scholarly journals Intrusion Induced Global Warming Preceding Continental Flood Basalt Volcanism

2021 ◽  
Author(s):  
Xiaochuan Tian ◽  
W Buck
Keyword(s):  
Global Warming ◽  
Flood Basalt ◽  
Causal Link ◽  
Mass Extinctions ◽  
Flood Basalts ◽  
Continental Flood Basalt ◽  
Major Phase ◽  
Continental Flood Basalts ◽  
Temporal Correlations ◽  
Crustal Density

Abstract Temporal correlations between continental flood basalt eruptions and mass extinctions are well known 1. Massive carbon degassing from volcanism of Large Igneous Provinces can cause catastrophic global climatic and biotic perturbations 1–3. However, recent more accurate dating of the Deccan Traps 4 and Columbia River Basalts 5 challenges this causal link by showing that global warming preceded the major phase of flood basalts eruptions by several hundred thousand years. Here, we argue that major eruptions of continental flood basalts may require densification of the crust by intrusion of larger volumes of magma than are extruded. Simple models show that magma crystallization and release of CO2 from such intrusions could produce global warming before the main phase of flood basalt eruptions on the observed timescale. Being consistent with many geological, geophysical, geochemical and paleoclimate data, our model suggests that the evolving crustal density has a first order control on timing of the major phase of continental flood basalt volcanism while the preceding intrusion induced underground degassing of CO2 plays a significant role in controlling the Earth's climate and habitability.

Flood Basalts and Mass Extinctions

2019 ◽  
Vol 47 (1) ◽  
pp. 275-303 ◽  
Author(s):  
Matthew E. Clapham ◽  
Paul R. Renne
Keyword(s):  
Environmental Changes ◽  
Flood Basalt ◽  
Respiratory Physiology ◽  
Mass Extinctions ◽  
Flood Basalts ◽  
Volatile Release ◽  
Ocean Carbon ◽  
Biological Extinction ◽  
Extinction Events ◽  
Environmental Disruption

Flood basalts were Earth's largest volcanic episodes that, along with related intrusions, were often emplaced rapidly and coincided with environmental disruption: oceanic anoxic events, hyperthermals, and mass extinction events. Volatile emissions, both from magmatic degassing and vaporized from surrounding rock, triggered short-term cooling and longer-term warming, ocean acidification, and deoxygenation. The magnitude of biological extinction varied considerably, from small events affecting only select groups to the largest extinction of the Phanerozoic, with less-active organisms and those with less-developed respiratory physiology faring especially poorly. The disparate environmental and biological outcomes of different flood basalt events may at first order be explained by variations in the rate of volatile release modulated by longer trends in ocean carbon cycle buffering and the composition of marine ecosystems. Assessing volatile release, environmental change, and biological extinction at finer temporal resolution should be a top priority to refine ancient hyperthermals as analogs for anthropogenic climate change. ▪ Flood basalts, the largest volcanic events in Earth history, triggered dramatic environmental changes on land and in the oceans. ▪ Rapid volcanic carbon emissions led to ocean warming, acidification, and deoxygenation that often caused widespread animal extinctions. ▪ Animal physiology played a key role in survival during flood basalt extinctions, with reef builders such as corals being especially vulnerable. ▪ The rate and duration of volcanic carbon emission controlled the type of environmental disruption and the severity of biological extinction.

Late Jurassic continental flood basalt doleritic dykes in northwestern Cuba: remnants of the Gulf of Mexico opening

2008 ◽  
Vol 179 (5) ◽  
pp. 445-452 ◽  
Author(s):  
James Allibon ◽  
Henriette Lapierre ◽  
François Bussy ◽  
Marc Tardy ◽  
Esther M. Cruz Gàmez ◽  
...  
Keyword(s):  
South America ◽  
Gulf Of Mexico ◽  
Late Jurassic ◽  
Crustal Contamination ◽  
Flood Basalt ◽  
Upper Jurassic ◽  
Continental Flood Basalt ◽  
Continental Flood Basalts ◽  
Accreted Terranes ◽  
Eastern Cuba

Abstract Accreted terranes, comprising a wide variety of Late Jurassic and Early Cretaceous igneous and sedimentary rocks are an important feature of Cuban geology. Their characterization is helpful for understanding Caribbean paleo-geography. The Guaniguanico terrane (western Cuba) is formed by upper Jurassic platform sediments intruded by microgranular dolerite dykes. The geochemical characteristics of the dolerite whole rock samples and their minerals (augitic clinopyroxene, labradorite and andesine) are consistent with a tholeiitic affinity. Major and trace element concentrations as well as Nd, Sr and Pb isotopes show that these rocks also have a continental affinity. Sample chemistry indicates that these lavas are similar to a low Ti-P2O5 (LTi) variety of continental flood basalts (CFB) similar to the dolerites of Ferrar (Tasmania). They derived from mixing of a lithospheric mantle source and an asthenopheric component similar to E-MORB with minor markers of crustal contamination and sediment assimilation. However, the small quantity of Cuban magmatic rocks, similarly to Tasmania, Antarctica and Siberia differs from other volumetrically important CFB occurrences such as Parana and Deccan. These dolerites are dated as 165-150 Ma and were emplaced during the separation of the Yucatan block from South America. They could in fact be part of the Yucatan-South America margin through which the intrusive system was emplaced and which was later accreted to the Cretaceous arc of central Cuba and to the Palaeogene arc of eastern Cuba. These samples could therefore reflect the pre-rift stage between North and South America and the opening of the gulf of Mexico.

40Ar-39Ar geochronology of the Karoo flood basalts: tracking disturbance in the isotopic system.

2020 ◽  
Author(s):  
Clémentine Antoine ◽  
Richard Spikings ◽  
Danijela Miletic Doric ◽  
Julian S. Marsh ◽  
Urs Schaltegger
Keyword(s):  
Grain Size ◽  
High Precision ◽  
Environmental Changes ◽  
Age Determination ◽  
Geodynamic Setting ◽  
Mass Extinctions ◽  
Flood Basalts ◽  
Continental Flood Basalts ◽  
Isotopic System ◽  
Precision And Accuracy

<p>High precision dating of Large Igneous Provinces (LIP) is not only useful to understand their link to environmental changes and mass extinctions (Courtillot and Renne, 2003), but they also provide insights into the geodynamic setting in which they form (Encarnación et al., 1996). The Drakensberg continental flood basalts of South Africa and Lesotho are part of the Karoo LIP, which is presumably responsible for a phase of global climate change and disturbance of the oceanic ecosystems (the so-called Toarcian oceanic anoxic event T-OAE; Pálfy and Smith (2000)). However, the paucity of zircon or baddeleyite in most continental flood basalts renders is difficult to match the sub-permil age precision and accuracy that is typical for high-precision U/Pb CA-ID-TIMS age determination. Previous attempts to date the Karoo lavas using the <sup>40</sup>Ar-<sup>39</sup>Ar method failed to yield sufficient precision and accuracy for resolving the sequential stacking of the different basalt units. For example, <sup>40</sup>Ar-<sup>39</sup>Ar  analyses of carefully selected plagioclase separates yielded dates that are inverted relative to their stratigraphic position, with uncertainties that encompass the entire duration of volcanism in the area (Jourdan et al., 2007; Moulin et al., 2017). Here we test the hypothesis that previous, inconsistent <sup>40</sup>Ar-<sup>39</sup>Ar dates of plagioclase were a consequence of degassing of primary, metasomatic and alteration phases (mainly zeolites with subordinate sericite and carbonate) within single or multiple crystals. The lavas are mainly tholeiitic basalts that display two distinct sizes of plagioclase, which can be dated separately. Petrological characterization of these two size fractions shows that the larger plagioclase crystals (100-400 μm) are more altered and fractured than the smaller grains and are therefore more likely affected by post-crystallization disturbance of the Ar isotopic system. We present preliminary <sup>40</sup>Ar-<sup>39</sup>Ar data from i) untreated plagioclase that hosts visible alteration phases, ii) untreated plagioclase that is devoid of visible alteration phases (2 grain size aliquots), and iii) leached plagioclase that is devoid of visible alteration phases (2 grain size aliquots). The results of this study may enhance the effectiveness of the <sup>40</sup>Ar-<sup>39</sup>Ar dating technique to accurately constrain the crystallisation ages of altered mafic lavas, which form the majority of the exposed Karoo LIP flood basalts. Ar isotope data were collected using a multi-collector Argus VI mass spectrometer, and irradiated in an un-shielded reactor position to optimize the formation of <sup>38</sup>Ar from Cl to permit identification of different gas reservoirs in the sample through isochemical dating, based on Ca, K and Cl in-situ concentration (EPMA) and Ar isotopic ratios.</p>

Morphological types in the Deccan Volcanic Province, India: implications on emplacement dynamics of continental flood basalts

2021 ◽  
pp. SP518-2020-246
Author(s):  
Vivek S. Kale ◽  
Gauri Dole ◽  
Shilpa Patil Pillai ◽  
Poushali Chatterjee ◽  
Makarand Bodas
Keyword(s):  
Lava Flow ◽  
Flood Basalt ◽  
Deccan Volcanic Province ◽  
Flood Basalts ◽  
Volcanic Province ◽  
Continental Flood Basalts ◽  
Substrate Topography ◽  
History Of ◽  
Multiple Pulses ◽  
Stacking Patterns

AbstractWe review and compare morphologies from continental basaltic lavas, using examples from the Deccan Volcanic Province to compile their internal configurations, mutual associations and compare them. The mechanism of endogenous transfer of lava within an insulating (rapidly developed) crust provides an efficient mode of dispersal of the molten lava in flood basalts. The growth of the lava flow can be achieved by a single extrusion or by multiple pulses of endogenous emplacement that enable the lava to efficiently spread over large areas and thicken.We show that the morphology of a lobe manifests the response of the molten lava to several parameters (including volumetric rate of emplacement, substrate topography, viscosity, vapour loss, etc) that govern the dynamics and cooling history of basaltic lava after it starts to spread on the surface. The lateral transition from one morphology to another within lobes of a lava flow is a testimony to the interactive response of the lava dynamics and rheology to variation in the local systems in which they were emplaced. The morphologies do not evolve as rigid partitioned categories from ‘áā and pāhoehoe lava types’ but as parametric progression of interactive variations in the spreading and cooling lava.A hierarchical recognition of lobes, flows and flow fields and mapping of the morphology (and their lateral transition or continuity) combined with the stacking patterns provides the volcanological framework for a sound stratigraphic mapping of flood basalts. Such an architectural documentation of flood basalt provinces will lead to robust models of their eruptive histories.

scholarly journals U-Pb constraints on pulsed eruption of the Deccan Traps across the end-Cretaceous mass extinction

Science ◽  
2019 ◽  
Vol 363 (6429) ◽  
pp. 862-866 ◽  
Author(s):  
Blair Schoene ◽  
Michael P. Eddy ◽  
Kyle M. Samperton ◽  
C. Brenhin Keller ◽  
Gerta Keller ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Temporal Correlation ◽  
High Volume ◽  
Flood Basalt ◽  
Deccan Traps ◽  
Zircon Geochronology ◽  
Mass Extinctions ◽  
Continental Flood Basalt ◽  
Environmental Deterioration ◽  
Before And After

Temporal correlation between some continental flood basalt eruptions and mass extinctions has been proposed to indicate causality, with eruptive volatile release driving environmental degradation and extinction. We tested this model for the Deccan Traps flood basalt province, which, along with the Chicxulub bolide impact, is implicated in the Cretaceous-Paleogene (K-Pg) extinction approximately 66 million years ago. We estimated Deccan eruption rates with uranium-lead (U-Pb) zircon geochronology and resolved four high-volume eruptive periods. According to this model, maximum eruption rates occurred before and after the K-Pg extinction, with one such pulse initiating tens of thousands of years prior to both the bolide impact and extinction. These findings support extinction models that incorporate both catastrophic events as drivers of environmental deterioration associated with the K-Pg extinction and its aftermath.

Rapid changes from arid to humid conditions during the onset of the Paraná-Etendeka Igneous Provinces: Can volcanic gas emissions from Continental Flood Basalts affect the precipitation regime?

2021 ◽  
pp. SP520-2020-176
Author(s):  
V. G. P. Cruz ◽  
E. F. Lima ◽  
L. M. M. Rossetti ◽  
N. G. Pasqualon
Keyword(s):  
Flood Basalt ◽  
Surface Cooling ◽  
Precipitation Regime ◽  
Volcanic Gas ◽  
Flood Basalts ◽  
Content Type ◽  
Continental Flood Basalts ◽  
Igneous Province ◽  
Volcaniclastic Rocks ◽  
Supplementary Material

AbstractDespite the intriguing correlation between Continental Flood Basalts (CFB) provinces and environmental crises, little is known about how the local/regional sedimentary systems and environment respond to flood basalt volcanism. Active sedimentary systems, and their interaction with volcanism, provides an important rock record to understand palaeoenvironments in volcanic settings. The Paraná-Etendeka Igneous Province is a well-known example of a CFB emplaced on a dry desert environment, but evidence has also shown the existence of humid conditions during the volcanic episode. This work describes and interprets non-volcanic sedimentary and volcaniclastic rocks interbedded with Paraná-Etendeka Igneous Province lavas in southernmost Brazil to better understand palaeoenvironmental process and changes during the onset of volcanism. Non-volcanic sedimentary rocks record the existence of ephemeral sheet-like flows and ponds/lakes while volcaniclastic rocks documents hydromagmatic activity, supporting a change to more humid conditions. Stratigraphic constrains indicate that this change started with the onset of volcanism and affected the whole province. We suggest that SO2 degassing from Paraná-Etendeka province may have caused a net global surface cooling resulting in precipitation redistribution and a local increase in rainfall. This hypothesis may help explaining the cooling and increased humidity observed elsewhere to be closely related with the Paraná-Etendeka emplacement.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5505710

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