CLUMPED ISOTOPE ANALYSIS OF THE CRETACEOUS-PALEOGENE MASS EXTINCTION LINKED TO VOLCANICALLY INDUCED GLOBAL WARMING

Joachimski et al. carried out geochemical investigations to study seawater temperature changes and their potential triggers across the Permian-Triassic Boundary (PTB). Unfortunately, in our opinion, an incorrect biochronology was applied to define the PTB, and the existing alternative was not considered, nor the reasoning explained. As a consequence, Joachimski et al. report diachronous temperature changes for the investigated Chanakhchi section with respect to the global stratotype section and point (GSSP) in Meishan, China. This discrepancy disappears when the, in our view, correct position of the PTB is adopted by using the proper biochronology.

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Deep marine anoxia of the southern Panthalassa during the Permian-Triassic – global impacts of the Siberian Traps

10.5194/egusphere-egu21-13733 ◽

2021 ◽

Author(s):

Stephen Grasby ◽

David Bond ◽

Paul Wignall ◽

Runsheng Yin ◽

Lorna Strachan ◽

...

Keyword(s):

Global Warming ◽

Ocean Circulation ◽

Surface Waters ◽

Mass Extinction ◽

Bottom Water ◽

Deep Ocean ◽

Marine Life ◽

Siberian Traps ◽

Southern Latitude ◽

Global Impacts

<p>The deep-water record of marine anoxia across the Permo-Triassic mass extinction (PTME) is highly controversial; both the length of time and severity of anoxic conditions are uncertain. Panthalassa Ocean circulation models show varying results, ranging from a well-ventilated deep ocean to rapidly developing northern, but not southern, latitude anoxia in response to Siberian Traps driven global warming. To address this uncertainty we examined a southern paleo-latitude pelagic record. Trace metal and pyrite framboid data show bottom water euxinc conditions developed in the southern Panthalassa Ocean at the PTME, coincident with enhanced volcanic activity indicated by Hg geochemistry. While a global deep-ocean euxinic event at the PTME placed extraordinary stress on marine life, southern surface waters appear to have recovered more quickly as radiolarian populations return several million years before they do in northern Panthalassa.</p>

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Conflicts with the Ecosystem

Technology versus Ecology ◽

10.4018/978-1-4666-4586-8.ch002 ◽

2013 ◽

pp. 20-45

Keyword(s):

Global Warming ◽

Side Effects ◽

Support System ◽

Economic Activity ◽

Mass Extinction ◽

Ozone Layer ◽

Toxic Substances ◽

Human Beings ◽

Human Economic Activity

Although human beings are part of nature, they are seriously damaging the ecosystem, our support system. Modern technological manufacturing regularly produces harmful side effects, either toxic substances or unexpected threats to the entire ecosystem such as ozone layer destruction or global warming. Human economic activity is leading to the mass extinction of other species. Humanity is threatening the entire ecosystem. This means that the view that humans are superior to nature is actually incorrect.

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Clumped Isotope Paleothermometry: Principles, Applications, and Challenges

The Paleontological Society Papers ◽

10.1017/s1089332600002576 ◽

2012 ◽

Vol 18 ◽

pp. 101-114 ◽

Cited By ~ 15

Author(s):

Hagit P. Affek

Keyword(s):

Isotope Composition ◽

Isotope Analysis ◽

Atomic Scale ◽

Clumped Isotopes ◽

Temperature Dependent ◽

Deep Time ◽

Diagenetic Alteration ◽

Carbonate Formation ◽

Rare Isotopes ◽

Clumped Isotope

Clumped isotopes geochemistry measures the thermodynamic preference of two heavy, rare, isotopes to bind with each other. This preference is temperature dependent, and is more pronounced at low temperatures. Carbonate clumped isotope values are independent of the carbonate δ13C and δ18O, making them independent of the carbon or oxygen composition of the solution from which the carbonate precipitated. At equilibrium, it is therefore a direct proxy for the temperature in which the carbonate mineral formed. In most cases, carbonate clumped isotopes record the temperature of carbonate formation, irrespective of the mineral form (calcite, aragonite, or bioapatite) or the organism making it. The carbonate formation temperatures obtained from carbonate clumped isotope analysis can be used in conjunction with the δ18O of the same carbonate, to constrain the oxygen isotope composition of the water from which the carbonate has precipitated. There are, however, cases of deviation from thermodynamic equilibrium, where both clumped and oxygen isotopes are offset from the expected values. Such carbonates must be characterized and calibrated separately. For deep-time applications, special care must be paid to the preservation of the original signal, in particular with respect to diagenetic alteration associated with atomic scale diffusion that may be undetectable by common tests for diagenesis.

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Impact of basin architecture on diagenesis and dolomitization in a fault-bounded carbonate platform: outcrop analogue of a pre-salt carbonate reservoir, Red Sea rift, NW Saudi Arabia

Petroleum Geoscience ◽

10.1144/petgeo2018-125 ◽

2019 ◽

Vol 26 (3) ◽

pp. 448-461 ◽

Cited By ~ 6

Author(s):

Khalid Al-Ramadan ◽

Ardiansyah Koeshidayatullah ◽

Dave Cantrell ◽

Peter K. Swart

Keyword(s):

Red Sea ◽

Elevated Temperatures ◽

Carbonate Platform ◽

Isotope Analysis ◽

Carbonate Reservoir ◽

Carbonate Platforms ◽

Hydrocarbon Reservoir ◽

Red Sea Rift ◽

Platform Margin ◽

Clumped Isotope

The early Miocene Wadi Waqb carbonate in the Midyan Peninsula, NE Red Sea is of great interest not only because of its importance as an archive of one of the few pre-salt synrift carbonate platforms in the world, but also as a major hydrocarbon reservoir. Despite this importance, little is known about the diagenesis and heterogeneity of this succession. This study uses petrographical, elemental chemistry, stable isotope (δ13C and δ18O) and clumped isotope (Δ47) analyses to decipher the controlling processes behind the formation of various diagenetic products, especially dolomite, from two locations (Wadi Waqb and Ad-Dubaybah) that have experienced different diagenetic histories. Petrographically, the dolomites in both locations are similar, and characterized by euhedral to subhedral crystals (50–200 µm) and fabric-preserving dolomite textures. Clumped isotope analysis suggests that slightly elevated temperatures were recorded in the Ad-Dubaybah location (up to 49°C), whereas the Wadi Waqb location shows a sea-surface temperature of c. 30°C. These temperature differences, coupled with distinct δ18OVPDB values, can be used to infer the chemistry of the fluids involved in the dolomitization processes, with fluids at the Wadi Waqb location displaying much higher δ18OSMOW values (up to +4‰) compared to those at the Ad Dubaybah location (up to −3‰). Two different dolomitization models are proposed for the two sites: a seepage reflux, evaporative seawater mechanism at the Wadi Waqb location; and a fault-controlled, modified seawater mechanism at the Ad-Dubaybah location. At Ad-Dubaybah, seawater was modified through interaction with the immature basal sandstone aquifer, the Al-Wajh Formation. The spatial distribution of the dolostone bodies formed at these two locations also supports the models proposed here: with the Wadi Waqb location exhibiting massive dolostone bodies, while the dolostone bodies in the Ad-Dubaybah location are mostly clustered along the slope and platform margin. Porosity is highest in the slope sediments due to the interplay between higher precursor porosity, the grain size of the original limestone and dolomitization. Ultimately, this study provides insights into the prediction of carbonate diagenesis in an active tectonic basin and the resultant porosity distribution of a pre-salt carbonate reservoir system.

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Towards a new understanding of the genesis of chalk: Diagenetic origin of micarbs confirmed by clumped isotope analysis

Sedimentology ◽

10.1111/sed.12802 ◽

2020 ◽

Cited By ~ 1

Author(s):

Mattia Tagliavento ◽

Cédric M. John ◽

Kresten Anderskouv ◽

Lars Stemmerik

Keyword(s):

Isotope Analysis ◽

Clumped Isotope

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Earliest Silurian faunal survival and recovery after the end Ordovician glaciation: evidence from the brachiopods

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s175569100807566x ◽

2007 ◽

Vol 98 (3-4) ◽

pp. 291-301 ◽

Cited By ~ 28

Author(s):

L. Robin M. Cocks ◽

Rong Jia-yu

Keyword(s):

Global Warming ◽

Recovery Rate ◽

Mass Extinction ◽

Ice Age ◽

Benthic Assemblages ◽

Ice Cap ◽

Extinction Event ◽

Mass Extinction Event ◽

Permian Mass Extinction ◽

Ecological Recovery

ABSTRACTEarliest Silurian (basal Llandovery) brachiopod faunas are surveyed and listed from around the globe, and divided between Lower Rhuddanian and Upper Rhuddanian occurrences. 60 genera are known from the Lower Rhuddanian within 20 superfamilies and there are 87 genera in 25 superfamilies in the Upper Rhuddanian. The 29 areas surveyed span the globe, both latitudinally and longitudinally. Only six superfamilies are Lazarus taxa which are known both from the Ordovician and Middle Llandovery (Aeronian) and later rocks but have not been recorded from the Rhuddanian. These are surprising results, since many previous studies have inferred that the Rhuddanian was a time of very sparse faunas. The global warming that followed the latest Ordovician (Hirnantian) ice age did not proceed quickly, with an ice-cap probably present through at least the Llandovery. There is a marked absence of Lower Rhuddanian bioherms even at low palaeolatitudes; however, the ecological recovery rate was far faster than that following the end-Permian mass extinction event. The partitioning of the Rhuddanian shelf faunas into well-defined benthic assemblages progressed slowly over the interval.

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