Barium and the Late Paleocene δ<sup>13</sup>C maximum: Evidence of increased marine surface productivity

Thompson, Elisabet I; Schmitz, Birger

doi:10.1029/96pa03331

Cited by 58 publications

(36 citation statements)

References 51 publications

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“…The quantity of barium that is not associated with the aluminosilicate fraction (Ba*) was calculated using the method outlined by (Thompson and Schmitz, 1997). Ba* is assumed to be derived from the formation of biogenic barite through the following calculation.…”

Section: Methodsmentioning

confidence: 99%

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Mort

Adatte

Keller

et al. 2008

Cretaceous Research

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a b s t r a c tWith a multi-proxy approach, an attempt was made to constrain productivity and bottom-water redox conditions and their effects on the phosphorus accumulation rate at the Mohammed Plage section on the Tarfaya coast, Morocco, during the Cenomanian-Turonian Anoxic Event (OAE 2). A distinct d 13 C org isotope excursion of þ2.5& occurs close to the top of the section. The unusually abrupt shift of the isotope excursion and disappearance of several planktonic foraminiferal species (e.g. Rotalipora cushmani and Rotalipora greenhornensis) in this level suggests a hiatus of between 40-60 kyrs at the excursion onset. Nevertheless, it was possible to determine both the long-term environmental history as well as the processes that took place immediately prior to and during OAE 2. TOC% values increase gradually from the base of the section to the top (from w2.5% to w10%). This is interpreted as the consequence of a longterm eustatic sea-level rise and subsidence causing the encroachment of less oxic waters into the Tarfaya Basin. Similarly a reduction in the mineralogically constructed 'detrital index' can be explained by the decrease in the continental flux of terrigenous material due to a relative sea-level rise. A speciation of phosphorus in the upper part of the section, which spans the start and mid-stages of OAE 2, shows overall higher abundances of P reactive mass accumulation rates before the isotope excursion onset and lower values during the plateau. Due to the probable short hiatus, the onset of the decrease in phosphorus content relative to the isotope excursion is uncertain, although the excursion plateau already contains lower concentrations. The C org /P total and V/Al ratios suggest that this reduction was mostly likely caused by a decrease in the available bottom oxygen content (probably as a result of higher productivity) and a corresponding fall in the phosphorus retention ability of the sediment. Productivity appears to have remained high during the isotope plateau possibly due to a combination of ocean-surface fertilisation via increased aridity (increased K/Al and Ti/Al ratios) and/or higher dissolved inorganic phosphorus content in the water column as a result of the decrease in sediment P retention. The evidence for decreased P-burial has been observed in many other palaeoenvironments during OAE 2. Tarfaya's unique upwelling paleosituation provides strong evidence that the nutrient recycling was a global phenomenon and therefore a critical factor in starting and sustaining OAE 2.

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Section: Methodsmentioning

confidence: 99%

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Mort

Adatte

Keller

et al. 2008

Cretaceous Research

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“…Geochemical and biotic proxis can be consulted to document a decrease of oligotrophic conditions and an increase of mesotrophic to eutrophic conditions during the PETM. High productivity can be inferred from black shale deposition in the Tethys (Speijer and Wagner, 2002;Gavrilov et al, 2003), the collapse of the oligotrophic Gavelinella beccariiformis benthic foraminiferal community , increased biogenic barium values Thompson and Schmitz, 1997;Bains et al, 2000;Schmitz, 2000), a widespread bloom of the organic-walled dinoflagellate Apectodinium and the coccolithophorid genus Toweius that resulted from intensified weathering and subsequent nutrient input into marginal basins through increased runoff (Crouch et al, 2001(Crouch et al, , 2003Crouch and Brinkhuis, 2005;Stoll and Bains, 2003). In a former shelf setting (New Jersey, USA), oligotrophic nannofossil genera are reduced in abundance, while mesotrophic genera increased due to increased nutrient availability during the PETM (Gibbs et al, 2006b).…”

Section: Trophic Resource Regimementioning

confidence: 99%

Late Paleocene–early Eocene Tethyan carbonate platform evolution — A response to long- and short-term paleoclimatic change

Scheibner

Speijer

2008

Earth-Science Reviews

178

163

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The early Paleogene experienced the most pronounced long-term warming trend of the Cenozoic, superimposed by transient warming events such as the Paleocene-Eocene Thermal Maximum (PETM). The consequences of climatic perturbations and associated changes on the evolution of carbonate platforms are relatively unexplored. Today, modern carbonate platforms, especially coral reefs are highly sensitive to environmental and climatic change, which raises the question how (sub)tropical reef systems of the early Paleogene reacted to gradual and sudden global warming, eutrophication of shelf areas, enhanced CO 2 levels in an ocean with low Mg/Ca ratios. The answer to this question may help to investigate the fate of modern coral reef systems in times of global warming and rising CO 2 levels. Here we present a synthesis of Tethyan carbonate platform evolution in the early Paleogene (~59-55 Ma) concentrating on coral reefs and larger foraminifera, two important organism groups during this time interval. We discuss and evaluate the importance of the intrinsic and extrinsic factors leading to the dissimilar evolution of both groups during the early Paleogene. Detailed analyses of two carbonate platform areas at low (Egypt) and middle (Spain) paleolatitudes and comparison with faunal patterns of coeval platforms retrieved from the literature led to the distinction of three evolutionary stages in the late Paleocene to early Eocene Tethys: Stage I, late Paleocene coralgal-dominated platforms at low to middle paleolatitudes; stage II, a transitional latest Paleocene platform stage with coralgal reefs dominating at middle paleolatitudes and larger foraminifera-dominated (Miscellanea, Ranikothalia, Assilina) platforms at low paleolatitudes; and stage III, early Eocene larger foraminifera-dominated (Alveolina, Orbitolites, Nummulites) platforms at low to middle paleolatitudes. The onset of the latter prominent larger foraminifera-dominated platform correlates with the Paleocene/Eocene Thermal Maximum. The causes for the change from coral-dominated platforms to larger foraminifera-dominated platforms are multilayered. The decline of coralgal reefs in low latitudes during platform stage II is related to overall warming, leading to sea-surface temperatures in the tropics beyond the maximum temperature range of corals. The overall low occurrence of coral reefs in the Paleogene might be related to the presence of a calcite sea. At the same time larger foraminifera started to flourish after their near extinction at the Cretaceous/ Paleogene boundary. The demise of coralgal reefs at all studied paleolatitudes in platform stage III can be founded on the effects of the PETM, resulting in short-term warming, eutrophic conditions on the shelves and acidification of the oceans, hampering the growth of aragonitic corals, while calcitic larger foraminifera flourished. In the absence of other successful carbonate-producing organisms, larger foraminifera were able to take over the role as the dominant carbonate platform inhabitant, leading to a stepw...

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“…time gap between Teredo Limestone (correlation with nannofossil zone NP5 implies an age of 59 Ma) and Lower Limestone (upper PCIM is dated as 57-56 Ma). The PCIM records the Cenozoic global maximum for marine δ 13 C between 59 and 56 Ma and is thought to represent massive burial of organic carbon caused by enhanced marine productivity or increased terrestrial biomass (Shackleton 1986;Corfield & Cartlidge 1992;Thompson & Schmitz 1997;Kurtz et al 2003). The onset is associated with a shortlived episode of global cooling (Zachos et al 2001).…”

Section: Journal Of the Royal Society Of New Zealand Volume 35 2005mentioning

confidence: 99%

Biostratigraphy and carbon isotope stratigraphy of uppermost Cretaceous‐lower Cenozoic Muzzle Group in middle Clarence valley, New Zealand

Hollis

Fielding

Jones

et al. 2005

Journal of the Royal Society of New Zealand

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Muzzle Group strata exposed along southeast-flowing tributaries of the Clarence River valley, Marlborough, record hemipelagic-pelagic sedimentation across a high latitude (c. 55°S), terrigenous sediment-starved, continental margin from latest Cretaceous to middle Eocene times. Studies of dinoflagellates, foraminifera, calcareous nannofossils, and radiolarians have been integrated with bulk carbonate δ 13 C profiles to establish the chronostratigraphy for two stratigraphic sections along Bluff and Muzzle Streams, middle Clarence valley. The two sections comprise similar successions. Uppermost Cretaceous (upper Haumurian) micritic limestone of Mead Hill Formation is overlain unconformably by Teredo Limestone, a c. 0.25 m thick bed of highly glauconitic, calcareous sandstone. This unit, the basal member of Amuri Limestone, is overlain conformably by c. 15 m thick Lower Limestone, micritic limestone that is glauconitic at base and progressively more marl-rich in its upper part. Lower Limestone grades up into Lower Marl, a poorly exposed, 40-70 m thick unit of alternating marl and micritic limestone beds. Biostratigraphy indicates that the base of Amuri Limestone is younger at Bluff Stream (earliest Eocene, early Waipawan) than at Muzzle Stream (late Paleocene, late Teurian). In the condensed (12 m) upper Paleocene-lower Eocene Amuri Limestone sequence at Muzzle Stream, a trend in δ 13 C from high ( 2.4‰) to low ( 1‰) values is consistent with global records across three major climate or carbon cycle perturbations: the late Paleocene carbon isotope maximum (PCIM, 59-56 Ma), the initial Eocene thermal maximum (IETM, 55.5 Ma), and the early Eocene climatic optimum (EECO,. Probably only the upper PCIM is preserved in the 4 m thick siliceous limestone interval overlying Teredo Limestone. The IETM is well-defined by a 1‰ negative δ 13 C excursion at the base of a 0.8 m thick marl-rich unit (Dee Marl), 5 m above the base of Lower Limestone at Muzzle Stream, and the abrupt appearances of Eocene-restricted species or distinctly warm-water elements within dinoflagellate, foraminiferal, calcareous nannofossil, and radiolarian assemblages. The lithological expression of the IETM as a recessive marly unit has now been identified in three Clarence valley sections (Muzzle, Dee, and Mead Streams), representing a 20 km continental margin transect. Sedimentation rate trends across this margin indicate that the local effects of extreme global warming were increased supply of terrigenous mud, probably due to enhanced precipitation, weathering and erosion, and a decrease in pelagic sedimentation, reflecting a decrease in oceanic productivity. Bluff section lacks an IETM record but contains an expanded (20 m) early Eocene succession that records the onset of the EECO as a progressive

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Barium and the Late Paleocene δ¹³C maximum: Evidence of increased marine surface productivity

Cited by 58 publications

References 51 publications

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Late Paleocene–early Eocene Tethyan carbonate platform evolution — A response to long- and short-term paleoclimatic change

Biostratigraphy and carbon isotope stratigraphy of uppermost Cretaceous‐lower Cenozoic Muzzle Group in middle Clarence valley, New Zealand

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Barium and the Late Paleocene δ13C maximum: Evidence of increased marine surface productivity

Cited by 58 publications

References 51 publications

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Organic carbon deposition and phosphorus accumulation during Oceanic Anoxic Event 2 in Tarfaya, Morocco

Late Paleocene–early Eocene Tethyan carbonate platform evolution — A response to long- and short-term paleoclimatic change

Biostratigraphy and carbon isotope stratigraphy of uppermost Cretaceous‐lower Cenozoic Muzzle Group in middle Clarence valley, New Zealand

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Barium and the Late Paleocene δ¹³C maximum: Evidence of increased marine surface productivity