Deep Zone Research Articles

Assessment of True Formation Resistivity and Water Saturation in Deeply Invaded Tight-Gas Sandstones Based on the Combined Numerical Simulation of Mud-Filtrate Invasion and Resistivity Logs

The process of mud-filtrate invasion involves immiscible fluid displacement and salt mixing between mud filtrate and formation fluids in porous and permeable rocks. Consequently, the post-invasion spatial distribution of fluids and electrolyte concentration around the borehole affects resistivity measurements with different depths of investigation (DOI). In the presence of deep mud-filtrate invasion, the assessment of water saturation in the uninvaded zone based on the deep resistivity log can be inaccurate. Deep and electrically conductive filtrate invasion coupled with shoulder-bed effects can artificially increase water saturation (Sw) estimations by 20 saturation units (s.u.) in the Barik reservoir, resulting in pessimistic estimates of hydrocarbon pore volume if no corrections are applied. The Barik sandstone reservoir, which is characterized by low porosity ( up to 14%), low-to-medium permeability (up to 40 md), and high residual gas saturation (40 to 50%), exhibits low storage capacity to admit the critical filtrate volume necessary for building an impermeable mudcake. Combined with multiple days of overbalanced exposure to saline water-based mud (WBM), mud-filtrate invasion results in deep and smooth radial transition zones where the uninvaded formation is far beyond the depth of investigation of laterolog tools. Deep resistivity values are, therefore, lower than the true formation resistivity. Additionally, numerical simulations of resistivity logs show that the resistivity reduction by conductive invasion is further aggravated by shoulder-bed effects when individual reservoir thickness falls below 2.5 m. This paper describes the implementation of a compositional fluid-flow simulator to numerically model WBM-filtrate invasion and mudcake buildup in vertical boreholes. The algorithm allows the simulation of physical dispersion and fluid displacement around the borehole in a multilayer model. Time-dependent radial profiles of Sw and salinity are combined with core-calibrated porosity and electrical properties to compute electrical resistivity via Archie’s formulation. Subsequently, numerically simulated logs are generated using vendor-specific forward model processing and compared against field measurements. This workflow was extensively tested in various reservoir intervals with a wide range of petrophysical rock types and drilling conditions. Results show that the deep laterolog exhibits low sensitivity to conductive filtrate invasion when reservoirs’ porosities are lower than 8%. Above that threshold value, invasion length is a nontrivial process involving multiple variables. Even though exposure time to openhole conditions is a key factor leading to deep invasion, certain reservoir characteristics can lead to deeper invasion at short exposure times and significantly increase uncorrected Sw estimates.

Geochemical constraints on the evolution of the magmatic system leading to catastrophic eruptions at Aira Caldera, Japan

Caldera-forming eruptions of Aira volcano at 30 ka were among the most explosive eruptions in Japan during the late Pleistocene. In this study, new data on whole-rock major and trace elements, Sr–Nd–Pb isotopes, and 238U-230Th disequilibrium were obtained for representative volcanic products of caldera-forming and pre-caldera eruptions (31–90 ka) to acquire insights on the evolution of the felsic magma system leading to catastrophic eruptions. Voluminous rhyolitic pumices from the caldera-forming eruptions at 30 ka and rhyolitic lavas and pumices of the younger pre-caldera eruptions (31–36 ka) have similar Sr, Nd, and Pb isotopic compositions, and differ from those of dacitic and rhyolitic pumices produced by eruptions at 90 and 60 ka, respectively. These three types of felsic magmas are considered to have formed by partial melting of hornblende gabbroic rocks with distinct isotopic compositions in the middle-lower crust. Most felsic products from the pre-caldera and caldera-forming eruptions are in secular 238U-230Th equilibrium, suggesting that the original magmas were generated > ∼ 400 ka and existed as long-lived crystalline mush in the deep hot crust. Felsic magmas originating from the deep crustal mush zones ascended to form the shallow felsic magma system, which was replaced by a new one after the explosive eruptions at 90 and 60 ka. The voluminous rhyolitic magmas for the caldera-forming eruptions accumulated in a shallow magma reservoir between 60 and 30 ka. Rhyolitic magmas with compositions similar to those of the voluminous magmas erupted catastrophically at 30 ka began to erupt effusively at 36 ka and 33 ka as lava flows with significant 238U-230Th disequilibrium, suggesting that these magmas were generated in the deep crust much later than the other main rhyolitic magmas. The effusive magma eruptions presumably resulted from the relatively low content of dissolved H2O in the melt due to the low crystallinity because of the shorter residence time in the shallow felsic magma system.

Structure of the Assynt window, Moine Thrust Zone and relationship of thrusts to alkaline igneous complexes, Caledonian orogeny, NW Scotland

AbstractThe Moine Thrust Zone forms the Caledonian orogenic thrust front where the Moine Supergroup metamorphic rocks have been thrust westward across the Laurentia plate stable foreland, comprising Archean-Proterozoic granulite and amphibolite facies rocks (Lewisian gneisses), with unconformably overlying Mesoproterozoic and Neoproterozoic Torridonian clastic sediments and Cambrian-Ordovician passive margin sedimentary rocks. Four major thrusts beneath the Moine thrust in the Assynt window include the (i) Ben More Thrust, which places the Loch Ailsh syenite intruded into Lewisian basement and Cambrian-Ordovician sedimentary rocks over the Sole thrust sheet, (ii) Glencoul thrust, which places Lewisian basement and folded cover rocks over Cambrian-Ordovician sedimentary rocks, (iii) Borralan thrust, which carries a large alkaline syenite intrusion beneath the Ben More roof thrust and (iv) the Sole thrust sheet, which carries imbricated Cambrian-Ordovician sedimentary rocks and lamprophyre sills over the stable foreland. Three further thrust sheets within the Lewisian basement gneisses are now recognised through restoration of balanced cross-sections, which were responsible for doming of the Assynt window. Although the Moine thrust is mapped as a single line on the map it encompasses, (a) deep ductile shear zone formed of mylonites derived from hangingwall Moine schists, footwall Cambrian quartzites and Ordovician limestones, and basement Lewisian gneisses, (b) roof thrust of the Glencoul and Ben More Thrust sheets and (c) brittle out-of-sequence motion where the Moine schists have been thrust over mylonites, which directly overlie the stable foreland (Knockan Crag).

Space-associated domain adaptation for three-dimensional mineral prospectivity modeling

ABSTRACT Geographical information systems (GIS) are essential tools for mineral prospectivity modeling (MPM). Three-dimensional (3D) MPM is able to learn the association between geological evidence and mineralization in shallow zones and thereby build a prospectivity model for deep zones, making it a desirable technique to target deep-seated orebodies. However, existing 3D MPM methods directly generalize the model learned in shallow zones to the deep zones without attention to model transferability caused by the different metallogenic mechanisms between the two zones. In this study, we aim to robustly transfer the prospectivity model learned from shallow zones to deep zones. We cast the 3D MPM as a domain adaptation problem, which is an important realm of transfer learning. Because the metallogenic mechanism can be closely associated with spatial locations, we specifically focus on domain adaption concerning the spatial locations that are ignored by conventional domain adaptation methods. To measure the spatial-associated domain discrepancy, we propose a novel spatial-associated maximum mean discrepancy (SAMMD), which compares the joint distributions of features and spatial locations across domains. Based on the SAMMD criterion, a deep neural network, referred to as the spatial-associated domain adaptation network, is devised to learn cross-domain but mineralization-indicative features for building prospectivity model that is transferable to deep zones. A case study of the world-class Sanshandao gold deposit, in eastern China, was carried out to validate the effectiveness of the proposed methods. The results show that compared with other leading MPM methods and other domain adaption variants, the proposed method has superior prediction accuracy and targeting efficiency, demonstrating the effectiveness and robustness of the proposed method in targeting deep-seated orebodies in areas with different metallogenic mechanisms and no labeled data.

3D coupled hydro-mechanical modeling of multi-decadal multi-zone saltwater disposal in layered and faulted poroelastic rocks and implications for seismicity: An example from the Midland Basin

Knowledge of subsurface coupled pore pressure and stress perturbations due to saltwater disposal (SWD) is crucial for understanding and managing induced seismicity. Current studies choose Biot poroelasticity to implement fluid-rock coupling and perform numerical modeling in relatively simple settings. In this study, we first introduce a general poromechanical framework to capture a broader range of hydro-mechanical coupling and then apply it to model real-world SWD problems with geological and operational complexities. We demonstrate a viable workflow through the case study of a 2500 km2, layered, faulted, and recently seismically awaken area that has undergone multi-decadal multi-zone injection by nearly 200 SWD wells in the Midland basin. The example provides a unique opportunity to study the respective impact of shallow and deep injections across depths and the role of inter-zone interactions, among others. Our modeling suggests over 500 and 250 psi increases in pore pressure and Coulomb stress, respectively, in the deep disposal zone in the last decade, which were 5 to 10 times greater than those accumulated over the past four decades in the two shallower disposal zones. Vertically, shallower injections impacted mostly shallower zones, whereas the deep injection produced changes across depths and dominated especially in the deep zone and the upper segment of the basement. Towards the mid-segment of the basement, changes due to shallow and deep injections were comparable, with the latter 2 to 5 times higher. Laterally, in-zone changes were dominated by pore pressure diffusion in the near field and poroelastic stressing in the far field in shallower zones but were dominated by pore pressure diffusion everywhere in the deep zone, owing to their different hydraulic diffusivities. Faults acted as pore pressure and Coulomb stress sinks for disposal zones and sources for non-disposal zones, and fault-zone permeability structure had a minor impact. Finally, seismological modeling suggests that seismicity in the area was most likely driven by the deep injection.

U–Pb ID-TIMS Age of Rutile from the North Muya Block Eclogites (Northeastern Transbaikal Area) as a Tracer of the Duration for Exhumation of the Continental Lithosphere

Rutile, an abundant mineral phase of high-grade rocks, is used as a tracer of lithospheric evolution for deep zones of orogenic belts. This study presents new ID-TIMS U–Pb geochronological, mineralogical, and geochemical data for rutile from eclogites of the North Muya block (Baikal–Muya fold belt) in order to examine the applicability of its age estimates relative to the exhumation process of high-grade rocks. The assemblage of mineral inclusions in rutile (mainly titanite, epidote, and amphibole) indicate rutile growth through titanite breakdown reactions during prograde metamorphism epidote–amphibolite or amphibolite–facies rocks. The range of Zr contents and estimated Zr-in-rutile crystallization temperatures correspond to conditions from prograde (619–638°С at 1.5 GPa) up to peak ones (659–684°С for 2.5 GPa). The U–Pb age estimate (605 Ma) is notably younger than that of peak eclogitic metamorphism (630 Ma) and highlight the protracted cooling history of the eclogite-bearing complex during its evolution below the closure temperature of the U–Pb isotope system in rutile (~500–525°С) during tectonic denudation or erosion of continental complexes.

Joint Bayesian Modeling of Velocity Break Points, Noise Characteristics, and Their Uncertainties in GNSS Time Series: Far‐Field Velocity Anomalies Concurrent With Magmatic Activity in Iceland

AbstractEstimating the timing of velocity changes (break points) in Global Navigation Satellite System (GNSS) coordinate time series is required for understanding various Earth processes and how they may couple with each other. We jointly estimate break points, noise parameters and their uncertainties in GNSS time series using Bayesian interference. Synthetic data experiments demonstrate that time‐correlated noise can cause spurious estimates of break points for small velocity change and suggest the lower limits of velocity change for reliable estimates. A case study at the Krafla volcanic system shows increased rift‐perpendicular movementof 7.6–9.8 mm/yr, preceding by 23–77 days the 2014 Bárðarbunga rifting episode that occurred ∼120 km to the south (maximum likelihood estimates). These far‐field velocity anomalies occur in the same period as enhanced near‐field seismicity and deformation before the dike intrusion at Bárðarbunga, possibly indicating the coupling between the two volcanic systems through a deep partial melt zone.

Response of phytoplankton functional types to Hurricane Fabian (2003) in the Sargasso Sea

Understanding how tropical cyclones affect phytoplankton communities is important for studies on ecological variability. Most studies assessing the post-storm phytoplankton response rely on satellite observations of chlorophyll a concentration, which inform on the ocean surface conditions and the whole phytoplankton community. In this work, we assess the potential of the Massachusetts Institute of Technology marine ecosystem model to account for the response of individual phytoplankton functional types (PFTs, coccolithophores, diatoms, diazotrophs, mixotrophic dinoflagellates, picoeukaryotes, Prochlorococcus and Synechococcus) in the euphotic zone to the passage of Hurricane Fabian (2003) across the tropical and subtropical Sargasso Sea. Fabian induced a significant mean concentration increase (t-test, p < 0.05) of all PFTs in the tropical waters (except for Prochlorococcus), which was driven by the mean nutrient concentration increase and by a limited zooplankton grazing pressure. More specifically, the post-storm nutrient enrichment increased the contribution of fast-growing PFTs (e.g. diatoms and coccolithophores) to the total phytoplankton concentration and decreased the contribution of slow-growing dominant groups (e.g. picoeukaryotes, Prochlorococcus and Synechococcus), which lead to a significant increase (t-test, p < 0.05) of the Shannon diversity index values. Overall, the model captured the causal relationship between nutrient and PFT concentration increases in the tropical waters, although it only reproduced the most pronounced PFT responses such as those in the deep euphotic zone. In contrast, the model did not capture the oceanic perturbations induced by Fabian as observed in satellite imagery in the subtropical waters, probably due to its limited performance in this complex oceanographic area.

Interplay of legacy irrigation and nitrogen fertilizer inputs to spatial variability of arsenic and uranium within the deep vadose zone

The vadose zone is a reservoir for geogenic and anthropogenic contaminants. Nitrogen and water infiltration can affect biogeochemical processes in this zone, ultimately affecting groundwater quality. In this large-scale field study, we evaluated the input and occurrence of water and nitrogen species in the vadose zone of a public water supply wellhead protection (WHP) area (defined by a 50-year travel time to groundwater for public supply wells) and potential transport of nitrate, ammonium, arsenic, and uranium. Thirty-two deep cores were collected and grouped by irrigation practices: pivot (n = 20), gravity (n = 4) irrigated using groundwater, and non-irrigated (n = 8) sites. Beneath pivot-irrigated sites, sediment nitrate concentrations were significantly (p < 0.05) lower, while ammonium concentrations were significantly (p < 0.05) higher than under gravity sites. The spatial distribution of sediment arsenic and uranium was evaluated against estimated nitrogen and water loading beneath cropland. Irrigation practices were randomly distributed throughout the WHP area and presented a contrasting pattern of sediment arsenic and uranium occurrence. Sediment arsenic correlated with iron (r = 0.32, p < 0.05), uranium negatively correlated to sediment nitrate (r = −0.23, p < 0.05), and ammonium (r = −0.19 p < 0.05). This study reveals that irrigation water and nitrogen influx influence vadose zone geochemistry and mobilization of geogenic contaminants affecting groundwater quality beneath intensive agricultural systems.

Распространение и формирование подземных содовых вод на водосборной площади Верхней Колымы

In the Upper Kolyma basin, mostly hydrocarbonate and sulfate waters are distributed with a predominance of alkaline earth metal cations in the composition. Hydro-carbonates with alkali metal cations (Na+ + K+), distinguished as soda, are found only in local areas in fault zones and those of granite intrusion contacts. They are the least mineralized (no more than 100 mg/dm3) in the seasonally thawed layer and river valley taliks, but even there, in separate foci at the elevation of above 1600 m, soda water springs with the mineralization exceeding 200 mg/dm3 occur. Soda waters in Cretaceous coal-bearing deposits within intermountain artesian basins are the most mineralized (up to 3000 mg/dm3). The association of these waters with deep fault zone has been assumingly traced. The sharp increase of the dissolved carbon dioxide and the carbonic acid anions in waters at local river valley sites is offered as the indicator of the current ingress of carbon dioxide into underground waters. Soda waters with mineralization exceeding 600 mg/dm3 , contained in some samples, are referred to balneal. Hydrogeochemical methods are proposed for further study of the role of deep faults in soda waters formation as well as for the possible use of them for curing and preventing diseases.

Spatio-temporal variations of nitrate pollution of groundwater in the intensive agricultural region: Hotspots and driving forces

Nitrate (NO3−) pollution of groundwater is a persistent and widespread problem worldwide, particularly in intensive agricultural regions with high nitrogen (N) surplus. Identifying spatio-seasonal variations, drivers and sources of NO3− in groundwater is key to controlling this pollution. In this study, we monitored 175 wells in areas with different irrigation practices (dryland, well irrigation and canal irrigation) in an intensive apple-planting region over a year (September 2020–October 2021) in the southern Loess Plateau, China. The integration of hydrochemical analysis, deep soil profiles, NO3− isotopic composition and a Bayesian isotope mixing model (SIAR) was used to identify the hotspots and hot moments of groundwater NO3− pollution, and main NO3− sources. The results showed that average NO3− concentrations of three regions gradually decreased from north to south, following the order of dryland region (9 mg NO3 L−1) < well irrigation region (23 mg NO3 L−1) < canal irrigation region (94 mg NO3 L−1), and orchard > residential area ≈ cereal land. In the study region, 44% of groundwater exceeded the drinking standard of the World Health Organization (50 mg NO3 L−1). The intensive apple planting in the canal irrigation regions has caused groundwater NO3− pollution, and changed hydrochemical types from HCO3−Ca‧Mg to SO4‧Cl‧NO3-Ca‧Mg. In the canal irrigation region, NO3− in the vadose zone has migrated to groundwater. The hotspots of groundwater NO3− pollution (NO3− vulnerable zones) were identified at low-altitude loess tableland and alluvial plains with canal irrigation. Irrigation and precipitation accelerated soil NO3− deep migration. The hot moments of NO3− pollution in the irrigated region was the period from the wet season to the dry season; and the “hidden reactive N pool” in the deep vadose zone (>2 m) caused a time lag of NO3− reaching into groundwater. Chemical N fertilizer and manure N applied in apple orchards were the main contributing sources of groundwater NO3− pollution in the apple-planting region. Our study highlights the significant effect of apple-planting industry development on groundwater quality.

Monoacylglycerol Lipase and Cyclooxygenase-2 Expression in Osteoarthritic Human Knees.

Background: Osteoarthritis (OA) is a progressive degenerative joint disease that presents with significant pain and functional disability. The endocannabinoid 2-arachidonoylglycerol activates cannabinoid receptors to reduce pain while its hydrolysis by the enzyme monoacylglycerol lipase (MAGL) generates arachidonic acid, the direct precursor to proalgesic eicosanoids synthesized by cyclooxygenase-2 (COX-2), highlighting the potential for crosstalk between MAGL and COX-2. While COX-2 expression in human OA cartilage has been described, the distribution of MAGL in knee osteochondral tissue has not been reported and was the goal of the current study. Methods: MAGL and COX-2 expression in International Cartilage Repair Society grade II and grade IV knee osteochondral tissue obtained from male and female subjects with OA was investigated through immunohistochemistry. Immunolocalization of both proteins was investigated within articular cartilage and subchondral bone. Results: MAGL is expressed throughout the cartilage of grade II arthritic tissue, with prominent distribution in the superficial and deep zones. Elevated expression of MAGL was evident in grade IV samples, with additional distribution observed in subchondral bone. COX-2 expression followed a similar pattern, with uniform distribution in cartilage and increased expression in grade IV tissue. Conclusions: This study establishes MAGL expression in arthritic cartilage and subchondral bone of subjects with OA. The proximity between MAGL and COX-2 suggests the potential for crosstalk between endocannabinoid hydrolysis and eicosanoid signaling in the maintenance of OA pain.

Deep hydrocarbon genesis and accumulation model of strike-slip fault reservoirs in the Yuemanxi area of the Tarim Basin

As a clean and environmentally friendly energy source, deep oil and gas has always been the focus of the oil and gas industry. The study of hydrocarbon accumulation in deep strike-slip fault zones is a challenging and important area of research in the oil and gas industry. In particular, accurately modeling oil and gas accumulation in the Yuemenxi area of the Tarim Basin presents significant difficulties due to the varying physical properties and gas composition of the Ordovician reservoirs, as well as the complex origin of oil and gas in the area. However, by calculating biomarker parameter maturity on oil samples from strike-slip faults, researchers have discovered that the light oil in the area is sourced from high maturity source rocks in the Later Caledonian, with vitrinite reflectance ranging from 0.79% to 1.11%. The complete distribution of n-alkanes and high concentration of low-carbon n-alkanes in the crude oil suggest that the fluid in the reservoir has not undergone any secondary alteration since its initial accumulation. The carbon isotope and component ratio analysis of natural gas in the Yuemanxi area indicates that the Ordovician natural gas is predominantly kerogen cracking gas. Comprehensive hydrocarbon genesis and accumulation conditions, this paper presents a differential accumulation model for the Ordovician reservoirs in the region, which were controlled by strike-slip faults and source rocks. Based on these findings, it can be inferred that there is significant potential for oil and gas exploration and development in the deeper layers of these strike-slip fault zones.

Efficacy and safety of subthreshold micropulse laser in the treatment of acute central serous chorioretinopathy.

To analyze the efficacy and safety of subthreshold micropulse laser (SML) in the treatment of acute central serous chorioretinopathy (CSC). This is a retrospective case analysis study. Totally 58 eyes of 58 patients were enrolled, and they were divided into different groups. And 39 patients were treated with SML (SML group) and 19 patients were only observed (observation group). The follow-up period was 3mo after diagnosis. The best corrected visual acuity (BCVA), central retinal thickness (CRT), superficial retinal vascular density (SRVD), deep retinal vascular density (DRVD), the superficial and deep foveal avascular zone (FAZ) area, retinal light sensitivity (RLS), perfusion area of choroidal capillary layer (CCL), subfoveal choroidal thickness (SFCT) and fundus autofluorescence (FAF) were investigated. The BCVA, CRT, SRVD, DRVD, the superficial and deep FAZ area, RLS, SFCT of SML group were significantly improved at 3mo (all P<0.05). In the observation group, only CRT, DRVD and SFCT were improved (all P<0.05). Other research items in the observation group were not significantly different from baseline (all P>0.05). At the last follow-up, the BCVA and RLS in the SML group were better than those in the observation group, and CRT was lower, SRVD and DRVD, perfusion area of CCL were larger (all P<0.05). On FAF, no change of treatment spots was found after treatment. No structural laser damage was observed on optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA), and no choroidal neovascularization was observed. SML treatment of acute CSC can improve BCVA, RLS, and perfusion area of CCL, reduce CRT, increase SRVD and DRVD, and is safe.

Raman Spectroscopy and Machine Learning Enables Estimation of Articular Cartilage Structural, Compositional, and Functional Properties.

To differentiate healthy from artificially degraded articular cartilage and estimate its structural, compositional, and functional properties using Raman spectroscopy (RS). Visually normal bovine patellae (n = 12) were used in this study. Osteochondral plugs (n = 60) were prepared and artificially degraded either enzymatically (via Collagenase D or Trypsin) or mechanically (via impact loading or surface abrasion) to induce mild to severe cartilage damage; additionally, control plugs were prepared (n = 12). Raman spectra were acquired from the samples before and after artificial degradation. Afterwards, reference biomechanical properties, proteoglycan (PG) content, collagen orientation, and zonal (%) thickness of the samples were measured. Machine learning models (classifiers and regressors) were then developed to discriminate healthy from degraded cartilage based on their Raman spectra and to predict the aforementioned reference properties. The classifiers accurately categorized healthy and degraded samples (accuracy = 86%), and successfully discerned moderate from severely degraded samples (accuracy = 90%). On the other hand, the regression models estimated cartilage biomechanical properties with reasonable error (≤ 24%), with the lowest error observed in the prediction of instantaneous modulus (12%). With zonal properties, the lowest prediction errors were observed in the deep zone, i.e., PG content (14%), collagen orientation (29%), and zonal thickness (9%). RS is capable of discriminating between healthy and damaged cartilage, and can estimate tissue properties with reasonable errors. These findings demonstrate the clinical potential of RS.

Soil Characteristics and Fertility of the Unique Jarrah Forest of Southwestern Australia, with Particular Consideration of Plant Nutrition and Land Rehabilitation

The jarrah forest is a natural ecosystem with significant endemism in the flora and fauna. The forest stands on the western edge of the ancient Great Plateau of Western Australia on the granitic shield of the Yilgarn craton (2.5 Gya). The long-term migration of soluble iron and aluminium led to the formation of bauxite ore. The regolith ore is bound by surficial topsoil and deep pallid zone kaolinite clays, primarily used in land rehabilitation. We investigated the chemical fertility of the substrates, along with key physical properties. We found the capacity of these soils to provide a stable growth medium differed considerably in their ability to retain and supply nutrients. These substrates are deficient in nitrogen, phosphorus, and micronutrients. In the topsoil, 15% of total P is plant-available, while in the pallid zone layer, only 1% of total P is available. 31P-NMR showed no organic P in the pallid zone, whereas the topsoil had significant organic P and, consequently, a supply of phosphate ions. This shows the importance of organic P in the topsoil for ecosystem nutrition when inorganic fertilisers are not applied in state-of-the-art restoration schemes.

Estimating the efficiency of primary health care services and its determinants: evidence from provincial panel data in China.

The efficiency of primary health care services is drawing increased attention worldwide, especially in developing countries. Health care reform in China has moved into the 'deep water zone' phase and is facing the dilemma of inefficiency in primary health care services, which is a critical challenge for universal health coverage. In this study, we estimate the efficiency of primary health care services in China and its determinants. A combination of a super-SBM (Slack-Based Measure) model, a Malmquist productivity index model and a Tobit model is used to study provincial panel data, and the results demonstrate the inefficiency of primary health care services in China and the variations in efficiency values between regions. Over time, the productivity of primary health care services shows a decreasing trend, mainly due to slowing technology change. Financial support is needed to improve the efficiency of primary health care services, but it is worth noting that existing social health insurance coverage decreases efficiency, while economic development, urbanization and education also have a significant impact. The findings suggest that increasing financial support should remain a priority in developing countries but that reasonable reimbursement design, appropriate payment methods and comprehensive supporting social health insurance policies are key to the next step of reform.

Zonation of The Waters of Spermonde Archipelago Base on Nutrient Concentration and Its Impact to Coral Reef Ecosystem

The Spermonde Archipelago is divided into four zones, the division of zones is based on the distribution of coral reefs, distance from the mainland, and water depth, but this condition tends to change as a result of high anthropogenic activity in the Spermonde Islands. Based on this, it is very necessary to re-zoning the Spermonde Archipelago Waters based on the condition of nutrient distribution. The research method uses the integration of remote sensing data analysis, field surveys, and secondary data which are then analyzed using the Boleean method for re-zoning. The results showed that the nutrient, in this case, chlorophyll-a, was concentrated in the deep zone (near the mainland) and the concentration was higher during the rainy season, this condition affected the coral reef cover in the Spermonde Islands. Based on these conditions, the Spermonde Islands waters are divided into three zones, namely the inner zone with high nutrient conditions with a benthic cover dominated by fleshy macroalgae, the middle zone with low nutrient conditions with crustose coralline dominance, and the outer zone with low nutrient conditions with algal turf dominance turf alga/corals.

Deformation patterns of icy satellite crusts: Insights for tectonic balancing and fluid migration through structural analysis of terrestrial analogues

The icy satellites of the Solar System, such as Europa and Ganymede, show widespread evidence for tectonic structures that provide insights to infer the kinematics and the mechanical properties of their crusts. Their investigation is pivotal for the understanding of the regimes responsible for their formation and the connection with subsurface layers. Icy satellite tectonics is dominated by extension and shear regimes, while paucity evidence for compression represents an open issue. Structural investigation is constrained at regional-scale coverage of the remote sensing imagery. The study of analogues on Earth represents a strong support for the geologic analysis of the icy satellites. Glaciers represent optimal terrestrial analogues, showing deformation styles at multiple scale similar to those in the icy satellites, and being the excellent sites to further explore, verify and confirm what observed through remote sensing on the icy satellite geology. Although the formation processes differ, the similarity of their structures at surface allows quantifying and predicting the state of deformation in the icy satellites at different scales of investigation. Moreover, glacier deformation shows corridor-like pattern (i.e., shear zone with internal associated deformation), analogous to the main tectonic setting recognized in the icy satellites. This work aims to investigate and compare the tectonic structures of the glaciers with those on the icy satellites, by means of multi-scale approach of both remote-sensing and field survey. We present a structural investigation in the Russell and Isunguata Sermia glaciers, located at the western margin of the Greenland Ice Sheet, where field campaign has been conducted by the UPSIDES project under the Europlanet 2024 RI's Transnational Access field analogue in Kangerlussuaq. This project aims i) to achieve knowledge of the ice tectonic setting at local-scale, ii) to compare with that at regional-scale, and in turn iii) to better understand the tectonic styles and to characterize structures that are exclusively identified at regional-scale (such as in the icy satellites). Field measurements of brittle structures (fractures/faults), concerning the quantification of their azimuth, dip, length, width, throw and spacing, have been performed. In parallel, remote sensing analysis, concerning structural mapping on areas including the locations of the investigated outcrops, allowed to derive the same quantities at regional-scale. In this way, both local- and regional-scale tectonic setting has been investigated, and the stress analysis has been performed. Obtained results have been compared and in turn related with areas that show similar tectonic setting on Ganymede. In particular, the lack of detection of the regional-scale counterpart of the low-angle structures, and in particular the compressional ones that have been recognized at local-scale in the investigated glaciers, has been related to the lack of evidence of such structures in the icy satellite's surfaces. Such comparison allows us to infer a tectonic model that accounts for the existence of deep zones of balanced deformation depicted by diffuse and low-angle structures, and can explain their limited detection at surface and regional-scale investigations.

A relocated earthquake catalog and ground motion database for the southern East African rift system

The southern East African rift system (EARS) is geologically rare considering its early-stage continental rift setting combined with a deep seismogenic zone. Several seismically vulnerable communities are located within this tectonically active region, resulting in a significant seismic risk. However, the ground motion and seismic hazard analyzes necessary to increase the earthquake preparedness in the region have been limited due to the relatively short instrumentation history and scarce ground motion data available. Here, we present a newly compiled ground motion database for the southern EARS which is critically lacking and preventing local ground motion studies. This database includes a regional catalog of 882 earthquakes spanning 1994–2022 (magnitudes 3–6.5) with available waveform records within epicentral distances of 300 km. Three different velocity models were used to relocate 256, 255, and 252 events, respectively, to quantify depth sensitivity, relocating events down to depths of 35–40 km. The final database contains 10,725 time-series records from 353 stations along with P- and S-wave phase arrivals for each record. The ground motion database contains peak ground acceleration and velocity and 5% damped pseudo-spectral acceleration for 291 frequencies from 1.0 to 30 Hz for the horizontal components. In addition, a Fourier amplitude spectrum table for 212 frequencies from 0.1 to 30 Hz is included. The database is accessible through the ISC repository ( https://doi.org/10.31905/4GGVBFBE ).