Potential Exploration Targets Research Articles

GIS-based mineral prospectivity mapping using machine learning methods: A case study from Zhuonuo ore district, Tibet

The Zhunuo ore concentration area (ZOCA) is the most potential prospective area of Cu-Au (Mo) in the west of the southern subterrane, Tibet. Single traditional prospective methods (e.g., stream sedimentary geochemistry) often produced larger area and false abnormal information in the Gangdese orogenic belt because of the high altitude and the intense weather and erosion, which can not meet the urgent demand of the current situation for Cu resources. In this study, we combinedamineral system approachwith GIS-basedmachine learningapproachsto obtain geologically meaningful mineral prospective maps. The detail steps include: (i) establishing the mineral system conception model of porphyry copper deposits (PCDs); (ii) transforming the targeted porphyry metallogenic system components into spatial proxies associated with the crucial ore-forming processes; (iii) extracting the spatial proxies: proximity to intrusive rocks (source), NE orientation faults (transport and/or physical trap), Fe-oxide and propylitization hydrothermal alterations zone (hydrothermal fluids) and the metallogenic strength diagram of Cu-Mo-W-Bi-Au-Ag-Pb-Zn (deposition); (iv) Radial Basis Functions Link Networks (RBFLN), Random forests (RF) Supervised and Fuzzy Clustering (FC) unsupervised machine learning methods were applied to capture the complex and crucial mineralization information between known deposit types and evidence layers; (vi) model estimation and delineating prospective potential targets: Receiver operating characteristic curve (ROC), predictive-area (P-A) plotting and normalised density (Nd) were used to evaluate the predictive models results. The results indicate that the RBFLN model, RF model, and FC model show high predictive accuracy. The AUC values under the ROC area of the RBFLN model, RF model, and FC model are 0.99, 0.96, and 0.94, respectively. The RBFLN model outperforms the RF model and FC model, the predictive-area plotting of RBFLN occupies 12% of the study area containing 88% of the known deposits. The predictive-area plotting of the RF model and FC model showed that 14% and 21% of the study area contained 86% and 79% of the known deposits, respectively. The normalized density (Nd) of a layer is defined as the ratio of the prediction success rate (Pr) of the P-A plotting to the corresponding area (Oa). The normalized density of the RBFLN model, the RF model, and the FC model are 7.33, 6.14, and 3.76, respectively, which revealed that the results of the three predictive models all have positive indications. These studies show that RBFLN supervised machine learning method is a more robustness and generalization capability. The predictive results also provide prospective potential targets (e.g., northern Cimabanshuo, northwest Wubaduolai, and southwestern and western Zhunuo PCD) for further exploration, and this method can be also applicable to other mineral systems and districts.

Formation mechanism of fault accommodation zones under combined stress in graben basin: Implications from geomechanical modeling

A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults structure. Increasing numbers of fault accommodation zones are being identified in graben basins, indicating the potential exploration target and petroleum accumulation areas. This study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical modeling. Using three-dimensional (3-D) seismic interpretation and fractal dimension method, exampled with the Dongxin fault zone, the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation zones. Combined with mechanical experiment test, a geomehcanical model was established for fault accommodation zones in a graben basin. Integrating the paleostress numerical simulations and structural physical simulation experiment, the developmental characteristics and genetic mechanism of fault accommodation zones were summarized. Influenced by multi movements and combined stresses, three significant tectonic evolution stages of the Dongxing Fault Zone (DXFZ) were distinguished: During the Es3 sedimentary period, the large difference in the stress, strain, and rupture distribution in various faults were significant, and this stage was the key generation period for the prototype of the DXFZ, including the FAZ between large-scale faults. During the Es2 sedimentary period, the EW-trending symmetric with opposite dipping normal faults and the NE-SW trending faults with large scale were furtherly developed. The junction area of two secondary normal faults were prone to be ruptured, performing significant period for inheriting and developing characteristics of fault accommodation zones. During the Es1 sedimentary period, the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity, and the fault accommodation zones were furtherly inherited and developed. This stage was the molded and formative period of the FAZ, the low-order faults, and the depression in the DXFZ.

The secretome atlas of two mouse models of progeria.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease caused by nuclear envelope alterations that lead to accelerated aging and premature death. Several studies have linked health and longevity to cell-extrinsic mechanisms, highlighting the relevance of circulating factors in the aging process as well as in age-related diseases. We performed a global plasma proteomic analysis in two preclinical progeroid models (LmnaG609G/G609G and Zmpste24-/- mice) using aptamer-based proteomic technology. Pathways related to the extracellular matrix, growth factor response and calcium ion binding were among the most enriched in the proteomic signature of progeroid samples compared to controls. Despite the global downregulation trend found in the plasma proteome of progeroid mice, several proteins associated with cardiovascular disease, the main cause of death in HGPS, were upregulated. We also developed a chronological age predictor using plasma proteome data from a cohort of healthy mice (aged 1-30 months), that reported an age acceleration when applied to progeroid mice, indicating that these mice exhibit an "old" plasma proteomic signature. Furthermore, when compared to naturally-aged mice, a great proportion of differentially expressed circulating proteins in progeroid mice were specific to premature aging, highlighting secretome-associated differences between physiological and accelerated aging. This is the first large-scale profiling of the plasma proteome in progeroid mice, which provides an extensive list of candidate circulating plasma proteins as potential biomarkers and/or therapeutic targets for further exploration and hypothesis generation in the context of both physiological and premature aging.

Simultaneous seismic inversion study for channel sandstone identification, northern part of the Eastern Shelf, King County, North-Central Texas

This paper documents the results of a prestack simultaneous seismic inversion conducted to investigate the Wolfcampian lower Tannehill sandstone channels within a mixed carbonate siliciclastic system in the northern Eastern Shelf in King County, North Central Texas. Previous exploration methods for the Tannehill sandstone were based largely on well-log correlation which, because of their widely spaced sample points, are not optimal for channel delineation. We have generated crossplots of P- and S-wave velocity ratios ([Formula: see text]/[Formula: see text] ratios) versus P-impedance to determine lithologic types. We then used 3D seismic data and wireline logs to implement a prestack simultaneous seismic inversion procedure to generate P- and S-impedances, density, and [Formula: see text]/[Formula: see text] ratio volumes to identify the valley-fill Tannehill lowstand systems. Our results find that (1) based on impedance and density, the sandstone-rich channels can be easily separated from the carbonate-rich zones but are difficult to distinguish using [Formula: see text]/[Formula: see text]. (2) Although there appeared to be several channel systems in the area of investigation, two of these, hereby referred to as channel A and channel B, are recognized to be the key contributors of sandstone sediments to the shelf edge, slope, and basin areas. (3) Of these two channels, channel A is the larger and highly sinuous; it is associated with a meander loop, a point bar, and an abandoned channel. At the point-bar location, channel A has a width of 890 m (2920 ft) and a depth of 29 m (94 ft). The point bar is structurally anticlinal and thus constitutes a potential exploration target. In contrast, channel B is less sinuous, without any associated point bar. It has a maximum depth and width of 23 m (75 ft) and 270 m (886 ft), respectively. Finally, the inversion results suggest that other potential Tannehill sandstone reservoirs may still be present elsewhere within King County.

Resercoir space characteristics and pore structure of Jurassic Lianggaoshan Formation lacustrine shale reservoir in Sichuan Basin, China: Insights into controlling factors

The Jurassic Lianggaoshan Formation lacustrine shale oil is the most potential exploration target of unconventional hydrocarbon resource in Southwest China. In this study, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), low-temperature N2 adsorption (LTNA), and high pressure mercury intrusion mercury injection capillary pressure are intergrated to reveal pore structure and its controlling factors of Lianggaoshan Formation lacustrine shale reservoir. Results indicate that three types of lithology combination are classified in the Jurassic Liangggaoshan lacustrine shale reservoir. Type A comprises pure shale. Type B is characterized by frequent shell limestone interbedding. Type C is characterized by frequent siltstone interbedding. The Type C shale is characterized by relatively high proportion of organic pores, high development and good connectivity of nanopores, and highest pore volume and Surface area. The nanopores of Lianggaoshan lacustrine shales are mainly dominated by mesopores and part of the macropores. Among them, the PV and SA are both mainly dominated by micropores. The enrichment of organic matter has little effect on the development of micropores, and does not affect the mesopore and macropore development. Quartz particles in Lianggaoshan lacustrine shale do not clearly facilitate the development of micropore and mesopore-macropore. Intraparticle pore in feldspar clast is an important component of mesopore and macropore. Clay minerals has no positive effect on the formation of micropore and mesopore-macropore.

Dysregulated low-density granulocyte contributes to early spontaneous abortion.

Spontaneous abortion (SA) is a common adverse pregnancy event with unclarified pathogenesis and limited therapeutic efficiency. Although most SA cases with the euploid embryo(s) are associated with immunological factors, the contribution of low-density granulocyte (LDG) in SA pathogenesis is rarely reported. This study aimed to investigate the serial characteristics and possible contribution of LDG and their subpopulations in early pregnancy, especially in early SA. Unpregnant (UP), normally pregnant (NP), and SA women were recruited, and the peripheral blood and endometrium/decidua were collected for LDG isolation and histological observation. The percentage, phenotype, and subpopulations of LDG were analyzed via flow cytometric analysis, and the ability of Nets formation was assessed by immunofluorescent and immunohistochemical assays. As a result, 43 participants were enrolled, including 10 UP, 15 NP, and 18 SA women. Compared with the UP group, the LDG percentage in peripheral blood mononuclear cells (PBMCs) and decidual immune cells (DICs) increased in the NP group, while the loss of this increase was observed in the SA group. Meanwhile, CD16int/- cell percentage in peripheral blood LDG (PB-LDG) increased in the NP and SA groups, and insufficient activation of CD16hi PB-LDG characterized by reduced CD11b expression was discovered in the SA group. Moreover, the LDG percentage in DICs was higher than that in PBMCs, and the decidual LDG (D-LDG) showed a surface marker expression profile that is easier to be activated in the pregnant cohort (NP + SA women). Finally, increased decidual Nets formation was observed in the SA group compared with the NP group, and more Nets formation was detected in D-LDG of NP and SA women following PMA stimulation. Overall, LDG participates in the maintenance of early pregnancy, while dysregulated LDG is responsible for early SA, providing novel potential targets for further exploration of SA pathogenesis and therapeutics.

Application of biomarkers in characterization of organic matter source, maturity and palaeoredox condition of black shales from the upper Permian Dalong Formation in Southern Anhui Province, South China

The organic‐rich shale in the upper Permian Dalong Formation in Southern Anhui Province is not only regarded as a high‐quality hydrocarbon source rock, but one of the potential targets for shale oil and gas exploration in Southern China. Organic matter types in such a setting remain a subject of debate. The major point of controversy is whether they are dominated by oil‐prone types or gas‐prone types. A total of 20 rock samples collected from Gangdi‐1 well were conducted for analysis of organic geochemistry. Results show that Dalong Formation shale extracts exhibit a wide range of C12‐C35 n‐alkanes and acyclic isoprenoids. The chromatograms display an unimodal distribution with carbon peak in the range of nC18‐nC22 and low quantities of long‐chain (nC25+) n‐alkanes. Relatively high ratios of nC21‐/nC22+ and C27/C29 regular steranes demonstrate that organic matter is mainly originated from lower aquatic organisms and followed by higher plants in a local area. This is also supported by the variations of the δ13C values of C13‐C26 n‐alkanes for the target samples being in the range of 3.0‰–5.6‰ offset, which is slightly higher than the corresponding value (1.6‰) of n‐alkanes from a single source. All these pieces of information decipher that the organic matter in Dalong Formation shale may be dominated by type I and followed by type II1. Moreover, the maturity proxies according to both organic petrography (Ro and Tmax) and biomarkers such as ratios of C29 20 S/(20 S + 20R) and C29 ββ/(αα + ββ) together indicate that organic matter in Dalong Formation shale is in a mature stage of hydrocarbon generation. Furthermore, a cross‐plot of total organic carbon versus total sulphur as well as Pr/Ph ratio and Pr/nC17‐Ph/nC18 diagram elucidates that Dalong Formation shales were mainly formed in a marine reducing environment. Finally, two depositional models of organic matter enrichment are proposed. The abundant lower aquatic organisms with few terrestrial detrital inputs and the reducing water environment together promote organic matter accumulation.

Network and pathway-based analysis of candidate genes associated with esophageal adenocarcinoma.

Previous studies have made some headway in analyzing esophageal adenocarcinoma (EA) with respect to pathogenic factors, treatment methods, and prognosis. However, far less is known about the molecular mechanisms. Thus, a comprehensive analysis focusing on the biological function and interaction of EA genes would provide valuable information for understanding the pathogenesis of EA, which may provide new insights into gene function as well as potential therapy targets. We selected 109 genes related to EA by reviewing 458 publications from the PubMed database. In addition, performing gene enrichment assays, pathway enrichment assays, pathway crosstalk analysis, and extraction of EA-specific subnetwork were used to describe the relevant biochemical processes. Function analysis revealed that biological processes and biochemical pathways associated with apoptotic and metabolic processes, a variety of cancers, and drug reaction pathways. Further, 12 novel genes (PTHLH, SUMO2, TYMS, APP, PTGIR, SP1, UBC, COL1A1, GSTO1, TRAF6, BMP7, and RAB40B) were identified in the EA-specific network, which might provide helpful information for clinical application. Overall, by integrating pathways and networks to explore the pathogenetic mechanisms underlying EA, our results could significantly improve our understanding of the molecular mechanisms of EA and form a basis for selection of potential molecular targets for further exploration.

High light REE enrichments in weathering crust in the Huangmeijian alkaline pluton in Luzong Volcanic Basin: A potential exploration target for ion-adsorption rare earth element deposit

The high light rare earth elements contents (up to 412 ppm) in the weathering crust over the REE industrial grade were observed in the Huangmeijian alkaline pluton of the Luzong Volcanic Basin, firstly revealing the mineralization potential of ion-adsorption rare earth elements deposit in central Anhui Province.

Exhumation and preservation of the Tianyu Cu-Ni deposit constrained by low-temperature thermochronology: Insights into the thermo-tectonic history of the Chinese Eastern Tianshan

The Chinese Eastern Tianshan is an important metallogenic region where major Cu-Ni ores are mined. Previous research in the region primarily focused on the ore genesis. Precise thermochronological data to constrain the exhumation history and preservation of the ore deposits are limited at best. Tianyu is one of these Cu-Ni deposits in the area. Here we present new low-temperature thermochronological data to contribute to the understanding of its exhumation and preservation history. Zircon (U-Th)/He ages of ∼ 134–69 Ma, apatite fission track ages of ∼ 100–75 Ma, and apatite (U-Th)/He ages of ∼ 117–38 Ma from five granodiorite samples of the ore wall rock at different depths of a borehole in the Tianyu deposit were obtained. Our thermochronological data and inverse thermal history modeling reveal a moderate to rapid and final basement cooling phase during the Cretaceous (∼115–85 Ma) with an averaged cooling rate of ∼ 3–4 ℃/Ma. It is envisaged that this phase eventually exposed the ore deposits and that posterior erosion was limited, contributing to the preservation of the deposit. Combined with previously published geochronological and thermochronological data, a multi-stage cooling history of the ore bearing host rocks can be established. After its late Permian (∼280–260 Ma) magmatic-hydrothermal formation, two phases of accelerated regional cooling (i.e., in the late Permian-Early Triassic, ∼260–240 Ma; and the mid-Cretaceous, ∼115–85 Ma) can be recognized. The more intense Cretaceous cooling is associated with the ore body finally being exhumed to the surface, and provides essential information for ore exploration in the region. Further, we propose that areas in the Eastern Tianshan with similar thermal histories to the Tianyu Cu-Ni deposit may be potential exploration targets.

Distribution characteristics and controlling factors of helium-rich gas reservoirs

With the increasing demand for helium and the gradual shortage of proven helium resources, discussing the distribution characteristics and controlling factors of helium-rich reservoirs discovered around the world can not only help us deeply understand the accumulation process of helium in the crust, but also provide guidance for finding helium resources. Based on the compilation of gas chemical composition, stable isotope and noble gas isotope data of helium-rich gas reservoirs found in the world, this paper discusses the distribution characteristics and key controlling factors in combination with geological data. According to the chemical composition, helium-rich gas reservoirs can be divided into three types: helium-rich CH4, helium-rich CO2 and helium-rich N2. Among them, helium-rich CH4 reservoirs are mainly distributed in cratons, while helium-rich CO2 and helium-rich N2 reservoirs are distributed in orogen and fault zones. The gas-producing layers of different types of helium-rich gas reservoirs almost show the characteristics of ancient age and shallow burial. The helium reserves of helium-rich CH4 and helium-rich CO2 reservoirs are similar and significantly larger than those of helium-rich N2 reservoirs, but the helium content shows the opposite characteristics. Helium source, supplying intensity of associated gas, helium accumulation mode, and tectonic-magmatic activity may be the key factors controlling the distribution of helium-rich gas reservoirs in the crust. As far as helium exploration is concerned, the Proterozoic and Paleozoic traps located in uplift structure which has developed Precambrian granite basement, moderate distance from the gas supply center, high geothermal gradient and developed faults are the most effective exploration target. At the same time, the Meso-Cenozoic traps connecting with the Precambrian granite basement through unconformity or deep-seated faults can also be used as potential exploration targets for helium resources.

Geochemical study of Mississippian to Pennsylvanian Namurian Shale in the Namur Synclinorium and Campine Basin (Belgium and S-Netherlands): Implication for paleo-redox reconstruction and organic matter characteristics

The Variscan foreland basin in Belgium and the Netherlands (Namur Synclinorium and Campine Basin) possesses potential targets for shale gas exploration based on the presence of Mississippian to Pennsylvanian Namurian black shales. Organic carbon and nitrogen contents and isotope data, major and trace element analysis, petrographic analysis, Rock-Eval pyrolysis, and basin modeling were carried out on a large sample set from 5 wells in the above-mentioned study area. Carbonate-dominated, silica-dominated, and quartz-rich mudstones with dominant type II kerogen were deposited within distal positions close to the basin floor while clay-rich, carbonate-rich, and silt-rich mudstones with mixed type II and III kerogens reflect depositional conditions at more proximal positions close to the basin margin. Sedimentary rocks were deposited in redox-stratified marine environments. Oxygen depleted environments occurred during the early Namurian A age, especially at distal depositional positions in contrast to elevated oxygenated environments during the late Namurian A age, especially at more proximal positions. From distal positions to proximal positions, redox conditions changed from mainly euxinic to anoxic conditions with some dysoxic episodes to mainly anoxic to dysoxic conditions with a few oxic episodes. The variation in δ15Nbulk values in the Namur Synclinorium suggests that N2-fixation dominated in anoxic environments during the early Namurian A age while nitrification, denitrification, and anammox in the water column dominated in anoxic to dysoxic environments with oxic episodes during the late Namurian A age. In the Campine Basin, denitrification and anammox dominated in anoxic to dysoxic environments during the early Namurian A age while N2-fixation dominated in anoxic environments at distal positions and nitrification dominated in dysoxic to oxic environments at proximal positions during the late Namurian A age. Namurian A mudstones are overmature with higher maturity in the Campine Basin than in the Namur Synclinorium. They display low potential for petroleum and gas generation based on Rock-Eval results. Basin modeling results indicate that the thermal maturity of Namurian A mudstones already reached its main phase of dry gas generation with overmature conditions during the Pennsylvanian in the Namur Synclinorium and the southern Campine Basin. In the northern Campine Basin corresponding to a depositional setting further away from the Variscan mountains, however, these sedimentary rocks became overmature during the Jurassic. Conversion of all type II kerogen to petroleum and dry gas occurred during increasing burial depth and thermal maturity. This left only overmature, hydrogen-poor kerogen remaining in the mudstones. The western Namur Synclinorium is regarded as the most prospective exploration area with high gas generation and storage potential as well as good hydraulic fracturing potential in terms of very high total organic matter content, large shale thickness, and high amount of brittle mineral contents. The Campine Basin is a secondary target with more limited gas generation and storage capacity, based on the moderate to high total organic matter content, the limited thickness of the mudstone interval, and limited brittle mineral contents.

The synergistic use of multi-scale remote sensing data for the identification of hydrothermal alteration patterns in Los Frailes, Spain

• FieldSpec4, SisuROCK, AisaFenix and WorldView-3 results are used synergistically. • Spectral data characterise hydrothermal alterations typical for massive sulphides. • Chlorite and white mica mapping results coincide mostly between the data scales. • Mapping discrepancies are explained by different data types and analysis methods. • Multi-scale spectral data can help to identify potential exploration targets. Remote sensing data can be successfully applied in mineral resource prospecting and exploration. With the increasing number of remote sensing sensors and methods, the application of multi-scale remote sensing data has met a broad audience in the geological remote sensing community over the last few years. Multi-scale remote sensing data close the scale gap between distal (satellite) and proximal (laboratory) remote sensing data, offering both a general and detailed overview of the target and allowing a synergistic use. In this study, the volcano-sedimentary hosted massive sulphide ore deposit Los Frailes in the east of the Iberian Pyrite Belt (IPB) in Spain is investigated for the first time with multi-scale remote sensing techniques. A typical hydrothermal alteration zonation is associated to the massive sulphide ore body in Los Frailes, which is characterised by an inner chlorite-rich zonation showing a strong Fe-enrichment and a peripheral muscovite-rich zonation, which is moderately enriched in Fe. The characterisation of these zones support traditional mineral exploration techniques especially in the prospecting phase by detecting regions of interest, thereby reducing time and cost consumption. By evaluating the synergistic use of multi-scale remote sensing data for massive sulphide exploration, an enhanced application for the economic prospecting and exploration of mineral resources in Los Frailes is introduced. Optical data are used for the detection, identification and characterisation of chlorite and white mica occurrences and compositions. A drill core is analysed with the FieldSpec4 Hi-res hyperspectral point spectrometer. Rock samples are investigated in the laboratory using the SisuROCK hyperspectral core imaging station. AisaFENIX hyperspectral field-based and WorldView-3 multispectral satellite data of the open pit are analysed. The mineral(-group) identification and characterisation are performed with either spectral feature fitting methods (hyperspectral) or mineral indices (multispectral). Hyperspectral analyses show Mg-/Al-substitutions due to Fe-enrichment owing to wavelength shifts of the absorption maximum in chlorite and white mica, respectively. The identification and characterisation of the Fe-OH absorption feature of chlorite at around 2250 nm is more challenging compared to the Al-OH absorption feature of muscovite at around 2200 nm because the spectral signature is more subtle regarding the depth and width. However, the chloritic hydrothermal alteration zonation in the footwall is successfully detected in all scales. The hydrothermal muscovite-rich zonation in the footwall is barely outcropping in the pit and is not captured in the drill core. However, the muscovite-rich alteration zonation in the hanging wall is indicated in all scales. Discrepancies in the results arise mainly from different spectral and spatial resolutions of the sensors and differing data acquirement conditions, such as different surface exposures, viewing angles and illumination conditions. The results show that the multi-scale method offers great opportunities to localise potential prospecting and exploration targets in the Iberian Pyrite Belt. The synergistic use of the different remote sensing scales offers a complete picture of the target by gaining macroscopic to regional spectral information collectively, which is superior to using only one scale. The method is relatively fast and cost-effective, which makes the identification of potential exploration targets more efficient.

Combining 3D Geological Modeling and 3D Spectral Modeling for Deep Mineral Exploration in the Zhaoxian Gold Deposit, Shandong Province, China

The Jiaodong Peninsula hosts the main large gold deposits and was the first gold production area in China; multisource and multiscale geoscience datasets are available. The area is the biggest drilling mineral-exploration zone in China. This study used three-dimensional (3D) modeling, geology, and ore body and alteration datasets to extract and synthesize mineralization information and analyze the exploration targeting in the Zhaoxian gold deposit in the northwestern Jiaodong Peninsula. The methodology and results are summarized as follows: The regional Jiaojia fault is the key exploration criterion of the gold deposit. The compression torsion characteristics and concave–convex section zones in the 3D deep environment are the main indicators of mineral exploration using 3D geological and ore-body modeling in the Zhaoxian gold deposit. The hyperspectral detailed measurement, interpretation, and data mining used drill-hole data (>1000 m) to analyze the vectors and trends of the ore body and ore-forming fault and the alteration-zone rocks in the Zhaoxian gold deposit. The short-wave infrared Pos2200 values and illite crystallinity in the alteration zone can be used to identify 3D deep gold mineralization and potential targets for mineral exploration. This research methodology can be globally used for other deep mineral explorations.

Multi-Step Gold Refinement and Collection Using Bi-Minerals in the Laozuoshan Gold Deposit, NE China

Gold and Bi-bearing parageneses are pivotal to understanding gold concentration and deposition processes. The large-scale Laozuoshan gold deposit is located in the Jiamusi Block, northeastern China, and has experienced complex mineralization processes with abundant gold and Bi-bearing minerals. However, the relationship between Bi-minerals and gold is unclear, preventing our understanding of the gold enrichment and precipitation mechanism in the Laozuoshan gold deposit. Optical microscope and SEM results show three stages of gold mineralization: pyrrhotite (Po-1) + arsenopyrite (Apy-1) + Bi-bearing minerals (Bis-1) + Au-1; arsenopyrite (Apy-2) + chlorite + Bi-bearing minerals (Bis-2) + Au-2; and arsenopyrite (Apy-3) + graphite + Bi-bearing minerals (Bis-3) + Au-3. The abundant amount of gold (Au-1~Au-3) is associated with Bi-bearing minerals (Bis-1~Bis-3), which coexist as inclusions and fill in fractures in these minerals. The mineral assemblages of arsenopyrite, Bi-minerals, and gold exhibit a clear As-Bi-Au mineralogy in the ores, and the ternary diagram of the chemical compositions of the Bi-minerals shows that Bi-minerals all fall in reducing regions, indicating that Bi-minerals are precipitated under reducing conditions. The gold compositions demonstrate a positive correlation (R2 = 0.58) between Au and Bi. Consequently, we propose that the gold experienced the ore-forming fluids concentration and further Bi-melts scavenging for the Laozuoshan gold deposit mineralization. The Bi collector model is essential in interpreting the high-grade gold in the Laozuoshan gold deposit, indicating that the geochemical anomalies observed with bismuth may be a critical potential exploration target for the high-grade gold deposits in the Jiamusi Block.

Acquisition and Preparation of 3D Seismic Data for Pre-Stack Inversion at Siba Oilfield, Southeastern Iraq

The current study includes preparing a geometric proposal of the main parameters that must be worked within a seismic reflection survey to prepare a three-dimensional subsurface image. This image represents the Siba oil field located in Basra, southern Iraq. The results were based on two options for selecting these approved elements to create a three-dimensional image of the Mishrif, Zubair and Yamama formations as well as the Jurassic and Permian Khuff and the pre-Khuff reservoir area. The first option is represented in the geometry in option -1 is 12 lines, 6 shots, and 216 chs. The receiver density is 66.67 receivers / km2, so the shot density is the same. Total shots are 21000, which is the same number of receiving points. The survey area (in km2) and full fold area (in km2) are 317and 328, respectively. However, the second option in the geometry are16 lines, 16 shots, and 208 chs. Receiver density and shot density are 50, while the total shots are 16200 and the total receiving points are 16000; with survey area and full folded area are 198 and 198 km2. The aim of the current study is to characterize the structure and reservoir quality of Yamama and Zubair intervals and to image potential exploration targets such as the Mishrif, Jurassic, Permian Kuff and Pre Khuff formations. The present study succeeded in preparing the geometric proposal and getting at a subsurface image of the reservoir in three dimensions.

Genetic dissection of lutein content in common wheat via association and linkage mapping.

Genetic architecture controlling grain lutein content of common wheat was investigated through an integration of genome-wide association study (GWAS) and linkage analysis. Putative candidate genes involved in carotenoid metabolism and regulation were identified, which provide a basis for gene cloning and development of nutrient-enriched wheat varieties through molecular breeding. Lutein, known as 'the eye vitamin', is an important component of wheat nutritional and end-use quality. However, the genetic manipulation of grain lutein content (LUC) in common wheat has not previously been well studied. Here, quantitative trait loci (QTL) associated with the LUC measured by high performance liquid chromatography (HPLC) were first identified by integrating a genome-wide association study (GWAS) and linkage mapping. A Chinese wheat mini-core collection (MCC) of 262 accessions and a doubled haploid (DH) population derived from Jinchun 7 and L1219 were genotyped using the 90K SNP array. A total of 124 significant marker-trait associations (MTAs) on all 21 wheat chromosomes except for 1A, 4D, and 5B that formed 58 QTL were detected. Among them, six stable QTL were identified on chromosomes 2AL, 2DS, 3BL, 3DL, 7AL, and 7BS. Meanwhile, three of the ten QTL identified in the DH population, QLuc.5A.1 and QLuc.5A.2 on chromosome 5AL and QLuc.6A.2 on 6AS, were stable and independently explained 5.58-10.86% of the phenotypic variation. The QLuc.6A.2 region colocalized with two MTAs identified by GWAS. Moreover, 71 carotenoid metabolism-related candidate genes were identified, and the allelic effects were analyzed in the MCC panel based on the 90K array. Results revealed that the genes CYP97A3 (Chr. 6B) and CCD1 (Chr. 5A) were significantly associated with LUC. Additionally, the gene PSY3 (QLuc.5A.1) and several candidate genes involved in the methylerythritol 4-phosphate (MEP) pathways colocalized with stable QTL regions. The present study provides potential targets for future functional gene exploration and molecular breeding in common wheat.

Exploration progress of the Paleogene in Jiyang Depression, Bohai Bay Basin

With increased exploration in the faulted basins of eastern China, petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution, complex reservoir and hydrocarbon enrichment patterns, and lacking of suitable exploration techniques. Aiming at resolving these problems, studies on source rocks, reservoirs, hydrocarbon accumulation and geophysical prospection were carried out by laboratory analysis, reservoir anatomy, and seismic analysis. A highly-efficient hydrocarbon generation/expulsion model of source rocks in saline environment was established, which aided in the discovery of a new set of source rocks in the Jiyang Depression. This study also reveals the formation process of high-quality reservoir by alternating acid and alkaline fluids during deposition and diagenesis, and pattern of secondary pores development in deep clastic rocks. Through the fine anatomy of the oil reservoirs, an orderly distribution pattern of the oil reservoirs is established, and the potential exploration targets in the undrilled area are identified. In addition, single-point high-density seismic acquisition and high-resolution imaging technologies are developed, enabling fine and efficient exploration in areas with high exploration maturity. The research result plays a leading and demonstrative role in the fine and efficient exploration of faulted basins in eastern China.

Late Triassic granitic magmatism and tungsten mineralization in NE China: Geochronological and geochemical constraints from the Tantoushan quartz-wolframite vein-type deposit

NE China, located at the eastern Central Asian Orogenic Belt, experienced extensive magmatism during the Mesozoic and hosts multistage granitic plutons and accompanying W mineralization. However, due to the limited number of studies on Triassic W deposits and spatially related granitoids, the petrogenesis of these granitoids and their relation to W mineralization remain enigmatic. The Tantoushan quartz-wolframite vein-type deposit is located on the southern margin of NE China. Tungsten mineralization occurs mainly in the veins and veinlets within monzogranites. A lower intercept 206Pb/238U age of 234.3 ± 6.2 Ma (1σ, MSWD = 0.41) was obtained for wolframite, which is identical within uncertainties to the zircon weighted mean 206Pb/238U age of 233.1 ± 1.8 Ma (1σ, MSWD = 0.41) from the W-bearing monzogranites. The monzogranites have the petrological, mineralogical, and geochemical characteristics of highly fractionated I-type granitoids. The rocks are enriched in Rb, Th, U, K, and Pb, and depleted in Ba, Sr, P, and Ti. They have higher W concentrations and Rb/Sr ratios, and lower Nb/Ta, Zr/Hf, and K/Rb ratios than the contemporary W-barren granitoids in NE China. These geochemical characteristics and negative zircon εHf(t) values (−17.7 to −8.6), as well as old two-stage model ages (TDM2 = 1807–2378 Ma), suggest that the monzogranites were derived as a product of the partial melting of the Paleoproterozoic lower crust and subsequently underwent extreme fractional crystallization. Geochronological and geochemical evidence collectively suggest that the W mineralization in the Tantoushan deposit is genetically related to the W-bearing monzogranites, and extreme fractional crystallization was essential for W enrichment in the granitic magma. In contrast, Triassic W-barren granitoids did not induce W mineralization, probably because of their low fractionated signatures. We preliminarily demonstrate that an isovalent substitution mechanism of 4A(Fe, Mn)2+ + 8BW6+ + B□ ↔ 3AM3+ + AN4+ + 7B(Nb, Ta)5+ + 2BN4+ played a critical role in the formation of hydrothermal wolframite in the Tantoushan deposit, and the trace elements compositions of wolframite were controlled by both the crystallochemical parameters and composition of the initial hydrothermal fluids. In the context of the regional geology, we propose that the Tantoushan monzogranites and corresponding W mineralization were formed in a post-collision extensional setting controlled by the closure of the Paleo-Asian Ocean during the Late Triassic. In combination with previous studies, we suggest that NE China may have enormous potential for Triassic W mineralization and the Triassic highly fractionated granitoids distributed on both sides of the Solonker-Xar Moron-Changchun Fault represent potential targets for future exploration of additional W resources.

Characterization of the Lower Cretaceous Shale in Lishu Fault Depression, Southeastern Songliao Basin: Implications for Shale Gas Resources Potential

Large thickness of shales over 180.0 m was developed in the source rocks of the Shahezi and Yingcheng formations in the Lishu Fault Depression. Moreover, the high amount of gas content and the total hydrocarbon value of gas logging in several boreholes illustrate that there is a great potential of shale gas resources in this region. Therefore, an integrated characterization of shales from the lower Cretaceous Shahezi and Yingcheng formations was provided to evaluate shale gas resources potential. The measurement results illustrated that the organic-rich shale samples with kerogen type Ⅱ during high to over thermal maturity had a higher content of brittle minerals (>50%) and clay mineral dominated by illite. The shales had a total porosity of 3.11–4.70%, a permeability of 1.24 × 10−3–1.52 × 10−3 μm2, and possessed pore types including dissolution pores, inter-layer pores of clay minerals, micro-fractures, intra-granular pores, and organic pores, which were dominated by micropores and mesopores (0.5–1.7 nm, 2.2–34.3 nm) with a significant contribution from OM and clay minerals. According to the N2 adsorption isotherms, the pore volume was comprised primarily of mesopores with mean widths of 4.314–6.989 nm, while the surface area was comprised primarily of micropores with widths in ranges of 0.5–0.8 nm and 1.0–1.7 nm. Thus, the shales have a suitable porosity and permeability, indicating that fine storage capacity and favorable gas flow capacity occur in the Shahezi and Yingcheng formations, which exhibit a good reservoir quality and excellent exploration potential since the considerable thickness of shales could form a closed reservoir and served as cap rocks for in situ gas generation and accumulation. Especially, according to the measured CH4 excess adsorption amount and the calculated maximum absolute adsorption capacities of CH4 based on the Langmuir adsorption model, the estimated GIP values (1.388–3.307 m3/t) of the shales happened to be in a sampling depth under geological hydrostatic pressure and temperature conditions. This means that the shale storage capacity and high gas content from well site desorption completely met the standard of industrial exploitation when synthetically considering the GIP model. As a consequence, shales in the Shahezi and Yingcheng formations in the Lishu Fault Depression could be potential targets for shale gas exploration.