A 485-million-year history of Earth’s surface temperature

Science, Год журнала: 2024, Номер 385(6715)

Опубликована: Сен. 19, 2024

A long-term record of global mean surface temperature (GMST) provides critical insight into the dynamical limits Earth's climate and complex feedbacks between broader Earth system. Here, we present PhanDA, a reconstruction GMST over past 485 million years, generated by statistically integrating proxy data with model simulations. PhanDA exhibits large range GMST, spanning 11° to 36°C. Partitioning states indicates that more time was spent in warmer rather than colder climates reveals consistent latitudinal gradients within each state. There is strong correlation atmospheric carbon dioxide (CO

Язык: Английский

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Dual clumped isotope thermometry resolves kinetic biases in carbonate formation temperatures

Nature Communications, Год журнала: 2020, Номер 11(1)

Опубликована: Авг. 10, 2020

Surface temperature is a fundamental parameter of Earth's climate. Its evolution through time commonly reconstructed using the oxygen isotope and clumped compositions carbonate archives. However, reaction kinetics involved in precipitation carbonates can introduce inaccuracies derived temperatures. Here, we show that dual analyses, i.e., simultaneous ∆47 ∆48 measurements on single phase, identify origin quantify extent these kinetic biases. Our results verify theoretical predictions evidence isotopic disequilibrium observed speleothems scleractinian coral skeletons inherited from dissolved inorganic carbon pool their parent solutions. Further, thermometry achieve reliable palaeotemperature reconstructions, devoid bias. Analysis belemnite rostrum implies it precipitated near equilibrium confirms warmer-than-present temperatures during Early Cretaceous at southern high latitudes.

Язык: Английский

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Thermally-induced clumped isotope resetting in belemnite and optical calcites: Towards material-specific kinetics

Geochimica et Cosmochimica Acta, Год журнала: 2023, Номер 350, С. 1 - 15

Опубликована: Март 30, 2023

The application of carbonate clumped isotope (Δ47) thermometry in deep-time is often limited by modification the original temperature signal thermal resetting. New modeling approaches to estimate initial isotopic composition partially reset calcites and maximal burial temperatures, however, open promising avenues reconstruction. Such strongly depend on laboratory-derived kinetic parameters calcite materials, which may differ their microstructure, water content distribution, minor trace element composition, thus have different resetting kinetics. rostra belemnites, an extinct group mollusks with a wide temporal spatial occurrence Mesozoic, been extensively used for paleoclimate reconstructions using oxygen geochemistry. Belemnites are also important targets isotope-based reconstructions, but found Δ47 compositions. Here, we present results from heating experiments belemnite rostral optical provide belemnite-specific We show that altered faster at lower temperatures than all other reported previous studies. suggest fast exchange internal skeletal as fluid inclusions or organic-derived water, process completed within 2–4 min experimental here. Extrapolation geological timescales solid-state bond reordering models shows starts brachiopod, spar, calcites. This susceptibility measurable (+3 °C) increase apparent even under shallow moderate conditions (i.e., 40–50 °C 106–107 years timescales). Following overprint higher during burial, further re-equilibrate exhumation resulting decrease temperatures. “retrograde resetting” similar what observed carbonatites marbles cooling, cause underestimation sample experienced its history. Overall, our demonstrate importance material-specific urge caution when interpreting Δ47-derived biogenic carbonates archives.

Язык: Английский

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Unravelling Middle to Late Jurassic palaeoceanographic and palaeoclimatic signals in the Hebrides Basin using belemnite clumped isotope thermometry

Earth and Planetary Science Letters, Год журнала: 2020, Номер 546, С. 116401 - 116401

Опубликована: Июль 7, 2020

Язык: Английский

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Marine temperatures underestimated for past greenhouse climate

Scientific Reports, Год журнала: 2021, Номер 11(1)

Опубликована: Сен. 27, 2021

Abstract Understanding the Earth’s climate system during past periods of high atmospheric CO 2 is crucial for forecasting change under anthropogenically-elevated . The Mesozoic Era believed to have coincided with a long-term Greenhouse climate, and many our temperature reconstructions come from stable isotopes marine biotic calcite, in particular belemnites, an extinct group molluscs carbonate hard-parts. Yet, temperatures reconstructed oxygen isotope composition belemnites are consistently colder than those derived other proxies, leading large uncertainties around sea temperatures. Here we apply clumped palaeothermometry two distinct phases exceptionally well-preserved order constrain their living habitat, improve based on isotopes. We show that precipitated both aragonite calcite warm, open ocean surface waters, demonstrate how previous low estimates belemnite calcification has led widespread underestimation by ca. 12 °C, raising some lowest Jurassic period values which approach modern mid-latitude Our findings enable accurate recalculation global temperatures, will thus understanding dynamics.

Язык: Английский

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Early Cretaceous climate for the southern Tethyan Ocean: Insights from the geochemical and paleoecological analyses of extinct cephalopods

Global and Planetary Change, Год журнала: 2023, Номер 229, С. 104220 - 104220

Опубликована: Авг. 31, 2023

Язык: Английский

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Absolute age and temperature of belemnite rostra: Constraints on the Early Cretaceous cooling event

Global and Planetary Change, Год журнала: 2024, Номер 233, С. 104353 - 104353

Опубликована: Янв. 21, 2024

Язык: Английский

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Ice sheet expansion in the Cretaceous greenhouse world

Fundamental Research, Год журнала: 2023, Номер 4(6), С. 1586 - 1593

Опубликована: Май 26, 2023

Globally elevated temperatures during the Cretaceous extreme greenhouse climate interval were punctuated by Valanginian cooling event, which was characterized a positive carbon isotope excursion, global cooling, and glacial event approximately at 135 Ma. Disentangling ocean temperature continental ice volume trends enables us to better understand fluctuations over deep time. We investigated temperature-ice sheet dynamics of glaciation events that occurred in world. New clumped

Язык: Английский

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Smithian and Spathian palaeontological records of the Vikinghøgda Formation in Central Spitsbergen

Lethaia, Год журнала: 2024, Номер 57(1), С. 1 - 15

Опубликована: Март 1, 2024

Vertebrate and invertebrate fossils from the Smithian (Early Triassic) to Early-Middle Triassic boundary interval of Svalbard, Arctic Norway have been known for a long time, but rarely extensively collected with precise stratigraphical control. We describe new bulk collections precisely measured sections in Vikinghøgda Formation Central Spitsbergen. Accompanying geochemical data provide further constraints on changes palaeoenvironments. Species richness both benthos nekton remains low throughout studied reduces minimum early Spathian, i.e. wake late extinction probable associated short ice age that straddled Smithian–Spathian as manifested by global hiatus continental shelves. The faunal succession series indicate regression event followed deepening sea level Spathian. This is consistent cooling phase has previously interpreted likely glacio-eustatic episode. lowermost Spathian marked near-absence benthos, compatible increased water depth also possibly linked aftermath Smithian-Spathian extinction. lateral expansion another younger gap ('the Marmierfjellet hiatus' or middle age) here an off-shore condensation horizon generated probably highest sea-level stand recorded These hiatuses opposite origin, well acute selective preservation carbonate content series, be factored out biases when estimating species interpreting palaeo-ecological changes. study identifies Early fossil taxa Spitsbergen, particular Peribositria sibirica bakevellid bivalves. orthoceratoids are reviewed, two distinct identified at different levels.

Язык: Английский

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Microstructural and geochemical evidence offers a solution to the cephalopod cameral deposits riddle

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Фев. 28, 2025

Abstract Orthoceratoid cephalopods are common in the Palaeozoic rock record but became extinct Late Triassic. Many orthoceratoids contain cameral deposits, which enigmatic calcareous structures within their chambered shell that presumably balanced straight conchs a horizontal position. Since mid-19 th century, palaeontologists have attempted to understand deposit formation process. The various hypotheses include growth from fluids, precipitation by mantle or even dismissal as post-mortem structures. All of these previous interpretations they complicated with contradictory evidence. Here, we present evidence well-preserved Trematoceras elegans specimens Triassic St. Cassian Formation (Dolomites, northern Italy). We studied using optical and electron beam microanalysis techniques argue deposits consist primary aragonite calcite fabrics. A fibrous microstructure, is bilaterally symmetrically arranged irregularities, documented. Thin organic sheets originally delimited radial sectors. Based on observations, propose new model explicitly involves sheets. These acted an extension pellicle held thin film supersaturated liquid otherwise emptied chambers via capillary effect. Ions were supplied through siphuncle, such living Nautilus , enabled This goes beyond interpretations, resolves observations has functional implications, suggesting adaptation increased rates.

Язык: Английский

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