Calcareous nannofossil assemblages and their response to the Paleocene-Eocene Thermal Maximum event at different latitudes: ODP Site 690 and Tethyan sections

2007 ◽  
Author(s):  
Eugenia Angori ◽  
Gilen Bernaola ◽  
Simonetta Monechi
Keyword(s):  
Calcareous Nannofossil ◽  
Thermal Maximum

Stratigraphic and sedimentological aspects of the worldwide distribution of Apectodinium in Paleocene/Eocene Thermal Maximum deposits

2021 ◽  
pp. SP511-2020-46
Author(s):  
Christopher N. Denison
Keyword(s):  
Global Warming ◽  
Sea Level ◽  
Environmental Changes ◽  
Calcareous Nannofossil ◽  
Shallow Marine ◽  
Worldwide Distribution ◽  
Carbon Isotope Excursion ◽  
Thermal Maximum ◽  
Taxonomic Changes ◽  
Data Gap

AbstractThe Paleocene/Eocene Thermal Maximum (PETM) is characterized by pronounced global warming and associated environmental changes. In the more-or-less two decades since prior regional syntheses of Apectodinium distribution at the PETM, extensive biological and geochemical datasets have elucidated the effect of rising world temperatures on climate and the biome. A Carbon Isotope Excursion (CIE) that marks the Paleocene/Eocene Boundary (PEB) is associated with an acme of marine dinocysts of the genus Apectodinium in many locations. Distinctive foraminiferal and calcareous nannofossil populations may also be present.For this up-dated, dinocyst-oriented view of the PETM, data from worldwide locations have been evaluated with an emphasis on stratigraphic and sedimentological context. What has emerged is that a change in lithology is common, often to a distinctive siltstone or claystone unit, which contrasts with underlying and overlying lithotypes. This change, present in shallow marine/coastal settings and in deepwater turbidite deposits, is attributed to radical modifications of precipitation and erosional processes. An abrupt boundary carries the implication that some time (of unknowable duration) is potentially missing, which then requires caution in the interpretation of the pacing of events in relation to that boundary. In most instances an ‘abrupt’ or ‘rapid’ CIE onset can be attributed to a data gap at a hiatus, particularly in shallow shelf settings where transgression resulted from sea-level rise associated with the PETM. Truly gradational lower boundaries of the PETM interval are quite unusual, and if present, are poorly known so far. Gradational upper boundaries are more common, but erosional upper boundaries have been reported.Taxonomic changes have been made to clarify identification issues that have adversely impacted some biostratigraphic interpretations. Apectodinium hyperacanthum has been retained in Wetzeliella, its original genus. The majority of specimens previously assigned to Apectodinium hyperacanthum or Wetzeliella (Apectodinium) hyperacanthum have been re-assigned to an informal species, Apectodinium sp. 1. Dracodinium astra has been retained in its original genus as Wetzeliella astra, and is emended.

scholarly journals Calcareous nannofossil assemblage changes across the Paleocene–Eocene Thermal Maximum: Evidence from a shelf setting

2012 ◽  
Vol 92-93 ◽  
pp. 61-80 ◽  
Author(s):  
Jean M. Self-Trail ◽  
David S. Powars ◽  
David K. Watkins ◽  
Gregory A. Wandless
Keyword(s):  
Calcareous Nannofossil ◽  
Thermal Maximum

Calcareous nannofossil biostratigraphy across the Paleocene-Eocene Thermal Maximum

2021 ◽  
Author(s):  
Alessandro Menini ◽  
Emanuela Mattioli ◽  
Arnauld Vinçon-Laugier ◽  
Guillaume Suan
Keyword(s):  
Calcareous Nannofossil ◽  
Thermal Maximum ◽  
Calcareous Nannofossil Biostratigraphy

scholarly journals Benthic Foraminifera and Geochemistry Across the Paleocene–eocene Thermal Maximum Interval in Jordan

2018 ◽  
Vol 48 (2) ◽  
pp. 100-120 ◽  
Author(s):  
Victor M. Giraldo-Gómez ◽  
Jörg Mutterlose ◽  
Olaf G. Podlaha ◽  
Robert P. Speijer ◽  
Peter Stassen
Keyword(s):  
Benthic Foraminifera ◽  
Oxygen Deficiency ◽  
Organic Content ◽  
Calcareous Nannofossil ◽  
Carbon Isotope Excursion ◽  
Thermal Maximum ◽  
Proximal Site ◽  
Oxygen Conditions ◽  
Bottom Waters ◽  
Distal Site

AbstractThis study presents benthic foraminiferal data from two sedimentary successions across the Paleocene–Eocene Thermal Maximum (PETM) from Jordan. Calcareous nannofossil biozones NP9a, NP9b, and NP10 of latest Paleocene and earliest Eocene age were encountered in proximal (core OS–01) and distal (core OS–28) sites. Lithologically, the investigated sequence consists of marls, shales, and limestones attributed to the Muwaqqar Chalk-Marl Formation and the Um Rijam Chert Limestone Formation. The δ13Corg curve records the typical carbon isotope excursion (CIE) and shows four distinctive intervals (pre-CIE, CIE-“core”, CIE-“recovery”, post-CIE) over the entire PETM interval in both cores.In the pre-CIE interval, the more proximal site (OS–01) shows high abundances of Neoeponides duwi co-occurring with an outer neritic Midway-type fauna. The fauna indicates meso- to eutrophic conditions in a middle- to outer-neritic setting. The more distal site (OS–28) is characterized by outer-neritic to upper-bathyal taxa (e.g., Cibicides pseudoacutus, Gavelinella beccariiformis, Nuttallides truempyi) suggesting well-ventilated, oligo- to mesotrophic seafloor conditions.The earliest Eocene corresponds to the CIE-“core” interval and is marked by a negative δ13Corg signal, high TOC, low CaCO3 contents, and near absence of benthic foraminifera. Oxygen deficiency in bottom waters with increased organic flux is the most likely scenario to explain the elevated organic content at the seafloor.The subsequent CIE-“recovery” interval of early Eocene age is marked by a restoration of oxygenated seafloor conditions. The proximal site is characterized by a relatively elevated TOC content and high abundance of Lenticulina spp., Valvulineria scrobiculata and common Anomalinoides zitteli, suggesting moderate oxygen conditions and mesotrophic bottom waters. The distal site is characterized by low TOC content and the presence of Lenticulina spp., Valvulineria scrobiculata, Anomalinoides zitteli and Oridorsalis plummerae, indicating a normalization of the organic flux and moderate oxygen concentrations near the seafloor.The post-CIE interval is marked by low TOC content in both cores. Benthic foraminifera include abundant Anomalinoides zitteli and common Lenticulina spp., Valvulineria scrobiculata, Oridorsalis plummerae, Cibicidoides rigidus, Cibicidoides pharaonis, and Anomalinoides praeacutus in the proximal setting. Mesotrophic conditions and a better ventilation of bottom waters are suggested for this interval. Lenticulina spp., Valvulineria scrobiculata, and Oridorsalis plummerae are also associated with the post-CIE interval in the distal site, suggesting similar mesotrophic conditions with renewed oxygenation in bottom waters.

scholarly journals Calcareous nannofossil changes linked to climate deterioration during the Paleocene–Eocene thermal maximum in Tarim Basin, NW China

2018 ◽  
Vol 9 (5) ◽  
pp. 1465-1478 ◽  
Author(s):  
Wenxin Cao ◽  
Dangpeng Xi ◽  
Mihaela C. Melinte-Dobrinescu ◽  
Tian Jiang ◽  
Sherwood W. Wise ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Calcareous Nannofossil ◽  
Nw China ◽  
Thermal Maximum
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