Geosciences, Volume 11, Issue 11 (November 2021) – 50 articles

The magnetotelluric (MT) method is one of the useful geophysical techniques to investigate deep crustal structures. However, in hilly terrains, e.g., the Garhwal Himalayan region, due to the highly undulating topography, MT responses are distorted. Such responses, if not corrected, may lead to the incorrect interpretation of geoelectric structures. In the present paper, we implemented terrain corrections in MT data recorded from the Garhwal Himalayan Corridor (GHC). We used AP3DMT, a 3D MT data modeling and inversion code written in the MATLAB environment. Terrain corrections in the MT impedance responses for 39 sites along the Roorkee–Gangotri profile in the period range of 0.01 s to 1000 s were first estimated using a synthetic model by recording the topography and locations of MT sites. Based on this study, we established the general character of the terrain and established where terrain corrections were necessary. The distortion introduced by topography was computed for each site using homogenous and heterogeneous models with actual topographic variations. Period-dependent, galvanic and inductive distortions were observed at different sites. We further applied terrain corrections to the real data recorded from the GHC. The corrected data were inverted, and the inverted model was compared with the corresponding inverted model obtained with uncorrected data. The modification in electrical resistivity features in the model obtained from the terrain-corrected response suggests the necessity of terrain correction in MT data recorded from the Himalayan region. Full article

The purpose of this paper is to discuss the lithosphere–atmosphere–ionosphere coupling (LAIC) effects with the use of multiparameter precursor observations for two successive Japanese earthquakes (EQs) (with a magnitude of around 7) in February and March 2021, respectively, considering a seemingly significant difference in seismological and geological hypocenter conditions for those EQs. The second March EQ is very similar to the famous 2011 Tohoku EQ in the sense that those EQs took place at the seabed of the subducting plate, while the first February EQ happened within the subducting plate, not at the seabed. Multiparameter observation is a powerful tool for the study of the LAIC process, and we studied the following observables over a 3-month period (January to March): (i) ULF data (lithospheric radiation and ULF depression phenomenon); (ii) ULF/ELF atmospheric electromagnetic radiation; (iii) atmospheric gravity wave (AGW) activity in the stratosphere, extracted from satellite temperature data; (iv) subionospheric VLF/LF propagation data; and (v) GPS TECs (total electron contents). In contrast to our initial expectation of different responses of anomalies to the two EQs, we found no such conspicuous differences of electromagnetic anomalies between the two EQs, but showed quite similar anomaly responses for the two EQs. It is definite that atmospheric ULF/ELF radiation and ULF depression as lower ionospheric perturbation are most likely signatures of precursors to both EQs, and most importantly, all electromagnetic anomalies are concentrated in the period of about 1 week–9 days before the EQ to the EQ day. There seems to exist a chain of LAIC process (cause-and-effect relationship) for the first EQ, while all of the observed anomalies seem to occur nearly synchronously in time for the send EQ. Even though we tried to discuss possible LAIC channels, we cannot come to any definite conclusion about which coupling channel is plausible for each EQ. Full article

The increase in geoheritage studies has secured recognition globally regarding the importance of abiotic natural features. Prominent in geoheritage screening practices follows a multicriteria assessment framework; however, the complexity of interest in values often causes decision making to overlook geoeducation, one of the primary facets of geosystem services. Auckland volcanic field in New Zealand stretches through the whole area of metropolitan Auckland, which helps preserve volcanic cones and their cultural heritage around its central business district (CBD). They are important sites for developing tourist activities. Geoeducation is becoming a significant factor for tourists and others visiting geomorphological features, but it cannot be achieved without sound planning. This paper investigates the use of big data (FlickR), Geopreservation Inventory, and Geographic Information System for identifying geoeducation capacity of tourist attractions. Through landform classification using the Topographic Position Index and integrated with geological and the inventory data, the underpromoted important geoeducation sites can be mapped and added to the spatial database Auckland Council uses for urban planning. The use of the Geoeducation Capacity Map can help resolve conflicts between the multiple objectives that a bicultural, metropolitan city council need to tackle in the planning of upgrading open spaces while battling of growing demand for land. Full article

After the Cretaceous/Paleogene boundary (KPB) catastrophic mass extinction event, an explosive evolutionary radiation of planktic foraminifera took place in consequence of the prompt occupation of empty niches. The rapid evolution of new species makes it possible to establish high-resolution biozonations in the lower Danian. We propose two biostratigraphic scales for low-to-middle latitudes spanning the first two million years of the Danian. The first is based on qualitative data and includes four biozones: the Guembelitria cretacea Zone (Dan1), the Parvularugoglobigerina longiapertura Zone (Dan2), the Parvularugoglobigerina eugubina Zone (Dan3), and the Parasubbotina pseudobulloides Zone (Dan4). The latter two are divided into several sub-biozones: the Parvularugoglobigerina sabina Subzone (Dan3a) and the Eoglobigerina simplicissima Subzone (Dan3b) for the Pv. eugubina Zone, and the Praemurica taurica Subzone (Dan4a), the Subbotina triloculinoides Subzone (Dan4b), and the Globanomalina compressa Subzone (Dan4c) for the P. pseudobulloides Zone. The second scale is based on quantitative data and includes three acme-zones (abundance zones): the Guembelitria Acme-zone (DanAZ1), the Parvularugoglobigerina-Palaeoglobigerina Acme-zone (DanAZ2), and the Woodringina-Chiloguembelina Acme-zone (DanAZ3). Both biozonations are based on high-resolution samplings of the most continuous sections of the lower Danian worldwide and have been calibrated with recent magnetochronological and astrochronological dating. Full article

In a volcanic area, the composition of air is influenced by the interaction between fluids generated from many different environments (magmatic, hydrothermal, meteoric, and marine). Any physical and chemical variation in one of these subsystems is able to modify the outgassing dynamic. The increase of natural gas hazard, related to the presence of unhealthy components in air, may depend on temporary changes both in the pressure and chemical gradients that generate transient fluxes of gases and can have many different causes. Sometimes, the content of unhealthy gases approaches unexpected limits, without clear warning. In this case, an altered composition of the air can be only revealed after accurate sampling procedures and laboratory analysis. The investigations presented here are a starting point to response to the demand for a new monitoring program in the touristic area of Baia di Levante at Vulcano Island (Aeolian archipelago, Italy). Three multiparametric geochemical surveys were carried in the touristic area of Baia di Levante at Vulcano Island (Aeolian archipelago, Italy) in 2011, 2014, and 2015. Carbon dioxide (CO₂) and hydrogen sulfide (H₂S) are the main undesired components, usually present at the local scale. Anomalous CO₂ and H₂S outputs from soil and submarine bubbling vents were identified; the thermal anomaly of the ground was mapped; atmospheric concentrations of CO₂ and H₂S were measured in the air 30 cm above the ground surface. Atmospheric concentrations above the suggested limits for the wellbeing of human health were retrieved in open areas where tourists stay and where CO₂ can accumulate under absence of wind. Full article

Peatlands in Canaan Valley National Wildlife Refuge hold a pedomemory of Pleistocene and Holocene climatic fluctuations in the central Appalachian Mountains of the eastern United States. A field investigation profiling 88 organic soil profiles, coupled with 52 radiocarbon dates and peat accumulation rates, revealed a distinct sequence of organic soil horizons throughout five study areas. The dominantly anaerobic lower portions of the organic soil profiles consist of varied thicknesses of hemic and sapric soil materials, typically layered as an upper hemic horizon, underlain by a sapric horizon, underlain by another hemic horizon. Peat deposition began after the Last Glacial Maximum with relatively high Heinrich Stadial 1 accumulation rates to form the lowest hemic horizon. Peat accumulated at significantly slower rates as the climate continued to warm in the early Holocene Greenlandian Age. However, between 10,000 and 4200 cal yr BP peat accumulation decreased further and the decomposition of previously deposited peat prevailed, forming the sapric horizon. This interval of greater decomposition indicates a drier climatic with dates spanning the late Greenlandian Age through the Northgrippian Age. The upper hemic horizon within the anaerobic portion of the soil profile formed from high peat accumulation rates during the wetter late Holocene Meghalayan Age. Full article

Ammonoid sutures are geometric patterns formed by the intersection of the septa and the shell wall, and have long been a diagnostic tool for ammonite researchers for such applications as species identification, taxonomic relationships, ontogenetic change, functional and evolutionary morphology, determination of ecological niche, and other aspects of ammonoid paleobiology. Researchers interested in a variety of paleobiological questions related to ammonoids have almost always required access to the entire hemisuture. Without access to specimens in museum or institutional collections, researchers must rely on previously published illustrations and photographs of ammonoid sutures. However, due to the perspective in photographs, distortion of the marginal elements of suture geometry occurs due to shell curvature near the venter and umbilicus when photographed in profile. The revised approach described here, which we refer to as the Lateral Lobe Saddle, or LLS approach, makes use of only the lateral lobe and second saddle S₂ (lateral lobe-second saddle pairs, or LLS) which lie in the central, mid-whorl undistorted sector of a suture line as viewed in lateral, profile shell photos and illustrations. The factors by which fractal dimension of LLS data convert to fractal dimension of the standard hemisuture measurements are largely consistent within genera. The LLS method’s non-requirement of a full hemisuture also facilitates comparisons among sutures within an ontogenetic sequence, or sutures from multiple ammonite taxa where ventral and umbilical sutural elements are hidden by whorl overlap or poor preservation. Full article

Back-arc basins in continental settings can develop into oceanic basins, when extension lasts long enough to break up the continental lithosphere and allow mantle melting that generates new oceanic crust. Often, the basement of these basins is not only composed of oceanic crust, but also of exhumed mantle, fragments of continental crust, intrusive magmatic bodies, and a complex mid-ocean ridge system characterised by distinct relocations of the spreading centre. To better understand the dynamics that lead to these characteristic structures in back-arc basins, we performed 2D numerical models of continental extension with asymmetric and time-dependent boundary conditions that simulate episodic trench retreat. We find that, in all models, episodic extension leads to rift and/or ridge jumps. In our parameter space, the length of the jump ranges between 1 and 65 km and the timing necessary to produce a new spreading ridge varies between 0.4 and 7 Myr. With the shortest duration of the first extensional phase, we observe a strong asymmetry in the margins of the basin, with the margin further from trench being characterised by outcropping lithospheric mantle and a long section of thinned continental crust. In other cases, ridge jump creates two consecutive oceanic basins, leaving a continental fragment and exhumed mantle in between the two basins. Finally, when the first extensional phase is long enough to form a well-developed oceanic basin (>35 km long), we observe a very short intra-oceanic ridge jump. Our models are able to reproduce many of the structures observed in back-arc basins today, showing that the transient nature of trench retreat that leads to episodes of fast and slow extension is the cause of ridge jumps, mantle exhumation, and continental fragments formation. Full article

Multidisciplinary studies have allowed us to describe the abiotic landscapes and, thus, reveal the ichnological and benthic foraminifera trends in a deep-water gateway. Mesoscale landscape mapping is presented based on the bathymetric position index, substrate types and near-bottom water temperature. Four sediment cores, retrieved from the entrance, centre and exit of the gap, were subject to computed tomography, ichnological and benthic foraminifera studies. A high diversity of abiotic landscapes in the relatively small area of Discovery Gap is detected and its landscape is characterized by 23 landscape types. The most heterogeneous abiotic factor is a topography that is associated with sediment patchiness and substrate variability. The ichnological and tomographical studies of the sediment cores demonstrate lateral and temporal differences in the macrobenthic tracemaker behaviour. The ichnofossils assemblage of the sediment core can be assigned to the Zoophycos ichnofacies with a higher presence of Zoophycos in the entrance site of the gap and during glacial intervals. Higher benthic foraminifera diversity and species richness during the Holocene are also registered in the southern part of the gap compared to the northern part. The spatial and temporal differences in macro-benthos behavior and benthic foraminifera distribution in the deep-water gateway are proposed to relate to the topographical variations of the Antarctic Bottom Water and its influence on the hydrodynamic regime, nutrient transport, etc. Full article

In this paper, we discuss a possible combination of Earthquake Early Warning (EEW) and Neo-deterministic Seismic Hazard Assessment (NDSHA), and propose a new warning model, EEW2.0. The aim is to provide a differentiated warning alert to various end-users based on the results of seismic hazard assessment evaluation. The implementation of such a system contains three basic steps: (a) classification of “potential to cause hazard” in terms of magnitude; (b) determination of the source areas and building a hazard database in terms of Modified Mercalli Intensity (MMI) maps, considering all possible earthquake scenarios in the source area, for the whole protected area; (3) equipping unique decision framework for specific end-users. When a damaging earthquake (M ≥ 5.0) is detected, EEW2.0 quickly matches the prepared MMI map by estimated magnitude and epicenter, then directly extracts the MMI value and issues an early warning to the public. With the great attention and resources put into the reduction in seismic and its secondary risk in the 21st century, the proposed EEW2.0 will likely play an active role in protecting lives and reducing economic losses. Full article

Piles provide a convenient solution for heavy structures, where the foundation soil bearing capacity, or the tolerable settlement may be exceeded due to the applied loads. In cohesionless soils, the two frequently used pile installation methods are driving and drilling (or boring). This paper reviews the results of a large database of pile load tests of driven and drilled piles in cohesionless soils at various locations worldwide. The load test results are compared with the static analysis design method for single piles recommended in the Canadian Foundation Engineering Manual (CFEM) and other codes and standards such as the American Association of State Highway and Transportation Officials, Federal Highway Administration, American Petroleum Institute, Eurocode, and the Naval Facilities Engineering Command. An improved pile design procedure is proposed linking the pile design coefficients $\left(\beta \right)$ and $\left(N_t\right)$ to the friction angle of the soil, rather than employing the generalized soil type grouping scheme previously used in the CFEM. This improvement included in the new version of the CFEM 2021 produces a more unified value of the pile capacity calculated by different designers, reducing the obtained design capacity discrepancies. Full article

Investigating surface displacements in high alpine environments is often subject to challenges due to the difficult accessibility or harsh climatic conditions. Measurement systems have improved greatly in recent years regarding accuracy, range, or energy consumption. Continuously receiving high-precision, real-time monitoring data from a remote location can still support a better understanding of slope dynamics and risk. We present the design, construction, operation, and performance of a complex surface displacement monitoring system installed in the surroundings of the Great Aletsch Glacier in the Swiss Alps, based on two robotic total stations to continuously measure 3D displacements with high accuracies. In addition, GNSS stations are also considered in order to pass from a local to a geographic reference system, as well as to improve the measurement accuracy. The monitoring network is aimed at studying several types of deformation processes, i.e., (i) gravitationally driven and irreversible rockslide movements around the tongue of the Great Aletsch Glacier, (ii) reversible rock slope deformations caused by annual cycles of groundwater recharge and depletion, and (iii) small irreversible deformations of stable rock slopes resulting from progressive rock damage driven by glacier retreat and cyclic hydraulic and thermal loading. We describe the technical details of the monitoring system, which has been in operation successfully for 6 years, and discuss the system performance in terms of its robustness and accuracy. Full article

There are numerous oil fields that are approaching the end of their lifetime and that have great geothermal potential considering temperature and water cut. On the other hand, the oil industry is facing challenges due to increasingly stringent environmental regulations. An example of this is the case of France where oil extraction will be forbidden starting from the year 2035. Therefore, some oil companies are considering switching from the oil business to investing in geothermal projects conducted on existing oil wells. The proposed methodology and developed conversions present the evaluation of existing geothermal potentials for each oil field in terms of water temperature and flow rate. An additional important aspect is also the spatial distribution of existing oil wells related to the specific oil field. This paper proposes a two-stage clustering approach for grouping similar wells in terms of their temperature properties. Once grouped on a temperature basis, these clusters should be clustered once more with respect to their spatial arrangement in order to optimize the location of production facilities. The outputs regarding production quantities and economic and environmental aspects will provide insight into the optimal scenario for oil-to-water conversion. The scenarios differ in terms of produced energy and technology used. A case study has been developed where the comparison of overall fields and clustered fields is shown, together with the formed scenarios that can further determine the possible conversion of petroleum assets to a geothermal assets. Full article

Mapping existing landslides is a fundamental prerequisite to build any reliable susceptibility model. From a series of landslide presence/absence conditions and associated landscape characteristics, a binary classifier learns how to distinguish potentially stable and unstable slopes. In data rich areas where landslide inventories are available, addressing the collection of these can already be a challenging task. However, in data scarce contexts, where geoscientists do not get access to pre-existing inventories, the only solution is to map landslides from scratch. This operation can be extremely time-consuming if manually performed or prone to type I errors if done automatically. This is even more exacerbated if done over large geographic regions. In this manuscript we examine the issue of mapping requirements for west Tajikistan where no complete landslide inventory is available. The key question is: How many landslides should be required to develop reliable landslide susceptibility models based on statistical modeling? In fact, for such a wide and extremely complex territory, the collection of an inventory that is sufficiently detailed requires a large investment in time and human resources. However, at which point of the mapping procedure, would the resulting susceptibility model produce significantly better results as compared to a model built with less information? We addressed this question by implementing a binomial Generalized Additive Model trained and validated with different landslide proportions and measured the induced variability in the resulting susceptibility model. The results of this study are very site-specific but we proposed a very functional protocol to investigate a problem which is underestimated in the literature. Full article

Within the scope of literature, the influence of openings within the infill walls that are bounded by a reinforced concrete frame and excited by seismic drift forces in both in- and out-of-plane direction is still uncharted. Therefore, a 3D micromodel was developed and calibrated thereafter, to gain more insight in the topic. The micromodels were calibrated against their equivalent physical test specimens of in-plane, out-of-plane drift driven tests on frames with and without infill walls and openings, as well as out-of-plane bend test of masonry walls. Micromodels were rectified based on their behavior and damage states. As a result of the calibration process, it was found that micromodels were sensitive and insensitive to various parameters, regarding the model’s behavior and computational stability. It was found that, even within the same material model, some parameters had more effects when attributed to concrete rather than on masonry. Generally, the in-plane behavior of infilled frames was found to be largely governed by the interface material model. The out-of-plane masonry wall simulations were governed by the tensile strength of both the interface and masonry material model. Yet, the out-of-plane drift driven test was governed by the concrete material properties. Full article

The exploitation of gravity fields in order to retrieve information about subsurface geological structures is sometimes considered a second rank method, in favour of other geophysical methods, such as seismic, able to provide a high resolution detailed picture of the main geological horizons. Within the current work we prove, through a realistic synthetic case study, that the gravity field, thanks to the availability of freely of charge high resolution global models and to the improvements in the gravity inversion methods, can represent a valid and cheap tool to complete and enhance geophysical modelling of the Earth’s crust. Three tests were carried out: In the first one a simple two-layer problem was considered, while in tests two and three we considered two more realistic scenarios in which the availability on the study area of constraints derived from 3D or 2D seismic surveys were simulated. In all the considered test cases, in which we try to simulate real-life scenarios, the gravity field, inverted by means of an advanced Bayesian technique, was able to obtain a final solution closer to the (simulated) real model than the assumed a priori information, typically halving the uncertainties in the geometries of the main geological horizons with respect to the initial model. Full article

The interest of the scientific community about geotourism is abruptly increasing, as well as that on geoparks. According to UNESCO, geoparks should define management policies addressed to increasing the awareness of local people and tourists about Earth’s dynamics to reduce the impact of climate change and natural disasters. With this aim in mind, we tried to provide a solid scientific approach to geotourism that could be useful to the development of a geotourism strategy in the Cilento, Vallo di Diano and Alburni (CVDA) Geopark, in Southern Italy. Starting from the official inventory of the CVDA Geopark, we defined the potential Education Value (EV) and potential Touristic Value (TV) of each of the 160 sites listed by applying the Brilha method. Then we selected 20 geosites and geomorphosites with high values of both the EV and TV, and we included them in two geoitineraries. The two geoitineraries move in the inner sector of the Geopark (i.e., from the Paestum archaeological area to the Vallo di Diano basin) and along a portion of the coastal stretch (i.e., from Punta Telegrafo cape to the Lambro and Mingardo rivers’ mouths). Selected sites are representative of several geoscience disciplines (e.g., geomorphology, structural geology, quaternary geology, hydrogeology), thus suggesting that the CVDA Geopark is an ideal place where dissemination of geoscience concepts may be carried out. The latter point enhances the high geotourism potential of the area. This kind of approach was not tried before in the CVDA Geopark and can be a useful example of how to promote touristic development strategies in the area. Full article

A rotation of the anisotropic soil fabric pattern is commonly observed in natural slopes with a tilted stratification. This study investigates the rotated anisotropy effects on slope reliability considering spatially varied soils. Karhunen–Loève expansion is used to generate the random fields of the soil shear strength properties (i.e., cohesion and friction angle). The presented probabilistic analyses are based on a meta-model combining Sparse Polynomial Chaos Expansion (SPCE) and Global Sensitivity Analysis (GSA). This method allows the number of involved random variables to be reduced and then the computational efficiency to be improved. Two kinds of deterministic models, namely a discretization kinematic approach and a finite element limit analysis, are considered. A variety of valuable results (i.e., failure probability, probability density function, statistical moments of model response, and sensitivity indices of input variables) can be effectively provided. Moreover, the influences of the rotated anisotropy, autocorrelation length, coefficient of variation and cross-correlation between the cohesion and friction angle on the probabilistic analysis results are discussed. The rotation of the anisotropic soil stratification has a significant effect on the slope stability, particularly for the cases with large values of autocorrelation length, coefficient of variation, and cross-correlation coefficient. Full article

The deep geothermal energy project at Soultz-sous-Forêts is located in the Upper Rhine Graben, France. As part of the Multidisciplinary and multi-contact demonstration of EGS exploration and Exploitation Techniques and potentials (MEET) project, this study aimed to evaluate the possibility of extracting higher amounts of energy from the existing industrial infrastructure. To achieve this objective, the effect of reinjecting fluid at lower temperature than the current fluid injection temperature of 70 °C was modeled and the drop in the production wellhead temperature for 100 years of operation was quantified. Two injection-production rate scenarios were considered and compared for their effect on overall production wellhead temperature. For each scenario, reinjection temperatures of 40, 50, and 60 °C were chosen and compared with the 70 °C injection case. For the lower production rate scenario, the results show that the production wellhead temperature is approximately 1–1.5 °C higher than for the higher production rate scenario after 100 years of operation. In conclusion, no significant thermal breakthrough was observed with the applied flow rates and lowered injection temperatures even after 100 years of operation. Full article

The vibration effects on the Torre della Moletta and the ruins of the Circus Maximus in Rome are analyzed in the framework of a preservation effort of this archaeological area. Thanks to its exceptional size, the Circus hosts many social events with large audience (pop-music, opera concerts, sport celebrations, etc.) every year, thus taking the structures under high anthropic and environmental stress. Recordings were completed before, during, and after the concert of a famous band, on 7 September 2019. Data were analyzed, both in time and frequency domains. The experimental dynamic recordings were coupled with a surface waves test and single-station ambient vibration recordings, which were useful for the geotechnical characterization of the soil. The results pointed out the differences in amplitudes but also in terms of frequency content of the recorded velocities during the concert with respect to before and after it. The maximum velocities recorded at various locations were almost similar to the limit values suggested by codes. The dynamic behavior of the ground and the structures is influenced by the presence of buried structures. Full article

The development model assumed by human society over the last century is opposed to the Earth system’s resilience, which has resulted in global environmental problems such as global warming, desertification, depredation of geoheritage, etc. The concept of geoethics, proposed in 1993, was initially associated with ethical principles to mining and environmental, social and economic issues inherent to the exploration of these resources. Over the last few years, geoethics has turned to education, proposing a reflection on the way human beings relate to the geosphere, and particularly on the way geologists work during their academic and professional activities. In Brazil, geoethics entered the Brazilian Society of Geology scenario only from the end of the second decade of the 20th century and promoted changes in the academic and professional spheres. Full article

Trakošćan Castle, built on a rocky peak in the late 13th century, is a cultural heritage site protected as a historical entity by the Republic of Croatia. The Castle is constructed as a highly irregular masonry structure with timber or shallow masonry arches, vaults or dome floors. It was substantially renewed, upgraded and partially retrofitted from the 16th century until the year 2000. The M5.5 (VIII EMS) and M6.2 (VIII-IX EMS) earthquakes, which struck the city of Zagreb on 22 March 2020 and the Pokupsko-Petrinja area on 29 December 2020, strongly shook the Castle’s structure. Earthquake damage was observed and assessed by visual inspection accompanied by ambient vibration measurements. The slight cracks that appeared on masonry arches were found to be critically positioned, and can likely lead to the arches’ collapse if their spreading is not prevented. Ambient vibration measurements, which were compared to pre-earthquake ones, revealed the decrease in the fundamental frequencies of the Castle’s central tower unit and the second floor, thus possibly indicating the loss of structural stiffness as a consequence of the earthquake damage. Full article

Late Cretaceous coastal plain deposits of the Prince Creek Formation (PCF) offer a rare glimpse into an ancient, high-latitude, arctic greenhouse ecosystem for which there is no modern analog. Here, we employ quantitative biofacies analysis to explore the spatio-temporal variability in PCF palynomorph and microbiota assemblages from nine paleosol horizons exposed along the Colville River, North Slope, Alaska. Biofacies results provide insight into paleoenvironmental controls on the coastal plain ecosystem. Cluster and ordination analyses recognize five biofacies and the following two assemblage types: (1) fern and moss dominated assemblages and (2) algae dominated assemblages. Ordination arrays biofacies along environmental gradients related to soil moisture and marine influence. Fern and moss dominated biofacies from regularly water-logged paleosols along lake and swamp margins on the lower delta plain clearly segregated from algae dominated assemblages of periodically drier levee-overbank paleosols. These results support previous interpretations from the sedimentology, paleopedology, and geochemistry of PCF paleosols that suggest that fluctuations in the water table, related to seasonal river discharge and variations in topography and drainage, controlled soil development and vegetation growth across the coastal plain. This quantitative biofacies-based approach provides an independent predictive tool and cross-check for interpreting environmental conditions along any ancient coastal ecosystem. Full article

The present work reviews studies with information on the effects of water by itself on stones of the built environment both to assess the impact of this substance and to discuss possible implications for conservation. The analysis concerns empirical results from previous publications dealing with the effects, on several rock types, of freeze–thaw, wetting, erosion by running water and substances resulting from the water–stone interaction. Laboratory studies have shown that water freezing can cause physical damage even in low porosity rocks. As far as we know, this is the first review that considers comparative laboratory studies of freeze–thaw and salt crystallization on the same rock specimens, and these point to lower erosive effects than salt weathering, as freeze–thaw can provoke catastrophic cracking. Wetting has shown strong damaging effects on some fine-grained clastic rocks. Erosive features have been reported for rain exposition and for some fountain settings albeit, in these field studies, it could be difficult to assess the contribution of pollutants transported by water (this assessment could have meaningful implications for stone conservation, especially in fountain settings). Water also interacts with stone constituents, namely sulfides and soluble salts, releasing substances that could impact those stones. Sulfides are a relatively frequent issue for slates and granites, and our observations suggest that for this last rock type, this issue is mostly associated with the presence of enclaves and, hence, avoiding the surface exposition of such enclaves could solve the problem. Full article

This study investigates four types of synoptic dust events in the Middle East region, including cyclonic, pre-frontal, post-frontal and Shamal dust storms. For each of these types, three intense and pervasive dust events are analyzed from a synoptic meteorological and numerical simulation perspective. The performance of 9 operational dust models in forecasting these dust events in the Middle East is qualitatively and quantitatively evaluated against Terra-MODIS observations and AERONET measurements during the dust events. The comparison of model AOD outputs with Terra-MODIS retrievals reveals that despite the significant discrepancies, all models have a relatively acceptable performance in forecasting the AOD patterns in the Middle East. The models enable to represent the high AODs along the dust plumes, although they underestimate them, especially for cyclonic dust storms. In general, the outputs of the NASA-GEOS and DREAM8-MACC models present greater similarity with the satellite and AERONET observations in most of the cases, also exhibiting the highest correlation coefficient, although it is difficult to introduce a single model as the best for all cases. Model AOD predictions over the AERONET stations showed that DREAM8-MACC exhibited the highest R² of 0.78, followed by NASA_GEOS model (R² = 0.74), which both initially use MODIS data assimilation. Although the outputs of all models correspond to valid time more than 24 h after the initial time, the effect of data assimilation on increasing the accuracy is important. The different dust emission schemes, soil and vegetation mapping, initial and boundary meteorological conditions and spatial resolution between the models, are the main factors influencing the differences in forecasting the dust AODs in the Middle East. Full article

In the aftermath of pyroclastic density current-dominated eruptions, lahars are the main geomorphic agent, but at the decadal scale, different sets of processes take place in the volcanic sediment cascade. At Unzen volcano, in the Gokurakudani gully, we investigated the geomorphologic evolution and how the topographic change and the sediment change over time is controlling this transition. For this purpose, a combination of LiDAR data, aerial photography and photogrammetry, ground penetrating radar and sediment grain size analysis was done. The results show choking zones and zones of enlargement of the gully, partly controlled by pre-eruption topography, but also by the overlapping patterns of the pyroclastic flow deposits of 1990–1995. The ground penetrating radar revealed that on top of the typical lahar structure at the bottom of the gully, side wall collapses were trapping finer sandy sediments formed in a relatively low-energy deposition environment. This shows that secondary processes are taking place in the sediment transport process, on top of lahar activity, but also that these temporary dams may be a source of sudden sediment and water release, leading to lahars. Finally, the sediments from the gully walls are being preferentially oozed out of the pyroclastic flow deposit, meaning that over longer period of time, there may be a lack of fines, increasing permeability and reducing internal pore pressure needed for lahar triggering. It also poses the important question of how much of a past event one can understand from outcrops in coarse heterometric material, as the deposit structure can remain, even after losing part of its fine material. Full article

It is generally accepted that during the Mesozoic NE−NNE-trending folds overprinted E−W-trending folds to form the Longshan dome in the central South China continent, although the interference map does not tell the relative ages of the fold sets. In an effort to deepen our understanding of the process of reworking the continent, paleostress analysis using calcite twins was carried out in this study to verify or falsify this model. Ten limestone samples were collected from Upper-Paleozoic limestones on the flanks of the dome and were measured using the universal stage for calcite e-twins. E-twins in the samples are divisible into two kinds, thick (≥1 μm) and thin (<1 μm), indicative of relatively higher and lower deformation temperatures, respectively. Stress estimates obtained using the improved version of Shan et al.’s (2019) method were grouped into two layer-parallel shortening (LPS) subsets and three non-LPS subsets. These subsets comprise four tectonic regimes: NWW−SEE compression (LPS1 and non-LPS1), NNE−SSW compression (LPS2 and non-LPS2), NW−SE extension (non-LPS3a) and NNE−SSW extension (non-LPS3b). They were further arranged in a temperature-decreasing order to establish a complex deformation sequence of the study area. In the sequence NE−NNE-trending folds have an older age than E−W-trending folds, something different from the model. The approximately N−S regional compression responsible for the former folds should have a profound effect on the intensely deformed continent, something ignored in earlier work. Full article

Cenozoic evaporites (gypsum and anhydrite) in southwestern North America have wide ranges of δ³⁴S (−30 to +22‰; most +4 to +10‰) and δ¹⁸O_SO4 (+3 to +19‰). New data are presented for five basins in southern Arizona. The evaporites were deposited in playas or perennial saline lakes in closed basins of Oligocene or younger age. Very large accumulations in Picacho, Safford and Tucson Basins have isotope compositions plotting close to a linear δ³⁴S-δ¹⁸O_SO4 relationship corresponding to mixing of two sources of sulfur: (1) sulfate recycled from Permian marine gypsum and (2) sulfate from weathering of Laramide-age igneous rocks that include porphyry copper deposits. In the large evaporites, sulfate with δ³⁴S > +10‰ is dominantly of Permian or Early Cretaceous marine origin, but has locally evolved to higher values as a result of bacterial sulfate reduction (BSR). Sulfate with δ³⁴S < −10‰ formed following exposure of sulfides, possibly formed during supergene enrichment of a porphyry copper deposit by BSR, and have values of δ¹⁸O_SO4 higher than those of local acid rock drainage because of participation of evaporated water in BSR. Accumulations of 30 to 100 km³ of gypsum in Picacho and Safford Basins are too large to explain as products of contemporaneous erosion of Permian and Laramide source materials, but may represent recycling of Late Cretaceous to Miocene lacustrine sulfate. Full article

The volcanic-hydrothermal geo-diversity of the Basse-Terre Island of Guadeloupe archipelago (Eastern Caribbean, France) is a major asset of the Caribbean bio-geoheritage. In this paper, we use Guadeloupe as a representative of many small island developing states (SIDS), to show that the volcanic-hydrothermal geodiversity is a major resource and strategic thread for resilience and sustainability. These latter are related to the specific richness of Guadeloupe’s volcanic-geothermal diversity, which is de facto inalienable even in the wake of climate change and natural risks that are responsible for this diversity, i.e., volcanic eruptions. We propose the interweaving the specificity of volcanic-geothermal diversity into planning initiatives for resilience and sustainability. Among these initiatives research and development programs focused on the knowledge of geodiversity, biodiversity and related resources and risks are central for the long-term management of the water resource, lato sensu. Such a management should include a comprehensive scientific observatory for the characterization, exploration, and sustainable exploitation of the volcanic-hydrothermal geodiversity alongside planning for and mitigating geophysical risks related to sudden volcanic-induced phenomena and long-term systemic drifts due to climate change. The results of this exercise for Guadeloupe could typify innovative paths for similar SIDS around their own volcanic-hydrothermal geodiversity. Full article