Basement, 639 pseudologs, 623 Basins and Site 398, correlation between regional, 647 stratigraphy, 91, 639 Bedoulian group, 290 Site 398, 761 Bejaouaennsis Zone (MCi 23), 292 unit 3, nature of, 86 Belemnites, 55, 297 velocity, 585 Benthic, foraminifers, 729 Age of opening of North Atlantic, 28 assemblages, 293 Agglutinated foraminifers, 290, 294, 691 residual, 290, 293, 295 residual, 292 Betic system, 658 Algerianus Zone (Mci 21), foraminifers, 291 Biogenic activity, indexes of organic matter, 419 Alkalinity, 578 minerals, Lower Cretaceous sediments, 686 Alteration indexes, 543 Biostratigraphy, 69 Ammonites, 56, 75, 290, 297 Cenozoic foraminifers, 69, 255 Douvilleiceras mammilatum Zone, 362 Lower Cretaceous, 688 Euhoplites lautus Zone, 362 nannofossils, 327 loricatus Zone, 362 Bioturbation: See Burrows Hoplites dentatus Zone, 362 evidence for, 258 Lower Cretaceous, 361 Bitumen content, Hole 397 sediments, 543 systematic descriptions, 362 Black shale deposition, 30, 55, 56, 405, 437, 665, 667 Amorphous kerogen, 550 719 Ampere Bank, 659 analysis of, 472 Angola Basin, 575, 735 organic matter in, 719 Angular unconformity, 56, 93 Block-faulting, 93 Anistropy, degree of cementation, relationship to, 585 Bottom currents, 375, 380 Anomaly /, 639 temperatures, 511 MO, 639 water, formation of, Antarctic,
    [Show full text]
  • 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. There is also considerable experience of using a variety of strategic planning processes which 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. 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. 6.1 SEA in Southern Africa1 EIA is now used extensively in most countries in southern Africa. However, many of the governments tend to be ad hoc in their planning and, as a result, EIA is often regarded as an ‘add on’ process “that gets done ‘later on’, after the government, board of directors or other body has decided that the intended initiative is viable and thus worthy of detailed planning” (Tarr, 2003). In recent years, there has been rapid progress in the formulation of policies, legislation and guidelines for EIA (SAIEA 2003b).
    [Show full text]
  • Formation and Collapse of the Kalahari Duricrust ['African Surface
    Formation and Collapse of the Kalahari Duricrust [‘African Surface’] Across the Congo Basin, 10 with Implications for Changes in Rates of Cenozoic Off-Shore Sedimentation Bastien Linol, Maarten J. de Wit, Francois Guillocheau, Michiel C.J. de Wit, Zahie Anka, and Jean-Paul Colin{ 10.1 Introduction margins, and to the east by the East African Rift System (EARS). Their relatively flat interior is covered by an exten- The Congo Basin (CB) of central Africa lies at about 400 m sive Upper Cretaceous-Cenozoic succession of sand dunes, above mean sea level (amsl), and is linked to the south, pan-lacustrine sediments and alluviums with hard-caps across a central African drainage divide, to the high interior (duricrusts) of calcrete, silcrete and ferricrete, collectively Kalahari Plateau (KP) at ca. 1,100 m amsl (Fig. 10.1). The named the Kalahari Group (SACS, 1980). This succession CB and KP are flanked by distinct marginal escarpments reaches a maximum thickness of about 500 m, but across along the South Atlantic and southwest Indian Ocean southern and central Africa is generally less than 100 m thick, representing one of the world’s most extensive, long- lived condensed stratigraphic sequences. The Kalahari Group directly overlies Precambrian base- ment of the Kalahari and Central African Shields (Fig. 10.1b), late Paleozoic to mid-Mesozoic sequences of {Author was deceased at the time of publication. the Karoo Supergroup including Lower Jurassic flood basalts in southern Africa, dated at 178–183 Ma (the B. Linol (*) AEON-ESSRI (African Earth Observatory Network – Earth Stormberg Group; Jourdan et al.
    [Show full text]
  • Ocean Drilling Program Initial Reports Volume
    Schmincke, H.-U., Weaver, P.P.E., Firth, J.V., et al., 1995 Proceedings of the Ocean Drilling Program, Initial Reports, Vol. 157 5. SITE 9511 Shipboard Scientific Party2 HOLE 951A Principal results: Site 951 is located in the northwestern Madeira Abyssal Plain at 32°1.90'N, 24°52.23'W, at a water depth of 5436.8 m in the Date occupied: 11 August 1994 Chads Fracture Zone Valley. Seismic profiles for the area show the same major units as at Site 950: an upper unit showing relatively high amplitude Date departed: 13 August 1994 parallel reflectors that onlap onto basement highs, and a lower unit that Time on hole: 2 days, 2 hr, 49 min drapes the basement highs. A third unit is present in the deepest part of the fracture zone and it shows reflectors with low coherency. The upper unit Position: 32°1.896'N, 24°52.232'W can be subdivided into three subunits by relatively strong reflectors at 180 Bottom felt (drill-pipe measurement from rig floor, m): 5447.7 ms and 235 ms. Reflectors within the lower two subunits are weaker than Distance between rig floor and sea level (m): 10.90 in the upper subunit. This seismic pattern, previously described by Searle (1987), is interpreted as pelagic drape over basement, with the deeper Water depth (drill-pipe measurement from sea level, m): 5436.8 draped sequences being later infilled by rapidly accumulated turbidites. Total depth (from rig floor, m): 5704.30 In combination with the other two abyssal plain sites, the primary ob- Penetration (m): 256.60 jective of this site was to determine the nature of the turbidite fill and to distinguish discrete sources for the various compositional groups of sedi- Number of cores (including cores having no recovery): 28 ment flows.
    [Show full text]
  • Turbidity Flows – Evidence for Effects on Deep- Sea Benthic Community Productivity Is Ambiguous but the Influence on Diversity Is Clearer Katharine T
    https://doi.org/10.5194/bg-2020-359 Preprint. Discussion started: 14 October 2020 c Author(s) 2020. CC BY 4.0 License. Review and syntheses: Turbidity flows – evidence for effects on deep- sea benthic community productivity is ambiguous but the influence on diversity is clearer Katharine T. Bigham1, 2, Ashley A. Rowden1, 2, Daniel Leduc2, David A. Bowden2 5 1School of Biological Sciences, Victoria University of Wellington, Wellington, 6140, New Zealand 2National Institute of Water and Atmospheric Research, Wellington, 6021, New Zealand Correspondence to: Katharine T. Bigham ([email protected]) Abstract. Turbidity flows – underwater avalanches – are large-scale physical disturbances that are believed to have profound and lasting impacts on benthic communities in the deep sea, with hypothesised effects on both productivity and 10 diversity. In this review we summarize the physical characteristics of turbidity flows and the mechanisms by which they influence deep sea benthic communities, both as an immediate pulse-type disturbance and through longer term press-type impacts. Further, we use data from turbidity flows that occurred hundreds to thousands of years ago as well as three more recent events to assess published hypotheses that turbidity flows affect productivity and diversity. We found, unlike previous reviews, that evidence for changes in productivity in the studies was ambiguous at best, whereas the influence on regional 15 and local diversity was more clear-cut: as had previously been hypothesized turbidity flows decrease local diversity but create mosaics of habitat patches that contribute to increased regional diversity. Studies of more recent turbidity flows provide greater insights into their impacts in the deep sea but without pre-disturbance data the factors that drive patterns in benthic community productivity and diversity, be they physical, chemical, or a combination thereof, still cannot be identified.
    [Show full text]