Mass Extinction Of Organisms Research Articles

The Influence of Gravity on the Frequency of Processes in Various Geospheres of the Earth. Biogenic and Abiogenic Pathways of Formation of HC Accumulations

Based on the results obtained in the study of the interaction of geological and biosphere processes, we found out that there is a close relationship between them. It was also found that the gravity of the bodies of the solar system on the Earth plays a significant role in the above relationship. The effect of gravity was demonstrated on the movement of lithosphere plates, on the processes in the atmosphere and hydrosphere, on related climatic cycles, and the biosphere processes, including "living" organisms' evolution and their mass extinctions. The periodicity of these processes due to gravity is shown. It is expressed in the alternation of short-term orogenic periods of the beginning of the processes with long-term geosynclinal periods of their development and completion. Both periods constitute the repetitive orogenic cycles. The relationship of the cycles with the evolution of photosynthesis, as well as with related Organic Matter (OM) accumulation in sediments after mass extinction of organisms, including OM transformation leading to the formation of Hydrocarbon (HC) accumulations, is shown. Biogenic processes accounting for the accumulation and transformation of organic matter in sediments constitute the biogenic pathway of the formation of hydrocarbon accumulations. It is shown that the influence of gravity extends to the processes in the inner geospheres, including the movement of magma in the asthenosphere under the lithosphere shell, to the movement of hydrogen gas coming from the Earth's core, combining with volatile compounds of elements present in magma, as well as to the rifting process. It is shown that rifting processes lead to the formation of gaseous HC accumulations and constitute a pathway called abiogenic. The obtained results shed light on the peculiarities of the formation of HC accumulations by biogenic and abiogenic pathways, allowing prediction of their chemical characteristics. This is essential when searching for oil and gas and planning exploration works.

A New View on the Global Redox-Cycle of Biosphere Carbon

The global carbon cycle model is presented as a natural self-regulating machine that provides renewable biomass synthesis during evolution. The machine consists of two parts, geological and biosphere. Between the parts, there is an interaction. The geological part is controlled by the movement of lithosphere plates, which is under the guidance of gravitational forces from celestial bodies acting on the Earth. The movement of the lithosphere plates is divided into a phase of a relatively quick movement, occurring in the tectonically active state of the Earth’s crust, named the orogenic period, and a phase of a relatively slow movement, occurring in the phase of the tectonically quiet state of the crust, named geosynclinal period. In the orogenic period, the energy of moving plates’ collisions is sufficient to initiate sulfate reduction, proceeding in the subduction zone. This is the reaction where sedimentary organic matter is oxidized. Resultant CO2 is injected into “atmosphere—hydrosphere” system of the Earth. Its concentration achieves maximal values, whereas oxygen concentration drops to a minimum since it reacts with the reduced sulfur forms that evolve in the thermochemical sulfate reduction and due to binding with reduced forms of metals, coming to the Earth’s surface with volcanic exhalations. Carbon dioxide initiates photosynthesis and the associated biosphere events. In the geosynclinal period, the sulfate reduction ceases, and CO2 does not enter the system anymore, though photosynthesis in the biosphere proceeds in the regime of CO2 pool depletion. Under such conditions, the surface temperature on the Earth decreases, ending with glaciations. The successive depletion of the CO2 pool results in a regular sequence of climatic changes on the Earth. The ratio of CO2/O2 is the key environmental parameter in the orogenic cycle providing climatic changes. They consistently vary from hot and anaerobic in the orogenic period to glacial and aerobic by the end of the geosynclinal period. The climatic changes provide biotic turnover. Especially abrupt changes accompany the transition to a new orogenic cycle, resulting in mass extinction of organisms and the entry of huge masses of biogenic material into the sediment. This provided the conditions for the formation of rocks rich in organic matter (“black shales”). It is shown that the suggested model is supported by numerous geological and paleontological data evidencing the orogenic cycles’ existence and their relationship with the evolution of photosynthesis.

Importance of carbon isotopic data of the Permian-Triassic boundary layers in the Verkhoyansk region for the global correlation of the basal Triassic layer

This paper is dedicated to a global correlation of marine Permian-Triassic boundary layers on the basis of partially published and original data on the δ13Corg and δ13Ccarb values of the Suol section (Setorym River, South Verkhoyansk region). The section consists of six carbon isotopic intervals, which are easily distinguishable in the carbon isotopic curves for a series of Permian-Triassic reference sections of Eurasia and Northern America, including paleontologically described sections of Central Iran, Kashmir, and Southern China. This suggests that the Permian-Triassic boundary in the Suol section is close to the carbon isotopic minimum of interval IV. In light of new data, we suggest considering the upper part of the Late Permian Changhsingian Stage and the lower substage of the Early Triassic Induan Stage of Siberia in the volumes of the rank Otoceras concavum zone and the Tompophiceras pascoei and Wordieoceras decipiens zones, respectively. The O. concavum zone of the Verkhoyansk region probably corresponds to the Late Changhsingian Hypophiceras triviale zone of Greenland. The carbon isotopic intervals II, III, IV, and V in the Permian-Triassic boundary layers of the Verkhoyansk region traced in a series of the reference sections of Eurasia correspond, most likely, to intensification of volcanic activity at the end of the Late Changhsingian and to the first massive eruptions of Siberian traps at the end of the Changhsingian and the beginning of the Induan Stages. New data indicate the possible survival of ammonoids of the Otoceratoidea superfamily at the species level after mass extinction of organisms at the end of the Permian.

Global correlation of basal Triassic layers in the light of the first carbon isotope data on the Permian-Triassic boundary in Northeast Asia

This paper is dedicated to the global correlation of the marine Permian-Triassic boundary layers based on some published and original data on the δ 13 Corg and δ 13 Ccarb values obtained for the section along the Suol Creek (Setorym River, southern Verkhoyansk region). The section includes six carbonisotope inter� vals readily distinguished in the corresponding curves obtained for several Permian and Triassic reference sec� tions in Eurasia and North America including palleontologically well substantiated sections of central Iran, Kashmir, and South China. This provides grounds for assuming the Permian-Triassic boundary's position in the Suol Creek section as being close to the carbonisoto pe minimum of Interval IV. In the light of new data, the upper part of the Upper Permian Changhsingian Stage in Siberia is proposed to correspond in range to the Otoceras concavum range zone, and the lower substage of the Lower Triassic Induan Stage, to the Tom� pophiceras pascoei and Wordieoceras decipiens zones. The Otoceras concavum Zone of the Verkhoyansk region in its new understanding is likely correlative with the upper Changhsingian Hypophiceras triviale Zone of Greenland. Carbonisotope intervals II, III, IV, and V defined in the Permian-Triassic boundary layers of the Verkhoyansk region, which are traceable in several reference sections of Eurasia and North America, evi� dently coincide with the period of some intensification of the volcanic activity in the initial late Changhsin� gian and with the first phases of extensive eruption of Siberian trappes in the terminal Changhsingian and ini� tial Induan ages. New data imply the probable survival of some ammonoid species from the superfamily Oto� ceratoidea after the mass extinction of organisms in the terminal Permian Epoch.

Evolution of manganese ore genesis in the earth’s geological history and the role of the biosphere

The formation of manganese rocks and ores occurred during the whole geological history of the Earth. Five metallogenic epochs (Early to Middle Proterozoic, Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, and Meso-Cenozoic) and 7 very important phases (Early, Middle, and Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, Late Mesozoic, and Meso-Cenozoic) can be distinguished. The phases of manganese ore genesis at many stratigraphic levels are closely related to the global climatic and tectonic reconstructions (the breakup of the continent of Gondwana and periods of glaciations and aridization) and biotic events (mass extinction of organisms). Based on carbon isotopic composition in manganese carbonates, participation of oxidized organic carbon is established.

Inquiring into indicators and origin of catastrophic events at stratigraphic boundaries

Since 1982, numerous indicators of catastrophic eventshave been observed at the main stratigraphic boundaries in China during the Phanerozoic, i.e. Precambrian-Cambrian, Permian-Triassic, Cretaceous-Tertiary as well as Ordovician-Silurian and Devonian-Carboniferous boundaries. These markers are boundary clay layer, microspherules, high Ir anomaly, mass extinction of organisms and impact of meteorite. We support the hypothesis of the extraterrestrial origin of catastrophic events and suggest that the events at different stratigraphic boundaries might be different in features and processes.