Fault slip analysis in the Koralm Massif (Eastern Alps) and consequences for the final uplift of “cold spots” in Miocene times

The Paleogene and Neogene evolution of Austroalpine basement units east of the Tauern Window is characterised by the formation of two major sets of faults: (1) ESE–WNW- to E–W-trending faults, associated with ENE- and NNW-trending conjugate structures and (2) N–S to NNE-SSW striking structures, mainly acting as high-angle normal faults, often associated with E-dipping low-angle normal faults along the western margin of the Styrian Basin.Together with the stratigraphic evolution of the Styrian and Lavanttal Basins and the related subsidence histories a tectonic evolution may be reconstructed for this part of the Eastern Alps. In the southern part of the Koralm Massif, WNW-trending fractures were activated as dextral strike-slip faults, associated with the evolution of WNW-trending troughs filled up with coarse block debris. W- to WNW-trending fractures were reactivated as normal faults, indicating N–S extension. It is assumed that these phases resulted in subsidence and block debris sedimentation in Karpatian and Badenian times (ca. 17–13 Ma).In the Western Styrian Basin no Sarmatian (13–11.5 Ma) sediments are observed; Pannonian (11.5 to 7.1 Ma) sediments are restricted to the Eastern Styrian Basin. This indicates, that the Koralm basement and the Western Styrian Basin were affected by post-Sarmatian uplift, coinciding with a re-activation of N-trending normal faults along the eastern margin of the Koralm Massif. Therefore, we suggest that the final uplift of the Koralm Complex, partly together with the Western Styrian Basin, occurred during the early Pannonian (at approximately 10 Ma). The elevation of clastic deposits indicates that the Koralm Complex was elevated by approximately 800 m during this phase, associated with an additional phase of E–W-directed extension accommodated by N–S striking normal faults.     

Fabric analysis of quartzites with negative magnetic susceptibility – Does AMS provide information of SPO or CPO of quartz?

We ask the question whether petrofabric data from anisotropy of magnetic susceptibility (AMS) analysis of deformed quartzites gives information about shape preferred orientation (SPO) or crystallographic preferred orientation (CPO) of quartz. Since quartz is diamagnetic and has a negative magnetic susceptibility, 11 samples of nearly pure quartzites with a negative magnetic susceptibility were chosen for this study. After performing AMS analysis, electron backscatter diffraction (EBSD) analysis was done in thin sections prepared parallel to the K₁K₃ plane of the AMS ellipsoid. Results show that in all the samples quartz SPO is sub-parallel to the orientation of the magnetic foliation. However, in most samples no clear correspondance is observed between quartz CPO and K₁ (magnetic lineation) direction. This is contrary to the parallelism observed between K₁ direction and orientation of quartz c-axis in the case of undeformed single quartz crystal. Pole figures of quartz indicate that quartz c-axis tends to be parallel to K₁ direction only in the case where intracrystalline deformation of quartz is accommodated by prism <c> slip. It is therefore established that AMS investigation of quartz from deformed rocks gives information of SPO. Thus, it is concluded that petrofabric information of quartzite obtained from AMS is a manifestation of its shape anisotropy and not crystallographic preferred orientation.     

Extraction of the anomaly magnetic field of the earth from stratospheric balloon magnetic surveys at altitudes of 20–40 km

The solution to the problem of extraction of the anomaly Earth’s magnetic field (EMF) from stratospheric balloon magnetic surveys with the help of global analytical models of the normal EMF is proposed. In the problem solution, errors for the analytical models of the normal EMF and its secular variation at a set moment of time are assessed; the found error is introduced as a correction to the extracted anomaly EMF. The error of the model is determined in the places where significant magnetic anomalies are absent. In this case, the error of the model corresponds to deviations of the normal EMF components, synthesized by coefficients of analytical models, and to deviations of the EMF secular variations from the measured values at quite a low value of the variable EMF or one being taken into account. These places are determined when carrying out additional measurements in vertical gradients of the EMF with the use of scalar magnetometers at the gauge length of 6 km. It has been shown that the found places can be considered as nonanomaly, if the difference of values of the anomaly EMF at the gauge length of 6 km does not exceed 1.5 nT within the profile’s portion of about 100 km in length. An experiment in nature has revealed that errors for the IGRF-2005 and IGRF-2010 models, corrected for secular variation of the EMF, can reach 200 and 140 nT, respectively, within the limits of the territory where the Kama-Emba magnetic anomaly is located; these errors are determined by the considered causes. Comparison of aerostatic profiles of magnetic anomalies with data on the anomaly EMF, derived from the maps, has shown that the realizations derived from the maps contain overestimated negative values of the anomaly EMF, because they reflect processes in the near-surface layer of the Earth’s crust. This fact causes the situation when attempts to recalculate the anomaly EMF into the upper half-space by the near-surface data still have not been successful. Only realizations derived at the altitudes comparable to the thickness of the Earth’s crust can give an adequate model of the anomaly EMF in the circumterrestrial space and enable us to recalculate magnetic anomalies reliably into any altitude levels.     

Ligand field analysis of the magnetic susceptibilities and Mössbauer spectra of ilvaite,a mixed valence iron mineral

The thermal characteristics of magnetic susceptibilities and their anisotropies of single crystal of ilvaite, a mixed valence iron sorosilicate, have been analysed in the light of Ligand Field (LF) theory using a minimum number of approximations. The electronic energy pattern and the corresponding wavefunctions were obtained from best fitting of these experimental results with the corresponding theoretical values. These results were next used to calculate the thermal characteristic of the quadrupole splitting E _Q in ilvaite. It was found that the values of E _Q are reasonably close to those reported from Mössbauer studies. The present analysis suggest appreciable molecular overlap between the orbits of the ligand electrons and those of the Fe²⁺ atoms, the overlap being prominent along the chain direction as also observed from electrical conductivity measurements.     

A new “slime star” (Echinodermata,Asteroidea, Velatida) from the Upper Cretaceous Chalk of the United Kingdom

New material of pterasterid asteroids from the UK chalk is described on the basis of ossicles recovered from washed residues. A new species, Pteraster lyddenensis sp. nov., is erected for oral and adambulacral ossicles and a primary radial ossicle from the Cenomanian Grey Chalk Subgroup of Dover (Kent), and the first UK record of Pteraster kutscheri Gale, 2022 is described from the upper Campanian Chalk of Norwich (Norfolk); both taxa belong to extant groups of Pteraster. Pteraster lyddenensis sp. nov. is the oldest known representative of the genus. The benthic invertebrate fauna of the Cretaceous chalk facies includes a number of extant genera which at the present day dwell in the deep sea. However, their presence was probably due to the low-productivity oceanic palaeoenvironment of the Chalk Sea, simulating deep-ocean conditions, rather than its depth.     

Knowledge, power, and tribal mapping: a critical analysis of the “return of the Truku people”

Over the past decade, Indigenous peoples in Taiwan have shown a strong desire for the ??return of the Native??; this includes the Truku people in eastern Taiwan. Seizing a favorable climate of political opportunity structure in 2004, the Truku people first succeeded in obtaining the Taiwanese government??s recognition as an independent Indigenous nation??formerly considered a subgroup of the Atayal Nation. Then, riding on accumulated political resources, a few Truku elites started to engage in a government-initiated tribal mapping project. However, while tribal mapping originated in some North American Indigenous communities with a bottom-up process and spirit, the Taiwanese government sent both money (through the municipal government) and an academic expert team into the community to initiate and to assist (the elite group) with the tribal mapping project. These top-down government initiatives resulted in at least two major ill effects. First of all, two other subgroups of the Atayal Nation living in the same region were systematically excluded from the tribal mapping project, to the extent that their own traditional territories became part of the traditional territory of the newly formed Truku Nation. Secondly, possibly expecting a high political payoff on the part of elites, elite competition arose during the process of tribal mapping, with the interests of other community members largely ignored. As such, instead of establishing a decolonizing force, the ??return of the Truku?? appears to have achieved ??colonialism from within.?? This paper analyzes this process and considers ways to develop a more democratic strategy for the ??return of the Truku.??     

Stability of the multiple star system ι UMa (ADS 7114)

The physical and orbital parameters of the quadruple star system ι UMa (HD 76644 = ADS 7114) were determined earlier, when it was concluded based on modeling the system’s dynamics and applying theoretical stability criteria that the system was probably unstable. Here the stability of the ι UMa system is studied by calculating the Lyapunov characteristic exponents for representative sets of parameters and initial conditions. The conclusions on the system’s stability (or instability) based on various stability criteria and the calculated Lyapunov exponents are compared. The instability of the system as a whole is confirmed rigorously based on massive computations of the Lyapunov exponents. This system appears to be the only known multiple system whose instability has been rigorously established. The Lyapunov time-disruption time statistical relations are constructed, which show that the Hamiltonian intermittency of the second kind dominates. Typical disruption times are shorter than 1000 years, and the Lyapunov times are shorter than 100 years.     

Quantitative Evaluation of the Sea-level Drop at the End-Permian: Based on Reefs

The amplitude of pre-Quaternary sea level drop, H, can be calculated by using the formula H = D + To, where To is the original thickness from the top of the tidal deposits on the reef core to the bottom of the tidal deposits on the reef front, or to the bottom of the ancient meteoric vadose zone, or to the edge of the mixed-water dolostone zone. The identity and similarity between the sea-level drop amplitudes calculated from different reefs far away from each other indicates that such sea-level changes are eustatic rather than relative changes. Evidence of an end-Permian sea-level drop has been found on the Changxingian (i.e. the end of the Palaeofusulina zone) reefs at Ziyun in South China, including algal laminated deposits, sabkha-related dolostone, desiccation cracks, dissolution collapse breccia. According to calculation based on the meteoric dissolution zone of the reef-core sequence at Ziyun, Guizhou province, the amplitude of the sea-level drop at the end-Permian is about 89.3 m. Calculation vi     

Rotational–translational mechanism for the upper bound stability analysis of slopes with weak interlayer

The presence of a weak interlayer has usually an adverse effect on the slope stability. However, the rotational failure mechanism in the conventional upper bound limit analysis cannot rationally describe the sliding of the failure mass along the weak interlayer. Therefore, a new failure mechanism was proposed in this study to evaluate the stability of slopes with weak interlayers using the upper bound limit analysis and the associated factor of safety was determined by the shear strength reduction technique. The new failure mechanism is comprised of rigid blocks undergoing rotational or translational movements, instead of the rotational movement in the conventional failure mechanism. It has also been extended to the stability analysis of slopes in presence of stabilizing piles and pore water pressures. Case studies were carried out on actual slopes with weak interlayers. The proposed rotational–translational failure mechanism was verified by the shear strength reduction finite element method (SSRFEM). Comparisons demonstrate the reliability of limit analysis method with the proposed rotational–translational failure mechanism for slopes with weak interlayers and therefore it can be used as a simple evaluation method for the engineering design.     

An experimental calibration of the “Nickel in Garnet” geothermometer with applications

The partitioning of Ni between olivine and garnet in two multi-component compositions was studied as a function of temperature and pressure in a 6–8 type multi-anvil apparatus. Weighted least squares regression of the experimental results for both compositions give a temperature dependence for Ni partitioning between olivine (Ol) and garnet (Gt) of the form: T=–10210(±114)/[lnD _Gt/Ol ^Ni –3.59(±67)] where DGt/Ol/Ni=Ni content of Gt/Ni content of olivine (by weight) and Tis in Kelvin. The pressure effect on Ni exchange between olivine and garnet is estimated to be 0.13 J/bar, and should therefore have a negligible effect on the geothermometer, as is demonstrated in the experiments. The experimentally derived Ni in Gt geothermometer is in agreement with an extant empirical version between 1100 to 900°C, but the two thermometers produce significantly different results outside of this temperature range.     

The Nature of the “Voice of the Sea”

Strong vibrations of the Earth’s crust in the frequency range of 7–9 Hz, referred to as the “voice of the sea,” have been recorded in the course of processing synchronous experimental data obtained during recording of variations in the deformation of the Earth’s crust using a shore laser strainmeter, atmosphere pressure variations using a laser nanobarograph, and hydrosphere pressure variations using a laser meter for hydrospheric pressure and wind velocity variations. The nature of these vibrations and their transformation to adjacent geospheres have been discussed.     

IR photometry of the symbiotic star BF Cyg: Detection of the red giant’s ellipsoidal brightness variability

We present the results of our IR photometric observations of the classical symbiotic star BF Cyg acquired in 1978–2003. The variability range in the J and K bands was ～0.2^m. A periodic component in the cool star’s brightness variations is clearly visible, its period being half the orbital one and its J amplitude being ～0.15^m. This component is associated with the ellipsoidal shape of the red giant, which model calculations show fills its Roche lobe. This is required in order to reproduce ellipsoidal brightness variability with such a large amplitude: the calculated amplitude for a red giant filling 90% of its Roche lobe is half the observed value. At the same time, it was not possible to confidently chose the optimum component-mass ratio, q = M _giant /M_hot, and orbital inclination, i, from possible values in the ranges q = 2–4, i = 70°–90°. Including the contribution from the hot radiation sources (the hot component and ionized envelope), which vary with a period equal to the orbital period, has a considerable influence on the estimated parameters associated with the red giant’s ellipsoidal brightness variations, and this contribution cannot be neglected. The deviations of the observed from the calculated light curve are irregular, with the rms deviation being σ(O-C) ≈ 0.04^m.     

A pre-outburst of the classical symbiotic star BF Cyg in 1987–1989

We analyze previously unpublished spectrophotometric data for the classical symbiotic star BF Cyg obtained in 1982–1989. These data show that BF Cyg already started a new period of activity in 1987–1989, earlier believed to correspond to quiescence. An optical spectrum taken on September 29, 1987 displays several features characteristic of activity in classical symbiotic stars. During the same time interval, excess near-UV radiation was detected, possibly from the accretion disk, and evidence for Rayleigh scattering of the hot component’s radiation on atomic hydrogen was detected in the far-UV, at phases previously believed not to be characteristic of this effect. This latter finding may testify to an enhanced (compared to 1979–1986) rate of mass loss from the cool component of BF Cyg. We discuss the interrelation between an increased mass-loss rate of the cool component and the hot component’s activity in the context of classical symbiotic stars. Original Russian Text ￠ A.A. Tatarnikova, E.A. Kolotilov, A.M. Tatarnikov, 2008, published in Astronomicheskiĭ Zhurnal, 2008, Vol. 85, No. 2, pp. 151–162.     

On the mechanism of the generation of seismic “nails”

The spatial and temporal peculiarities of seismic “nails” are analyzed. Some nails are related to strong earthquakes, or volcanic eruptions, while some do not show any coincidence with any fault zone or other tectonic structures. In some cases, poorly expressed trends in the depths of earthquake occurrence sequences occur. Based on the calculation of the Hurst exponent, a stable tendency in the order sequence for the depths of hypocenters that form a nail has been revealed. This tendency is consistent with self-organization models, which demonstrate positive feedback during interactions between fluid flows and tectonic deformations and have been used to explain the earthquake generation mechanism. The peculiarities of changes in earthquake numbers on the day when a nail is formed agree well with the acoustical emission dynamics during earthquake triggering through water injections, based on the long-term experimental data. The most probable mechanism that generates the seismic nails that are not related to strong earthquakes is seismic activation under the effects of fluids.     

Combining multiple correspondence analysis with factorial kriging analysis for geochemical mapping of the gold–silver deposit at Marrancos (Portugal)

This study concerns the application of multiple correspondence analysis and factorial kriging analysis to soil data, and aims to identify spatial patterns and superficial soil anomalies of the Au and Ag deposit at Marrancos, Vila Verde. The mineral deposit can be described as a quartz auriferous shear-zone, consisting of a quartz breccia of tectonic origin hosted by metamorphic rocks (hornfels). Gold is associated with arsenopyrite and pyrite, and Ag with galena and galenobismuthite. A total of 286 soil samples were analysed for Fe, Cu, Zn, Pb, Co, Ni, Mn, Ag and Bi by atomic absorption spectrometry, As, Se, Te and Sb by atomic absorption spectrometry–hydride generation system and Au by inductively coupled plasma–atomic emission spectroscopy after extraction of the metal by an organic solvent (methyl-isobutylketone). The methodology used included (a) multiple correspondence analysis applied to soil data to obtain some factors that summarize geochemical information, (b) a structural analysis (variography) in order to account for spatial variability of these factors, and (c) factorial kriging analysis used to split these factors into their spatial components. This methodology allowed an efficient multi-element characterization of the spatial patterns as well as the identification and interpretation of significant anomalies, not always associated to Au-bearing geological structures.     

On the use of unmanned aerial vehicles for high-precision measurements of the Earth’s magnetic field

A brief account of the evolution of Russian airborne geomagnetics is given. It is shown that the development of aeromagnetic systems based on unmanned aerial vehicles (UAVs) is of great interest. This paper presents theoretical and experimental data that concern the development of the optimal UAV layout in order to create a UAV-based aeromagnetic survey system using a new-generation optically pumped quantum rubidium aeromagnetometer. The new UAV-based aeromagnetic system is planned for use for high-precision aeromagnetic surveying at low altitude (30 m and more) for geological, engineering, and environmental applications.     

Lyα Flux Impact from the Parent Star on Hα Absorption in the Atmospheres of the Hot Jupiters HD189733b and HD 209458b

Astronomy Reports - Simulation results are presented for the Lyα flux impact from the parent star on the Hα absorption spectrum in the atmospheres of the hot Jupiters HD189733b and HD...     

The application of chromatographic gas ratio analysis in reservoir fluid evaluation of “Beta” field in the Congo basin

This study assessed the hydrocarbon generation potentials/timing of the Awgu source rock horizons encountered in Igbariam-1, Iji-1 and Ajire-1 wells drilled in the southern Benue Trough; using one-dimensional (1D) Genesis Zetaware basin modelling software. This software enabled the integration of burial and thermal influences on Awgu source rocks with kinetic parameters. Thermal and burial history models indicate that the Awgu source horizons encountered at 3249m in Igbariam-1 well (northern part of the basin), expelled 85mg/gtoc of oil and 12 mg/gtoc of gas and hydrocarbon generation began in early Eocene with maximum expulsion in the mid-Eocene (52my) at the rate of 7mg/gtoc/my. To the south of the basin, the Awgu source horizons were encountered at greater depths in Iji-1 and Ajire-1 wells and hydrocarbon generation began in the mid-Palaeocene and peaked in the late Palaeocene (58my) at the rate of 32–38mg/gtoc/my. This resulted in an increase in generated hydrocarbon volume to the south due to (a) increased burial depth and early maturation, and (b) changing source lithofacies -more marine. The fault system linking potential reservoirs such as the Agbani sandstone and the overlying Owelli sandstone to the source rock suggests a possible migration of the generated hydrocarbons to those reservoirs at that time.     

Chemistry of serpentine “polymorphs” in the Pan-African serpentinites from the Eastern Desert of Egypt,with an emphasis on the effect of superimposed thermal metamorphism

Mineralogy and Petrology - The present work deals with some Pan-African serpentinites of Neoproterozoic age from five localities in the Eastern Desert of Egypt namely, Abu Fannani, Fawakhir,...     

Finding the Location of Generation Zones of “Voice of the Sea” Microseisms

Doklady Earth Sciences - The generation zones of “voice of the sea” microseisms of three typhoons were determined from the field data using a two-coordinate laser strainmeter. From...