The Middle Eocene Epoch was a pivotal period marked by pronounced climatic instability during the transition from a greenhouse to icehouse climate. The Jiyang Depression, located in the Bohai Bay Basin of East Asia, experienced the deposition of marginal-marine black shales under episodic marine influence, preserving a continuous and highly detailed record of past environmental changes. This study analyzes approximately 400 m of core samples from the Shahejie Formation in the Jiyang Depression to investigate carbon and nitrogen cycling processes and assess the environmental impacts of both volcanic activity and the Middle Eocene Climatic Optimum (MECO) during the deposition of Eocene marginal-marine shales formed under episodic marine influence. Geochemical analyses reveal nitrogen isotope anomalies in the middle part of the lower third member of the Shahejie Formation (Es3l), coinciding with the MECO and accompanied by significant fluctuations in nitrogen cycling during this transitional period, indicating climatic instability. A second episode of nitrogen disruption is observed in the lower part of the upper fourth member of the Shahejie Formation (Es4u), where fluctuations in nitrogen isotopes likely reflect the combined effects of episodic marine incursions and localized volcanic activity. The identification of two distinct nitrogen isotope anomalies provides new insights into the mechanisms controlling organic carbon enrichment in black shales.

Bitumen contains abundant nitrogen-, sulfur-, and oxygen-bearing (NSO) compounds whose molecular structures record critical geological information. To enhance the evaluation of high-to over-mature stages rock or sediment samples, due to the highly thermal destruction of molecular biomarkers, this study analyzes high-maturity bitumen from the Tarim Basin, China. The molecular geochemical results reveal that the evolution of organic matter at high-maturity stages is dominated by thermal cracking, ring-opening, and hydrogenation reactions. This process leads to a reversal in the molecular distribution trends of oxygen-containing compounds compared to those observed at low-to medium-maturity stages: complex "precursor" molecules with high double bond equivalents (DBE) and high carbon numbers are consumed, while simpler "product" molecules with low DBE and low carbon numbers become relatively enriched. In contrast, aromatic sulfur compounds (S1class) exhibit no significant differences in their DBE distribution patterns across samples of varying maturity due to their higher thermal stability. This suggests that they may exist in a "dynamic equilibrium" between condensation and cracking, which diminishes their utility as maturity indicators. Based on these systematic evolutionary patterns, this study proposed a series of novel maturity parameters i.e., the DBE1-5O2/DBE8-15O2 and C6-23DBE0-21O/C2445DBE0-21O ratios. These novel parameters demonstrate excellent linear correlations with aromatic maturity parameters based on alkylphenanthrene, alkylnaphthalene, etc., whose effectiveness has been extensively validated, and can serve as effective complementary tools for the evaluation of high-to over-mature source rocks and crude oils, providing new molecular geochemical approaches for deep hydrocarbon exploration.

In the Ordos Basin,the Ordovician Majiagou Formation is an important replacement for natural gas exploration.Large-scale natural gas resources,such as those in the Jingbian gas field,have been discovered in the weathered crust at its top.However,the origins and sources of these resources remain highly controversial.In this study,we analyze the components and geochemical characteristics(e.g.,carbon and hydrogen isotopic compositions)of natural gas from the Daniudi gas field.Accordingly,the origins and sources of natural gas are clarified within the Ordovician weathered crust reservoirs.The results indicate that the natural gas exhibits dryness coefficient(C1/C1-5)values ranging from 0.911 to 0.979 and CO2 content from 1.68%to 14.39%.H2S is observed in some samples,with content varying from 0.07×10-6 to 3.37×10-6 and gas sweetness index(GSI)values of merely 10-7 to 10-6 order of magnitude.Additionally,the δ13C1,δ13C2,δ13C3,and δD1 values of natural gas range from-40.0‰ to-33.2‰,-35.6‰ to-24.9‰,-30.7‰ to-24.1‰,and-209‰ to-184‰,respectively.The natural gas in the Ordovician weathered crust reservoirs did not undergo significant thermochemical sulfate reduction(TSR).However,CO2 of inorganic origin,produced by the dissolution of carbonate reservoirs,was mixed into some samples during acid fracturing.Origin identification and gas-source correlation reveal that the natural gas in the weathered crust reservoirs is dominated by coal-derived gas generated from coal-measure source rocks in the Taiyuan Formation.Such coal-derived gas experienced significant fractionation during both vertical and lateral migration into the weathered crust reservoirs.Additionally,the gas reservoirs also contain a minor proportion of oil-associated gas formed by the secondary cracking of crude oil generated from the carbonate source rocks in the Majiagou Formation.

Precious gases (mainly helium and molecular hydrogen therein) belong to critically strategic resources. According to the series genetic identification methods and detailed geological-geochemical analysis, the formation and enrichment are classified into two types: tectonomagmatic active basins (the Songliao and Bohai Bay basins) and stable cratonic basins (the Ordos Basin). For tectonomagmatic active basins, the origins of precious gases are represented by crust-mantle mixing, primarily linked to mantle degassing, water-rock reactions in mafic ultramafic magmatic rocks, and water radiolysis. In contrast, for stable cratonic basins, precious gases are mainly derived from crustal degassing. Specifically, helium originates through radioactive decay in sedimentary and basement rocks, while natural hydrogen is formed from reactions of water and rock in crystalline basements, radiolysis of water, and thermal evolution of hydrocarbon source rocks. Based on the detailed analysis of several cases discovered in the sedimentary basins, the favorable conditions for precious gases enrichment include sufficient gas flux, favorable migration pathways and tectonic positions, and effective seals. The enrichment process of precious gas is primarily controlled by generation timing, geological temperatures, and accumulation-dispersion efficiency. Accordingly, we identify potential enrichment formations for precious gas: the Shahejie Formation of Boxing Subsag (Bohai Bay Basin), Huoshiling Formation of the Changling and Xujiaweizi Fault Depressions (Songliao Basin), and Lower Shihezi and Majiagou Formations (Ordos Basin).

Helium, vital for advanced technologies, is generated in the crust via uranium (U) and thorium (Th) decay. The crystalline basement is a proven source of helium. In contrast, the role of sedimentary rocks, while often considered significant, has lacked definitive proof. This study provides the isotopic evidence to deconvolve these two crustal sources and verify the significant role of sediment. Our analysis of the Dongsheng Gas Field, Ordos Basin, China, reveals that air-derived noble gases reflect open-system water-gas equilibration, a process occurring within the reservoir. Whereas crust-derived noble gases likely pre-aggregated and migrated together with hydrocarbons, thereby preserving a clear signature of their original sources. Within this preserved signature, a depletion of Ne-21* (where * denotes a crustal origin) is observed. This depletion produces an unusual negative correlation between Ne-21*/Ar-36 and Ar-40*/Ar-36, in contrast to the expected positive trend. This pattern is interpreted as the mixing of a fluid from coal-bearing strata (Ar-40*/Ar-36 = 130 +/- 10) with a Ne-21*-depleted fluid from the basement (Ar-40*/Ar-36 = 2250 +/- 150). Modeling suggests that only similar to 0.26 % of basement-generated Ne-21* is retained. We propose a helium accumulation model in which initial preservation was inefficient owing to the absence of a seal, whereas the main accumulation was driven by hydrocarbon charging, which acted as a carrier fluid stripping helium from coal-bearing strata. These results demonstrate that U- and Th-rich sedimentary rocks can serve as a potential helium source in natural gas, which refines exploration strategies for helium in cratonic basins.

The Ordovician Majiagou Formation (O1m) in the Ordos Basin is a crucial exploration field for natural gas, and exploration of the Ordovician middle assemblage (O1m5 5-7) has recently yielded great breakthrough. The Daniudi gas field provides a good case study to determine the gas source for the strata. The O1m5 5-7 gas displays C1/C1-5 ratios of 0.932-0.985 and CO2 contents of 1.56%-11.75%, and the detectable H2S content ranges from 0.0002% to 1.8617%. The delta 13C1, delta 13C2, delta 13CCO2, and delta D1 values are -39.7 parts per thousand to -35.6 parts per thousand, -30.4 parts per thousand to -23.7 parts per thousand, -12.4 parts per thousand to -4.6 parts per thousand, and -204 parts per thousand to -185 parts per thousand, respectively. Identification of the gas origin and source indicates that the gaseous alkanes are commonly coal-derived gas. The gas was generated from the coal measures in the Taiyuan Formation (C3t) and subsequently migrated. A small amount of oil-associated gas, mainly from O1m carbonate source rocks, has been incorporated into the gas reservoir. The natural gas has experienced insignificant alteration by thermochemical sulfate reduction, and the relatively high levels of CO2 are probably associated with corrosion alteration of carbonate reservoirs by injected fluid during acid fracturing.

Helium and natural hydrogen resources in the subsurface have attracted substantial attention due to their essential roles in contemporary society. Globally, accumulations of these gases were predominantly found in the shallow crust; however, the impact of the multi-spherical interactions within the Earth, particularly crust-mantle interaction, on their generation-accumulation in tectonomagmatically active sedimentary basins remains unexplored. In this study, we have compiled 806 global gas data coupled with volcanic rock degassing experiments for the purpose of evaluating how the crust-mantle interaction influences the generation-accumulation of helium and hydrogen in the Bohai Bay Basin, China. In the Bohai Bay Basin, helium is primarily sourced from the decay of radioactive elements in the basement rock, with mantle-derived helium providing an additional contribution that averages at 18.85%. The formation of helium-rich reservoirs in natural gas systems, primarily driven by groundwater degassing dynamics, exhibits critical dependence on the gas-to-water ratio. Natural hydrogen is predominantly generated through low-temperature water-rock reactions in iron-rich rocks, radiolysis of water, and mantle-derived hydrogen-rich fluids. The subduction of the west Pacific Plate has induced the upwelling of asthenospheric materials, which transport deep mantle-derived volatiles (He, H2, CO2, N2, etc.) into the Bohai Bay Basin via deep-seated faults. As a result, helium and hydrogen resources are widely distributed yet locally concentrated in the Bohai Bay Basin. Our calculation reveals that the crust of the study area has cumulatively produced 68.0 & times; 109 m3 STP of helium and 23.1 & times; 1012 m3 STP of hydrogen, while the mantle has contributed 16.0 & times; 109 m3 STP of helium and 10.3 & times; 1012 m3 STP of hydrogen. The natural gas system in the Bohai Bay Basin has trapping efficiencies of 2.9% and 0.07% for these helium and hydrogen resources, respectively. A calculated maximum abiotic CH4 resource of 3.74 & times; 1012 m3 STP may be generated by the potential Fischer-Tropsch Type reactions. Such a large potential abiotic CH4 resource explains the very low trapping efficiency of hydrogen.

Abyssal hydrothermal vents are regarded as reactors for simple reduced carbon transforming into more complex forms of prebiotic organic chemistry. While the organic geochemical continuum and evolutionary transitions remain elusive, due to the intense hydrothermal alteration. We apply a metabolomics-inspired molecular fingerprinting strategy integrating mass spectral networking and hierarchical organization, to construct a molecular relatedness phylogenetic tree for vents from ultraslow-spreading Indian Ridge. Here we show that organic molecules from different vent fields and activity states share common molecular connection patterns. The observed progressive molecular evolution from alkanes through aromatics to complex heteroatom-bearing compounds reveals a systematic increase in molecular functionalization and polarity. This finding helps bridge the gap between simple reduced carbon and prebiotic molecular complexity, underscoring the role of hydrothermal systems in shaping life's essential feedstock on the primordial Earth. This framework may contribute to the search for life-markers on other astrobiological contexts, e.g., Mars, Enceladus, Callisto and Europa.

[Objective]Uranium(U)and thorium(Th)in rocks and minerals are the material basis for the generation and release of crust-derived helium.[Methods]The enrichment characteristics and mechanisms of U and Th are key to un-derstanding the accumulation of crust-derived helium reservoirs.Taking the bauxite series of the Benxi Formation in the central North China Block as the research object,this study reveals the enrichment mechanisms of U and Th in the baux-ite series and calculates the helium generation rate by means of petrogeochemical and chronological research methods,combined with detrital zircon dating,sedimentary environment identification,and mass balance calculation.It provides theoretical support for exploring bauxite-type helium reservoirs.[Results and Conclusions]The results show that the bauxite series of the Benxi Formation in the central North China Block is widely developed,but its planar thickness var-ies significantly,being relatively thicker on both the north and south sides close to the provenance area.From bottom to top,the bauxite series can be divided into an iron-rich interval,an aluminum-bearing interval,a bauxite ore interval,an-other aluminum-bearing interval,and a dark mudstone interval,with diaspore as the main component in the bauxite in-terval.The enrichment of U and Th in the bauxite series is mainly controlled by provenance supply,sedimentary envir-onment evolution,and supergene leaching.The detrital zircons have main peak ages of 320 and 453 Ma,indicating that the provenance is magmatic rocks input from both north and south directions.After weathering and diagenesis of the source rocks,U and Th are preserved in detrital zircons in the form of isomorphism.During the formation of the bauxite series,there were dynamic changes in the oxidation-reduction environment,which provided conditions for the release,reduction,and precipitation of U.Under the influence of acidic leaching fluids,alkali metal ions(e.g.,K+,Na+)and al-kaline earth metal ions(e.g.,Mg2+,Ca2+)exhibit high chemical reactivity and undergo significant leaching loss.In con-trast,Al and Th,characterized by their chemical stability,are less mobile during the leaching process.Subject to the pH value and chemical composition of the system,U can be adsorbed and enriched by aluminum,iron,and manganese ox-ides/hydroxides.In the bauxite series,the U content in bauxite ranges from 13.26×10-6 to 57.10×10-6,the Th content ranges from 42.19×10-6to 136.00×10-6,and the helium generation rate is 2.85× 10-12 to 10.94×10-12 cm3/(a·g),showing good helium-generating capacity.The areas with thicker bauxite rock distribution in northwestern Henan Province,as well as in southern and northern Shanxi Province,exhibit strong helium generation capacity,making them potential fa-vorable zones for helium enrichment.

The origins of natural hydrogen in natural gas systems of sedimentary basins and the capacity of these systems to store hydrogen remain inadequately understood, posing crucial questions for the large-scale exploration of natural hydrogen. This study reports on the natural gas composition, stable carbon and hydrogen isotopic values, and helium isotopic values of gas samples collected from the Qingshen gas deposit within volcanic rocks of the Songliao Basin. Natural hydrogen primarily originates from water radiolysis, water-rock interactions (WRI), and mantle. The Qingshen gas deposit contains 95.23 × 10 9 cubic meters of abiotic CH 4 , of which 15.24 × 10 9 cubic meters was generated through hydrogen conversion via Fischer-Tropsch synthesis, with the maximum original hydrogen reserves calculated to be approximately 61.9 × 10 9 cubic meters. We estimated that the study area has generated a maximum total of 572 × 10 9 cubic meters of radiolytic hydrogen, 248 × 10 9 cubic meters of WRI hydrogen, and 127 × 10 9 cubic meters of mantle-derived hydrogen.

The conventional biomarkers are limited due to the extremely high thermal stresses in ultra-deep hy-drocarbon reservoirs.The diamondoid with cage structure has excellent thermal stability and is an effective tool for characterizing the ultra-deep hydrocarbon and linking its source.We investigated the distribution of diamondoids in ultra-deep reservoirs including black oils,volatile oils,and condensates.The source-related diamondoids indicate that crude oils are mainly sourced from marine siliceous shale.The bulk characteristics(e.g.color,density,Sat/Aro)of crude oils reveal the variations of thermal maturity:low maturity for black oils,moderate maturity for volatile oils,and high maturity for con-densates.Based on regular variations in the thermal maturity of crude oils,the thermal evolution of diamondoids is characterized.The abundance of C1-and C2-alkylated diamantanes increases with increasing maturity,and hydrothermal activity may lead to an abnormal increase in the percentage of C3-alkylated adamantanes.Despite the higher thermal stability of 4-methyldiamantane(4-MD),a more sensitive change in relative abundance with maturity for 1-methyldiamantane(1-MD)among all methyldiamantanes(MDs)is observed.Ethyl diamondoids are thermally less stable and their derived indices can effectively indicate the thermal maturity of ultra-deep hydrocarbons.The applications of commonly maturity-related indices should be cautious(e.g.MDI),whereas the novel methyl-ethyl diamantane index(MEDI)is highly recommended.The combination of high MAI values and low MEDI values most likely reflects the influence of late-charged light hydrocarbons.Overall,multiple charging and in-reservoir mixing of light hydrocarbons and oils with various maturities constrained the present phase states of ultra-deep oil reservoirs.This study gives a new perspective to understanding the fate of molecular evolution and phase states of hydrocarbons in the ultra-deep basins.

Natural gas from ancient strata in sedimentary basins tends to be enriched with helium (He). Lower Paleozoic gas in the Daniudi field (DNDF) of the Ordos Basin in central China provides a good case study to reveal He generation and accumulation mechanisms in deep strata. Understanding He accumulation in the Daniudi field is crucial because the increasing global demand for He requires the identification of new sources in existing natural gas reservoirs. Here, the geochemical characteristics of Lower Paleozoic gas from the DNDF are investigated, aiming to reveal the concentration, origin, and controlling factors of He accumulation. Natural gas in Lower Ordovician Majiagou Formation (O1m) reservoirs is He-depleted (0.0126 %-0.0187 %, mean 0.0153 %). The 3He/4He and corresponding R/Ra ratios range from 3.12 to 3.95 x 10- 8 and 0.022 to 0.028, respectively, indicative of a crustal origin of He. The He concentration was diluted by alkane gases, as indicated by a negative correlation between He content and the CH4 content, as well as the dryness coefficient; however, it was not affected by the degree of thermal maturity or the type of organic matter in the source rocks, as indicated by a lack of correlation between He content and the carbon isotopic ratios of CH4 and C2H6. The N2/He ratio of O1m gas is generally in a range from 1.14 to 7.65, which is markedly lower than the ratio (19-50) in natural gas with He commercial production value (He% >= 0.1 %). The He content in O1m gas is negatively correlated with the content of total dissolved solids (TDS) in formation water; the low He content may be attributable to the high TDS content. The pressure in Paleozoic strata of the DNDF has decreased since the Late Cretaceous due to continuous regional uplift, resulting in decreased He solubility in the formation water and the exsolution of previously dissolved He into gas pools.

Although the productivity of modern volcanic soils is well established, the fertilization effects of ancient volcanic ash on aqueous ecosystems remains contentious. Here we demonstrate volcanic fertilization effects on a Late Triassic lacustrine ecosystem based on micropaleontological and geochemical records from the Yanchang Formation of North China. Frequent eruptions of a regional volcanic arc system increased cyanobacterial populations and organic carbon sinking fluxes, as recorded by extreme total organic carbon content (>30 wt.%) and positive organic carbon and negative nitrogen isotopic excursions. In turn, high levels of primary productivity induced intense water-column anoxia, facilitating preservation of organic matter. These findings underscore the potential influences of volcanism on ecological conditions, primary productivity, and carbon sequestration throughout geological history.

The Lower Cambrian organic-rich mudstones preserve extensive records of microbial life, potentially contributing to the 'Cambrian explosion' (similar to 540 to 520 Ma) and the formation of ancient petroleum resources. However, the link of organic delta C-13 variations to microbial communities in the Lower Cambrian Formation within the Tarim Craton, part of the Central Asian Orogenic Belt, remains incompletely understood. Here, we conducted a comprehensive biomarker and delta C-13 analysis of mudstone extracts. The prevalence of eukaryotic organisms relative to prokaryotes, together with increased primary productivity, results in substantial C-12 enrichment in organic matter, with the converse relationship being equally valid. The Lower Cambrian mudstones formed in more reducing yet confined stratified environments. The presence of cholestane, ergostane, stigmasterane, and 4-methylsterane (e.g., dinosterane) indicates the occurrence of red algae, prasinophytes, green algae, and dinoflagellates, respectively. Notably, the predominance of ergosterane and stigmasterane over cholestane suggests a greater contribution from green algae over red algae. The even-carbon preference across the C-14-C-20 range is indicative of limited contributions from Gloeocapsomorpha prisca. The presence of 3 beta-methylhopane, 7-+8-monomethylheptadecane and 2 alpha-methylhopane points to contributions from methanotrophs and cyanobacteria. Since methanotrophs are active in an oxygen- and sulfate-depleted environment, we speculate that C-13-rich organic matter with a high value of 3-methylhopane index (3-MHI) may be deposited in waters with expanded anoxic zones and a scarcity of photoautotrophic sulfur bacteria (e.g., Chlorobiaceae and Chromatiaceae). This study highlights the constraints of microbial communities on organic delta C-13 variations and enhances our understanding of the evolution of ecology and primary productivity during the Precambrian-Cambrian transition.

Occurrence and abundance of molecular hydrogen in natural geologic reservoirs are enigmatic, due to its various sources, diverse migration pathways and complicated biological and chemical reactions. Natural gas samples containing hydrogen from producing wells in several sedimentary basins in China were collected in this study, and gas abundances and isotopic compositions of these gases were compared with those in global petroliferous basins and deep intrusive rocks. Several geochemical indicators were suggested for identifying sources, migration and accumulation mechanisms of hydrogen in the subsurface environment. Hydrogen contents in natural gas deposits have contributions from various sources with the following high-to-low order: microbial degradation > serpentinization > deep mantle volatile release > radiation-induced water decomposition > thermal cracking of organic matter. A hydrogen-rich reservoir in Kansas, USA, is specifically analyzed to determine its formation mechanism. This study suggests that future exploration of geological hydrogen resources may focus on the igneous rock bodies with overlying dense sedimentary rocks in the continental rift systems.

A series of large-scale abiotic gas reservoirs have been discovered in a few rift basins in eastern China. However, the compositions of the abiotic gases in each gas reservoir differ significantly, dominated by CO2 or CH4. This study aims to explore the factors controlling the large-scale generation and accumulation of different types of abiotic gases in the reservoirs. CO2 is the major component of the abiotic gases in the Huangqiao, Huagou, and Pingfangwang reservoirs, exceeding 60 % up to 95 % and the delta C-13(CO2) values are generally greater than -8 parts per thousand. CH4 is the major component in the Qingshen and Songnan reservoirs with content up to 94.98 %. The delta C-13(CH4) values are commonly greater than -30 parts per thousand (up to -16.8 parts per thousand) and the alkanes exhibit a reverse sequence (delta C-13(CH4) > delta C-13(C2H6) > delta C-13(C3H8) > delta C-13(C4H10)). Most of the He-3/He-4 ratios of the reservoirs are commonly greater than 1 Ra. The carbon isotope values and He-3/He-4 ratios indicate that most of the gas components (CO2 or CH4) are abiotic. The abiotic CO2 is associated with mantle-degassing, and abiotic CH4 is mantle-derived and/or attributed to Fischer-Tropsch (FT) reactions. The ratios of Fe3+/& sum;Fe of the basalt near the Huangqiao reservoir are higher than those near the Qingshen and Songnan reservoirs, suggesting the relatively oxygen-fugacity controls the major component of the abiotic gases. The northwestward subduction of the western Pacific Plate, starting from the Japan Trench, triggered extensive magmatic and volcanic activities, resulting in the release and accumulation of abiotic gases in the rift basins. The variation in oxygen fugacity associated with oxidizing materials (e.g., iron and manganese oxides) and carbonate and sulfate sediments carried by the subducted plate determined the presence of abiotic CO2 or CH4. As the subduction slab continues moving forward beneath the continental plate, the influence of high-oxygen-fugacity materials gradually decreases, causing the abiotic gases to transition from CO2 to CH4. The Huangqiao, Huagou, Pingfangwang, Songnan, and Qingshen gas reservoirs are located farther away from the subducting slab, which explains the gradual shift in the abiotic component in these reservoirs. In general, the majority of the abiotic gases are released from deep faults and magmatic eruptions. Therefore, we conclude that the abiotic gas reservoirs are located near deep faults and igneous rocks.

Helium, a scarce strategic resource, and hydrogen, a zero-carbon clean energy source, are abundantly stored in sedimentary basins and are essential components of underground energy systems. However, comprehensive studies on their occurrence, resources, and exploration prospects in tectonically active sedimentary basins remain limited. Herein, helium and natural hydrogen resources in the Bohai Bay Basin in China, a tectonically active sedimentary basin, were investigated through comparisons with tectonically stable basins such as the Hugoton-Panhandle gas field and Mali. An average helium content of 372 ppm and an average natural hydrogen content of 0.34 % were identified in the natural gas reservoirs of the Bohai Bay Basin. Radioactive element decay, water-rock interactions, and water radiolysis within Earth's crust, along with mantle-derived gas, contribute helium and natural hydrogen to the natural gas reservoirs of the Bohai Bay Basin. Our assessment revealed 2.46 x 109 m3 of helium and 22.4 x 109 m3 of natural hydrogen in the Bohai Bay Basin, of which the natural hydrogen resources are equivalent to 67.12 TWh. The Boxing subsag in the Bohai Bay Basin was identified as a promising exploration area for helium and natural hydrogen due to sufficient helium and natural hydrogen production and favorable reservoir-cap rock assemblages. Moreover, the Boxing subsag with developed iron-rich intrusive rocks can produce orange hydrogen through water injection, and this area is also considered as an ideal site for carbon capture and storage and underground hydrogen storage.