High-resolution carbon isotope record for the Paleocene-Eocene thermal maximum from the Nanyang Basin, Central China

2010 ◽  
Vol 55 (31) ◽  
pp. 3606-3611 ◽  
Author(s):  
Min Zhu ◽  
ZhongLi Ding ◽  
Xu Wang ◽  
ZuoLing Chen ◽  
HanChao Jiang ◽  
...  
Keyword(s):  
High Resolution ◽  
Carbon Isotope ◽  
Central China ◽  
Thermal Maximum ◽  
Isotope Record

scholarly journals New Chronostratigraphic Constraints on the Lower Jurassic Pliensbachian–Toarcian Boundary at Chacay Melehue (Neuquén Basin, Argentina)

2021 ◽  
Author(s):  
Aisha H. Al-Suwaidi ◽  
Micha Ruhl ◽  
Hugh C. Jenkyns ◽  
Susana E. Damborenea ◽  
Miguel O. Manceñido ◽  
...  
Keyword(s):  
High Resolution ◽  
Carbon Isotope ◽  
Volcanic Ash ◽  
Lower Jurassic ◽  
Zircon Geochronology ◽  
Organic Carbon Isotope ◽  
Carbon Isotope Excursion ◽  
Isotope Record ◽  
Age Model ◽  
Zonal Boundary

Abstract The Pliensbachian–Toarcian boundary interval is characterized by a ~3‰ negative carbon-isotope excursion (CIE) in organic and inorganic marine and terrestrial archives from sections in Europe, such as Peniche (Portugal) and Hawsker Bottoms, Yorkshire (UK). A new high-resolution organic-carbon isotope record, illustrating the same chemostratigraphic feature, is presented from the Southern Hemisphere Arroyo Chacay Melehue section, Chos Malal, Argentina, corroborating the global significance of this disturbance to the carbon cycle. The negative carbon-isotope excursion, mercury and organic-matter enrichment is accompanied by high-resolution ammonite and nannofossil biostratigraphy together with U-Pb CA-ID-TIMS geochronology derived from intercalated volcanic ash beds. A new age of ~183.71 ± 0.40/-0.51 Ma for the Pliensbachian–Toarcian boundary, and 182.77 +0.11/-0.21 for the tenuicostatum–serpentinum zonal boundary, is assigned based on high-precision U-Pb zircon geochronology and a Bayesian Markov chain Monte Carlo (MCMC) stratigraphic age model.

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 High-resolution ammonite, belemnite and stable isotope record from the most complete Upper Jurassic section of the Bakony Mts (Transdanubian Range, Hungary)

2011 ◽  
Vol 62 (5) ◽  
pp. 413-433 ◽  
Author(s):  
István Főzy ◽  
Nico Janssen ◽  
Gregory Price
Keyword(s):  
High Resolution ◽  
Stable Isotope ◽  
Carbon Isotope ◽  
Isotopic Analysis ◽  
Upper Jurassic ◽  
Western Tethys ◽  
Isotope Record ◽  
Transdanubian Range ◽  
The Rich ◽  
Stable Isotope Record

High-resolution ammonite, belemnite and stable isotope record from the most complete Upper Jurassic section of the Bakony Mts (Transdanubian Range, Hungary)This research focuses on the cephalopod fauna and biostratigraphy of the latest Jurassic succession of the Lókút Hill (Bakony Mts, Transdanubia, Hungary). Fossils were collected bed-by-bed from Ammonitico Rosso facies and from the subsequent Biancone type rock. The poorly preserved cephalopods from the lowermost part of the profile, immediately above the radiolarite, may represent a part of the Oxfordian stage. The rich Kimmeridgian ammonite fauna is published for the first time while the formerly illustrated Tithonian fauna is revised. All the successive Kimmeridgian and Early Tithonian Mediterranean ammonite zones can be traced. The highest documented ammonite zone is the Late Tithonian Microcanthum Zone. The beds above yielded no cephalopods. Particular attention was paid to the belemnite fauna of over 120 specimens collected under strict ammonite control. Among the belemnite faunas an Early Tithonian, an early middle Tithonian, a late middle Tithonian, and a latest Tithonian assemblage can be distinguished. Thereby, an association is distinguished in the middle Late Kimmeridgian and one that characterizes the Oxfordian-Kimmeridgian boundary beds. The main difference from previously published belemnite data appears to be that the Hungarian assemblages are impoverished with respect to contemporary faunas from Italy and Spain (Mediterranean Province). An isotopic analysis of the belemnites show that the carbon-isotope data are consistent with carbon-isotope stratigraphies of the Western Tethys and show a decrease in values towards the Jurassic-Cretaceous boundary.

scholarly journals Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342)

2016 ◽  
Author(s):  
Oliver Friedrich ◽  
Sietske J. Batenburg ◽  
Kazuyoshi Moriya ◽  
Silke Voigt ◽  
Cécile Cournède ◽  
...  
Keyword(s):  
High Resolution ◽  
Carbon Cycle ◽  
Carbon Isotope ◽  
North Atlantic ◽  
Climatic Variability ◽  
Stable Carbon Isotope ◽  
The North ◽  
Depositional Processes ◽  
Isotope Record ◽  
The North Atlantic

Abstract. Earth’s climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Site U1403, providing an expanded deep ocean record from the North Atlantic (IODP Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role on depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4 ‰), typical for open ocean settings, are compared to the hemipelagic Zumaia section (N-Spain), with a well-established independent cyclostratigraphic framework. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both records, patterns diverge around 67.5 Ma, with Site U1403 more reliably reflecting global climate change. Our new carbon isotope record and the established cyclostratigraphy from Site U1403 may serve as a future reference for detailed studies of late Maastrichtian events in the North Atlantic.

High-resolution organic carbon isotope record across the Cretaceous–Tertiary boundary in south-central Alberta: implications for the post-impact recovery rate of terrestrial ecosystems and use of δ13C as a boundary marker

2007 ◽  
Vol 44 (4) ◽  
pp. 529-542 ◽  
Author(s):  
François Therrien ◽  
David A Eberth ◽  
Dennis R Braman ◽  
Darla K Zelenitsky
Keyword(s):  
High Resolution ◽  
Organic Carbon ◽  
Carbon Isotope ◽  
Terrestrial Ecosystems ◽  
Terrestrial Organic Matter ◽  
Sedimentary Environments ◽  
South Central ◽  
Organic Carbon Isotope ◽  
Isotope Record ◽  
Post Impact

A high-resolution study identified a δ13C excursion of –1.8‰ to –2.3‰ in terrestrial organic matter across the Cretaceous–Tertiary (K–T) boundary at two localities in the Scollard Formation of south-central Alberta, one of the northernmost occurrences of the K–T boundary in terrestrial settings. δ13C values are at their lowest within 6 cm above the K–T boundary claystone and return to pre-boundary levels within 10 cm above the boundary claystone. Statistical analyses reveal that the K–T isotopic shift in Alberta is related to the nature of floral changes that occurred across the K–T boundary. A radiometrically dated bentonite resting on the boundary-hosting Nevis coal at one of the localities permits us to estimate that the terrestrial carbon cycle recovered ~100 000 years after the K–T boundary event, a value that supports an existing hypothesis that terrestrial ecosystems recovered more rapidly than marine ecosystems. The organic carbon isotope record of the entire Scollard Formation demonstrates that the δ13C excursion across the K–T boundary did not reach anomalously low values by late Maastrichtian standards in Alberta. Furthermore, the occurrence of the K–T carbon isotope shift within a restricted stratigraphic interval (<10 cm) greatly limits the probability of its preservation in the context of terrestrial sedimentary environments. These observations suggest that, on their own, δ13C profiles may be unreliable for locating the K–T boundary (and possibly other geologically instantaneous events) and that they should be used in combination with other approaches (e.g., palynology) to identify the K–T boundary in sections lacking the boundary claystone and iridium anomaly.

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