Early Eocene environmental development in the northern Peri-Tethys (Aktulagay, Kazakhstan) based on benthic foraminiferal assemblages and stable isotopes (O, C)

Deprez, Arne; Tesseur, Steven; Stassen, Peter; D’haenens, Simon; Steurbaut, Étienne; King, Christopher; Claeys, Philippe; Speijer, Robert P.

doi:10.1016/j.marmicro.2014.11.003

Cited by 19 publications

(16 citation statements)

References 58 publications

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“…In addition, methanogenesis increased in the deep-sea sediments, thus favoring the formation of early diagenetic siderite. Siderite and benthic foraminiferal assemblages similar to those found in the North Iberian continental margin also characterized other continental margins during the early Eocene climatic optimum (Jacobs and De Batist, 1996;Schmitz et al, 1996;Huggett et al, 2000;Racey et al, 2001;Kaminski and Gradstein, 2005;Silver, 2009;King et al, 2013;Deprez et al, 2015;Waskowska, 2015), suggesting that the inferred paleoenvironmental conditions may have extended supraregionally. These processes, together with terrestrial clay dilution, may actually account for the carbonate decrease also found in many other continental margins during the early Eocene climatic optimum (e.g., Slotnick et al, 2012), thus blurring the deepening of the lysocline generally modeled for long-term global warming episodes (Leon-Rodriguez and Dickens, 2010;Sluijs et al, 2013).…”

Section: Discussionsupporting

confidence: 54%

“…Rainfall, runoff, and weathering increased on land in some locations during the early Eocene climatic optimum (e.g., Smith et al, 2008;Slotnick et al, 2012;Hyland et al, 2013;Deprez et al, 2015), and the same most likely occurred in the North Iberian continental margin. In the Barinatxe-Gorrondatxe section, these processes are deduced from the abundance of plant remains and terrestrial clay from 205 m upwards (Fig.…”

Section: Core Of the Early Eocene Climatic Optimummentioning

confidence: 99%

“…Interestingly, abundant iron concretions and high organic carbon content, both related to dysoxic conditions, also characterize many coeval (NP12, E5, C23r-C22r) Boreal and Tethyan continental margin deposits (Fig. 6), such as those in Belgium (Kortemark Member of the Ieper Clay Formation in the VR1 well; Jacobs and De Batist, 1996), Denmark (units E and F of the Rosnaes Clay Formation; Schmitz et al, 1996) basins; Silver, 2009;Waskowska, 2015), and Kazakhstan (unit B1 of the Aktulagay section; King et al, 2013;Deprez et al, 2015). This all suggests that methanogenesis may have been a widespread process in continental margin seabed sediments during the early Eocene climatic optimum, but further data from other areas would be required in order to determine whether methanogenesis increased globally (Gu et al, 2011).…”

Section: Core Of the Early Eocene Climatic Optimummentioning

confidence: 99%

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Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

Payros

Ortíz

Millan³

et al. 2015

Geological Society of America Bulletin

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The early Eocene climatic optimum, which constituted the peak of the long-term early Cenozoic global warming, had a significant impact on the environmental evolution of terrestrial and oceanic areas. Surprisingly, however, its influence on continental margins is poorly known. New insights are provided from a sedimentological, stable isotope, mineralogical, and micropaleontological study of an 1100-m-thick Lower-Middle Eocene deep-marine succession that accumulated on the North Iberian continental margin. The early Eocene climatic optimum is represented by a 410-m-thick interval characterized by scarcity of hemipelagic limestones, abundance of dark marls, which record a reduction in calcium carbonate content and an increase in kaolinite, and the occurrence of conspicuous red layers with high siderite and pyrite content.Series of stratigraphically significant events frame the early Eocene climatic optimum. Based on this analysis, the environmental influence of the early Eocene climatic optimum started at 52.6 Ma and lasted ~2.3 m.y. Its onset is marked by rapid drops in δ 13 C and δ 18 O, which record the addition of 13 C-depleted carbon into the ocean-atmosphere system for 80 k.y. and a concomitant warming. A hotter climate and a perennial rainfall regime increased the supply of terrestrial clays, organic matter, and iron oxides into the sea. Eventually, these changes affected the deepsea bottom 270 k.y. after the onset of the early Eocene climatic optimum, creating conditions in which opportunistic benthic foraminifera thrived, and leading to increased methanogenesis in the subsurface, which caused the formation of siderite. A subsequent gradual recovery culminated abruptly at 50.3 Ma with a global cooling episode, which is locally recorded by the accumulation of lowstand resedimentation deposits.

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Section: Discussionsupporting

confidence: 54%

Section: Core Of the Early Eocene Climatic Optimummentioning

confidence: 99%

Section: Core Of the Early Eocene Climatic Optimummentioning

confidence: 99%

See 1 more Smart Citation

Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

Payros

Ortíz

Millan³

et al. 2015

Geological Society of America Bulletin

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“…Because of the great similarity with the Aktulagay area in Kazakhstan (King et al, 2013;Deprez et al, 2015) and the Suvlu-Kaya area in the Crimea (King et al, 2017), in biofacies succession (e.g. Subbotina influx) as well as biostratigraphic events (especially calcareous nannofossil and to a lesser degree dinoflagellate cyst events), the composite Kortrijk section is proposed as a reference for mid-Ypresian stratigraphy in middle to high latitudes of the Northern Hemisphere.…”

Section: Discussionmentioning

confidence: 99%

The composite Kortrijk section (W Belgium): a key reference for mid-Ypresian (Early Eocene) stratigraphy in the southern North Sea Basin

Steurbaut

King²

2017

Geol. Belg.

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ABSTRACT. The upper part of the Kortrijk Clay Formation (the Roubaix Clay and Aalbeke Clay Members of mid-Ypresian age) has been exposed in road and canal cuttings and clay quarries in the Kortrijk area (western Belgium), and penetrated by several cored boreholes. It is overlain disconformably by the Mont-Panisel Sand Member of the Hyon Sand Formation (upper middle Ypresian). The Roubaix Clay Member contains diverse and well-preserved calcareous nannofossils, dinoflagellate cysts, foraminifera, ostracods and other calcitic microfossils, and less well-preserved mollusc assemblages, while the Aalbeke Clay Member is secondarily decalcified. The calcareous nannofossil subdivision of upper NP11 and lower NP12 has been recognised in the Kortrijk area, and calibrated with the NW European mid-Ypresian dinoflagellate cyst, ostracod and planktonic foraminiferal zones and datums (e.g. Subbotina influx). Several medium-scale depositional sequences, with an estimated duration of 400 kyr or less, have been recorded. Their respective boundaries coincide with the resistivity maxima identified on the majority of the wireline log profiles of the Belgian Ypresian. Integrated biostratigraphic, magnetostratigraphic and sequence stratigraphic analysis enables correlation with other areas in Belgium, with the London Clay Formation of southern England, and with the standard chronostratigraphic scale. A marine erosion surface has been identified at the base of Unit 20 in the Kortrijk area (mid-Ypresian, early Biochron NP12, middle C24n.1n, ~ 52.8 Ma), corresponding to the first occurrence of estuarine channel-fill units in southern England. This indicates a brief but profound sea-level fall, either eustatically or tectonically controlled. The composite Kortrijk section is proposed as a reference section for the middle Ypresian in the southern North Sea Basin, and for similar settings in mid-to high-latitudes of the Northern Hemisphere (e.g. Kazakhstan and Crimea).

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“…subglobosa and occasionally even N . truempyi have been reported in outer neritic parts of the Tethyan shelves during the early Eocene (e.g., [ 97 , 98 ]), and Osangularia plummerae , another common species, typically inhabits a wide range of depths, from lower sublitoral to upper bathyal depths [ 99 ]. Thus we infer a lower bathyal to abyssal paleodepth for Site 1258 as most probable during the Ypresian.…”

Section: Methodsmentioning

confidence: 99%

Early Eocene deep-sea benthic foraminiferal faunas: Recovery from the Paleocene Eocene Thermal Maximum extinction in a greenhouse world

et al. 2018

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The early Eocene greenhouse world was marked by multiple transient hyperthermal events. The most extreme was the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma), linked to the extinction of the globally recognised deep-sea benthic foraminiferal Velasco fauna, which led to the development of early Eocene assemblages. This turnover has been studied at high resolution, but faunal development into the later early Eocene is poorly documented. There is no widely accepted early Eocene equivalent of the Late Cretaceous-Paleocene Velasco fauna, mainly due to the use of different taxonomic concepts. We compiled Ypresian benthic foraminiferal data from 17 middle bathyal-lower abyssal ocean drilling sites in the Pacific, Atlantic and Indian Oceans, in order to characterise early Eocene deep-sea faunas by comparing assemblages across space, paleodepth and time. Nuttallides truempyi, Oridorsalis umbonatus, Bulimina trinitatensis, the Bulimina simplex group, the Anomalinoides spissiformis group, pleurostomellids, uniserial lagenids, stilostomellids and lenticulinids were ubiquitous during the early Eocene (lower-middle Ypresian). Aragonia aragonensis, the Globocassidulina subglobosa group, the Cibicidoides eocaenus group and polymorphinids became ubiquitous during the middle Ypresian. The most abundant early Ypresian taxa were tolerant to stressed or disturbed environments, either by opportunistic behavior (Quadrimorphina profunda, Tappanina selmensis, Siphogenerinoides brevispinosa) and/or the ability to calcify in carbonate-corrosive waters (N. truempyi). Nuttallides truempyi, T. selmensis and other buliminids (Bolivinoides cf. decoratus group, Bulimina virginiana) were markedly abundant during the middle Ypresian. Contrary to the long-lived, highly diverse and equitable Velasco fauna, common and abundant taxa reflect highly perturbed assemblages through the earliest Ypresian, with lower diversity and equitability following the PETM extinction. In contrast, the middle Ypresian assemblages may indicate a recovering fauna, though to some extent persistently disturbed by the lower-amplitude Eocene hyperthermals (e.g., Eocene Thermal Maximum 2 and 3). We propose the name ‘Walvis Ridge fauna’ for future reference to these Ypresian deep-sea benthic foraminiferal assemblages.

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Early Eocene environmental development in the northern Peri-Tethys (Aktulagay, Kazakhstan) based on benthic foraminiferal assemblages and stable isotopes (O, C)

Cited by 19 publications

References 58 publications

Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

The composite Kortrijk section (W Belgium): a key reference for mid-Ypresian (Early Eocene) stratigraphy in the southern North Sea Basin

Early Eocene deep-sea benthic foraminiferal faunas: Recovery from the Paleocene Eocene Thermal Maximum extinction in a greenhouse world

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