Mineral Changes Research Articles

Effects of Changes in Physical Properties of Porous Media and Fluid under Supercritical CO2 Huff-n-Puff in Low-Permeability Reservoir

The low-permeability reservoirs have abundant reserves and broad development prospects, and the supplementary energy methods have gradually become a hot research topic. In addition, the technology of enhanced oil recovery through supercritical CO2 injection is becoming increasingly mature; however, the changes in reservoir properties at the microscopic level still need further investigation. In this study, natural rock cores from low-permeability reservoirs were used to simulate reservoir conditions and conduct supercritical CO2 injection experiments for energy supplementation. The study aimed to investigate the changes in reservoir microstructure, minerals, and crude oil properties before and after the experiments. The research results indicate that after supercritical CO2 injection into the reservoir, it dissolves in the formation water to form carbonic acid. Under the effect of dissolution, the porosity of the low-permeability reservoir increases by 1.06–5.68%, and permeability can be improved by 40–60%. The rock becomes more water-wet and less oil-wet. The content of calcite and feldspar in the rock minerals decreases due to the dissolution of carbonic acid, resulting in a reduction in plagioclase and calcite. After the CO2 injection, the light components (C8–C10) in the crude oil in the rock cores decreased by approximately 14.6%, while the heavy components (C16–C39) increased by 6.99%. The viscosity of the crude oil decreases, and its flowability is further enhanced.

Soil aggregate-associated organic carbon mineralization and its driving factors in rhizosphere soil

Understanding the determinants of soil carbon mineralization at both the aggregate and rhizosphere levels is crucial for providing precise feedback on climate change. However, the specific patterns and relative contributions of rhizosphere effects on carbon mineralization at the aggregate scale remain unclear. To address this, we conducted an incubation experiment to examine the impact of warming on soil carbon mineralization. We also assessed variations in microbial activities and soil properties across different aggregates in both rhizosphere and non-rhizosphere soils, while exploring how the rhizosphere effects modulated the response of soil respiration to warming. Our findings revealed that rhizosphere soil provides a favorable environment for microbial activities through increased nutrient input and aggregate stability, leading to significant increases in microbial biomass and enzyme activity, thus promoting soil carbon mineralization. Moreover, the spatial heterogeneity of soil aggregates contributes to the differentiation and diversity of microbial community distribution, which further enhances the diversification of carbon mineralization at the aggregate level. Notably, macroaggregates play a significant role in soil carbon flux, making a substantial contribution to carbon turnover in the ecosystem. The partial least squares (PLS) path analysis indicated that the rhizosphere positively increased the contributions of soil properties and microbial variables to the overall amount of soil cumulative mineralization, with soil nutrients playing a crucial role among these factors. These findings highlight the complex regulatory role of substrate quality in soil carbon mineralization dynamics at the aggregate scale, underscoring its far-reaching implications for accurately predicting the feedback to climate change in soil carbon mineralization.

Bentonite alteration and retention of cesium and iodide ions by Ca-bentonite in alkaline and saline solutions

The nuclide retention capacity of bentonite can be affected by changes in the repository environments, such as alkaline and saline conditions. This study investigated the effects of bentonite alteration on the nuclide retention capacity of Ca-bentonite. A series of batch experiments was conducted at room temperature (25°C) for 7 d using Ca-bentonite and alkaline and saline solutions spiked with 10 mM each of cesium (Cs) and iodide (I). Cation exchange and a decrease in the basal spacing (d001) of montmorillonite were observed, as was the formation of zeolite minerals in bentonite samples reacted with an alkaline solution (0.1 M KOH and 0.1 M NaOH). Illitization, partial dissolution, and aluminum ions substitution for silicon ions in the tetrahedral sheets of montmorillonite were also observed in the bentonite samples reacted with an alkaline solution (0.1 M KOH). However, the Cs retention capacity of bentonite was not significantly affected by the mineral and physicochemical changes of montmorillonite in alkaline and saline solutions. Competing ions, including Mg, Ca, K, and Na ions in solutions with high ionic strength, all played a crucial role in Cs retention. Further, the cation exchange capacity of bentonite samples increased due to the formation of zeolite minerals under alkaline conditions.

Magnetic Mineral Consistency Analysis the main ingredients of cement and Rowmix materials with Magnetic Susceptibility Method using Bartington Magnetic Susceptibility Type B (MS2B)

Cement has hydraulic properties (mixed with water) will form a bond and harden. Cement-making materials consist of the main ingredients (Limestone, Iron Sand, Silica, and Clay) which are the ingredients in the manufacture of Rowmix in the Rowmill. In the main ingredient there is a magnetic mineral content for the manufacture of Component Compoun. To see changes in magnetic minerals from the cement manufacturing process, it is necessary to analyze the consistency of the material until the initial manufacture. The purpose of this study was to determine the consistency of the magnetic mineral as the main ingredient of cement in the Rowmix manufacturing process. The research method used is rock magnetism using a Bartington Susceptibility Meter Type B (MS2B) which can measure based on mass and volume with 2 different frequencies, namely Low Frequency and High Frequency. This measurement uses 6 different samples, namely the main ingredients of cement (Limestone, Irond Sand, Silica, Clay) and Rowmix materials (Rowmix 1 (RX1) and Rowmix 2 (RX2). From these measurements, the susceptibility values obtained from the main ingredients including Limestone approx. 23.7 x 10−8 m3/kg - 46.6 x 10−8 m3/kg, Irond Sand ranged from 470 x 10−8 m3/kg - 1791.1 x 10−8 m3/kg, Clay ranged from 852.7 x 10−8 m3/kg - 986.4 x 10−8 m3/kg, Silica ranges from 148.2 x 10−8 m3/kg - 166.9 x 10−8 m3/kg, while in Rowmill I process (Rx1) around 133, 4 x 10−8 m3/kg - 180.3 x 10−8 m3/kg, Rowmill 2 (Rx2) 133.4 x 10−8 m3/kg - 244.2 x 10−8 m3/kg, Magnetic susceptibility values in the main material range from 1532 x 10−8 m3/kg up to 2838,6 x 10−8 m3/kg, while the value of Rowmix 1 (RX1) and Rowmill 2 (Rx2) is lower than the magnetic susceptibility value of the main ingredient.

Mechanistic understanding of the effect of sodium citrate soaking of red kidney beans on their cooking behaviour

In this study, the role of soaking beans in a sodium citrate solution (a cation chelator) at pH = 4.4 and 41 °C in directing/improving the cooking behaviour of common beans was explored. The cooking behaviour of the pre-soaked red kidney beans was determined and the corresponding changes of phytate, minerals, starch, protein and pectin were quantified. Soaking beans in citrate buffer could accelerate softening of the beans during cooking in deionised water while subsequent cooking of beans in this buffer had a limited additional effect on softening compared to cooking in deionised water. Phytate hydrolysis during soaking in citrate buffer results in a release of Mg2+ and Ca2+. Both cations were leached into the soaking medium, higher amounts being observed for Mg2+ release to the soaking media because of the lower affinity of Mg2+ for pectin. It was observed that the pectin solubilisation rate in beans treated by sodium citrate buffer was positively correlated to bean softening. All of these results point out that soaking in a citrate buffer prohibits pectin Ca2+ cross linking therefore enhancing pectin solubilisation and thus increasing the bean softening rate constants during cooking, while starch and protein were not responsible for texture evolution.

Chronic kidney disease mineral bone disorder in childhood and young adulthood: a ‘growing’ understanding

Chronic kidney disease (CKD) mineral and bone disorder (MBD) comprises a triad of biochemical abnormalities (of calcium, phosphate, parathyroid hormone and vitamin D), bone abnormalities (turnover, mineralization and growth) and extra-skeletal calcification. Mineral dysregulation leads to bone demineralization causing bone pain and an increased fracture risk compared to healthy peers. Vascular calcification, with hydroxyapatite deposition in the vessel wall, is a part of the CKD-MBD spectrum and, in turn, leads to vascular stiffness, left ventricular hypertrophy and a very high cardiovascular mortality risk. While the growing bone requires calcium, excess calcium can deposit in the vessels, such that the intake of calcium, calcium- containing medications and high calcium dialysate need to be carefully regulated. Normal physiological bone mineralization continues into the third decade of life, many years beyond the rapid growth in childhood and adolescence, implying that skeletal calcium requirements are much higher in younger people compared to the elderly. Much of the research into the link between bone (de)mineralization and vascular calcification in CKD has been performed in older adults and these data must not be extrapolated to children or younger adults. In this article, we explore the physiological changes in bone turnover and mineralization in children and young adults, the pathophysiology of mineral bone disease in CKD and a potential link between bone demineralization and vascular calcification.Graphical abstractA higher resolution version of the Graphical abstract is available as Supplementary information

Seedling growth declines in warmed tropical forest soils

AbstractThe response of plants to a warming climate could have a large feedback on further climatic change. This feedback is especially important for tropical forests, where the global peak in plant productivity and biodiversity occurs. Here we test the response of tropical forest tree seedling growth, photosynthesis and herbivory to 3 years of in situ full‐soil profile warming. We studied six species, three of which are known nitrogen‐fixers and we hypothesized that the warming response of growth will be mediated by nutrient availability to plants. Across species, growth was significantly lower in warmed soil compared to soil at ambient temperature, and the same pattern was observed for light‐saturated photosynthesis, pointing toward a growth decline associated with decreased C fixation. Within species, the relative growth decline was significant for two species,Inga laurinaandTachigali versicolor, both of which are N‐fixers. Together our results suggest a growth decline may have resulted from a negative effect of warming on N‐fixation, rather than via changes in nutrient mineralization from soil organic matter, which was unchanged for N and increased for P during the dry‐to‐wet season transition. Overall, our study demonstrates that belowground warming causes species‐specific declines in the growth and photosynthesis of seedlings, with a suggestion—requiring further investigation—that this growth decline is larger in N‐fixing species.Abstract in Spanish is available with online material.

The effects of Na2O/K2O flux on ash fusion characteristics for high silicon-aluminum coal in entrained-flow bed gasification

Composite additives are widely used to regulate coal ash fusion characteristics to meet the requirement of entrained-flow bed gasification. In this paper, the effects and corresponding mechanisms of the Na2O/K2O ratio on ash fusion behavior of high silicon-aluminum coal (Jincheng coal, JC) were investigated. The results showed that at the same total mass fractions of Na2O and K2O (15%), the JC ash fusion temperatures (AFTs) decreased quickly and then increased slowly with increasing Na2O/K2O ratio, the lowest AFT reached when Na2O/K2O ratio was at 9/6. The variations in volume and morphology of mixed JC ashes during heating indicated the AFT variation. The mineral change from KAlSi2O6 (MP: 1686 °C) to NaAlSiO4 (MP: 1100 °C) with increasing Na2O/K2O mass ratio mainly resulted in a decrease in the AFT. This indicated that the Na2O/K2O synergy flux effect was related to the formation of a NaAlSiO4–KAlSiO4 eutectic structure. The AFT variation with increasing Na2O/K2O ratio was also explained by the fact that a quick increase and then a slow decrease in the temperature at which all solid phase changes into liquid-phase was calculated by FactSage.

Changes in mineral and vitamin profiles after bariatric surgery in Korea: a before and after study

Changes in mineral and vitamin profiles after bariatric surgery in Korea: a before and after study

A study on the collapse characteristics of loess based on energy spectrum superposition method

Mineral types form the basis for studying the structural stability of loess, and identifying mineral types at the microscopic scale has always been a difficult task. Identifying mineral types at the microscopic scale is very helpful in understanding the differential role that different minerals play in the structural stability of loess, and it can also clarify the specific mineral changes that occur during the process of humidification and dehumidification. Using an innovative energy spectrum superposition method, this article combines backscattered electron imaging and X-ray energy spectrum analysis results to achieve direct identification of the eight main minerals in loess, including quartz, illite, and chlorite, within SEM images. The mineral identification results provide a basis for statistical analysis of mineral water sensitivity and morphological changes under wetting conditions. The results demonstrate that chlorite and hematite, which account for no more than 23% of the loess composition, play a crucial role in binding. Furthermore, these minerals exhibit significant hydrolysis phenomena. Particularly, the intense decomposition of chlorite leads to the displacement of non-binding quartz and feldspar particles, thereby altering the pore structure of loess. These findings are of great significance in understanding the multi-level collapsibility of loess.

The Clay Mineralogy and Geochemistry of Sediments in the Beibu Gulf, South China Sea: A Record of the Holocene Sedimentary Environmental Change

In this study, we analyzed the clay mineralogy and geochemistry of surface and drill core samples from the northeastern Beibu Gulf in order to unravel the sediment provenance of, and factors controlling, the sedimentary environment. The main clay mineral assemblage in the surface sediment samples included kaolinite (27–72%), smectite (4–51%), illite (7–20%), and chlorite (8–17%). The study area comprises three major clay distribution zones (from the northeastern coastal area to central Beibu Gulf basin), i.e., the kaolinite-dominated, kaolinite–smectite, and smectite-dominated zones. The zoning of the clay mineralogy and major and trace elements indicated the mixing of coarse terrigenous sediments with distal fine sediments. Early Holocene sea level rise was documented in core B15-1, which had three sedimentary units (divided into Units 1–3 from top to bottom), as revealed by the changes in the dominant clay minerals and geochemical/oxide ratios (SiO2/Al2O3, Rb/Sr, Sr/Ba, and Ti/Ca) in Unit 2. Unit 1 and Unit 3 were likely deposited in the continental and marine environments, respectively. The low sedimentation rate and hydrodynamic disturbance may have influenced the deposition process more than climatic fluctuations.

Understanding CO2 mineralization and associated storage space changes in illite using molecular dynamics simulation and experiments

Clay minerals have the potential to capture anthropogenic CO2 emissions permanently and safely. Understanding the kinetics of cation leaching and carbonate formation, as well as changes in clay structure, has resource and environmental implications. However, metadynamics mechanism and relevant structural changes in representative clay minerals exposed to supercritical carbon dioxide (scCO2) are rarely studied in current research. In this work, ReaxFF molecular dynamics simulation in combination with scCO2‒H2O‒illite experiments at 10 MPa and 333 K were carried out to investigate the mechanisms of mineralization and structure alteration under geological conditions. The results show that interlayer K+ cations were leached out due to surface non-bridging oxygen protonation, subsequently bonding with HCO3− and forming K2CO3 molecules at the surface. Upon analyzing the chemical and structural results of experiments, carbonate precipitation and accumulation reduce storage space and modify the composition of illite, but the octahedral and tetrahedral sheets of the illite are structurally stable. The efficiency of mineralization is typically dominated by the exposed surface, where sufficient cations can be provided to enhance interactions at the illite/liquid interface. In comparison to a decrease in plane porosity of 27.3%, the mineralization degree with values between 15.22% and 33.12% is comparable and acceptable. These findings present a non-structural mechanism in clay minerals that might have critical influence on CO2 geo-sequestration in shale gas reservoirs.

Regenerative and Protective Effects on Dental Tissues of a Fluoride-Silicon-Rich Toothpaste Associated with a Calcium Booster: An In Vitro Study.

Calcium boosters have been used as a supplement for fluoride toothpastes to repair the dental tissues and reduce dentin permeability. This in vitro study aimed to characterize the regenerative and protective effects of the treatment of dental tissues with a fluoride-silicon-rich toothpaste associated with a calcium booster. Bovine enamel and dentin blocks (n = 5) were obtained (4 × 4 × 6 mm). A fluoride-silicon-rich toothpaste and a calcium booster were used to brush the enamel and dentin both immediately and five days afterwards. The outcomes were then compared to those of the untreated control group. After that, the specimens were cross-sectioned. SEM was used to evaluate the micromorphology of the surface and cross-section. Energy-dispersive X-ray spectroscopy (EDS) was used to determine the elemental analyses (weight%). After treatment for 5 days with a booster/silicon-rich toothpaste, EDS analysis demonstrated that it induced a significant mineral change. It was also able to form a protective silicon-enriched mineral layer on both enamel and dentin surfaces. It was demonstrated in vitro that a fluoride-silicon-rich toothpaste associated with a calcium booster regenerates the dental tissues, remineralizing the enamel structure and occluding the dentin tubules.

Coprecipitation with Ferrihydrite Inhibits Mineralization of Glucuronic Acid in an Anoxic Soil.

It is known that the association of soil organic matter (SOM) with iron minerals limits carbon mobilization and degradation in aerobic soils and sediments. However, the efficacy of iron mineral protection mechanisms under reducing soil conditions, where Fe(III)-bearing minerals may be used as terminal electron acceptors, is poorly understood. Here, we quantified the extent to which iron mineral protection inhibits mineralization of organic carbon in reduced soils by adding dissolved 13C-glucuronic acid, a 57Fe-ferrihydrite-13C-glucuronic acid coprecipitate, or pure 57Fe-ferrihydrite to anoxic soil slurries. In tracking the re-partitioning and transformation of 13C-glucuronic acid and native SOM, we find that coprecipitation suppresses mineralization of 13C-glucuronic acid by 56% after 2 weeks (at 25 °C) and decreases to 27% after 6 weeks, owing to ongoing reductive dissolution of the coprecipitated 57Fe-ferrihydrite. Addition of both dissolved and coprecipitated 13C-glucuronic acid resulted in increased native SOM mineralization, but the reduced bioavailability of the coprecipitated versus dissolved 13C-glucuronic acid decreased the priming effect by 35%. In contrast, the addition of pure 57Fe-ferrihydrite resulted in negligible changes in native SOM mineralization. Our results show that iron mineral protection mechanisms are relevant for understanding the mobilization and degradation of SOM under reducing soil conditions.

Photosynthetic apparatus variability of the rigid hornwort (Ceratophyllum demersum L.) from the Saksagan River influenced by the mine activity

Aquatic ecosystems are the final absorbers of various pollutants, so require complex monitoring to control their condition. Macrophytes and other aquatic plants serve as reliable indicators of the hydro ecosystems ecological state, as they provide an integral assessment of the aquatic environment in time and space. Changes in chlorophyll a and chlorophyll b content and ratio in the rigid hornwort (Ceratophyllum demersum L.) leaves depending on the water hydro chemical parameters of Saksagan River in the zones of influence of "Ternivska" and "Oktyabrska" mines (Kryvyi Rih city) were studied. The purpose of the work was to find out the features of C. demersum photosynthetic apparatus reorganization as plants adaptive reaction to the technogenic transformation of river ecosystem. The water mineralization changes in the range of 1.2–2.9 g/L and fluctuations in the nitrates and nitrites content in the Saksagan River different sections were established. Both an increase and a decrease in the content of chlorophyll both forms in C. demersum leaves were detected, but more significant changes were related to chlorophyll b content. The photosynthetic pigments total content in plant leaves was the highest in the most mineralized areas (points of return water discharge and 500 m below of "Ternivska" mine), and it was the lowest due to sharp water mineralization increasing (500 m below the return water discharge of "Oktyabrska" mine). Significant variability in the photosynthetic pigments content and ratio indicates flexible regulation of their synthesis in C. demersum leaves to maintain the efficiency of the photosynthetic apparatus under conditions of water pollution. The revealed regularities indicate the active protection of the photosynthetic process in the C. demersum leaves, which is an important prerequisite for the plant’s survival in adverse conditions and the preservation of the structure and productivity of the water ecosystem of the Saksagan River.

Nitrogen mineralization following fall‐applied compost to subsurface drip‐irrigated processing tomatoes in California

AbstractOrganic wastes diverted from landfills can reduce greenhouse gas emissions and are used as supplemental nutrient sources for agricultural crops after they are composted. In California, compost should be applied in the fall to processing tomatoes (Solanum lycopersicum L.) to avoid delaying field preparation and transplanting in the spring. The objective of this study was to determine soil nitrogen (N) mineralization following fall application of greenwaste compost (GWC) based on the change of mineral N during a 4 month in‐field buried bag soil incubation in 2 prospective subsurface drip‐irrigated processing tomato fields (PTF1 and PTF2). GWC rates of 0, 11, 22, and 34 Mg ha−1 were evaluated in PTF1 and PTF2 in October 2019. Very dry surface soil conditions in fall 2019 and the disruptive procedure used to prepare soil for in‐field incubation using the buried bag method led us to calculate net N mineralization after adjusting for the initial mineral N concentration of the unamended (0 Mg ha−1) control. The adjusted net N mineralization was significantly less in PTF1 (8.6 mg N kg−1) than PTF2 (16.4 mg N kg−1) and the estimated net N mineralization rate of the surface 0–15 cm soil depth following GWC application to PTF1 was less than PTF2 (1.6–1.9 vs. 2.3–3.1 kg N ha−1 week−1). In‐field incubation requires soil disturbance that likely affected N mineralization and additional research should consider the feasibility of using pretreatments or pre‐incubations to account for disruption to antecedent soil conditions.

Effects of Supercritical CO2 on the Pore Structure Complexity of High-Rank Coal with Water Participation and the Implications for CO2 ECBM.

To reveal how mineral changes affect a coal pore structure in the presence of water, an autoclave was used to carry out the supercritical CO2 (ScCO2)-H2O-coal interaction process. To reveal the changes in pore complexity, mercury intrusion capillary pressure (MICP), low-pressure nitrogen adsorption, CO2 adsorption, and field emission scanning electron microscopy (FESEM) experiments were combined with fractal theory. The experimental data of MICP show that the MICP data are meaningful only for the pore fractal dimension with pore sizes >150 nm. Therefore, the pores were classified into the classes >150, 2-150, and <2 nm. The results show that the pore volume and specific surface area of the coal increased significantly after the reaction. ScCO2-H2O can cause the formation of many new pores and fractures in the coal. The presence of H2O may increase the potential for the injection of CO2 into the coal seam. The complete dissolution of calcite surfaces caused a significant increase in the pore volume and specific surface area of the pores >150 nm. The morphologies of these pores are controlled by the morphologies of the complete dissolution carbonate particles. The pore morphologies were relatively uniform, and the fractal dimensions decreased. However, the incomplete dissolution of calcite leads to irregular variations in the morphologies for the pores in the 2-150 nm pore size range. The pore morphologies that are produced by incompletely dissolved calcite particles are more complex, which increases the fractal dimensions after the reaction. The fractal dimensions of the pores <2 nm decreased after the reaction, indicating that the newly generated micropores were more uniform and had regular pore morphologies.

Utilization of recycled concrete powder in modification of the dispersive soil: A potential way to improve the engineering properties

Recycled concrete was used in dispersive soil as admixture in this paper to improve the mechanical properties and dispersivity of dispersive soil. Recycled concrete blocks were collected, ground to powder and mixed into dispersive soil with the weight ratios of 1%, 2%, 3%, 4%, and 5%. Soil samples were prepared and cured in a curing chamber for 0, 1, 3, 7, 14, and 28 days with temperature and humidity at 20 °C and 98%, respectively. Dispersivity, pH, and electronic conductivity of soil samples were determined at different curing time. Flow speed of seepage water and eroded soil weight were measured during pinhole test. Unconfined compression test and splitting test were performed to determine compressive strength and tensile strength of soil samples. Microstructures and mineral changes were obtained by SEM, XRD and TG/DTG tests. Validation test was performed on a natural dispersive soil to prove the effectiveness of recycled concrete powder on the dispersivity. Experiments show that dispersive soil turns into nondispersive soil with increase content of recycled concrete powder. Results of remoulded sphere sample crumb test are more conservative due to the remoulding process of soil during the test. Compressive and tensile strength of soil samples present a significant increase tendency with both the mixing ratio of recycled concrete powder and curing time. Results indicate that recycled concrete powder can be used to improve both the dispersivity and mechanical properties of dispersive clay, simultaneously help to solve the disposal of abandoned construction concrete waste. Enhancing of water stability of dispersivity soil would also ensure the safety and normal operation of both agricultural irrigation facility and hydraulic engineering.

Application of elemental chemostratigraphy to refine the stratigraphy of the Adavale Basin, Queensland

A prerequisite to understanding the evolution and resource potential of a basin is to establish a reliable stratigraphic framework that enables the correlation of rock units across multiple depocentres. Establishing a stratigraphic model for the Adavale Basin is challenging due to its structurally complexity, lack of well penetration and its lateral changes in facies. Biostratigraphy appears broad-scale, and despite providing chronostratigraphic control for the Lower Devonian Gumbardo Formation when combined with U/Pb zircon geochronology, the rest of the Devonian succession is hampered by a lack of microfossil assemblages and their poor preservation. The aim of this study is to establish an independent chemostratigraphic correlation across the Adavale Basin using whole rock inorganic geochemistry. Within this study, a total of 1489 cuttings samples from 10 study wells were analysed by Inductively Coupled Plasma – Optical Emission Spectrometry and Inductively Coupled Plasma – Mass Spectrometry for whole rock geochemistry, in order to establish an independent chemostratigraphic zonation scheme. Based on key elemental ratios selected to reflect changes in feldspars, clay minerals and provenance, the Devonian-aged stratigraphy is characterised into four chemostratigraphic mega-sequences that encompass the Gumbardo Formation (Mega-sequence 1); the Eastwood Formation, the Log Creek Formation and the Lissoy Sandstone (Mega-sequence 2); the Bury Limestone and the Boree Salt formations (Mega-sequence 3); and the Etonvale and the Buckabie formations (Mega-sequence 4). These mega-sequences have been further subdivided into a series of chemostratigraphic sequences that can be correlated across the study wells, establishing a regional correlation framework.

Predicting new mineral occurrences and planetary analog environments via mineral association analysis.

The locations of minerals and mineral-forming environments, despite being of great scientific importance and economic interest, are often difficult to predict due to the complex nature of natural systems. In this work, we embrace the complexity and inherent "messiness" of our planet's intertwined geological, chemical, and biological systems by employing machine learning to characterize patterns embedded in the multidimensionality of mineral occurrence and associations. These patterns are a product of, and therefore offer insight into, the Earth's dynamic evolutionary history. Mineral association analysis quantifies high-dimensional multicorrelations in mineral localities across the globe, enabling the identification of previously unknown mineral occurrences, as well as mineral assemblages and their associated paragenetic modes. In this study, we have predicted (i) the previously unknown mineral inventory of the Mars analogue site, Tecopa Basin, (ii) new locations of uranium minerals, particularly those important to understanding the oxidation-hydration history of uraninite, (iii) new deposits of critical minerals, specifically rare earth element (REE)- and Li-bearing phases, and (iv) changes in mineralization and mineral associations through deep time, including a discussion of possible biases in mineralogical data and sampling; furthermore, we have (v) tested and confirmed several of these mineral occurrence predictions in nature, thereby providing ground truth of the predictive method. Mineral association analysis is a predictive method that will enhance our understanding of mineralization and mineralizing environments on Earth, across our solar system, and through deep time.