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2010, Geology
Geology
Climate changes caused by degassing of sediments during the emplacement of large igneous provinces2009 •
Eruption of the Siberian Traps large igneous province (LIP) is thought to have triggered the Permian-Triassic biological crisis, the largest of the Phanerozoic mass extinctions. Mercury concentration enrichments have been widely used as a proxy for volcanic inputs to sediments, especially for ancient LIP eruptions. However, detailed correlations of magmatic pulses with extinction events in the terrestrial and marine realms are not fully resolved. Here we use paired coronene (a six-ring polycyclic aromatic hydrocarbon, a high-temperature combustion proxy) and mercury spikes as a refined proxy for LIP emplacement. In records from stratigraphic sections in south China and Italy, we identify two sets of paired coronene-mercury spikes accompanied by land plant biomarker spikes, followed by a rapid decrease coinciding with terrestrial ecological disturbance and extinction of marine metazoans. Each short-term episode is likely caused by high-temperature combustion of sedimentary hydrocarbo...
Although many sources of atmospheric CO 2 have been estimated, the major sinks are poorly understood in a deep-time context. Here we combine plate reconstructions, the eruption ages and outlines of Large Igneous Provinces (LIPs), and the atmospheric CO 2 proxy record to investigate how their eruptions and weathering within the equatorial humid zone impacted global atmospheric CO 2 since 400 Ma. Wavelet analysis reveals significant correlations between the eruption of the Emeishan LIP (259 Ma), the Siberian Traps (251 Ma), the Central Atlantic Magmatic Province (201 Ma), the second pulse of the North Atlantic Igneous Province (55 Ma), the High Arctic LIP (130 Ma), and the Deccan Traps (65 Ma) and perturbations in atmospheric CO 2. Our analysis also reveals a clear relationship between the weathering of the Central Atlantic Magmatic Province (~200–100 Ma), the Deccan Traps (50–35 Ma), and the Afar Arabian LIP (30–0 Ma) and a significant atmospheric CO 2 drawdown. Our results illustrate the significant role of subaerial LIP emplacement and weathering in modulating atmospheric CO 2 and Earth's surface environments. Plain Language Summary Carbon dioxide in the atmosphere plays a significant role in regulating Earth's climate. There are many processes, which over geologic timescales add to or sequester CO 2 from the atmosphere, and in turn alter Earth's climate. Here we investigate processes involved in the eruption and weathering of Large Igneous Provinces (LIPs), massive nonexplosive volcanic eruption of basaltic lava and rock. During eruptions, LIPs contribute significant amounts of CO 2 to the atmosphere in very short periods of geologic time, and subsequently, when basalt is exposed to physical and chemical weathering, the process will draw CO 2 from the atmosphere. We consider both eruptions, and the subsequent latitudinal positions of the LIPs in the context of their weathering, which is most severe at low latitudes due to high tropical precipitation rates. We find that periods of elevated atmospheric CO 2 were related to the eruption of the Emeishan LIP and Siberian Traps (260—240 Ma), the Central Atlantic Magmatic Province (210—190 Ma), and the North Atlantic Igneous Province, High Arctic LIP, and the Deccan Traps (90—60 Ma) and those of lowered CO 2 to be related to weathering of the Central Atlantic Magmatic Province (~200–100 Ma), the Deccan Traps (as it drifted through low latitude regions ~50–35 Ma), and the Afar Arabian LIP (30–0 Ma). Our analysis reveals the significant role LIPs have played in modulating Earth's climate.
1999 •
Earth-Science Reviews
The volcanic response to deglaciation: Evidence from glaciated arcs and a reassessment of global eruption records2013 •
Earth and Planetary Science Letters
Volatile fluxes during flood basalt eruptions and potential effects on the global environment: A Deccan perspective2006 •
We examine the role that flood basalt eruptions may have played during times of mass extinction through the release of volcanic gases. Continental flood basalt provinces have formed by numerous eruptions over a short period of geologic time, characteristically a few million years. Within this period, a short-lived climactic phase that lasts about 1 Ma typically emplaces a large proportion of the lava volume. This phase consists of a series of huge eruptions, each yielding 103–104 km3 of magma. Each eruption lasted on the order of a decade or more, and built an immense pāhoehoe-dominated lava flow field by eruptive activity along fissures tens to hundreds of km long. High fire-fountains, emanating from vents along the fissures, at times sustained eruption columns that lofted gas and ash into the upper troposphere and lower stratosphere while the lava flows covered huge areas. The combination of large eruption magnitudes, maintained high effusion rates during eruptions, and the repeated nature of the characteristic, large-scale eruptive activity occurs in Earth history only during periods of flood basalt volcanism. Based on recent analogs and determination of volatile contents of ancient flood basalt lavas, we estimate that individual eruptions were capable of releasing 10,000 Tg of SO2, resulting in atmospheric loadings of 1000 Tg a− 1 during a sustained decade-long eruptive event. We apply this model of flood basalt volcanism to estimate the potential mass of CO2 and SO2 released during formation of the ∼ 65 Ma Deccan province. The Deccan lava-pile contains the record of hundreds of enormous pāhoehoe flow-fields erupted within a period of about 1 Ma. Consequently, atmospheric perturbations associated with SO2 emissions from just one of these long-lasting eruptions were likely to have been severe, and constantly augmented over a decade or longer. By contrast, the amounts of CO2 released would have been small compared with the mass already present in the atmosphere, and thus much more limited in effect. Individual eruptions were followed by hiatuses of hundreds to thousands of years during which the gas contributions to the atmosphere would be recycled. It is clear that the nature and potential atmospheric impact of a series of huge-volume, repeated, long-term degassing events requires further investigation in conjunction with appropriate climate models.
American Scientific Research Journal for Engineering, Technology, and Sciences
Household Water Conditions in Gombe: A Profile of Water Scarcity in Nassarawo, Palliative and Mitigation Measures2018 •
Computational Intelligence and Neuroscience
Asymmetric Variate Generation via a Parameterless Dual Neural Learning Algorithm2008 •
Journal of Parallel and Distributed Computing
Special issue on Communication Architectures for Scalable Systems2012 •
Necatibey Eğitim Fakültesi Elektronik Fen ve Matematik Eğitimi Dergisi
Türkiye’de Fen Bilgisi Ve Biyoloji Öğretmen Adaylarına Yönelik Yapılmış Evrim Eğitimi Araştırmalarının Tematik Analizi2020 •
2014 •
American Journal of Biochemistry and Biotechnology
Chemical Composition of Propolis from Different Regions in Java and their Cytotoxic Activity2009 •
História, Ciências, Saúde-Manguinhos
Covid-19 en el Perú: respuestas estatales y sociales