Orbital Forcing of Early Eocene dissolution events and Carbon Isotope Excursions from the Contessa Road-Bottaccione composite section (Gubbio, central Italy)

2014 ◽  
Vol 31 ◽  
pp. 81-82
Author(s):  
Simone Galeotti ◽  
Matteo Moretti
Keyword(s):  
Carbon Isotope ◽  
Central Italy ◽  
Early Eocene ◽  
Orbital Forcing ◽  
Composite Section

Cyclochronology of the Early Eocene carbon isotope record from a composite Contessa Road-Bottaccione section (Gubbio, central Italy)

2017 ◽  
Vol 50 (3) ◽  
pp. 231-244 ◽  
Author(s):  
Simone Galeotti ◽  
Matteo Moretti ◽  
Nadia Sabatino ◽  
Mario Sprovieri ◽  
Mattia Ceccatelli ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Central Italy ◽  
Early Eocene ◽  
Isotope Record

Late Paleocene-Early Eocene Foraminiferal Assemblage and Carbon Isotope Excursion Indicating Hyperthermal Events in Paleotropical Succession of Northwestern India

2021 ◽  
Vol 51 (1) ◽  
pp. 4-13
Author(s):  
Sonal Khanolkar ◽  
Tathagata Roy Choudhury ◽  
Pratul Kumar Saraswati ◽  
Santanu Banerjee
Keyword(s):  
Carbon Isotope ◽  
Detrended Correspondence Analysis ◽  
Western India ◽  
Early Eocene ◽  
Foraminiferal Assemblage ◽  
Trophic Conditions ◽  
Jaisalmer Basin ◽  
Early Eocene Climatic Optimum ◽  
Late Paleocene ◽  
Carbon Isotope Excursion

ABSTRACT This study focuses on marine sediments of the late Paleocene-early Eocene (∼55.5–49 Ma) interval from the Jaisalmer Basin of western India. It demarcates the Paleocene Eocene Thermal Maximum (PETM) using foraminiferal biostratigraphy and carbon isotope stratigraphy. A negative carbon isotope excursion of 4.5‰ delineates the PETM within the basin. We demarcate five foraminiferal biofacies using the detrended correspondence analysis. These reflect characteristics of ecology, bathymetry, relative age, and environment of deposition of the foraminifera. They record the response of foraminifera to the warmth of the PETM. Biofacies A was deposited within an inner neritic setting ∼55.5 Ma and includes benthic foraminifera Haplophragmoides spp., Ammobaculites spp., and Lenticulina spp. The presence of Pulsiphonina prima and Valvulineria scorbiculata in Biofacies B suggests an increase in runoff conditions in the basin. Fluctuating trophic conditions prevailed between ∼54–50 Ma. It is evidenced by alternating Biofacies C (endobenthic and chiloguembelinids of eutrophic conditions) and Biofacies D (epibenthic and acarininids of oligotrophic conditions). Biofacies E is dominated by deep-dwelling parasubbotinids, indicating an increase in bathymetry, possibly corresponding to the Early Eocene Climatic Optimum (∼49 Ma).

Orbital forcing of carbonate versus siliceous productivity in the late Albian–late Cenomanian (Umbria-Marche Basin, central Italy)

2019 ◽  
Vol 52 (2) ◽  
pp. 197-220 ◽  
Author(s):  
Gabriele Gambacorta ◽  
Alberto Malinverno ◽  
Elisabetta Erba
Keyword(s):  
Central Italy ◽  
Orbital Forcing

scholarly journals Geochemical indications for the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM-2) hyperthermals in terrestrial sediments of the Canadian Arctic

Geosphere ◽  
2022 ◽  
Author(s):  
Lutz Reinhardt ◽  
Werner von Gosen ◽  
Andreas Lückge ◽  
Martin Blumenberg ◽  
Jennifer M. Galloway ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Early Eocene ◽  
Isotope Data ◽  
Complete Section ◽  
Thermal Maximum ◽  
Terrestrial Sediments ◽  
Deformation Features ◽  
Isotope Record ◽  
Hydrological System ◽  
Hyperthermal Events

During the late Paleocene to early Eocene, clastic fluvial sediments and coals were deposited in northern high latitudes as part of the Marga­ret Formation at Stenkul Fiord (Ellesmere Island, Nunavut, Canada). Syn-sedimentary tectonic movements of the Eurekan deformation continu­ously affected these terrestrial sediments. Different volcanic ash layers occur, and unconformities subdivide the deposits into four sedimentary units. Rare vertebrate fossils indicate an early Eocene (Graybullian) age for the upper part of the Stenkul Fiord outcrop. Here, we present carbon isotope data of bulk coal, related organic-rich mud and siltstones, a plant leaf wax-derived alkane, and additional plant remains. These data provide a complete carbon isotope record of one stratigraphic section with defined unconformity positions and in relation to other Eurekan deformation features. A previously dated ash layer MA-1 provided a U-Pb zircon age of 53.7 Ma and is used as a stratigraphic tie point, together with a discrete negative carbon isotope excursion found above MA-1 in a closely sampled coal seam. The excursion is identified as the likely expression of the I-1 hyperthermal event. Based on our isotope data that reflect the early Eocene dynamics of the carbon cycle, this tie point, and previous paleontological constraints from vertebrate fossils, the locations of the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM-2) hyperthermals and their extent along the complete section are herein identified. Within the intervals of the PETM and ETM-2 hyperthermal events, increasing amounts of clastic sediments reached the site toward the respective end of the event. This is interpreted as a response of the fluvial depositional system to an intensified hydrological system during the hyperthermal events. Our study establishes an enhanced stratigraphic framework allowing for the calcula­tion of average sedimentation rates of different intervals and considerations on the completeness of the stratigraphic record. As one of the few high-latitude outcrops of early Eocene terrestrial sediments, the Stenkul Fiord location offers further possibilities to study the effects of extreme warming events in the Paleogene.

scholarly journals Paleoenvironmental response of midlatitudinal wetlands to Paleocene–early Eocene climate change (Schöningen lignite deposits, Germany)

2019 ◽  
Vol 15 (5) ◽  
pp. 1741-1755 ◽  
Author(s):  
Katharina Methner ◽  
Olaf Lenz ◽  
Walter Riegel ◽  
Volker Wilde ◽  
Andreas Mulch
Keyword(s):  
Carbon Isotope ◽  
North Sea ◽  
Terrestrial Ecosystems ◽  
High Pco2 ◽  
Organic Carbon Content ◽  
Early Eocene ◽  
Thermal Maximum ◽  
Early Paleogene ◽  
Sea Coast ◽  
North Sea Coast

Abstract. The early Paleogene is marked by multiple negative carbon isotope excursions (CIEs) that reflect massive short-term carbon cycle perturbations that coincide with significant warming during a high-pCO2 world, affecting both marine and terrestrial ecosystems. Records of such hyperthermals from the marine–terrestrial interface (e.g., estuarine swamps and mire deposits) are therefore of great interest as their present-day counterparts are highly vulnerable to future climate and sea level change. Here, we assess paleoenvironmental changes of midlatitudinal late Paleocene–early Eocene peat mire records along the paleo-North Sea coast. We provide carbon isotope data of bulk organic matter (δ13CTOC), organic carbon content (%TOC), and palynological data from an extensive peat mire deposited at a midlatitudinal (ca. 41∘ N) coastal site (Schöningen, Germany). The δ13CTOC data show a carbon isotope excursion of −1.3 ‰ (mean decrease in δ13CTOC; −1.7 ‰ at the onset of CIE) coeval with a conspicuous Apectodinium acme. Due to the exceptionally large stratigraphic thickness of the CIE at Schöningen (10 m of section) we established a detailed palynological record that indicates only minor changes in paleovegetation leading into and during this event. Instead, paleovegetation changes mostly follow natural successions in response to changes along the marine–terrestrial interface. The available age constraints for the Schöningen Formation hamper a solid assignment of the detected CIE to a particular hyperthermal such as the Paleocene–Eocene Thermal Maximum (PETM) or any succeeding hyperthermal event such as the Eocene Thermal Maximum 2 (ETM2). Compared to other nearby peat mire records (Cobham, UK; Vasterival, F) it appears that wetland deposits around the Paleogene North Sea have a consistent CIE magnitude of ca. −1.3 ‰ in δ13CTOC. Moreover, the Schöningen record shares major characteristics with the Cobham Lignite PETM record, including evidence for increased fire activity prior to the CIE, minor plant species change during the hyperthermal, a reduced CIE in δ13CTOC, and drowning of the mire (marine ingressions) during much of the Schöningen CIE event. This suggests that either the Schöningen CIE reflects the PETM or that early Paleogene hyperthermals similarly affected paleoenvironmental conditions of a major segment of the paleo-North Sea coast.

scholarly journals Orbitally induced cycles in benthonic foraminiferal morphogroups and trophic structure distribution patterns from the Late Albian “Amadeus Segment” (Central Italy)

1993 ◽  
Vol 12 (2) ◽  
pp. 227-239 ◽  
Author(s):  
Rodolfo Coccioni ◽  
Simone Galeotti
Keyword(s):  
Primary Productivity ◽  
Bottom Water ◽  
Trophic Structure ◽  
Central Italy ◽  
Distribution Patterns ◽  
Orbital Forcing ◽  
Sea Floor ◽  
Marche Region ◽  
Cyclical Fluctuations ◽  
Foraminiferal Distribution

Abstract. A detailed analysis was made of benthonic foraminiferal distribution patterns and morphogroups in the late Albian “Amadeus Segment” of the Aptian-Albian organic-rich Scisti a Fucoidi Formation outcropping over a widespread area of the Umbria-Marche region, Central Italy. Rhythmic changes in the trophic structures and composition of benthonic foraminiferal assemblages suggest cyclical fluctuations of the sea floor environment which appear to be orbitally induced. Benthonic foraminiferal assemblages varied significantly through the section and appear to contain a strong paleoecological signal. Fluctuations in both bottom water oxygenation and the surface primary productivity as a result of the orbital forcing are interpreted to have been the primary controls on benthonic foraminiferal distribution patterns.

scholarly journals Multiple early Eocene carbon isotope excursions associated with environmental changes in the Dieppe-Hampshire Basin (NW Europe)

2020 ◽  
Vol 191 ◽  
pp. 33
Author(s):  
Sylvain Garel ◽  
Christian Dupuis ◽  
Florence Quesnel ◽  
Jérémy Jacob ◽  
Johan Yans ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Environmental Changes ◽  
Climatic Changes ◽  
Coastal Sediments ◽  
Carbonate Dissolution ◽  
Early Eocene ◽  
Higher Plant ◽  
Carbon Isotopic ◽  
Paleoclimatic Changes ◽  
Thermal Maximum

The early Eocene experienced a series of short-lived global warming events, known as hyperthermals, associated with negative carbon isotope excursions (CIE). The Paleocene-Eocene Thermal Maximum (PETM or ETM-1) and Eocene Thermal Maximum 2 (ETM-2) are the two main events of this Epoch, both marked by massive sea-floor carbonate dissolution. Their timing, amplitude and impacts are rather well documented, but CIEs with lower amplitudes also associated with carbonate dissolution are still poorly studied (e.g. events E1 to H1), especially in the terrestrial realm where hiatus/disconformities and various sedimentary rates in a single succession may complicate the assignation to global isotopic events. Here we present a new high-resolution multi-proxy study on the terrestrial, lagoonal and shallow marine late Paleocene-early Eocene succession from two sites of the Cap d’Ailly area in the Dieppe-Hampshire Basin (Normandy, France). Carbon isotope data (δ13C) on bulk organic matter and higher-plant derived n-alkanes, and K-Ar ages on authigenic glauconite were determined to provide a stratigraphic framework. Palynofacies, distribution and hydrogen isotope values (δ2H) of higher-plant derived n-alkanes allowed us to unravel paleoenvironmental and paleoclimatic changes. In coastal sediments of the Cap d’Ailly area, δ13C values revealed two main negative CIEs, from base to top CIE1 and CIE2, and 3 less pronounced negative excursions older than the NP11 nannofossil biozone. While the CIE1 is clearly linked with the PETM initiation, the CIE2 could either correspond to 1) a second excursion within the PETM interval caused by strong local environmental changes or 2) a global carbon isotopic event that occurred between the PETM and ETM-2. Paleoenvironmental data indicated that both main CIEs were associated with dramatic changes such as eutrophication, algal and/or dinoflagellate blooms along with paleohydrological variations and an increase in seasonality. They revealed that the intervals immediately below these CIEs are also marked by environmental and climatic changes. Thus, this study shows either 1) a PETM marked by at least two distinct intervals of strong environmental and climatic changes or 2) at least one “minor” CIE: E1, E2, F or G, was associated with strong environmental and climatic changes similar to those that occurred during the PETM.

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