Salt Lake Research Articles

Hydrogeochemical characteristics and evolution of formation water in the continental sedimentary basin: A case study in the Qaidam Basin, China.

In deep formations, oil or gas reservoir rocks are generally accompanied by groundwater with high total dissolved solids (TDS), commonly referred to as "formation water". The enrichment of trace and/or metallic elements such as K, B, Li, Br, Sr in this type of groundwater holds significant industrial values and socioeconomic benefits. However, the processes involved in the burial and generation of formation water remain not fully understood. In this study, totally 468 sets of major ions and trace elements were collected from current study and literatures to investigate the hydrogeochemical characteristics and evolution mechanisms of formation water from different regional geological structure units in Qaidam Basin, China. The results indicated that TDS of formation water in Western (QW), Central (QC) and Northern (QN) units of Qaidam basin ranged from 173 to 290g/L, 101 to 152g/L and 32 to 73g/L, respectively, which were several to dozens of times higher than those of seawater, but lower than those of intercrystalline brine and salt lake water. The enrichment of Ca, Li, B, Br and depletion of Mg and SO42- were observed in the formation water in comparison to seawater and salt lake water. Formation water especially in QC and QW was identified as typical dissolved brine of terrestrial rock origin, experiencing prolonged water-rock interactions. However, the time and degree of water-rock interaction and metamorphism differed regionally due to the sedimentary history and patterns of Qaidam Paleolake. Overall, the large paleolake deposits under the control of multiple tectonic movements laid the material foundation for the burial and generation of the formation water, and a variety of fluids and deep faults became the sources and migration channels for formation water. It mainly experienced two stages, including the sedimentary process of saline strata and the transformation in the later period.

Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA

Great Salt Lake is a critical habitat for migratory birds that is threatened by elevated metal concentrations, including mercury (Hg) and lead (Pb), and is subject to severe hydrologic changes, such as declining lake level. When assessing metal profiles recorded in Great Salt Lake sediment, a large data gap exists regarding the sources of metals within the system, which is complicated by various source inputs to the lake and complex biogeochemistry. Here, we leverage Hg and Pb stable isotopes to track relative changes in metal source contributions to Great Salt Lake over time. Mercury and Pb concentrations increase in sediments deposited after 1920 and peak between 1965 and 1995, following closure of several local smelters and the onset of increased emission controls. The nominal associations above are confirmed via Hg stable isotopes in pre-1920 background sediments, which reflect atmospheric inputs from regional and global origin, whereas Hg and Pb stable isotopes together indicate that elevated metal concentrations in mid-late 20th century sediments reflect increased mining/smelting inputs. The observed minimal rebound towards pre-1920 Pb isotope signatures in 21st century sediments indicates that mining/smelting inputs, though reduced, remain a primary source of Pb to Great Salt Lake. In contrast, the more pronounced rebound of Hg stable isotope signatures to pre-1920 values indicate a greater contribution of atmospheric inputs of regional/global origin to current Hg inputs, though Hg concentrations are ~10 times greater than pre-1920 background values due to global increases in atmospheric Hg concentrations or possibly slow recovery from local contamination. The importance of regional/global Hg sources to the system suggests that reductions in Hg bioaccumulation in the open water food webs of Great Salt Lake are more dependent on national and global reductions in Hg emissions and management strategies to limit methylmercury production within system. This work highlights the utility of using coupled Hg and Pb stable isotope values to assess trace metal pollution sources and pathways in aquatic systems.

Carbon sequestration behavior of magnesium oxychloride cement based on salt lakes magnesium residue and industrial solid waste

With the extensive utilization of lithium-ion battery in the electric vehicle and energy storage field, the consumption of lithium has been sharply increasing. Lithium resource occurrence area were facing increasing environmental pressure, particularly the magnesium residue (MR) produced in the lithium extraction process, and a sustainable exploitation pathway have not been established. In the framework of "net-zero", MRs were onverted to Salt lake magnesium oxide (SL-MgO) which was characterized by various elemental and surface analysis methods. Magnesium oxychloride cement (MOC) was prepared form SL-MgO and two industrial solid wastes [fly ash (FA) and phosphogypsum (PG)], and its carbon sequestration capacity was analyzed and evaluated. If all the MRs produced from the lithium extraction process were used to manufacture MOC materials for CO2 sequestration. When the PG content was 20 %, the CO2 sequestration capacity of the MOC was 0.29 kg/m2, the compressive strength was 85.30 MPa, and the MOC neutralized 220.10 % of the CO2 emissions from the lithium extraction process. In this procedure, evidence was found of the typical metastable carbonate products identifiable. Overall, utilizing MRs and industrial solid waste to manufacture new low-carbon MOCs may become the most direct and effective countermeasures to alleviate environmental pressure in these regions.

Selective recovery of lithium from aqueous solution with hydrophobic deep eutectic solvent based on quantum chemical calculations and experimental investigation

Developing green and efficient extractants for selectively recovering lithium from salt lake brine is beneficial for alleviating the increasingly growing demand for lithium resources. This study developed a novel hydrophobic deep eutectic solvent (HDES) for selective recovery of Li+ from simulated salt lake brine solutions. Under the optimal experimental parameters, the single extraction efficiency of Li+ was 70.18%, β (Li+/ Na+) and β (Li+/Mg2+) were 22.32 and 947.58, respectively. Cycle experiments verified the high stability and good cycle performance of HDES. The conditions affecting the extraction efficiency of Li⁺ were optimized through experiments, and the high stability and good cyclic performance of HDES were verified. The extraction ability and mechanism of HDES for different metal ions were studied based on FTIR spectra combined with density functional theory. The calculation results showed that the order of extraction capacity of HDES for metal ions was: Li+>Na+>Mg2+. This calculation results were identical to the experimental results. This research will help develop HDES for the selective recovery of lithium from aqueous solutions containing high concentrations of Mg2+, helping to address the urgent global demand for lithium resources.

Conflict, politics, and ideology: Human remains in central Kansas Little River Focus council circles

More than a century after their discovery, archaeologists continue to debate the purpose of structures, known as council circles, found in the Little River focus of central Kansas. Waldo Wedel ([1940a.] Rv2: Ossuary. This is the field notes for the council circle excavations at Tobias in 1940. Waldo R. Wedel and Mildred Mott Wedel Papers, Box 42. National Anthropological Archives, National Museum of Natural History, Smithsonian Institution, Washington, DC.) thought they were ossuaries. Later, he suggested solstice registers (Wedel [1967a] The Council Circles of Central Kansas: Were They Solstice Registers? American Antiquity 32:54–63.). Vehik ([2002]. Conflict, Trade, and Political Development on the Southern Plains. American Antiquity 67:37–64; [2022]. Ideology and Political Development: The Little River Focus Council Circles of Central Kansas. In People in a Sea of Grass: Archaeology’s Changing Perspectives on Indigenous Plains Communities, edited by Matthew E. Hill, and Lauren W. Ritterbush, pp. 72–97. University of Utah Press, Salt Lake City.) proposed they were ritual facilities built as part of a strategy to increase political power, wealth, and authority. Baugh and Blaine ([2017]. Enduring the Violence: Four Centuries of Kirikir’i‧s Warfare. Plains Anthropologist 62(242):99–132.) argued the presence of human bone indicated the facilities were fortifications. Investigated here is the distribution of human bone in council circles and other Little River focus contexts. Also explored are several test implications for their use as fortifications. Results indicate that the council circles were not fortifications, but instead reflect continued attempts to increase power and authority.

Peloids in Skin Care and Cosmeceuticals

Peloids are mixtures of clays, sediments, or peat with mineral–medicinal water or seawater, or salt-lake water used in spa therapy for different treatments, including dermatological ones. The origin of peloids can be natural; that is, they are formed in situ at the place where the thermal water emerges or on the shores of the sea or salt lake, or they are prepared ad hoc from high-quality materials, such as clays or peat. Peloids are also used as cosmeceuticals in skin care to treat different skin disorders and/or conditions, such as psoriasis, eczema, and other scaly disorders, sensitive skin, and acne. This review reports all available scientific data concerning the effects and specific activities of peloids in skin care and cosmeceuticals, providing a better understanding of the clinical and cosmetic benefits. Finally, the safety and regulation of peloids are also discussed.

Characteristics and Material Sources of Global Brine‐Type Lithium Deposits

ABSTRACTLithium brine deposits are mainly distributed in the three major plateaus of the world: the Qinghai‐Tibet Plateau in China, the Andean Plateau in South America and the Western Plateau in North America, forming the three major lithium ore‐forming regions in the world. The lithium‐rich salt lakes on the Qinghai‐Tibet Plateau in China include Zabuye Salt Lake, Nam Co Salt Lake and Da Qaidam Salt Lake. The lithium‐rich salt lakes on the Andean Plateau in South America mainly include Uyuni Salt Lake and Atacama Salt Lake, while the lithium‐rich salt lakes on the Western Plateau in North America mainly include the Salton Sea and Clayton Valley. Based on a large amount of data collection, this article analyses the characteristics of the lithium‐rich salt lakes on the three plateaus, and concludes that the tectonic background of the lithium‐rich salt lakes is mostly associated with subduction‐collision orogenic belts, surrounded by abundant igneous rocks. The main source of lithium is deep‐seated hydrothermal fluids leaching lithium from rocks and bringing it to the surface in the form of hot springs, replenishing the salt lakes.

Drought conditions disrupt atmospheric carbon uptake in a Mediterranean saline lake

Abstract. Inland saline lakes play a key role in the global carbon cycle, acting as dynamic zones for atmospheric carbon exchange and storage. Given the global decline of saline lakes and the expected increase of periods of drought in a climate change scenario, changes in their potential capacity to uptake or emit atmospheric carbon are expected. Here, we conducted continuous measurements of CO2 and CH4 fluxes at the ecosystem scale in an endorheic saline lake of the Mediterranean region over nearly 2 years. Our focus was on determining net CO2 and CH4 exchanges with the atmosphere under both dry and flooded conditions, using the eddy covariance (EC) method. We coupled greenhouse gas flux measurements with water storage and analysed meteorological variables like air temperature and radiation, known to influence carbon fluxes in lakes. This extensive data integration enabled the projection of the net carbon flux over time, accounting for both dry and wet conditions on an interannual scale. We found that the system acts as a substantial carbon sink by absorbing atmospheric CO2 under wet conditions. In years with prolonged water storage, it is predicted that the lake's CO2 assimilation capacity can surpass 0.7 kg C m2 annually. Conversely, during extended drought years, a reduction in CO2 uptake capacity of more than 80 % is expected. Regarding CH4, we measured uptake rates that exceeded those of well-aerated soils such as forest soils or grasslands, reaching values of 0.2 µmol m−2 s−1. Additionally, we observed that CH4 uptake during dry conditions was nearly double that of wet conditions. However, the absence of continuous data prevented us from correlating CH4 uptake processes with potential environmental predictors. Our study challenges the widespread notion that wetlands are universally greenhouse gas emitters, highlighting the significant role that endorheic saline lakes can play as a natural sink of atmospheric carbon. However, our work also underscores the vulnerability of these ecosystem services in the current climate change scenario, where drought episodes are expected to become more frequent and intense in the coming years.

Abstract Su304: The Effect of Time to DC Shock on Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest with Recurrent Shockable Rhythm

Objective: The optimal timing for defibrillation attempts in out-of-hospital cardiac arrest (OHCA) patients with recurrent shockable rhythms [ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT)] is uncertain. This study examined the association between "time to DC shock" and the return of spontaneous circulation (ROSC) in OHCA patients with recurrent shockable rhythms. Methods: This was a retrospective analysis of data from the Salt Lake City Fire Department (SLCFD) from 2012 to 2023. Rhythm-filtering technology, used since 2012, enabled real-time and accurate interpretation of cardiac rhythms during CPR, with local protocols allowing early defibrillation for recurrent VF/ pulseless VT cases. Patients who experienced four or five episodes of shockable rhythms and received defibrillation were included. Generalized estimating equation (GEE) analysis was used to evaluate the association between time to shock preceding recurrent defibrillation and ROSC. Results: A total of 142 patients were included, with a mean age of 59.7 ± 15 years; 105 (73.9%) were male, 63 (44.4%) arrested in public locations, and 101 (71.1%) had witnessed arrests. Adjusted GEE analysis revealed that longer time to shock was associated with lower odds of achieving ROSC (OR: 0.81, 95% CI: 0.72–0.93, p = 0.005). Every one-minute delay in defibrillation is predicted to decrease the likelihood of achieving ROSC by 19%. Conclusion: In patients with recurrent shockable rhythms, every one-minute delay in delivering a shock was associated with a statistically significant 19% reduction in the chance of achieving ROSC. This finding highlights the importance of reducing the time to defibrillation in managing recurrent shockable rhythms and suggests reevaluating the current recommendation of two-minute intervals for rhythm check and shock delivery.

A molecular assessment of species boundaries and relationships in the Australian brine shrimp Parartemia (Anostraca: Parartemiidae).

Australian salt lakes contain a diverse range of endemic invertebrates. The brine shrimp Parartemia is among the most speciose and salt-tolerant of these invertebrates. The morphotaxonomy of Parartemia is well established but there has only been limited molecular assessment of the phylogenetic relationships and boundaries of the morphospecies. We used multiple genetic markers (nuclear 28S and mitochondrial 16S and COI ) and tree-building methods (Bayesian inference and maximum likelihood) to investigate the phylogeny of Parartemia . We also used species delimitation methods to test the validity of morphological species designations. The data set included all but 2 of the 18 described Parartemia morphospecies, collected from a total of 93 sites from across southern Australia plus some sequences from GenBank. The results identified large amounts of molecular divergence (e.g. COI P- values of up to 25.23%), some groups of closely related species (which also usually shared some morphological similarities) and some distinctive species, although the relationships among divergent lineages were generally not well resolved. The most conservative set of results from the species delimitation analyses suggests that the morphotaxonomy is largely accurate, although many morphospecies comprised divergent genetic lineages separated by COI P- values of up to 17.02%. Two putative new morphospecies, three cryptic species and one synonymy were identified. Our findings improve the knowledge of Parartemia taxonomy and will facilitate the development of future studies and conservation of this taxon.

Potential Impact of Rapid Molecular Microbiologic Diagnosis for Mechanically Ventilated Children in Intensive Care With Suspected Pneumonia

Background: Lower respiratory tract infections (LRTIs) remain a leading cause of community-acquired and nosocomial infection in children and a common indication for antimicrobial use and intensive care admission. Determining the causative pathogen for LRTIs is difficult and traditional culture-based methods are labor- and time-intensive. Emerging molecular diagnostic tools may identify pathogens and detect antimicrobial resistance more quickly, to enable earlier targeted antimicrobial therapy. Methods: This is a single-center, prospective observational laboratory study evaluating the use of the Biofire FilmArray pneumonia panel (FA-PP) (BioFire Diagnostics, Salt Lake City, UT) for bronchoalveolar lavage specimens from mechanically ventilated children admitted with suspected or presumed pneumonia. We aimed to determine its feasibility and utility for identifying pathogens, antimicrobial resistance and its potential influence on antibiotic prescribing. Results: We analyzed 50 samples taken from 41 children with a median age of 6 months. Positive agreement between culture and FA-PP was 83% and negative agreement was 76%. Agreement between FA-PP (mecA/C or MREJ) and culture was high for methicillin-resistant Staphylococcus aureus. In 3 cases, extended-spectrum beta-lactamase-producing Gram-negative organisms were detected by culture and not FA-PP. Hypothetically, FA-PP results would have affected antimicrobial prescribing in approximately half the cases (24, 48%). Conclusions: FA-PP is a useful adjunct to traditional culture methods in mechanically ventilated children with LRTIs and may influence clinical decision-making regarding antibiotic escalation or stewardship.

Photo-fenton catalysis degradation of 4-dodecylmorpholine by heterogeneous microprocessor Cu2O/SnO2

The increasing demand for potash has led to the increased use of 4-dodecyl morpholine (DMP), an important froth flotation agent for the extraction for potash extraction by “reverse flotation-cold crystallization”. As it is not easy to be stable and decompose in its natural state, it has seriously endangered the environment of salt lakes and the development of salt lake resources. The development of a safe and harmless catalytic system to accomplish the degradation and removal of DMP is urgent. Herein, A Cu2O/SnO2/PDA (CSP) nanoparticle with a synergistic effect of photocatalysis and Fenton-like catalysis was developed, and the CSP had a good photothermal conversion efficiency. Under 808 nm NIR irradiation, not only the catalyst activity was enhanced, but also the complexation rate of electron-hole pairs was reduced, which effectively increased the degradation efficiency of DMP (an increase of about 31.56 %). In addition, by analyzing the degradation products of DMP, the possible pathways of the DMP degradation process were proposed and, at the same time, the degradation catalytic system we used was proved to be safe and harmless. A new pathway is provided for the degradation and removal of DMP in the salt lake environment.

Genome-Based Classification of 'Haloarcula aidinensis' and Description of Three Novel Halophilic Archaea Isolated from an Inland Saline Lake, Coastal Saline Soil, and a Marine Solar Saltern.

'Haloarcula aidinensis' was described by a pioneer Chinese scientist focused on halophilic archaea thirty years ago, and the type strain of 'Haloarcula aidinensis' was recently classified based on phylogenetic, phylogenomic, and comparative genomic analyses. Other three novel halophilic archaeal strains, CK38T, DT43T, and SYNS111T, isolated from diverse saline environments in China, were simultaneously subjected to polyphasic classification. 'Haloarcula aidinensis' A5 was found to be related to Haloarcula amylolytica, while strains CK38T, DT43T, and SYNS111T represented three novel species of Haloarcula based on phylogenetic, phylogenomic, and comparative genomic analyses. These strains can be distinguished from other species within the genus Haloarcula based on multiple phenotypic characteristics. The major phospholipids, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and phosphatidylglycerol sulfate can be detected in these strains, while the glycolipid profiles of these strains are diverse. Strains A5 and DT43T contained glucosyl mannosyl glucosyl diether and a diglycosyl diether, while other strains CK38T and SYNS111T had sulfated mannosyl glucosyl diether and mannosyl glucosyl diether. Thus, strain A5 should be a reference strain of Har. amylolytica and three novel species of Haloarcula, Haloarcula sediminis sp. nov., Haloarcula brevis sp. nov., and Haloarcula regularis sp. nov. are proposed to accommodate strains CK38T (= CGMCC 1.62732T = JCM 36675T), DT43T (= CGMCC 1.18924T = JCM 36146T), and SYNS111T (= CGMCC 1.62601T = JCM 36149T).

SALINITY-Induced Changes in Diversity, Stability, and Functional Profiles of Microbial Communities in Different Saline Lakes in Arid Areas

Saline lakes, characterized by high salinity and limited nutrient availability, provide an ideal environment for studying extreme halophiles and their biogeochemical processes. The present study examined prokaryotic microbial communities and their ecological functions in lentic sediments (with the salinity gradient and time series) using 16S rRNA amplicon sequencing and a metagenomic approach. Our findings revealed a negative correlation between microbial diversity and salinity. The notable predominance of Archaea in high-salinity lakes signified a considerable alteration in the composition of the microbial community. The results indicate that elevated salinity promotes homogeneous selection pressures, causing substantial alterations in microbial diversity and community structure, and simultaneously hindering interactions among microorganisms. This results in a notable decrease in the complexity of microbial ecological networks, ultimately influencing the overall ecological functional responses of microbial communities such as carbon fixation, sulfur, and nitrogen metabolism. Overall, our findings reveal salinity drives a notable predominance of Archaea, selects for species adapted to extreme conditions, and decreases microbial community complexity within saline lake ecosystems.

The interaction and the interface migration between salt lake water and fresh groundwater in small salt lake: a case of Lake Cherigele, Badain Jaran Desert, China

The interaction and the interface migration between salt lake water and fresh groundwater in small salt lake: a case of Lake Cherigele, Badain Jaran Desert, China

Distribution and Evaporation Characteristics of Rb and Cs in Complex Salt Brine Systems

The brine in salt lakes is rich in resources, including not only K, Mg, and B, but also valuable trace elements. During the enrichment and extraction of trace elements (Rb, Cs) from sodium sulfate subtype salt lake brines, the process is significantly influenced by the presence of other coexisting ions such as Li+, K+, and Mg2+.The physical and chemical properties of K+ are extremely similar to those of Rb+ and Cs+, and its impact on the extraction of Rb+ and Cs+ is particularly significant. When K+, Rb+, and Cs+ coexist, they can form solid solutions such as [(K, Rb)2SO4], [(K, Cs)2SO4], and [(Rb, Cs)2SO4]. The formation of these solid solutions can lead to severe losses of Rb and Cs during the evaporation process of the brine, resulting in low yield. In response to the aforementioned issues regarding the evaporation process of Rb and Cs, this paper uses the aqueous-salt system phase diagram as a guide and combines experimental research with simulation calculations to study the enrichment patterns of trace elements Rb and Cs in the Na+, K+//Cl-, CO32-, SO42--H2O aqueous-salt system, as well as the migration mechanism of Rb and Cs.

Interaction regimes of surface water and groundwater in a hyper-arid endorheic watershed on Tibetan Plateau: Insights from multi-proxy data

The interaction between surface water and groundwater is crucial for the management of water resources and the preservation of ecosystems within arid basins, but knowledge on their interaction regimes at the watershed scale remains relatively limited. The present research synthesizes a range of multi-proxy data, including satellite thermal infrared remote sensing, water piezometric level, hydrochemical analyses, and isotopic signatures (2H, 18O and 222Rn), to elucidate the interaction dynamics and patterns between surface water and groundwater within a representative hyper-arid closed basin on Tibetan Plateau. The findings indicate that the water in the basin originates primarily from the glacier/snow melt water and precipitation in the mountainous regions, and would experience multiple but spatially heterogeneous interactions between river and aquifers from the mountain pass to the tail salt lakes after entering the basin. Water interaction in the piedmont alluvial plain is dominated by the pattern of river seepage into aquifers with a water flux of 25.82 m3/s, which drives the development of hierarchical groundwater flow systems in the basin. The interaction pattern converts to groundwater discharge of the local groundwater flow system at the front of alluvial fan plain, which forms the principal spring-fed rivers and the predominant overflow zone in the basin with the groundwater discharge flux of 3.22 m3/s. Most of these discharged groundwaters would infiltrate back into the aquifers in the middle-upper part of the loess plain with the river water leakage flux of 2.89 m3/s. River water and phreatic groundwater present a gradual enrichment of hydrochemcial components and water stable isotopes (2H and 18O) along the flow path due to the intense evaporation in the loess plain. The multiple water interactions between surface water and groundwater lead to the anomalous distribution of fresh water in the middle-lower stream area, which is related to the intermediate groundwater flow system and the local variable groundwater flow system. Water interaction in the lowest salt-marsh plain is in the pattern of regional groundwater flow system discharge into the tail salt lakes under natural condition, but evolves to only discharge into the artificial brine extraction canals rather than the tail salt lakes after decades of brine exploitation. Our findings provide a conceptual and preliminarily quantificational understanding of the interaction regimes between surface water and groundwater in large arid closed basins at the watershed scale.

Unveiling the paleosalinity constraints on southern peri-Pannonian Lower Miocene lacustrine systems in Serbia and Bosnia and Herzegovina: Lopare (Dinaride Lake System) versus Toplica basin (Serbian Lake System)

Early Neogene saline lakes were widely developed across Central Paratethys, particularly across its „Dinaride-Anatolide“ landbridge (area of Dinarides, Balkans). The constraints on Lopare (western part of Jadar block; eastern Bosnia and Herzegovina) and Toplica (Jastrebac Mt., central Serbia) Neogene paleolakes provide a better understanding of deep-time climate evolution. The study focused on early Neogene paleolacustrine configuration, paleogeography, and the factors affecting a considerable paleosalinity increase. The study integrated available records on the predominantly Lower Miocene sedimentary sequence by analyzing and interpreting several paleosalinity markers (inorganic geochemical proxies, mineralogical data). The constraints on paleosalinity markers are afterward coupled with rather complex tectonic inferences. The two wellbores drilled in the Lopare and Toplica basins expose Neogene sections from which the critical paleosalinity markers are extracted (drillhole depths up to 350 and 1000 m, respectively). The mineral searlesite (NaBSi2O5(OH)2), and high B/Ga, markers of alkaline and arid paleoenvironmental lacustrine conditions, suggested intense evaporation (frequent drought periods). The evaporation was associated with paleoclimatic conditions during the Miocene Climatic Optimum. The Early Neogene arid climate and frequent evaporation episodes resulted in significant salinization of the Lower Miocene Lopare lacustrine sequence. The salinity in the Lopare sequence changed its character between brackish and saline, as evidenced by S/TOC and Ca/(Ca + Fe) ratios (TOC—Total Organic Carbon). At the same time, the salinity in the early Toplica basin was significantly lower and characterized by freshwater and brackish environments. The salinity variations between Toplica and Lopare were further exposed by Fe/(Ca + Mg), (Al + Fe)/(Ca + Mg), and C-value, yielding the change in the (paleo)water column. These markers further indicated the influence of warm climate conditions, consistent with the Miocene paleoclimatic record. Regarding paleogeography and Early Neogene tectonics, the results showed that before the Middle Miocene Badenian transgression, the Paratethyan Sea had no interference with the investigated intramontane lacustrine basins.

Irrigation rates and turfgrass evapotranspiration in cities with contrasting water availability

AbstractAs water scarcity is worsened by drought and climate change, there is more interest in efficient management of urban irrigation, requiring understanding of the drivers of evapotranspiration (ET) and the role of irrigation inputs. We developed and validated a method to accurately measure ET of turfgrass lawns in contrasting climates using portable static chambers. We made in situ measurements of ET and irrigation inputs in lawns across three metropolitan areas in the United States with varying climatic conditions, water availability, and water conservation policies: Salt Lake Valley, Utah; San Fernando Valley, California; and Tallahassee, Florida. In full sun, mean daily ET estimates (ETsun) were 0.7 ± 0.4 mm day−1 in Tallahassee, 1.6 ± 0.8 mm day−1 in Los Angeles, and 3.3 ± 1.1 mm day−1 in Salt Lake Valley. In the shade, daily ET estimates (ETshade) were two to three times lower. In all three regions, ET was primarily driven by solar radiation (I0) and atmospheric vapor pressure deficit (D). Across the cities, irrigation rates were a key driver of ET, along with I0 and D. Daily irrigation ranged from 0 mm day−1 in Tallahassee (most were unirrigated) to 1.9 ± 1.2 mm day−1 in Los Angeles and 5.1 ± 2.9 mm day−1 in Salt Lake Valley. ET increased linearly with irrigation up to ~3 mm day−1, after which ET remained relatively constant despite irrigation increases. Our results highlight the importance of accounting for nonlinear responses and shading effects on ET in developing accurate irrigation recommendations.

The Effectiveness of Face Mask Mandates on COVID-19 Transmission in Utah.

Throughout the COVID-19 pandemic, the effectiveness of face mask mandates was intensely debated. The objective of this study was to describe how face mask mandates at the state, county, and local levels differed in their effectiveness in reducing the number of COVID-19 cases in the jurisdiction where the mandate was implemented and throughout Utah. We used publicly available data from the Utah Department of Health and Human Services. We calculated the effectiveness of face mask mandates (EFm) in each local health district after 3 key mandates: the enactment of face mask mandates in Salt Lake and Summit counties (SLSC) on June 28, 2020, and June 27, 2020, respectively; the enactment of a statewide face mask mandate on November 9, 2020; and the lifting of the statewide face mask mandate on April 10, 2021. Most counties in Utah had a reduction in the growth rate of COVID-19 cases after enactment of face mask mandates. We found an average 11.9% reduction in EFm after the introduction of the SLSC face mask mandates, with 8 of 13 local health districts experiencing a reduction, and an average 12.7% reduction after introduction of the statewide mandate, with 12 of 13 local health districts experiencing a reduction. After mandates were lifted, many counties had an increase in EFm. Face mask mandates were an effective way to reduce transmission of COVID-19 in local jurisdictions and in neighboring jurisdictions in Utah. Our evidence supports the use of face mask mandates as a way to prevent disease transmission and be better equipped to respond to future pandemics.