Core Hole Research Articles

Sulfur-bearing molecules in a sample of early star-forming cores

The sulfur content in dense molecular regions is highly depleted in comparison to diffuse clouds. The reason for this phenomenon is unclear, and it is therefore necessary to carry out observational studies of sulfur-bearing species toward dense regions, mainly in early evolution stages. In this context, the analysis of sulfur-bearing molecules in a large sample of dense starless molecular cores is of great importance to help us uncover the early sulfur chemistry in these regions. From the Atacama Large Millimeter Array (ALMA) data archive, we selected a project in Band 7 (275--373 GHz), which contains the emission of several sulfur-bearing species. The observations were performed toward a sample of 37 dense cores that are embedded in the most massive infrared-quiet molecular clumps from the ATLASGAL survey. The lines of 34SO, SO$_ $, NS, SO, SO$^ $, and H$_ $CS were analyzed, and the column densities of each molecular species were obtained. Based on the continuum emission and two CH$_ $OH lines, the 37 cores were characterized in density and temperature, and the corresponding H$_ $ column densities were derived. The abundances of these sulfur-bearing species were derived and studied. We find that the abundances of the analyzed sulfur-bearing species increase with increasing gas temperature. Based on the correlation between abundances and temperature, we suggest that the chemistry involved in the formation of each of the analyzed molecules may similarly depend on T$_ k $ in the range 20 to 100 K. Additionally, we find that the comparisons among abundances are highly correlated in general. Taking into account that this correlation decreases in more evolved sources, we suggest that the sulfur-bearing species we analyzed have a similar chemical origin. Our observational results show that the X(SO$_ $)/X(SO) ratio can be used as a chemical clock of molecular cores. Based on the line widths of the molecular lines, we point out that molecules with an oxygen content (34SO, SO$_ $, SO, and SO$^ $) may be associated with warmer and more turbulent gas than the other molecules. H$_ $CS and NS are associated with more quiescent gas, probably in the external envelopes of the cores, which trace similar physical and chemical conditions. We complement recent similar works done toward more evolved sources with a large sample of sources, but also provide quantitative information about abundances that might be useful in chemical models for explaining the sulfur chemistry in the interstellar medium.

Shock petrographic and numerical modeling constraints on the morphology and size of the Morokweng impact structure, South Africa

AbstractThe 369 m deep M4 drill hole, located ~18 km NNW of the center of the 146 Ma Morokweng impact structure (MIS), intersects shocked Archean granitoid gneisses and subsidiary dolerite intrusions that are cut by faults, cataclasites and mm‐ to m‐wide suevitic and pseudotachylitic breccia dikes. The shock features in quartz in the gneisses and breccia dikes include decorated planar deformation features (PDFs), planar fractures, feather features, and toasting. Other minerals show features that may be shock‐related, such as multiple sets of planar features and alternate twin ladder structures in feldspars, kink bands in biotite, and planar features in titanite, apatite, and zircon; however, these are variably annealed and/or overprinted by hydrothermal alteration effects, and confirmation of their origin awaits further study. Universal Stage measurements of PDF sets in quartz from 12 gneissic target rocks and from lithic and mineral clasts in three suevitic and three pseudotachylitic breccia dikes reveal four dominant sets: (0001), {}, {} and {}. Based on these observations, the average peak shock pressure in these rocks is estimated at ≤16 GPa, which supports the original proximity (within one transient cavity radius) of these rocks to the point of impact. No discernible depth‐dependent shock attenuation was noted in the core. These shock levels and the elevated structural position of the rocks in the M4 core relative to the impact melt sheet intersected in drill holes closer to the center of the MIS suggest that the M4 lithologies represent part of the parautochthonous peak ring volume that subsequently experienced 1.5–2 km of post‐impact erosion before it was buried beneath younger sediments. Numerical modeling using the iSALE‐2D code suggests that the original Morokweng crater had a rim‐to‐rim diameter of between 70 and 80 km, and that the rocks in the M4 core were originally located at a depth of 7–8 km and a radial distance of 8–9 km from the point of impact.

Multiscale Characterization of the Albian-Cenomanian Reservoir System Behavior: A Case Study from the North East Abu Gharadig Basin, North Western Desert, Egypt

Since its discovery in 2010, the NEAG 2 has been one of the most productive oil fields of the Badr El-Din Petroleum Company (BAPETCO) in the northern Western Desert of Egypt. The Albian-Cenomanian reservoir system has a unique performance but suffers from several issues hindering its production. The latest production report in 2023, NEAG-2 Field was producing 1760 bbls of oil with 36500 bbls of water, i.e., 95% water cut. Despite that, the field has reached a 39% recovery factor but the reservoir forecast suggests a much higher recovery factor. Therefore, the NEAG 2 Field requires a comprehensive geological model to depict its reservoir heterogeneities better. We introduce a solid and integrated workflow to investigate the reservoir characters among different scales of geological heterogeneity and offer solutions to overcome some data gaps. After characterizing the reservoir elements by the structural, stratigraphic, petrographic, and petrophysical analyses, a machine learning-based method was applied to overcome the missing whole rock cores in creating a detailed electro-facies log for all field wells. The Neural-Network algorithm required the facies types to be grouped into definitive reservoir qualities to be applied. The resultant electro-facies log had a very good match with the input logs, which validated the facies grouping. This was followed by the porosity-permeability transforms, estimated from mobility data, to create a permeability curve for all field wells, despite the unavailability of core data. The reservoir was categorized into three rock types, each with a specific range of quality, signifying their different flow abilities which were supported by dynamic data. The Lower Bahariya-Kharita in NEAG 2 was ultimately concluded to be a complex heterogeneous reservoir with varying flow abilities and production behaviors. The recovery factor mismatch is due to unrecovered reserves, and a new production strategy should be introduced to reach the ultimate recovery. This integration of geologic and dynamic data is strongly recommended for any reservoir characterization study to avoid oversimplifying the reservoir system and to design the right reservoir development plan.

Sandstone wettability in supercritical CO2-brine-rock interactions evaluated with 13C and 1H magnetic resonance

During the first decades of geologic CO2 storage in saline formations and depleted reservoirs, structural trapping is the most important storage mechanism. The effectiveness of CO2 containment hinges on the assumption that the sealing formation remains water wet in the presence of dense CO2. In this work, multiple 13C and 1H magnetic resonance (MR) methodologies were employed for the first time to evaluate the interactions between supercritical CO2, brine, and the pore surface of a Berea sandstone core plug under reservoir conditions. These studies employed a novel variable field superconducting MR and magnetic resonance imaging (MRI) instrument which permitted sequential 1H and 13C measurements of core plugs at high-pressure and high-temperature. To systematically study the wettability of rock core exposed to supercritical CO2, four experiments were designed including bulk CO2 in a high-pressure vessel, bulk CO2-brine, 13CO2 in dried rock core, and a 13CO2-brine-rock experiment.The measured 13C and 1H MR relaxation times in this work indicate that the Berea sandstone remained strongly water-wet when the brine saturated core plug was exposed to supercritical CO2 under reservoir conditions. For both 13C and 1H, T1 relaxation times provide more reliable wettability evaluation as compared to T2 due to the impact of molecular diffusion through internal magnetic field gradients. One-dimensional (1D) MRI was employed to spatially resolve 13CO2 and brine in the core plug. Two-dimensional (2D) MRI was able to image 13CO2 and brine in a PEEK vessel. The quantities of CO2 and brine in the core plug were determined from the MR signal intensities of 13CO2 and brine.

Selective enhancement of 1H signal from water and oil in porous media at low field with Overhauser DNP.

In porous media MR studies, discriminating between oil and water presents a challenge because MR lifetimes are often similar and spectra overlap. Low saturations might suggest an experimental strategy of increasing the static field for increased sensitivity, but susceptibility effects are exacerbated at higher field. Overhauser dynamic nuclear polarization, effective at low static field, was employed with water and oil-soluble nitroxide to selectively enhance water and oil signals. We employ a home-built 2MHz ceramic magnet to achieve selective enhancement of water and oil, in bulk, and in a rock core. For imaging, we employ a 705kHz ceramic magnet with a 4 gauss/cm constant gradient configuration to image the hyperpolarized signal. A rock core flooding experiment was undertaken to highlight the advantages of Overhauser enhancement. A simple phase cycling technique may be employed to cancel the thermally polarized 1H signal to isolate the enhanced signal of interest.

Development of a novel rotational metallic damper as a dissipative connector in rocking steel core systems: Cyclic behavior and seismic demand

Rocking systems with stiff rocking cores have been proposed as a promising solution for mitigating concentrations of story drift and enhancing structural seismic resilience. This study introduces a novel rotational metallic damper, termed the rotational steel rod damper (RSRD), developed for use in rocking steel core systems to improve energy dissipation capacity. The configuration, working mechanism, and application of the RSRD in rocking steel core systems are described. Three critical energy-dissipating elements, low-yield-point steel rods with different edge shapes, were isolated from the RSRD and tested to validate the efficacy of an optimal hourglass shape, defined through cubic equations, in enhancing low-cycle-fatigue performance. Two RSRD specimens were then tested and analyzed, focusing on failure modes, cyclic behavior, rotational strength, and energy dissipation. Both specimens demonstrated positive and stable hysteretic performance and energy dissipation capacity, with maximum equivalent viscous damping ratios of 0.51 and 0.53. Subsequently, structural models of seven steel frames were developed in OpenSees for case studies. Nonlinear response history analyses were performed under 20 ground motion records scaled to DBE and MCE levels. Dynamic behaviors, particularly the seismic demand on RSRDs, were examined. Numerical results confirmed the efficacy of the RSRD in mitigating inter-story drift. The location of the pivoting point of the rocking core significantly influenced the rotational demand on the RSRD. The proposed RSRD presents an innovative energy-dissipating alternative for the development of rocking steel core systems.

Characterization of Stages of CO2-Enhanced Oil Recovery Process in Low-Permeability Oil Reservoirs Based on Core Flooding Experiments

Understanding the CO2 displacement mechanism in ultra-low-permeability reservoirs is essential for improving oil recovery. In this research, a series of displacement experiments were conducted on sandstone core samples from the Chang 6 reservoir in the Huaziping area using a multifunctional core displacement apparatus and Nuclear Magnetic Resonance (NMR) technology. The experiments were designed under conditions of constant pressure, variable pressure, and constant effective confining stress to simulate various reservoir scenarios. The results indicated that the distribution characteristics of the pore structure in the rock samples significantly influenced the CO2 displacement efficiency. Specifically, under identical conditions, rock cores with a higher macropore ratio exhibited a significantly enhanced recovery rate, reaching 68.21%, which represents a maximum increase of 31.97% compared to cores with a lower macropore ratio. Though fractures can facilitate CO2 flowing through pores, the confining pressure applied during displacement caused a partial closure of fractures, resulting in reduced rock permeability. Based on the oil-to-gas ratio and oil recovery in the outlet section of the fractured rock samples, the CO2 displacement process exhibited five stages of no gas, a small amount of gas, gas breakthrough, large gas channeling, and gas fluctuation. Although the displacement stage of different cores varies, the breakthrough stage consistently occurs within the range of 2 PV. These insights not only enhance our understanding of CO2 displacement mechanisms in low-permeability reservoirs but also provide actionable data to inform the development of more effective CO2-EOR strategies, significantly impacting industrial practices.

Influence of reactivated basement structures on evolving orogens: Along-strike diachronous Himalayan metamorphism in far west Nepal

Determining the geometry and evolution of a basal detachment and its influence on orogenesis is a challenging, but important, aspect to understanding orogenic evolution. The basal detachment of the Himalayan orogen in far west Nepal is presently segmented by a documented tear fault. New pressure-temperature-time-deformation paths from the Himalayan metamorphic core along the Seti Khola river transect were integrated to compare the tectonometamorphic evolution on either side of the basal detachment tear fault to outline its history. Peak metamorphic conditions of 645−745 °C and 0.85−1.1 GPa were reached in the Seti Khola Himalayan metamorphic core rocks during the Oligocene to earliest Miocene, 10−14 m.y. prior to equivalent along-strike rocks in the adjacent Karnali valley, which indicates segmentation of the Himalayan metamorphic core across the tear fault. We interpret the segmentation of the orogen to have been caused by the development of the tear fault in the basal detachment of the Himalayan orogen and differing ramp-flat geometries on either side. The segmentation and change in basal detachment geometry is consistent with the reactivation of an underthrusted Indian plate inherited basement structure, the Great Boundary Fault, during the Oligocene to earliest Miocene. The comparison of tectonometamorphic histories along-strike in far west Nepal highlights the basal detachment geometry through time and the need to consider the pre-orogenic structural features of the plates involved in orogenesis. This study reinforces the importance of combining tectonometamorphic studies with geophysical and geomorphological data to fully understand the causes of along-strike segmentation of orogenic systems through time.

Investigations on Unconventional Tight Carbonate Rock Cores by Low-Field Nuclear Magnetic Resonance Relaxometry

Investigations on Unconventional Tight Carbonate Rock Cores by Low-Field Nuclear Magnetic Resonance Relaxometry

Observation of molecular resonant double-core excitation driven by intense X-ray pulses

The ultrashort and intense pulses of X-rays produced at X-ray free electron lasers (XFELs) have enabled unique experiments on the atomic level structure and dynamics of matter, with time-resolved studies permitted in the femto- and attosecond regimes. To fully exploit them, it is paramount to obtain a comprehensive understanding of the complex nonlinear interactions that can occur at such extreme X-ray intensities. Herein, we report on the experimental observation of a resonant double-core excitation scheme in N2, where two 1σ core-level electrons are resonantly promoted to unoccupied 1πg*\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1{\\pi }_{g}^{* }$$\\end{document} molecular orbitals by a single few-femtosecond broad-bandwidth XFEL pulse. The production of these neutral two-site double core hole states is evidenced through their characteristic decay channels, which are observed in good agreement with high-level theoretical calculations. Such multi-core excitation schemes, benefiting from the high interaction cross sections and state- and site-selective nature of resonant X-ray interactions, should be generally accessible in XFEL irradiated molecules, and provide interesting opportunities for chemical analysis and for monitoring ultrafast dynamic processes.

Subsurface Microbial Colonization at Mineral-Filled Veins in 2-Billion-Year-Old Mafic Rock from the Bushveld Igneous Complex, South Africa

Recent advances in subsurface microbiology have demonstrated the habitability of multi-million-year-old igneous rocks, despite the scarce energy supply from rock-water interactions. Given the minimal evolution coupled with exceedingly slow metabolic rates in subsurface ecosystems, spatiotemporally stable igneous rocks can sustain microbes over geological time scales. This study investigated a 2-billion-year-old mafic rock in the Bushveld Igneous Complex, South Africa, where ultradeep drilling is being executed by the International Continental Scientific Drilling Program (ICDP). New procedures were successfully developed to simultaneously detect indigenous and contaminant microbial cells in a drill core sample. Precision rock sectioning coupled with infrared, fluorescence, and electron microscopy imaging of the rock section with submicron resolution revealed microbial colonization in veins filled with clay minerals. The entry and exit of microbial cells in the veins are severely limited by tight packing with clay minerals, the formation of which supplies energy sources for long-term habitability. Further microbiological characterization of drilled rock cores from the Bushveld Igneous Complex will expand the understanding of microbial evolution in deep igneous rocks over 2 billion years.

Enhance Oil Recovery by Carbonized Water Flooding in Tight Oil Reservoirs

The low permeability of tight sandstone reservoirs limits the application of water flooding to enhance oil recovery. Due to the properties of CO2, people improve crude oil recovery by carbonizing water flooding. However, many studies have not prioritized determining the concentration of carbonated water before comparing the recovery rates of carbonated water flooding and pure water flooding after water flooding. This article takes the Chang 6 oil reservoir as the research object, and uses a combination of nuclear magnetic resonance testing and displacement experiments to conduct experiments on optimizing the concentration of carbonated water. Based on this, experiments on water flooding and carbon water flooding after water flooding to improve crude oil recovery are conducted to compare and analyze the oil enhancement potential of carbonated water flooding. The experimental results show that the physical properties, pore throat structure and seepage capacity of sandstone samples of type I, II and III decrease in turn. With the increase of carbonated water concentration, the expansion coefficient, viscosity reduction rate, contact angle reduction rate and core permeability loss rate of crude oil increase. The damage rate of 0.4mmol/cm3 carbonated water solution (17.6g CO2: 1L water) to the core permeability is only 0.98%, which is the optimal experimental concentration. During the water flooding process, crude oil in pores of different scales in Type I rock cores is utilized, and the degree of utilization in large pores is relatively high. Continuing to use carbonated water to drive oil in the rock cores after water flooding increased the recovery rate of crude oil by 15.24%; The degree of crude oil utilization in small pores of Tpye II core after carbonization and water flooding increased by 29.4%, and the final recovery rate of crude oil increased by 11.35% compared to the core after water flooding; The physical properties of Tpye III core are poor, with a small proportion of large pores, resulting in a 9.04% increase in crude oil recovery rate. Compared with pure water flooding, the recovery rate and utilization degree of large and small pores in the three types of rock cores after carbonization water flooding have been improved to varying degrees. Among them, the utilization degree of crude oil in large pores is the most significant, which increases the recovery rate of crude oil in the rock core after displacement. This study can provide a theoretical basis for improving crude oil recovery by carbonizing water flooding.

Elucidating Anomalous Intensity Ratios in Chlorine L-Edge X-ray Absorption Spectroscopy: Multiplet Effects and Core Rydberg Transitions.

A relativistic core-valence-separated equation-of-motion coupled cluster (CVS-EOM-CC) study of chlorine L2,3-edge X-ray absorption near-edge structure (XANES) spectra using CH3Cl and CH2ICl as representative molecules is reported. The nearly identical intensity for the main features in the L2- and L3-edge XANES spectra is attributed to multiplet effects and the overlap between core-valence and core Rydberg transitions. The multiplet effects originating from the interaction between the core hole and the C-Cl σ* orbitals account for around half of the deviation of the L3 and L2 intensity ratio from the 2:1 ratio of the numbers of 2p3/2 and 2p1/2 electrons. The 2p3/2 → 4s core Rydberg transitions are shown to overlap with the 2p1/2 → σ* transitions and contribute to the other half of the intensity anomaly. We demonstrate that triple excitations in CVS-EOM-CC calculations play important roles in accurate simulation of the overlap between the 2p1/2 → σ* and 2p3/2 → 4s transitions.

Core‐flooding experiments of various concentrations of CO2/N2 mixture in different rocks: II. Effect of rock properties on residual water

AbstractDuring CO2 storage in deep saline aquifers, the presence of residual water has an important influence on the storage efficiency and safety. In this study, natural rock cores taken from deep reservoirs in the Ordos Basin and Fukang, Xinjiang are used as research objects. Nine groups of core‐flooding experiments are performed under different CO2/N2 gas mixture ratios to study the influence of rock properties (mineral composition, permeability, porosity and pore structure) on the residual water. Furthermore, the geophysical and chemical properties of rock cores are analyzed by X‐ray diffraction, electron microscopy, field emission scanning electron microscopy and piezoelectric mercury method. The results show that residual water saturation is a quantitative power function of drainage time. The residual water saturation is positively correlated with the total amount of quartz and feldspar and increases with increasing permeability. Moreover, both the average and median pore throat radius show a strong inverse correlation with irreducible residual water saturation; as these radius increase, the residual water saturation decreases. In contrast, the porosity and maximum pore throat radius display a weaker correlation with irreducible residual water saturation. This study is of great value for engineering practices such as the site selection of CO2 storage projects in saline aquifer and improvement of CO2 storage efficiency. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Research on microscale displacement characteristics of supercritical CO2 fracturing in shale oil reservoirs

AbstractThe great success of CO2 fracturing in shale oil reservoirs has not only increased the production capacity of shale oil, but also effectively carried out CO2 geological storage. In this paper, focusing on the microscale displacement characteristics of CO2 fracturing in shale oil reservoirs, first, the impact of oil saturation and gas invasion pressure on gas invasion is discussed. Then, the coupling control mode of oil saturation/pressure for various mechanisms of gas invasion is revealed. Results show that: (a) at lower displacement, the rock core has a lower initiation pressure and is fractured in a shorter period of time; (b) at higher displacement, the required fracturing time is longer and the fracturing pressure increases, but the fracturing effect is good and it is easy to form complex fracture networks; and (c) under higher pressure conditions, more complex fractures can be formed, which is beneficial for reservoir transformation and production improvement.

X-ray circular dichroism measured by cross-polarization x-ray transient grating

Abstract Measuring natural circular dichroism in the x-ray regime to extract stereochemical information from chiral molecules in solution remains a challenge. This is primarily due to technical limitations of the existing synchrotron sources, which hinder access to measurements of local chirality by exploiting core hole electronic transitions. In response to this challenge, we propose an alternative approach: utilizing XFEL-based cross-polarization x-ray transient grating (XTG). This method provides an indirect means to measure x-ray circular dichroism (XCD). Notably, our findings reveal that the signal emerges only once the excited cores have undergone dephasing through relaxation. XTG is now routinely measured in the XUV regime and has recently been made available for hard x-rays. Free electron lasers now offer polarization controls, and XTG can be extended to various polarization states for the two pump beams, making XCD measured by XTG feasible with the current state-of-the-art technology.

Micro–Nano 3D CT Scanning to Assess the Impact of Microparameters of Volcanic Reservoirs on Gas Migration

Volcanic rock reservoirs for oil and gas are known worldwide for their considerable heterogeneity. Micropores and fractures play vital roles in the storage and transportation of natural gas. Samples from volcanic reservoirs in Songliao Basin, CS1 and W21, belonging to the Changling fault depression and the Wangfu fault depression, respectively, have similar lithology. This study employs micro–nano CT scanning technology to systematically identify the key parameters and transport capacities of natural gas within volcanic reservoirs. Using Avizo 2020.1software, a 3D digital representation of rock core was reconstructed to model pore distribution, connectivity, pore–throat networks, and fractures. These models are then analyzed to evaluate pore/throat structures and fractures alongside microscopic parameters. The relationship between micropore–throat structure parameters and permeability was investigated by microscale gas flow simulations and Pearson correlation analyses. The results showed that the CS1 sample significantly exceeded the W21 sample in terms of pore connectivity and permeability, with connected pore volume, throat count, and specific surface area being more than double that of the W21 sample. Pore–throat parameters are decisive for natural gas storage and transport. Additionally, based on seepage simulation and the pore–throat model, the specific influence of pore–throat structure parameters on permeability in volcanic reservoirs was quantified. In areas with well–developed fractures, gas seepage pathways mainly follow fractures, significantly improving gas flow efficiency. In areas with fewer fractures, throat radius has the most significant impact on permeability, followed by pore radius and throat length.

Advanced classification of drill core rock type and weathering grade using detection transformer-based artificial intelligence techniques

Rock classification plays a crucial role in various fields such as geology, engineering, and environmental studies. Employing deep learning AI (artificial intelligence) methods has a high potential to significantly improve the accuracy and efficiency of this task. The paper delves into the exploration of two cutting-edge AI techniques, namely Mask DINO and Mask R-CNN (convolutional neural network), as means to identify rock weathering grades and rock types. The results demonstrate that Mask DINO, which is a Detection Transformer (DETR), outperforms Mask R-CNN for the aforementioned purposes. Mask DINO achieved f-1 scores of 91% and 86% in weathering grade detection and rock type detection, as opposed to the Mask R-CNN’s f-1 scores of 84% and 75%, respectively. These findings underscore the substantial potential of employing DETR algorithms like Mask DINO for automatic classification of both rock type and weathering states. Although the study examines only two AI models, the data processing and other techniques developed in this study may serve as a foundation for future advancements in the field. By incorporating these advanced AI techniques, logging personnel can obtain valuable references to aid their work, ultimately contributing to the advancement of geological and related fields.

Simulation Study on the Heat Transfer Characteristics of Oil Shale under Different In Situ Pyrolysis Methods Based on CT Digital Rock Cores

Simulation Study on the Heat Transfer Characteristics of Oil Shale under Different In Situ Pyrolysis Methods Based on CT Digital Rock Cores

Strontium isotopes in the atmosphere, geosphere and hydrosphere: Developing a systematic “fingerprinting” framework of rocks and water in sedimentary basins in eastern Australia

Understanding the connection between aquifers, aquitards, and groundwater-dependant ecosystems remains a key challenge when developing a conceptual hydrogeological model. The aim of this study was to develop a systematic strontium isotope (87Sr/86Sr) fingerprinting framework of rocks and water within the sedimentary Surat and Clarence-Moreton basins (SCM basins) in eastern Australia – an area of extensive coal seam gas development and high potential for aquifer and groundwater-surface water connectivity. To do this, new groundwater samples (n = 298) were collected, analyzed and integrated with published data (n = 154) from the basins' major sedimentary, volcanic and alluvial aquifers, including the major coal seam gas target, the Walloon Coal Measures. Samples were also analyzed from rainfall (n = 2) and surface water (n = 40). In addition, rock core samples (n = 39) from exploration and stratigraphic wells were analyzed to determine the range of Sr isotope composition from host rocks. The analyses of cores demonstrate a distinct and systematic contrast in 87Sr/86Sr between different hydrogeological units. This confirms that all major hydrogeological units have a narrow range with unique 87Sr/86Sr population characteristics that are useful for guiding conceptual model development. Comparison with selected hydrochemical and groundwater age tracers (14C and 36Cl) suggests only limited changes of 87Sr/86Sr from recharge beds to the deeper parts of the basins or with a decrease in natural 14C and 36Cl tracer content along flow paths. Stream sampling during baseflow conditions confirms that 87Sr/86Sr in surface waters are similar to those of the underlying bedrock formations. We demonstrated that 87Sr/86Sr analyses of rocks and water provide a powerful hydrostratigraphic and chemostratigraphic fingerprinting framework in the SCM basins, enabling reliable assessments of plausible aquifer and groundwater-surface water interconnectivity pathways. Applied in other complex multi-aquifer sedimentary basins in Australia, and globally, a similar approach can help to constrain conceptual hydrogeological models and facilitate improved water resource management.