ABSTRACT In recent models of earth-system crises, the correlation between the major Phanerozoic mass extinctions and large igneous provinces has been well established. Specifically, pulsed massive exhalations of large amounts of volcanogenic CO 2 transformed Earth’s atmosphere, leading to an excessive greenhouse effect and global warming, combined with slowed oceanic circulation, oxygen deficiency, and seawater acidification. In a historical context, however, the path leading to this neocatastrophic doctrine, traced by way of ever-more-convincing proofs (in recent years, via mercury anomalies), was convoluted for many objective and notional-personal reasons. From the late eighteenth century to the revolutionary 1980s, the reception of this conceptual route in the English-language mainstream science was determined principally by the rise and fall of the orthodox nonprogressive (steady-state) paradigm of the Lyellian uniformitarian. The main cognitive steps, pioneered frequently in continental Europe, included such principal conclusions as: (1) volcanic eruptions are a natural process, consisting of heat being vented from a central incandescent core, itself a relic of an initial nebular state; (2) cataclysmic phenomena were far more intense in the geologic past, both in orogenic and nonorogenic time intervals, with a dominant nonactualistic style of fissure-type effusive activity in intraplate settings, recorded in vast trap-type basalt successions (= large igneous provinces); (3) volcanogenic gaseous emanations, dominated by carbon dioxide and water vapor, had a strong impact on the global climate in the geological past toward the global warmth mode; and (4) this “volcanic greenhouse” was deleteriously augmented by several forms of immanent stress feedback (resulting in anoxia, acidification, hypercapnia, acid rains, ultraviolet radiation, etc.). Overall, diverse global ecosystem interactions, combined with the updated large igneous province scenario, can elucidate all major destructive factors in the biosphere, such as regressive versus transgressive sea-level changes and cooling versus warming climatic responses. Notwithstanding the particularity of each major biodiversity crisis in the Phanerozoic, however, a greenhouse/icehouse volcanism-driven catastrophe is a well-confirmed key toward better understanding these biotic turnovers over a variety of time scales and feedbacks. The holistic volcanic “press-pulse” model involves the joint action of two different types of stress factors: long-lived (“press”) large igneous provinces and a variety of critically sudden (“pulse”) disturbances. Therefore, the killing effectiveness of volcanic cataclysm should be viewed not only by the large igneous province size but also by their host geology, magma plumbing system, and eruption dynamics, determining the magnitude and composition of disastrous thermogenic outgassing. In search of possible pulse signals, emphasis has recently been placed on large igneous province–related, volatile-rich, mafic-ultramafic intrusions (owing to the great fluid-bearing capacity of their magmas) and sill-type intrusions (resulting in the most-effective devolatilization of sedimentary rocks). A simultaneous burst of arc magmatism and coeval impact of arc-continent collisions (especially in tropical domain) on global weatherability are additional cumulative cataclysmic stimuli awaiting more rigorous numerical simulations.

Abstract The overlooked geological ideas of Hugo Kołłątaj (1750–1812), who was well known as a progressive Polish Enlightenment statesman and Catholic writer, are presented. Following the Kościuszko insurrection, he was imprisoned in Olomouc from 1795 to 1802. While there he wrote a great treatise (probably finished in 1807) on the natural setting of the prehistory of the people in Polish territories. More than half of his voluminous manuscript dealt with the history of the Earth. Unfortunately, this monumental work in three volumes was only published in Polish in 1842. This comprehensively heuristic discourse presents a truly intellectual apogee of ‘the Heroic Age of Geology’. Kołłątaj advocated a continuous, step-by-step investigation of natural processes in terms of their contemporary actions, and considered them extensively in reference to permanent physical laws in geological history, although essentially in connection to Noah’s Deluge. Kołłątaj clearly proposed the in-depth inductive actualistic analysis of geological processes, but combined it with some elements of the non-gradualistic model (spasmodic sedimentation), as key to the proper understanding of the Earth and the history of the biosphere and mankind. Consequently, he distinctly pioneered the commonly celebrated methodological uniformitarian approach, as proposed by Charles Lyell in the 1830s.

Various scenarios have been proposed to explain the Late Devonian mass extinction, foremost among which are bolide impact and sea-level fall. We hereby propose a gas hydrate-induced model based on detailed geochemical and sedimentological data. The period of enhanced organic carbon burial in Iran, in south China, and in subpolar Urals corresponds to a brief negative δ 13 C excursion of 3.5‰ at the Frasnian-Famennian (F-F) transition. Prior to this event, oceanic δ 13 C increased for a period of several million years. However, major perturbations of the carbon geochemical cycle, and corresponding sharp and strong negative spikes of δ 13 C, which require a large input of isotopic light carbon into the ocean, also characterize the boundary horizons. Oxygen isotope ratios show negative excursions of 1.7‰ in south China and 4.1‰ in subpolar Urals that parallel the negative excursions in δ 13 C values. Synchronous negative spikes of δ 18 O are likely to imply a rapid increase of ocean temperature. We propose that the F-F boundary event was ultimately caused by voluminous and abrupt release of methane from marine gas hydrate into the ocean and atmosphere to trigger rapid global warming. Assuming that the total amount of inorganic carbon of the Devonian ocean was 40,000 gigatons (Gt) and δ 13 C of gas hydrate methane was −80‰, only 2600 Gt carbon from the total amount of 10,000 Gt gas hydrate carbon could have changed the oceanic δ 13 C values from +1‰ to −3‰, the observed magnitude of the F-F boundary excursion. Therefore only ∼26% of the gas hydrate could have triggered the boundary events. Widespread rift-related, basaltic volcanism along eastern Laurussia and northern Gondwana during the middle Late Devonian is believed to have contributed greatly to the global warming surrounding the F-F boundary, which in turn would have triggered massive dissociation of methane hydrate, especially if paired with intensive igneous and tectonic activity and rapid sea-level fall.