Cretaceous Coral-Rudist Formations in Tunisia

Zaghbib-Turki, Dalila

doi:10.1007/978-94-010-0015-4_5

Cited by 10 publications

(4 citation statements)

References 17 publications

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“…Geologically, the Kalâat Senan area extends over the south-eastern side of a NE-SW trending Cretaceous-Eocene syncline (Figure 1), which belongs to the Central Tunisian Atlassic domain (Castany, 1951). As a part of the southern margin of the Palaeo-Tethys (Figure 2) during the Cretaceous, the north-western segment of this structural unit acted as connected deep basins known as the "Tunisian trough", which was characterised by subsidence and sediments rich in pelagic fauna (Burollet, 1956;Salaj, 1980;Turki, 1985;Maamouri et al, 1994;Rami et al, 1997;Robaszynski et al, 2000;Steurbaut et al, 2000;Bouaziz et al, 2002;Jarvis et al, 2002;Hennebert and Dupuis, 2003;Zaghbib-Turki, 2003;El Amri and Zaghbib-Turki, 2005;Guasti et al, 2006;Hennebert et al, 2009). Among the sediments that were deposited within the trough area, those that are now exposed at the Oued Necham section (with the geographical coordinates X = 35°46′28.3″N and Y = 8°28′55.7″E) provide a coherent and continuous Campanian-Maastrichtian transition.…”

Section: Geological and Stratigraphical Settingsmentioning

confidence: 99%

Planktonic foraminiferal biostratigraphy and quantitative analysis during the Campanian-Maastrichtian transition at the Oued Necham section (Kalâat Senan, central Tunisia)

Saïdi¹,

Zaghbib-Turki²

2016

Turkish J Earth Sci

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The Oued Necham (ON) section (Kalâat Senan, central Tunisia) provides a well-exposed outcrop of a Campanian-Maastrichtian series that consists essentially of chalky limestones (i.e. the Abiod Formation) grading progressively to a marly unit (i.e. the El Haria Formation). The transitional Abiod-El Haria succession comprises a rich hemipelagic-pelagic fauna in the study area, but ammonites (e.g., Pachydiscus neubergicus, the Campanian/Maastrichtian (C/M) boundary index taxon) are scarce to absent, thus preventing the recognition of the standard zones defined for the Tethyan realm. However, the rich planktonic foraminiferal taxa of the El Haria Formation allow us to establish an accurate biostratigraphical scheme. Accordingly, this work presents a high-resolution planktonic foraminiferal biostratigraphy that is characterised by distinct bioevents associated with the reported C/M boundary (i.e. lowest occurrences (LOs) of Rugoglobigerina scotti and Contusotruncana contusa) at the Global Stratotype Section and Point (GSSP) of the Tercis-les-Bains section, south-western France. Based on these zonal markers, the rugoglobigerinids and multiserial heterohelicids are used to define a subzonal scheme spanning the standard Gansserina gansseri Zone, including the Rugoglobigerina rotundata Subzone indicative of the late Campanian and the Rugoglobigerina scotti Subzone and the Planoglobulina acervulinoides Subzone, respectively, indicative of the early Maastrichtian. The abundance of foraminiferal assemblages allowed us to carry out high-resolution quantitative analyses that document a significant climate cooling during the early Maastrichtian intermittent with short-term warming episodes. Thus, opportunist taxa (r strategists, mostly heterohelicids) thrived during the earliest Maastrichtian cooling event, whereas specialist taxa (k strategists, mostly double-keeled) that had dominated the late Campanian assemblages declined gradually without any extinction. Opportunist and specialist taxa fluctuated in opposite phases throughout the early Maastrichtian (LO of Rugoglobigerina scotti -LO of Abathomphalus mayaroensis), suggesting essentially variations in water temperature. Since surface dwellers dominated the assemblages, they imply continuous sea surface optimal conditions of nutrient supply and water connectivity induced from upwelling currents.

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Section: Geological and Stratigraphical Settingsmentioning

confidence: 99%

Planktonic foraminiferal biostratigraphy and quantitative analysis during the Campanian-Maastrichtian transition at the Oued Necham section (Kalâat Senan, central Tunisia)

Saïdi¹,

Zaghbib-Turki²

2016

Turkish J Earth Sci

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“…Few studies on Berriasian – lower Barremian shallow‐water carbonates report Chondrodonta accumulations in the Southern Tethys (e.g. Pratt & Smewing, 1990; Zaghbib‐Turki, 2003; Masse et al ., 2015) and in the proto‐North Atlantic (e.g. Phelps et al ., 2014).…”

Section: Interpretation and Discussionmentioning

confidence: 99%

Proliferation of Chondrodonta as a proxy of environmental instability at the onset of OAE1a: Insights from shallow‐water limestones of the Apulia Carbonate Platform

et al. 2021

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Chondrodonta is an opportunistic, oyster-like bivalve, common in shallowwater carbonates of the Cretaceous Tethyan Realm. Despite its high abundance and widespread geographic distribution, the precise relationship between the early Aptian proliferation and environmental perturbations resulting from the Oceanic Anoxic Event 1a (OAE1a), has not been investigated. Stratigraphic and geochemical analyses of the lower Aptian Chondrodonta bedsets within the inner platform limestones of the Apulia Carbonate Platform (Gargano Promontory, southern Italy) are conducted to assess the environmental controls on the Chondrodonta proliferation and its timing and causal relationship to OAE1a. Chondrodonta occurs with sparse to common individuals within requieniid rudist floatstone-rudstones, forms monospecific biostromes during the early phase of stressed environmental conditions and then rapidly disappears at the peak of OAE1a. It proliferates in dysoxic seawater with relatively increased trophic sources, which correlate to increasing nutrient levels in the nearby pelagic realm. Chondrodontarich beds are associated worldwide with the onset of OAE1a and occur in a transitional context between a stable and a strongly stressed environment, where the opportunistic behaviour of Chondrodonta is rather efficient. Increasing nutrient load and unstable environmental conditions right below the peak of OAE1a created an environmental 'window' favourable for Chondrodonta to proliferate, outplaying the less tolerant benthos (for example, rudists). The occurrence, duration and position of the environmental window were controlled by local palaeogeographic and hydrodynamic settings (i.e. low energy, decreased seawater oxygenation and circulation). Further increase in inhospitable conditions, leading to OAE1a, constituted an upper threshold for Chondrodonta and allowed mesotrophic taxa like Bacinella-Lithocodium and orbitolinids to dominate the benthic 3191

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“…Several parts displayed erosion (Figure 17), which was very active during this period, sometimes inducing emerged areas characterized by early diagenesis, karstification, cementation, and dolomitization Zghal 1994;El Euchi et al 2002;Zaghbib-Turki 2003). In general, during the early to late Albian, four zones of black shale accumulation have been differentiated in Tunisia.…”

Section: Distribution and Characteristics Of Organic-rich Stratamentioning

confidence: 95%

Cretaceous oceanic anoxic events (OAEs) recorded in the northern margin of Africa as possible oil and gas shale potential in Tunisia: An overview

Soua

2015

International Geology Review

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Significant attention has been given, during the last decade, to Palaeozoic unconventional oil and gas shale in northern Africa where the productive Palaeozoic basins are located. New tentative strategies shed light on Mesozoic unconventional plays represented by Cretaceous shale reservoirs. In most petroleum systems the proven Cretaceous oceanic anoxic events (OAEs), represented mainly by the Fahdene and Bahloul Formations, played the main role in hydrocarbon generation with good distribution. Their deposition was restricted to the early Aptian (Bedoulian), the early/late Albian, and the Cenomanian-Turonian transition. Additional black shales have been detailed for the first time in Tunisia which relate to the Valanginian Weissert and late Hauterivian Faraoni events. Biostratigraphic and complete geochemical reviews have been undertaken from published papers and unpublished internal reports to better assess these important source intervals. These black shale levels, pertaining to OAEs, were deposited in almost deep marine environments during short-lived periods of anoxia (ca. 2 Ma). In the course of this review, thickness, distribution, and maturity maps have been established for each level using well data from published sources. ARTICLE HISTORY

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Cretaceous Coral-Rudist Formations in Tunisia

Cited by 10 publications

References 17 publications

Planktonic foraminiferal biostratigraphy and quantitative analysis during the Campanian-Maastrichtian transition at the Oued Necham section (Kalâat Senan, central Tunisia)

Planktonic foraminiferal biostratigraphy and quantitative analysis during the Campanian-Maastrichtian transition at the Oued Necham section (Kalâat Senan, central Tunisia)

Proliferation of Chondrodonta as a proxy of environmental instability at the onset of OAE1a: Insights from shallow‐water limestones of the Apulia Carbonate Platform

Cretaceous oceanic anoxic events (OAEs) recorded in the northern margin of Africa as possible oil and gas shale potential in Tunisia: An overview

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