Lithosphere Research Articles

Surficial serpentinite emplacements and their potential links with the mantle wedge in NW South America

Understanding the distribution and behavior of serpentinite bodies in subduction zones is crucial for unraveling the complex processes associated with subduction dynamics. This study presents a geophysical analysis of serpentinite bodies at west of the RSZ (Romeral Suture Zone) to investigate their occurrence patterns and potential implications for the subduction system. The results indicate that serpentinite bodies in the RSZ exhibit a distinct occurrence trend. They are primarily located in zones characterized by low anomalies of geothermal gradient, negative Bouguer anomalies, positive magnetic anomalies, and areas of intermediate depth seismicity (100-160 km). Notably, these bodies are predominantly distributed west of the active volcanic arc, coinciding with a region of reduced volcanism. The presence of some serpentinite bodies correlates with areas of low seismicity and high anomalies of the b-value parameter, suggesting a connection between the fracturing behavior of these rocks and seismic activity. Detailed profiles crossing the RSZ provide further insights into the characteristics of serpentinite bodies. High anomalies of b-values are observed in areas where serpentine slivers outcrop, indicating their association with ductile volumes. Seismicity patterns also support the presence of magmatic reservoirs at depths beyond 50 km, exhibiting a dominant ductile behavior. Moreover, the absence of volcanic activity signals on the surface inside the central area of the current volcanic arc corresponds to regions of minimal seismicity, suggesting the presence of either ductile rocks or highly resistant rocks beneath the critical stress threshold. These rocks may represent magmatic bodies that are potentially connected to volcanic manifestations at the surface. Geophysical evidence, including negative anomalies, reveals lateral and depth connections between serpentinite bodies in the RSZ. These anomalies are situated within the zone of influence of the RSZ and the Western Cordillera, suggesting their association with the ongoing subduction process. The spatial distribution of serpentinite bodies is influenced by the lithospheric structure, particularly the Caldas Tear, which leads to flatter, thicker, and continuous occurrences of serpentines north of the tear. Interpretations of geophysical anomalies are not conclusive in hypothesizing a possible lateral and depth connection between serpentinite bodies along the RSZ. These anomalies are also situated within a broad zone of influence between the RSZ and the Western Cordillera, suggesting their possible association with the current mantle wedge and conforming a pervasive structure in the continental lithospheric. This study proposes the presence of large serpentine layers with contrasting thicknesses at the north and south of the Caldas Tear and as extensions of the mantle wedge at the base of the continental crust. These layers may contribute to changes in plate buoyancy and provide an additional mechanism to explain the phenomenon of flat subduction. The findings highlight the importance of considering serpentinite bodies and their associated fracture regimes in understanding subduction dynamics, particularly in active subduction systems such as the RSZ. This research sheds light on the interplay between geophysical characteristics, such as b-values, a seismological parameter used to interpret seismicity rates and physical strength heterogeneity of the rocks during the earthquake cycle, and the presence of serpentinite bodies. It contributes to our understanding of subduction processes, providing valuable insights into the behavior of rocks within the subduction system and their implications for the evolution of the RSZ. Further studies integrating geological and geophysical data will enhance our knowledge of serpentinite dynamics and their role in subduction zones, ultimately improving our comprehension of plate tectonics and associated geological hazards.

General relativistic center-of-mass coordinates for composite quantum particles

Recent proposals suggested quantum clock interferometry for tests of the Einstein equivalence principle. However, atom interferometric models often include relativistic effects only in an fashion. Here, instead, we start from the multiparticle nature of quantum-delocalizable atoms in curved spacetime and generalize the special-relativistic center of mass (c.m.) and relative coordinates that have previously been studied for Minkowski spacetime to obtain the light-matter dynamics in curved spacetime. In particular, for a local Schwarzschild observer located at the surface of the Earth using Fermi-Walker coordinates, we find gravitational correction terms for the Poincaré symmetry generators and use them to derive general relativistic c.m. and relative coordinates. In these coordinates we obtain the Hamiltonian of a fully first-quantized two-particle atom interacting with the electromagnetic field in curved spacetime that naturally incorporates special and general relativistic effects. Published by the American Physical Society 2025

Analysis of Influencing Factors and Countermeasures for Experimental Determination of Soil Moisture Content Index

Due to early geological movements, the formation of rock layers near the surface of the Earth's crust varied. In the later stages, intact rock layers were repeatedly subjected to external forces, resulting in varying degrees of damage. Additionally, during physical and chemical weathering, the properties of soil and rock materials in different regions of the Earth's surface showed certain differences. Therefore, in civil engineering construction, it is necessary to test the performance indicators of soil and rock in different regions in order to provide reliable basis for civil engineering design and construction. As an important physical property index of geotechnical materials, the testing process of soil moisture content is prone to some human or instrument equipment problems, which can affect the reliability of moisture content index determination. In the teaching of soil mechanics physical and mechanical performance index experimental courses in various higher education institutions, it is necessary to guide students to take some technical measures in testing experiments, enhance the sense of responsibility and standardized operation of testing personnel, and by formulating experimental plans and guidance documents, while following the various operational requirements of geotechnical testing regulations, accurately judge the type of rock and soil, correctly collect experimental samples, standardize the use of instruments and equipment, carry out experiments step by step, accurately weigh, scientifically read, set reasonable drying times, and use multiple sets of data averages. For the testing of moisture content indicators of special soil types in some areas, specialized methods can be used for experimental operations to avoid human operation errors and minimize experimental errors, thereby achieving ideal and efficient soil mechanics experimental goals.

Coordinate Measurement Method of the Earth Station Based on the Two Spacecraft Use

Relevance. The existing methods of coordinate measurement, such as goniometric, goniometric-range-measuring, difference-range-measuring, total-range-measuring are well studied and optimized. However, the application of these methods is not always possible or advisable, which stimulates the development and study of new methods and their integration with the existing ones. The article presents the developed method of coordinate measurement of the earth station, based on the use of two spacecraft. The derivation of analytical relationships for calculating the coordinates of earth stations based on the values of mutual time delays and frequency shifts is shown. The specified time delays and frequency shifts are due to different distances and Doppler frequency shifts of the same implementations of radio signals on different radio paths.The main expressions for time delays and frequency shifts of radio signals of earth stations retransmitted by spacecraft are presented. A system of three independent equations is composed. The first equation is the difference-range equation, the second is the difference-radial-velocity equation, and the third is the equation of the Earth's reference ellipsoid. The result of solving the system of equations is the coordinates of the earth station.The study used the methods of modeling and mathematical analysis. When solving the second-order equation, the iterative Newton-Raphson method was used with the expansion of functions in Taylor series with an accuracy of up to the first derivatives.A particular example of calculation is given as an illustration of the developed method. The developed method of coordinate measurement is invariant to the type of orbits of spacecraft used to determine the coordinates of earth stations. Two spacecraft are given as an example: the first is in geostationary orbit, the second is in low orbit.The scientific novelty of the developed technical solution is the unambiguous one-time determination of the coordinates of earth stations located on the surface of the Earth's reference ellipsoid, based on the use of only two spacecraft. In this case, there is no need for synchronization with the radiation of radio signals of earth stations, which is a necessary condition for most existing methods of coordinate measurement. The practical significance of the proposed combined (difference-range and difference-Doppler) method of coordinate measurement of earth stations lies in the possibility of its application in existing and prospective radio monitoring complexes for assessing the coordinates of earth stations that illegally use the frequency-time resource of a spacecraft, as well as being sources of intentional or unintentional radio interference.

Origin and Evolution of Rhyolitic Intraplate Magmatism; a Case Study from the Peak Ranges Volcanics, Central Queensland, Australia

Abstract The Peak Ranges Volcanics represent one of the most extensive and compositionally diverse Cenozoic volcanic centres of eastern Australia, and hence can provide crucial insights into the evolution of continental intraplate magmatic systems. Trachytic to rhyolitic volcanic suites are well preserved as a series of eroded plugs, domes and lava flow stacks, and can be divided into three zones based on spatial and temporal associations, mineralogy and geochemistry. The Southern Volcanic Zone features peralkaline silicic volcanic rocks with highly-enriched incompatible element (e.g. REE, Zr, Nb, Ta) contents and isotopic compositions (ɛNdi ~ +3 to +4; 87Sr/86Sri ~ 0.704 to 0.7045) that overlap with the mafic volcanic rocks (ɛNdi ~ +3.5 to +6; 87Sr/86Sri ~ 0.703 to 0.7045) that dominate Peak Ranges. The Northern Volcanic Zone largely comprises peraluminous rhyolites, with relatively unradiogenic Nd isotope (ɛNdi ~ −1 to +1) and radiogenic 87Sr/86Sri (~ 0.7045 to 0.7065) compositions. The Central Volcanic Zone has chemical and isotopic affinities that are intermediate between the Northern and Southern Volcanic Zones. We interpret the rhyolites of the Northern Volcanic Zone (and most of the Central Volcanic Zone) to represent erupted products of highly-fractionated mantle-derived magmas that had experienced approximately 10 to 20% crustal assimilation at lower crustal depths. This magmatic evolution was favoured by an overall N-S compressional regime at this time (ca. 30 to 32 Ma). Subsequent relaxation of compressional stress by ca. 28 Ma allowed effective tapping of alkaline, mantle-derived magmas to upper crustal chambers, where they underwent extensive crystal fractionation, largely or completely free of crustal contamination, to produce the enriched peralkaline southern rhyolites. Despite the dominant mantle origin for Peak Ranges magmatism, our study highlights the major control that the physical state and structure of the overlying continental lithosphere has on the compositional evolution of silicic volcanic rocks, and in turn their potential to host critical metal mineralisation. Lithospheric geodynamics is, therefore, considered integral to understanding continental intraplate magma evolution.

A Network Beneath the Soil

A Network Beneath the Soil is a short fiction story that follows a young person who is struggling with their existence in a heteropatriarchal, colonial, racial capitalist society. They transform into part of the Amanita muscaria’s mycelium, a network of fungal threads that form a symbiotic relationship with the roots of plant organisms in the forest. The character is presented with a choice: to abandon their humanity and become fungi, or continue to exist as a human. A Network Beneath the Soil looks toward mycorrhizal fungi to express what we, as humans, might learn from the symbiotic relationships that occur below the surface of the Earth.

Spherulites as Recorders of Multi-batch Felsic Magma Transport and Time Scales: A Case Study from Southeast of China

Abstract Granite, formed by the consolidation of felsic magma, is widely exposed on the surface of the Earth’s continents. However, the physical processes behind the transport of felsic magma from the deep crust to the surface remain poorly understood. Recently, the fracture-dike transfer model has gained widespread acceptance as a comprehensive theory explaining the ascent, transport, and emplacement of felsic magma in the crustal magma plumbing. Observing the magma migration process has been challenging due to the hidden geological evidence. Currently, no geological feature accurately tracks the transport path, composition evolution, and time scale of magma during its ascent. In this paper, we report the discovery of numerous spherulites that developed in two spherulitic rhyolite porphyry dikes. Based on the petrographic and geochemical characteristics of spherulites, we established that the ascent and emplacement processes of the magma were caused by continuous supply from deep magma sources and repeated episodes of ascent. Finally, magma source depletion halted its ascent and stabilization of its location at a depth of about 3 km below the ancient surface. According to the growth rate of the spherulites when the magma resided in the magma chamber, we quantitatively calculated that the magma resided in the three magma chambers for a total residence time of about 90 days. These findings provide valuable insights into the accumulation, ascent, and emplacement of multiple batches of magma into large rock bodies. These insights advance the understanding of the felsic magma plumbing system and provide constrained quantitative data on the dynamics of magma migration in the subsurface magma plumbing systems of volcanoes. Natural spherulites usually occur in rhyolite and obsidian around volcanic institutions. The magma migration path recorded by spherulites in this case study and the established spherulite geochronological method should have general applicability to a larger range of volcanic rock areas with similar geological backgrounds.

The Water Scarcity and Its Impact on Environmental Displacement in Dhi-Qar Governorate

Dhi Qar Governorate has recently begun to suffer from the consequences of climate change, especially the water deficit, the effects of which have appeared clearly on the various aspects of life in maintaining the economic, social and even cultural levels, because water enters into the various details and details of human life on the surface of the Earth, and Iraq is one of Within the global system affected by climate change, especially water scarcity, the volume of water imported into Iraq decreased, recording (31.24 billion/m3) during the year 2021 after it was (49.67 billion/m3) in the year 2020, which led to forced migration. To move large numbers of the population from their areas to other new areas, especially from agricultural areas and marshland areas, and cities are one of the targeted areas for displacement, the Ministry of Immigration and Displacement in Iraq / Dhi Qar Branch recorded the displacement of (8,498 families) due to the crisis of desertification and drought, and this portends an environmental and humanitarian catastrophe for the people. Both the lack of a safe environment and sufficient sources of livelihood for the population results in a group of other problems associated with it, including the spread of diseases, epidemics, and tribal conflicts, as is happening now in the marshland areas, the conflict over environmental resources.

Lithospheric Thinning of the Northeastern Arabian Margin Revealed by Matrix‐Free Teleseismic Traveltime Tomography

AbstractThe obduction of the Tethys oceanic lithosphere is documented by the Semail ophiolite along the northeastern Arabian continental margin. Although the ophiolite is continuous and of similar age across the region, the eastern and western segments display distinct geological contrasts. To investigate the deep structural mechanisms underlying these surface variations, we applied teleseismic traveltime tomography using an advanced eikonal solver and a matrix‐free adjoint‐state approach on data from a dense seismic array. Our 3D upper mantle P‐wave model reveals a significant velocity contrast, with positive anomalies in the west and negative anomalies in the east, separated by a prominent fault zone. We propose that the continental lithosphere beneath northeastern Arabia underwent thinning during the Permian breakup of Pangaea. This pre‐obduction lithospheric segmentation likely influenced the subduction dynamics associated with the ophiolite obduction process. Additionally, early Cenozoic thermal activity may have further amplified lithospheric thinning, contributing to the observed structural variations.

The geology of the Shyok suture zone: evidence for Cretaceous extension of the southern Eurasian margin and Eocene India–Eurasia collision

This study discusses whether the Eurasian margin, before the onset of the India–Eurasia collision, was a Cordillera-style accretionary orogen or a more complex Japan–Mariana-style margin with extended back-arc basins and oceanic crust between the volcanic arc(s) and continental lithosphere. This distinction is critical to understanding the development of the India–Eurasia orogenic system because each of these scenarios has very different implications for the timing of the continental collision between India and Eurasia. We present new field mapping, U/Pb zircon dates and whole-rock geochemical results that constrain the tectonostratigraphic and structural development of the Shyok suture zone, which separates the Kohistan–Ladakh arc from the Karakoram terrane in northwestern India and Pakistan. Our results suggest that the Shyok suture comprises a Jurassic forearc ophiolite overlain by Eurasia-derived sedimentary strata interlayered with andesites, which accumulated throughout the Cretaceous in a back-arc basin that was under extension between 115 and 72 Myr ago. Closure of this back-arc basin post-dates the formation of the Indus suture zone between the Kohistan–Ladakh arc and India.

Waveform tomography of the Antarctic Plate

Summary We present a new seismic shear wave velocity model of the upper mantle of the Antarctic Plate region, AP2024. It includes the lithosphere and underlying mantle down to 660 km depth beneath both the continental and oceanic portions of the plate. To augment the limited seismic station coverage of Antarctica, we assemble very large regional and global data sets, comprising all publicly available broadband seismic data. The model is built using 785 thousand seismograms from over 27 thousand events and 8.7 thousand stations. It is constrained by both body and Rayleigh surface waves, ensuring the dense data sampling of the entire upper mantle depth range. The tomographic inversion is global but focused on the Antarctic Plate, with the data sampling maximised in the Southern Hemisphere, with elaborate automated and manual outlier analysis and removal performed on the regional data, and with the regularisation tuned for the region. The upper mantle of the Antarctic continent exhibits a bimodal nature. The sharp boundary along the Transantarctic Mountains separates the cratonic eastern from tectonic western Antarctica and shows a shear-velocity contrast of up to 17% at ∼100 km depth. The bimodal pattern is also seen in the oceanic part of the plate, with the older oceanic lithosphere beneath the Indian sector of the Southern Ocean showing higher shear velocities. The continental lithosphere in East Antarctica shows high velocity anomalies similar to those beneath stable cratons elsewhere around the world. It is laterally heterogeneous and exhibits significant thinning in the near-coastal parts of Dronning Maud Land and Wilkes Land. A low velocity channel is observed along the southern front of the West Antarctic Rift System and is probably related to Cenozoic rifting. High seismic velocity anomalies are detected beneath the Antarctic Peninsula and are likely to indicate fragments of the recently subducted Phoenix Plate Slab. Low velocity anomalies beneath Marie Byrd Land extend into the deep upper mantle and are consistent with a deep mantle upwelling feeding West Antarctica intraplate magmatism.

The Effect of Ozone Gas Change of Temperature Change Over Iraq

The ozone layer and the ozone gas it carries have become a global issue, and people in different countries of the world are concerned about it due to the dangers it entails and warns of due to its various effects on living organisms on the surface of the Earth, including humans, animals and plants. Given the effect of the ozone layer on temperature rates, which is considered one of the causes of climate change on planet Earth, it has become necessary to know the effect of ozone gas changes on temperature changes over Iraq by analyzing the relationship between ozone gas and temperature rates for selected cities, representing the regions of Iraq, namely Mosul, Kirkuk, Baghdad, Najaf, Wasit, Muthanna and finally Basra. For the period (1989-2022, it represents Iraq's northern, central, and southern regions.The study's objective is to determine the correlation between ozone gas concentrations and temperature rates for every month of the year. It has been discovered that there is a negative (inverse) relationship between ozone gas and temperature rates in all months. Higher temperatures are associated with lower ozone concentrations. Depending on the seasons of the year, the relationship also changed. Our observations indicate that the relationship is weak during most winter months, moderate during many spring and autumn months, and strong to very strong during most summer months.

The two-sided continental subduction of the Adria microplate (Mediterranean)

The recycling of the continental lithosphere back into the mantle significantly impacts the structure and dynamics of orogens, particularly in the central Mediterranean region. We demonstrate that variations in the rheological properties of the continental lithosphere, as revealed by high-resolution regional tomography, influence the style of continental subduction. We explain the geometry and evolution of the oppositely verging Apennines and Dinarides orogens, as given by contrasting subduction processes, such as underplating and continental delamination, affecting the same plate (the Adriatic microplate, or Adria). In the case of the Apennines, slab peel-back predominates during subduction, resulting in a steeply dipping slab. In contrast, the Dinarides experience flat subduction due to the underplating of continental material. These different mechanisms, influencing kinematics and surface processes, are governed by rheological heterogeneities and different buoyancies of the continental lithosphere.

A two-step geospace storm as a new tool of opportunity for experimentally estimating the threshold condition for the formation of a substorm current wedge

Abstract. In the study of coupling processes acting within the upper atmosphere, a major challenge remains in quantifying the transformation of energy. One of the energy pathways between the ionospheric heights and the magnetosphere is the diversion of the cross-tail electric current into the ionosphere through the current wedge. One of the most interesting observations made in this study shows that during one of the two steps of the two-step storm, part of the near-Earth cross-tail current closed itself via the ionosphere, to which it was linked by the substorm current wedge, and manifested itself in the magnetograms acquired at equatorial and high-latitude stations on the night side of the Earth. As result, the two-step character of this storm has allowed us to suggest that the Bz interplanetary magnetic field component threshold for the formation of the substorm current wedge lies within the −(22–30) nT interval. Consequently, this study suggests, for the first time, that the emergence of a current wedge during a two-step geospace storm may be quantified by a threshold value of the interplanetary magnetic field (IMF) Bz component utilizing observations made during a two-step geospace storm with ground-based magnetometers. The study, for the first time, convincingly attests to the two-step geospace storm to be the best possible solar–terrestrial event of opportunity for realizing a technique for estimating the IMF Bz component threshold for the formation of the substorm current wedge. These conclusions have been drawn from the examination of the latitudinal dependence of variations in the geomagnetic field on the surface of the Earth on the global scale during the severe two-step geomagnetic storm of 23–24 April 2023, a major two-step storm in solar cycle 25. The data available via the INTERMAGNET magnetometer network (https://imag-data.bgs.ac.uk/GIN_V1/GINForms2, last access: 19 December 2024) were chosen for two near-meridional chains of stations, one in the Western (eight stations) and the other in the Eastern (10 stations) Hemisphere, which were situated, for the first time, in such a way that one of them was in the night hemisphere during both of the two steps of the geomagnetic storm. Other features of this two-step storm include the following. In the Western Hemisphere, the fluctuations in the geomagnetic field strength on the days used as a quiet-time reference period usually did not exceed a few tens of nanoteslas (nT), whereas in the course of the disturbed days, the variations in the geomagnetic field strength increased by a factor of 2 to 10 and reached a few hundred nanoteslas. In the Eastern Hemisphere during quiet times, the middle- and low-latitude magnetometer stations generally recorded strength fluctuations smaller than 10–20 nT, while during the disturbed period, the fluctuations increased by a factor of 2–5 and greater, attaining ± (50–70) nT. The strength fluctuations showed a considerable increase of up to 300–700 nT at high latitudes. The northward component of the geomagnetic field, X, exhibited the greatest perturbations at all latitudes in both hemispheres as the level of strength fluctuations decreased with decreasing latitude. The geomagnetic field strength fluctuations recorded at the magnetometer stations nearly equidistant from the Equator were observed to be close in magnitude. The strength fluctuations observed with the stations at close latitudes but in different hemispheres were also close in value.

Obligations across time and membership: some implications of Jakob Huber’s retrieval of Kant’s grounded cosmopolitanism

ABSTRACT Jakob Huber’s brilliant new reading of Kant’s Doctrine of Right begins with a simple Kantian observation: human beings sharing the surface of the earth cannot avoid interacting with one another. Using this observation to frame Kant’s mature political thought, Huber illuminates Kant’s ‘grounded cosmopolitanism’, distinguishing it from earlier readings and vindicating a ‘global standpoint’ that recognizes everyone’s ‘right to be somewhere’ while obliging us to seek ‘mutually justifiable terms of co-existence’. In this essay, I survey Huber’s account and suggest some extensions to it. Limits to the application of the idea of shared earth dwellership, especially across time and between different modes of political organization, are in tension with the revolutionary implications of the Kantian notion that we are always engaged with everyone across the surface of the planet. I argue that the distinction between state and non-state peoples is used here in a way that Kant’s own argument for the ideal of universal right relation pushes against, and I argue that this account of the ideal of universal right relation points towards something even more basic than concurrent earth dwellership: shared earth dwellership across time.

Unique C‐Ring Methylated Hopene Biomarkers in a Paleocene Lake

AbstractHopanoids are bacterial lipids that are ubiquitous on the surface of the Earth and in the sedimentary record. Hopanoids with an extra methyl group located in the A‐ring (at the C‐2 or C‐3 position) of the carbon skeleton are well known and these 2‐ or 3‐methylhopanoids have been used to infer specific biogeochemical or environmental conditions in the geological past, including the Paleogene. However, hopanoids with additional methylations outside the A‐ring and/or more than one additional methylation in their pentacyclic ring system are rare. This paper reports the occurrence of hop‐17(21)‐enes methylated in the C‐ring (tentatively assigned to the C‐12 position) and dimethylated hop‐17(21)‐enes with methylations at both C‐3 (A‐ring) and C‐12 (C‐ring) in sediments from the Boltysh Core, Ukraine, that represents an early Paleocene (∼65 Myr) lake system. These (di)methyl hop‐17(21)‐enes are 1–2 orders of magnitude more abundant compared to regular hopanes in some samples. The occurrence of these unique hopanoids suggests abnormal environmental conditions during their deposition, likely attributable to volatile ecosystems in the aftermath of the Cretaceous ‐ Paleogene boundary extinction and/or the environmental stressors associated with the lower C29n hyperthermal (65.3 Myr) that is recorded in this section.

Multiscale inhomogeneities on the surface of the Earth's inner core

The analysis of differential travel-time residuals of reflected PcP and PKiKP waves that probe the core regions under Eurasia, Southeast Asia, and South America indicates a mosaic picture of the surface properties of the inner core, including large-scale and small-scale lateral inhomogeneities. A strong anomaly has been discovered under the Caspian Sea.

Assessment of radon level and the associated radiological risk from soil samples of quarry area at Hakim Gara, Ethiopia.

Excavation of terrestrial surface of the Earth could enhance the chance of exposure to radon while gases in the underground get access to escape. This study was aimed to assess the level of radon concentration from soil samples of quarrying sites at Hakim Gara in Ethiopia using CR-39 detectors in sealed container technique. The results of the measured radon concentration level were ranging from 164.3 to 494.0Bq/m3 with average value of 295.7 ± 87.09Bq.m-3. The activity concentration value of radium ranging from 0.63 to 2.74Bq.kg-1 with average value of 1.59 ± 0.55Bq.kg-1. The radon surface exhalation rate ranging between 0.95 to 4.1 Bqm-2h-1 with mean value of 2.38 ± 0.83 Bqm-2h-1. The mass exhalation rate ranging between 0.01 and 0.11 Bqkg-1h-1 with average 0.06 ± 0.03 Bqkg-1h-1. The AED and ELCR values for the study area were calculated and the mean value of the quarry area were determined on the basis of altitude variation and foundto be different for individual and group sample locations. Compared to values recommended by WHO for outdoor radon exposure, the measured levels of radon concentration were observedto be higher in the study area. But residential areas under construction in the area need further studies since the measured and calculated values were high for indoors in some soil samples.

Chemical thermodynamics of fluoride-ammonium processing of ash and slag technogenic waste

Relevance. The need to replace the import of alumina in the aluminum industry with its production from domestic raw materials for solving the problem of raw material safety, and accumulation of a large amount of ash and slag technogenic waste of thermal power plants. On the one hand, they violate the environmental situation, and, on the other hand, are a kind of minerals located on the surface of the Earth and, therefore, are not required the cost of their extraction from the bowels of the earth. Aim. To study chemical thermodynamics of reactions of ammonium fluoride processing of technogenic ash and slag raw materials in order to optimize the technological process using a program for preliminary calculations of thermodynamics of chemical reactions. Methods. Theoretical analysis, computer calculation, experimental research using chemical, X-ray phase, emission and absorption spectral and of other types of analysis. Results and conclusions. The authors have studied chemical thermodynamics of ammonium fluoride technology for processing ash and slag man-made waste from thermal power plants of the Amur region. They obtained various useful products: nanoscale amorphous silica, alumina grades G0 and G1, red iron oxide pigment Fe2O3, concentrate (Ca, Y)F2 enriched with rare earth and refractory elements, noble metals and other useful components. For preliminary calculations of thermodynamics of chemical reactions, the authors applied a vb program with thermodynamic potentials and their derivatives of more than 300 chemicals database, which they created on the basis of a text file. The program allowed calculating the changes of enthalpy, Gibbs potential, equilibrium constants, as well as errors of calculations of Gibbs potential and enthalpy changes.

Searching for dark torsion signatures at LIGO in Nieh–Yan teleparallel chiral gravitational waves and Chern–Simons invariants

Romano has recently found that frequency modulation of gravitational waves (GWs) could be used as a dark matter probe. Many candidates for dark matter (DM) of various sources have been proposed in the literature. In this work, we use a teleparallel modified GW model to obtain DM dark torsion from LIGO data, where frequency modulation and frequency bands from various sources of GWs are investigated with regard to their suitability for DM dark torsion detection. In particular, nonhomogeneous and nonuniform chiral chemical potential generates GWs and dark torsion from primordial magnetic fields. It is shown that pulsar sources for GWs bathing the surface of the Earth on a contortion background of 10-15s-1 possess amplitudes well within the parameters of LIGO capabilities of amplitudes on the order of 10-22. GWs are also investigated in the context of having been produced by a primordial magnetic field and inhomogeneity on the chiral chemical potential. The torsion signatures at LIGO correspond to the amplitude dependence of massive torsion by GWs.