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This paper presents, for the first time, geochemical data related to the Battle of Jenipapo, a significant event that occurred on March 13, 1823, marking a political activity favorable to Brazil's independence. The present work aimed to analyze the contents of lead and copper as markers of historical armaments in sediments for geochemical prospecting of the archaeological area in which the Battle of Jenipapo probably occurred. Nine sediment samples were collected: seven from the prospect area and two control samples. Sedimentological characteristics were evaluated, such as pH (6.1–6.9), acidity (0.19–3.00 mmol L−1), organic matter (0.86–3.37% w/w), and granulometric classification (sandy predominance). The metals (lead and copper) were determined by inductively coupled plasma mass spectrometry (ICP‐MS) after acid digestion of the sediments. Lead content ranged from 7.9 to 14.9 mg kg−1 for samples and 5.4 mg kg−1 for control samples. Copper content ranged from 14.2 to 29.3 mg kg−1. The results showed that only lead could be used for the geochemical prospecting of the area that presented strong evidence of anthropic intervention allowing the carrying out of excavation steps. [ABSTRACT FROM AUTHOR]

Purpose: In this study, a methodology is developed that involves geochemical and geophysical prospecting methods to identify the type and concentration of hydrocarbons, soil and water resistivity-salinity, and the delineation of hydrocarbon migration in the subsurface within an agricultural region in the northern part of the state of Veracruz, Mexico, where a landfill resulting from hydrocarbon exploitation is the contamination source. Materials and methods: The methodology involves hydrocarbon fractionation by packed open column liquid chromatography (SARA: Saturates, Aromatics, Resins, and Asphaltenes), textural analysis by sieving, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM–EDX), salinity concentration, total petroleum hydrocarbon concentration in water (TPH), water resistivity, and salinity determination using a laboratory geo-electrical method and Electrical Resistivity Tomography (ERT). Results and discussions: The hydrocarbon exhibited a stable colloidal stability, and the soil composition is of the general type, classified as clay-sandy with high concentrations of iron and strong salinity. The water showed TPH concentrations, and the resistivity and salinity exceeded the permissible limits set by Mexican standards. Electrical Resistivity Tomography delineated both recent and mature contamination. Conclusions: With this methodology, it was determined that the region exhibits active contamination directly related to the exploration, exploitation, and pipeline leakage of hydrocarbons. The most affected area was the agricultural zone (low-lying area) due to the overflow of contaminated water from the landfill. [ABSTRACT FROM AUTHOR]

The Xiaohongshilazi Pb–Zn–(Ag) ore district, located in the Jizhong–Yanbian Metallogenic Belt in NE China, presents challenges in identifying geochemical anomalies and prospecting minerals due to thick covers, complex geological evolution and mining activities. To overcome these obstacles, we adopted an innovative approach that combines multifractal theory with concentration-area (C-A) modelling and local singularity analysis (LSA) to characterize the geochemical signature. Initially, factor analysis of log-transformed data was used to identify ore-forming factors, which were then modelled using C-A and LSA. Subsequently, modelling results were compared to conventional maps generated using inverse distance weighted (IDW) interpolation. Additionally, the C-A model was employed to establish thresholds for singularity indices generated by LSA for target mapping. The results revealed a close relationship between Factor 1 (F1) and mineralization. The C-A model of F1 failed to detect weak anomalies compared to the IDW-interpolated map, while LSA not only identified weak anomalies but also enhanced the detection of reliable anomalies. Three prospecting targets (PT-01, PT-02 and PT-03) were identified. Validation of PT-01 using new drillholes and existing mineralization confirms the effectiveness of targets and the accuracy of the model. Our approach provides a robust alternative for prospecting at ore districts encountering similar challenges. [ABSTRACT FROM AUTHOR]

The study aims to achieve several objectives: determine background element concentrations in Taraxacum officinale F.H. Wigg-common dandelion roots, stems, and flowers; clarify T. officinale's ability to accumulate trace elements (TEs) in plant parts; calculate accumulation and translocation factors to identify hyperaccumulator potential; and contribute to practical applications in geochemical prospecting, exploration geochemistry, phytomining, and environmental remediation. To accomplish this, 34 samples of T. officinale and associated soil samples were gathered from the plant's habitat along the roadside for trace element (TE) analysis. The elemental composition of both plants and soils underwent analysis using diverse statistical approaches, including factor analysis, ANOVA tests, and descriptive parameters. Plant element accumulation patterns and tendencies across various plant parts were explored through bioconcentration (BCFs) and translocation factors (TFs). Results showed that T. officinale accumulates some TEs in its roots, stems, and flowers, with the highest concentrations found in the roots. The factor analysis of plant element contents indicated a grouping tendency among elements. Specifically, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn exhibited a tendency to co-occur, while Ba, Mo, and Sr formed a separate group. Furthermore, in the flowers of the plant, Al, Ba, Co, Cr, Fe, Mn, Ni, and Sr showed a similar grouping, while Cu, Pb, and Zn formed a distinct cluster. ANOVA tests demonstrated significant variations in the accumulation of Al, Ba, Cr, Fe, and Sr among the roots, flowers, and stems of the plant. Additionally, Ni and Pb exhibited noteworthy differences in accumulation between these plant parts. Furthermore, Mn and Zn showed significant discrepancies in their accumulation capacities across all parts of the plant. T. officinale was identified as a lead hyperaccumulator by the study, with BCFs and concentrations exceeding 1000 mg kg−1. These findings inform strategies for phytoremediation and enhance our understanding of the plant's potential role in exploration studies and environmental management in metal-rich regions. [ABSTRACT FROM AUTHOR]

Within the framework of an Armenian–German research project, taking place between 2019 and 2021 on the Artanish Peninsula at Lake Sevan (Armenia), in addition to numerous (geo‐) archaeological investigations, methods of geochemical prospection have been carried out. The ancient burial grounds of Artanish 23 and Artanish 29 have served as model sites to successfully test the well‐known method of geochemical prospection and evaluation of metal deposits in geology (mineral sector). As a result, a new experimental archaeo‐geochemical prospecting and evaluation method has been developed, which has been adapted for the exploration of archaeological monuments. It is planned to use this experimental method (which we consider new and important in archaeogeochemical investigation, but not a conclusive and comprehensive work per se), which has already proven its work capacity, in archaeological research, in the prospective areas of Armenia and other countries. In addition to these investigations, research on the transformations in the landscape of the ancient tombs related to Lake Sevan fluctuations has also been carried out. The anthropogenic impact of humans on the environment (geochemical halos formed in the soil on the surface of the tombs) has been studied, as well as the problem of the impact of geological environment on human life activities, that is, the relocation of the burial grounds to more elevated areas due to the rise in the lake level. Based on the results of geochemical sampling and high‐resolution magnetometer surveys, excavations have been performed at the site. Here, we present the results of an experimental study exploring the potential of combined magnetometer prospection and chemical soil analyses to locate and characterize the burial ground of Artanish on Lake Sevan, Armenia. The results have demonstrated the capability of these analyses to detect the sites, outline hotspots and interpret the features identified in the magnetometer results. [ABSTRACT FROM AUTHOR]

The Mahuagou gold deposit is among the most important gold deposits in the core of the Huangling Anticline. However, the geochemical exploration on the surface of the mining area presents challenges due to the thin overburden. This paper focuses on the overburden soil of the Fengxiangshugou (FXS)-Mahuanggou (MHG) section as the research object. It utilizes chemical form analysis of gold, soil halogen survey, and heat-released mercury survey to determine the key deep-penetrating geochemical methods for the mining area. The results indicated that Si and Al components of samples exhibit minimal variation, suggesting that drift loads did not influence the overburden soil. Based on the systematic clustering, As, Sb, Mo, Bi, W, and Hg emerge as ore-body or ore-belt front elements of hydrothermal gold deposits. In the study area, the predominant chemical form of gold in soil is the strong organic bond. Compared to the total amount, strong organic bound gold and heat-released mercury show higher anomaly contrasts, making them crucial indicators of faults, intrusions, and hidden ore bodies. Consequently, chemical form analysis of gold and heat-released mercury surveys can enhance the anomaly contrast, proving beneficial for geochemical prospecting for weak anomalies in this area. [ABSTRACT FROM AUTHOR]

Xiangyanggou Gold Deposit is located in the western part of the East Kunlun orogenic belt. In the area, gold deposits such as Dazaohuo Gold Deposit and Heicigou Gold Deposit have been discovered. The ore bodies mainly occur in fracture altered zones at the contact areas of clastic rocks of different eras or the contact areas of clastic rocks and carbonate rocks of the same era. The fracture altered zones provide transport channels and precipitation sites for ore-bearing fluids. The intersection of faults, the intersection of faults with favorable rock masses and strata, and the expansion areas such as fault turning points are important mineralization areas. 1: 10 000 soil geochemical survey delineated 8 comprehensive anomalies and it is believed that the areas with Au maximum value greater than 50.00 x 10-⁹ are important geochemical prospecting locations. Based on an in-depth summary of prospecting indicators, a comprehensive geological geochemical prospecting model was established. 6 prospecting target areas were delineated in the Xiangyanggou Gold District, and a total of 17 ore bodies and 37 mineralized bodies were verified, which is a prospecting breakthrough. The ore (mineralized) body is 80-320 m long, with an average actual thickness of 0.82-6.46 m and a gold grade of 1. 16 x 10-6 -14.30 x 10-6. In general, the comprehensive prospecting model applies to Xiangyanggou Gold Deposit and can provide references for similar deposits in the region. [ABSTRACT FROM AUTHOR]

Sineqan mine, 25 km away from Delijan city (Markazi province), has shown important evidences of iron oxide ores containing copper, gold and rare earth elements (REE) in the early stages of exploration. In the present study, a low-grade sample of the mine from the albite zone containing 0.69% of copper and 223, 186 and 55 g/t of cerium, lanthanum and neodymium was processed and compared with the results of elements correlation in geochemical samples. Cerium, neodymium and lanthanum showed the highest correlation with each other and with the thorium. The correlation coefficient of light REEs with phosphorus was negative. The results of ammonium sulfate leaching showed that the occurrence of REE in the sample is not as adsorption on clay minerals and the study of the correlation coefficient of REE with aluminum and sodium in geochemical samples also confirmed this result. The results of leaching with H2SO4 showed that selective leaching of copper is possible. The low efficiency of leaching with H2SO4, HCl and HNO3 and the higher efficiency of 96% for leaching with cerium and lanthanum under acidic baking conditions showed that a significant part of REEs is in the form of refractory minerals. The concentration ratio of REEs in the magnetic concentrate was close to iron. According to the correlation analysis of elements in geochemical samples, the correlation of calcium with REE was in the range of -0.2 to-0.3. In the flotation test, although the grade of calcium increased 3.5 times in the flotation concentrate, this was not the case for REEs. The results of this research can be used in similar cases in the early stages of exploration and processing feasibility studies. [ABSTRACT FROM AUTHOR]

Mining activity at Taxco produces seven mining waste deposits, which are problematic for the health of the community and for the environment in general. This study targets the Guerrero I mining waste dam (the youngest of the region), located south of Taxco de Alarcon, in the northern portion of Guerrero State, Mexico. This study reports the vertical magnetic susceptibility prospecting results and geochemical characterization of 27 tailing samples from the Guerrero I dam. Results from magnetic techniques provide evidence for different deposit layers of variable mineral composition, in agreement with the lithological column. The short evolution period of this relatively young dam is corroborated by the practically constant and close to 1 S-300 ratio (low oxidation degree of the magnetic mineralogy) and the mainly neutral pH character at the dam's upper part. Most maximum concentrations of potentially toxic elements are below the maximum permissible levels for agriculture/residential use, except for those of Pb and Zn, with average enrichment factors above 90 and 50 times the corresponding regional background concentrations, respectively. Simple sample preparation and fast magnetic and X-ray fluorescence elemental concentration measurements, together with a suitable systematic sampling distribution, result in an advantageous proxy method for a quick and cost-effective heavy metal evaluation of mining waste dams. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Sarakan Gold Deposit is located in the vicinity of the Songsanu and Napafa villages, north of Sarakan County, Vientiane Province, Laos. It forms part of the Luang Prabang–Loei polymetallic metallogenic belt, and its metallogenic geological conditions are good and mineral resources are abundant. At present, most orebodies (mineralization) are deeply buried and greatly vary in terms of their characteristics; furthermore, the distribution and output of orebodies (mineralization) are not clear, which makes it difficult to find minerals in the area. Based on the comprehensive geological characteristics, geophysical anomalies, and interpretation results in the study area, it is believed that the Sarakan Gold Deposit is closely related to Indosinian felsic substance magmatic intrusions and is controlled by their structure. The type of deposits in the belt are brittle–ductile, shear structured, Quartz-pyrite, vein-type gold deposits. In this study, we carried out comprehensive geophysical methods, including the high-precision magnetic survey, induced polarization survey, and the transient electromagnetic measurement. Based on the characteristics of geophysical anomalies, geological inference, and interpretation, the integrated geophysical and geochemical prospecting criteria of the ore area have been determined: high magnetism, high polarization, and medium–high resistance are the signs pointing to concealed mineralization bodies in the study area, and this provided the best framework for us to discuss the deep geological bodies in the study area. The drilling verification results are consistent with the abnormalities delineated by the magnetic and electrical measurements. Our geophysical exploration results revealed the coupling relationship between the concealed intrusive body of the Sarakan Gold Deposit and the metallogenic structure, which provided a great opportunity for finding potentially similar deposits in the Luang Prabang–Loei polymetallic metallogenic belt. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lighvan hot spring and Toptapan mineral spring are located in the Eastern Azarbaijan, NW of Iran. The host rocks of Lighvan hot spring are dacite, andesite and Quaternary volcanic tuffs. Their main rock forming minerals are quartz, plagioclase, biotite and rarely amphibole. The host rocks of Toptapan mineral water spring are Cretaceous and Jurassic sandstone, shales and carbonate sedimentary rocks. Their main rock forming minerals are quartz, calcite, dolomite and clays. Due to the deposition of mineral water springs, travertine is the main Quaternary sediments around the springs. Water samples were collected from Toptapan mineral spring and Lighvan hot spring in July (dry season). The sampling method was according to standard methods for geochemical analysis. Field parameters such as PH, temperature, and EC were measured in situ, and samples were analyzed by ICP-OEC and ICP-MS in the laboratory of the Geological Survey of Iran. The measuring data showed that pH varies between 6.1 to 6.4. The surface temperature varies from 20.1°C to 32.8°C. The concentration of anions and cations in the Piper diagram show calcic bicarbonate type for Toptapan mineral spring and sodic bicarbonate type for Lighvan hot spring respectively. According to Lunglier - Ludwig diagram, the dissolution of carbonate and silicate minerals is the most important factor in increasing calcic cation. The Cl-Li-B diagram shows that the dissolution of sodic minerals and clays and ionic exchange are also the most important factors for increasing sodium in these springs. These data are in agreement to the host rocks, their mineralogy and their chemical composition. Based on the Ca-Mg-K geothermometer diagram, the geothermal reservoir temperature for Lighvan hot spring is 95-100 °C with a depth of about 2Km and for Toptapan mineral spring is 65-85 °C with a depth of less than 1Km. Also, high concentrations of chlorine show a deep geothermal primary reservoir in the Lighvan hot spring. These geochemical data show that these cold and hot springs are not polluted and not harmful for environmental point of views. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geology & Resources is the property of Geology & Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Oyu Tolgoi world-class porphyry copper-gold deposits in Mongolian are that supergene and epithermal hydrothermal system superimposed in the early stage of porphyry system. Lithofacies of alterations, mineral and geochemical comprehensive methods were employed. Objective of this article are to investigate their formation environment of alteration rocks and mineralization in order to establish REEs and comprehensive prospecting indicators of alteration lithofacies, especially to find ore-forming center for this superimposed mineralization systems. Based on this study, REEs and geochemical prospecting indicators of alteration veins are of evident positive Eu anomaly, and are higher in concentrations of Fe 2 O 3 , CaO, S and TiO 2 , with obvious positive U–K, Pb, P and Ti anomalies. It is very useful to catch the advanced argillic alteration lithofacies to delineate coverage of the later stage epithermal system, in which they are characterized by "U"-shape pattern normalized by chondrite as well as obviously anomalous concentrations of Cu, As, Se, Ba, Pb and Bi, with higher concentrations of K 2 O, Al 2 O 3 and S. Moreover, it is very valuable to discovery the intermediate argillization lithofacies to outline the mineralized center in which are typified by veinlets and brecciated hematite-magnetite silicification rock, and hematite-ferrocarbonatization rock. The mineralized center is typified by silicification altered rock in structure of veinlets-shape or the lithocap. The hydrothermal breccia zone may be an indicator of structure-lithology for the excrete channel and feeder of metallogenic fluid transportation in the epithermal system. Therefore, it is very more important that they are characterized by noticeable negative Eu anomaly (Eu*＝－0.57) and smooth-shape pattern normalized by chondrite. Copper mineralized center is implied by transitional environment of oxidation-reduction characterized by the ratios of Fe3+/Fe2+ from 0.72 to 2.13, plus Cu、As、Se、Ba、Pb and Bi anomalies, occurred lithofacies of the intermediate argillic alteration are considered to be localization markers whenever associations of Cu、V、Zn、Se and Mo anomalies may be signs for orebody finder. [ABSTRACT FROM AUTHOR]

The geochemical data from surface soils are often neglected or questioned when prospecting for ore deposits within active mining districts due to the "background noise" produced by anthropogenic pollution derived from mining activity. Large datasets on a national and international scale offer interesting possibilities to discover prospective zones. In the present work, data from the Geochemical Atlas of Castilla–La Mancha were treated in an area with an intense history of mining Hg, Pb, Zn, and Sb: the Almadén and Guadalmez synclines and the Alcudia Valley. The sampling grid was densified to adapt it to the scale of the main geological formations, and a cluster analysis was carried out to establish the relationships between the variables and a factor analysis to distinguish between geogenic and metallogenic factors. The results showed very high concentrations of some elements of prospective interest in local background areas: Hg (51 mg kg−1), Pb (1190 mg kg−1), and Sb (45 mg kg−1), with high variation coefficients. Cluster analysis unveiled a relationship between most of the local ore-forming metals (As, Sb, Hg, Pb, and Ag) with a clear correlation between Hg and organic matter, suggesting a notable contribution of Hg in soil. The factor analysis highlighted five factors, three geogenic and two ore-forming elements. Despite Hg being the main candidate to form a separate factor, its aerial deposition and a large number of outliers in the Almadén syncline contributed to integrating the element into a geogenic factor. Instead, factors F4 (Pb and Zn) and F5 (As and Sb) delimited the prospective areas in both synclines far from the known and the exploited mines. Some of these areas coincided with discovered mineralized zones, specifically in the area SE of a derelict Sb mine, confirming the usefulness of these datasets and statistical tools in areas with recent mining activity. [ABSTRACT FROM AUTHOR]

Saint‐Maurice Abbey in Carnoët (Finistère) underwent an in‐depth archaeological appraisal during 2018–2019, involving several non‐destructive technologies: the geophysical survey revealed the presence of expected structures, drawn on ancient plans, but also the presence of structures unknown up until now. A group of buildings on the edge of the pond in particular raised several questions. A geochemical survey was carried out there in order to try to characterize these buildings and observe the potential complementarity between geophysical and geochemical surveys. The results of the chemical analysis do not highlight the same level of detail of the structures as electrical resistivity, but these analyses seem to be able to clarify the geophysical diagnosis by discriminating signals of structures from echoes linked to the geological substrate. [ABSTRACT FROM AUTHOR]

Helium, a coordinated resource in natural gas, is an essential and strategic resource, but research on its enrichment mechanism is relatively weak. This study investigated helium enrichment in major reservoirs in China using geochemical methods to address the challenging topic of how helium accumulates in helium-rich gas reservoirs. It concludes that helium is enriched in a few reservoirs which capture additional helium exsolution from ancient groundwater. Released dissolved helium from ancient groundwater into the reservoir is the main mechanism of helium accumulation in helium-rich gas reservoirs. This was the first time that the concept of “multiple sources of helium supply and primary sources of helium enrichment” was applied to guide the formation of helium-rich gas reservoirs. Moreover, the main sources of helium comes from the radioactive decay of uranium (U) and thorium (Th) in hydrocarbon rocks, reservoirs, and the decay of U and Th dissolved in groundwater from other rocks. When dissolved helium in ancient groundwater crosses free gas or gas reservoirs, the partial pressure of helium in the water is significantly higher than the partial pressure of helium in the free gas or gas reservoirs, proving Henry's Law which states that the helium in the water is almost completely exsolution into the gas reservoir, forming a helium-rich gas reservoir. [ABSTRACT FROM AUTHOR]

China is rich in lithium resource, among which lithium ore in the Salt Lake has huge reserves, but the development and utilization technology has yet to be developed, and the main target of development is hard-rock lithium ore at present. Hard-rock lithium ore is mainly pegmatitic and concentrated in Xinjiang and Sichuan. The Mesozoic is the most important metallogenic period for pegmatite-type lithium deposits in China. A relatively stable tectonic environment after an orogeny is favored by the formation of pegmatite-type lithium deposits. After a decade of exploration practice and theoretical research, the types of lithium resource in China have shown a great variety. The brine-type lithium resource has expanded from surface brine to both shallow brine and deep brine, and the hard-rock lithium resources from single granitic pegmatite-type to altered granite-type, cryptoexplosion breccia tube-type and sedimentary-type. The metallogenic age has extended from the Meso-Cenozoic to the Paleozoic and other epochs. The metallogenic zones has increased from 12 to 16, and a number of new mineralized areas have been discovered in the Jiajika and Ke'eryin areas in western Sichuan and the Dahongliutan and Shaligou areas in Xinjiang. A new resource pattern of lithium is being formed. Moreover, Prospecting methods and exploration techniques have also developed from single surface prospecting and mapping to an integration of new techniques and methods, e.g., remote sensing to determine the prospective area, geological surveying to determine the type, geochemical prospecting to determine the mineral, geophysical prospecting to determine the location of drilling, drilling to determine the reserves, as well as biological prospecting, deep penetration of the deep exploration. In view of the rigid demand for lithium resources due to the rapid development of strategic emerging industries, it is suggested to strengthen a) the investigation, research, development and utilization of new types of lithium resources with lepidolite as the main industrial mineral and sedimentary-type lithium resources with Li-bearing clay as the main lithium resources; b) the research and prospecting of the Paleozoic and even Precambrian lithium deposits; c) the exploration of new lithium mineralization belts such as Altyn Tagh, Himalaya, Gangdise and western slope of Great Hinggan Mountains; d) the research on new mechanisms of dynamic management of lithium resources under market economy; e) the advanced research and resource reserve on lithium isotope as the raw material of controllable nuclear fusion, for leading the development of high-end mining industry. [ABSTRACT FROM AUTHOR]

The Tongshan intrusion is located at the Guichi ore cluster field along the Lower Yangtze River metallogenic belt (LYRB) in eastern China. Elemental data and major elements of biotite are reported for Late Mesozoic plutons in the Guichi ore cluster in the Middle-Lower Yangtze River Region, attempting to explain their diagenetic age, petrogenesis, and tectonic implications. The Tongshan intrusion is dated at 146.3±3.2 Ma, with zircon εHf(t) average value of -5.23, illustrating that the Tongshan intrusion could be derived from crust mantle mixing magmatite provenance. The two-stage Hf model ages between 1184~1422 Ma is indicated magma source relationship with those of the Mesoproterozoic basement in south Anhui. The Tongshan intrusion is high-K calcalkaline, and exhibit adakite-like geochemical feature, such as high Al2O3, Sr contents, Sr/Y value, low Y and Yb contents. The geochemical and reexplained published isotopic data indicate that these adakites are most likely from partial melting of subducted oceanic crust, and mixed with enriched lithospheric mantle components in the rising process. [ABSTRACT FROM AUTHOR]

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Geological and geochemical studies of gold mineralization in Bode-Saadu axis, Southwestern Basement Complex, Nigeria have been conducted in order to study their mode of occurrence, structural settings, pattern of distribution and potential. Geological studies reveal that granite and gneiss granite are the prominent rocks in the area and exist in the north-eastern, north-western and southwestern part of the area whereas mica and amphibole schist occur as low-lying exposure. Petrographic studies reveal spatial association between gold mineralization and the fractured zones. Geochemical studies show that the gold concentration in rocks and stream sediments from the region is low with the exception of a few areas with high values ​​and is related to the occurrence of fissure in the northeast-west direction. The distribution pattern of gold in the region is skewed NE-SW, indicating that gold mineralization is structurally controlled.

We inferred hydrological changes in Lake Petén Itzá (Guatemala) during Marine Isotope Stages (MIS) 3-2 using geochemical (Ti, Ca/Ti+Al+Fe ratio and Mn/Fe) and mineralogical (carbonates, gypsum, quartz, clay) data from sediment core PI-2 to reconstruct changes in runoff, lake evaporation, organic matter sources and potential oxic/anoxic conditions associated with variations in water-level during the last ~59 cal ka BP. Early MIS3 (57.0–52.5 cal ka BP) was dominated by relatively wet conditions, higher lake primary productivity and anoxic waters, which persisted into the subsequent interval (52.5–39.0 cal ka BP), except for two periods of possible low water-level at 52 and 46 cal ka BP when our data suggest higher evaporation, high terrestrial organic matter input and persistent oxic conditions. Towards the end of MIS3 and start of MIS2 (39.0–23.0 cal ka BP), lake evaporation increased considerably, as did inputs of terrestrial organic matter, and waters became more oxic as water-levels dropped and the site moved from the hypolimnion to the epilimnion. These conditions reversed during the Last Glacial Maximum (23.0–18.0 cal ka BP) when runoff and lake productivity increased and waters again became anoxic as a result of rising water-levels. Refining the age-depth model for the Site PI-2 also allowed the correlation to Greenland Interstadials (GI14-2), Greenland Stadial (GS14-2) and Heinrich Stadials (HS5-1). HS and GS were characterized by increases in Ca/Ti+Al+Fe ratios and gypsum content generally indicative of drier conditions. GS13, 9 and 5 showed the driest conditions associated with the contemporaneous establishment of HS5-3, respectively. In contrast, GI show high Ti values which suggests relatively greater runoff and overall wetter conditions compared with GS and HS, with the most marked GI peaks between 40 and 30 cal ka BP. This runoff variability is in accord with shifts in the average position of the Intertropical Convergence Zone and strength of the Atlantic Meridional Oceanic Circulation during the Late Pleistocene. [ABSTRACT FROM AUTHOR]

The Heilongjiang Duobaoshan area is located at the confluence of the Great Xing'an Range and the Lesser Xing'an Range, and the area has undergone a complex magmatic and tectonic evolutionary history resulting in a complex and diverse geological background for mineralization. As a result of this geological complexity and the multi-period nature of mineralization, the geochemical data of the area are usually not satisfied with a single statistical distribution form, so traditional statistical methods cannot adequately explore and identify the distribution of deep-seated information in the geochemical data. Based on the above problems, this paper adopts a multivariate component data analysis method to process 14 mass fraction data elements, namely Ag, As, Au, Bi, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, W, and Zn, in the 1:50,000 soil geochemical data from the Duobaoshan area of Heilongjiang. The spatial distribution and internal structural characteristics of raw, logarithmic transformation and isometric logarithmic ratio (ILR) transformed data were compared using exploratory data analysis (EDA); robust principal component analysis (RPCA) was applied to obtain the PC1 and PC2 principal component combinations associated with mineralization, and a spectrum–area (S–A) fractal model was further used to decompose the geochemical anomalies of the PC1 and PC2 principal component combinations as composite anomalies. The results show the following: (i) The data transformed by the isometric logarithmic ratio (ILR) eliminate the influence of the original data closure effect, and the spatial scale of the data is more uniform; the data are approximately normally distributed, based on which RPCA can be applied to better explore the correlation between elements and the pattern of co-associated combinations. (ii) The S–A method was further used to decompose the composite anomalies of the PC1 and PC2 principal component combination in the study area. The anomalous and background fields of the screened-out PC1 and PC2 principal component combinations reflect anomalous information on mineralization dominated by Au mineralization. Moreover, the anomaly and background information after extraction were in good agreement with the known Au deposits (points), and many geochemical anomalies with prospecting potential were obtained in the periphery, providing a theoretical basis and exploration focus for the next step in the searching and exploring of the study area. [ABSTRACT FROM AUTHOR]

Accurate characterization of geochemical anomaly related to metal mineralization and quantification of uncertainty propagation in space prediction are important for assessment of geochemical exploration risk. In this study, an efficient method that integrates sequential indicator co-simulation (SIcS) with local singularity analysis (LSA) is presented to characterize uncertainty propagation in geochemical anomaly and to construct exploration risk-related probability expression model. The method yields a series of realizations to reproduce some expected statistical and spatial characteristics including spatial correlation structure and the expected fluctuations between these realizations. The advantage of the method is that, in the uncertainty evaluation of geochemical anomaly, an auxiliary variable can be incorporated into rebuilding the spatial structure of the primary variable. To demonstrate the proposed method, a case study for uncertainty analysis of iron mineralization-related geochemical anomalies was conducted in the Chinese Western Tianshan region. Two variables, Fe2O3 and Ti, were considered in the case study. Under the constraint of covariate Ti, uncertainty analysis of Fe2O3 anomaly was investigated by integrating SIcS with LSA. In comparison with SIS, the results indicate that SIcS is superior to SIS in modeling Fe2O3 concentrations and in enhancing local anomalies when the auxiliary variable Ti was considered to restore the spatial structure of the primary variable Fe2O3. The results show that areas with high probability values have strong spatial consistency with the known iron ore locations. Therefore, the method proposed in this study helps greatly in delineation of areas with high probability of metal mineralization and in assessment of geochemical prospecting risk. [ABSTRACT FROM AUTHOR]

Extensive research has been conducted to evaluate mineral resource potential based on geochemical data, but this work is still challenging due to the existence of multiple evaluation solutions based on different methods. In this paper, we combine the multifractal analysis method with typical multivariate statistical methods to analyse the spatial characteristics of geochemical stream sediment data, aiming to quantitatively study the ore-forming potential of the elements in the Central Kunlun area of Xinjiang, China. An R-type cluster analysis, Pearson correlation analysis, and principal component analysis are used to explore the correlations among the 12 target elements. The multifractal model is constructed using the method of moments to analyse the spatial distribution patterns of the elements, and corresponding multifractal parameters are extracted to quantitatively describe their ore-forming strengths in the study area. The results show that Co, V, Ti, Fe2O3, MgO and Cu compose a group of elements closely related to the regional geological background, while Pb, Zn, Bi, Sn, Au and Ba are potential metallogenic elements with relatively high ore-forming strengths and favourable ore-forming potential. Multifractal theory further validates and evaluates the favourable ore-forming element group obtained through conventional geochemical multivariate statistical methods, thus providing a new idea for small-scale geochemical prospecting. Thematic collection: This article is part of the Applications of Innovations in Geochemical Data Analysis collection available at: https://www.lyellcollection.org/cc/applications-of-innovations-in-geochemical-data-analysis [ABSTRACT FROM AUTHOR]

At present, the challenge for geochemical prospecting of deep-sea, rare, earth-rich sediments is the selection of exploration sites. Because of the unpredictability of offshore operations, the distribution and selection of survey line stations face great challenges. In this paper, we study the fact that the concentration distribution of geochemistry in space may be a part of a special complex process, which is called the multifractal. It requires a large number of indexes to characterize its scale characteristics. Based on the multifractal spectrum, 38 geochemical indices in the Pigafetta Basin region of the western Pacific Ocean are divided into three categories. The three indexes are distinguished by the multifractal parameters. The results of multifractals are in good agreement with those of the cluster analysis and principal component analysis. In addition, on the basis of principal component analysis, we further used the multifractal filtering method to extract element anomalies and delineate element enrichment regions. The first principal component clearly represents the potential element enrichment area. The spatial analysis technique and multifractal method proposed in the paper provide a new idea for geochemical prospecting of deep-sea, rare, earth-rich sediments. [ABSTRACT FROM AUTHOR]

Quantification and recognition of geochemical patterns are extremely important for geochemical prospecting and can facilitate a better understanding of regional metallogenesis. Recognition of such patterns with deep learning (DL) algorithms has attracted considerable attention, as these algorithms can generally extract high-level geochemical features and thus create models in which geochemical patterns are fully exploited. These DL algorithms are usually constructed to be compatible and consistent with the underlying data, but their interpretability and pertinent physical constraints (such as granitic intrusions related to magmatic-hydrothermal mineralization) are generally overlooked. This paper introduces a physically constrained variational autoencoder (VAE) architecture to identify geochemical patterns associated with tungsten polymetallic mineralization. We first identify physical constraints from geological characteristics and metallogenic regulation via the methods of fry analysis, standard deviation ellipses, and fractal analysis to reveal the controlling function of granitic intrusions on mineralization. Subsequently, we construct the physical constraints based on the nonlinear controlling function and add the geological constraints into the VAE loss function as a penalty term. After optimization of the network parameters, the well-trained physically constrained VAE architecture can recognize the geochemical anomaly patterns that the conventional VAE cannot. These extracted geochemical anomaly patterns generally show a strong spatial relationship with the granitic intrusions. In addition, the performance measures involving the receiver operating characteristic curve and success-rate further indicate that the generalization accuracy of the conventional VAE can be enhanced via physics-based regularization. These results suggest that the proposed physically constrained VAE, which integrates physical knowledge into the VAE loss function, not only improves the geochemical pattern recognition performance but also demonstrates consistency with geological and physical domain knowledge. [ABSTRACT FROM AUTHOR]

Geochemical prospecting is an important and effective approach for discovering mineral deposits. Collection, management, visualization, interpretation, modelling and publishing of geochemical survey data remain challenging. The main aim of this study is to illustrate the application of Google Earth in the visualization and interpretation of geochemical survey data using a dataset collected from the Daqiao district, Gansu Province, China. Google Earth, a free web-based program that provides a rich set of global images along with satellite and map data, can be applied to design geochemical sampling strategies, display geochemical sampling location landscapes, collect and manage geochemical survey data, visualize and publish 0D (point), 1D (profile), 2D (raster map) and 3D (superposition of multiple maps) geochemical maps, and interpret and model geochemical patterns using various Google Earth functions and the Keyhole Markup Language. Thematic collection: This article is part of the Applications of Innovations in Geochemical Data Analysis collection available at: https://www.lyellcollection.org/cc/applications-of-innovations-in-geochemical-data-analysis [ABSTRACT FROM AUTHOR]

Particle size exerts significant control on the concentration of elements in stream sediments and is therefore critical in stream sediment-based geochemical exploration, which has proved important in China's National Geochemical Mapping Project. There are various geographical landscapes in China with different distribution characteristics of stream sediments. Therefore, we studied the relationship between particle size and element distribution in stream sediments, which is always a crucial but challenging issue in geochemical surveys. The distributions of minerals and elements in eight size fractions of stream sediments (2–0.84, 0.84–0.42, 0.42–0.25, 0.25–0.177, 0.177–0.125, 0.125–0.096, 0.096–0.074, and <0.074 mm) from the Dongyuan W-Mo deposit in eastern China were studied. The results show that the 2–0.25 mm particle size fraction of stream sediments is composed mainly of rock debris and various minerals from broken bedrock upstream, while the <0.25 mm fraction is composed mainly of clay, individual minerals, and organic matter. The pilot survey results prove that using 2–0.25 mm as the sampling particle size fraction is better than using <0.25 mm, especially in geochemical prospecting and geological body delineation. Sampling the 2–0.25 mm particle size fraction of stream sediments can help to delineate proven ore bodies, ore-related anomalies, and geological bodies more effectively and more credibly. The suggested sampling particle size fraction for a stream sediment geochemical survey in a humid to semi-humid low mountain landscape in eastern China is therefore 2–0.25 mm, rather than the particle size fraction of <0.25 mm that was used for sampling in this area before. This paper depicts a successful example for determining the optimal sampling particle size fraction for stream sediment-based geochemical exploration. [ABSTRACT FROM AUTHOR]

Interpretation of various exploration data, in particular geochemical prospecting, offers a powerful and rapid assessment of grass‐root projects in a green‐field terrain. Here, we present an example of the Collins epithermal prospect in Aceh Province, Indonesia. In this area, the Au+ base‐metal‐bearing sheeted quartz veins (individually mostly 2–4 cm wide), which are controlled by a 250 m wide by 800 m long NNE‐trending structural corridor within Paleogene sandstone and volcanic rocks, are the product of two main stages of deposition. Stage I formed veins with a sliver of cryptocrystalline quartz wall zone followed by an inner zone of comb quartz with interstitial rhombic adularia that terminates in open space. Stage I or main‐stage sulfide mineralization consisting of early galena + sphalerite and later chalcopyrite occurs with the quartz + adularia. Small amounts of galena also occur in the wall zone. Stage II mineralization brecciated Stage I veins and overprinted them with silicification characterized by vuggy texture. Mineralization associated with this episode consists of earlier chalcopyrite + sphalerite + tennantite–tetrahedrite and later, vug‐filling Au–Ag alloy (Ag0.37–0.41Au0.62–0.59). The above mineralized veins are successively flanked by silicic selvages, an illite + chlorite + pyrite ± kaolinite zone and a chlorite + epidote + carbonate + pyrite zone. Local supergene alteration induced replacement of galena by plumbogummite and anglesite and chalcopyrite by covellite. Data from fluid inclusion microthermometry in quartz indicated that the inner zone of Stage I veins formed from fluids with a 2.3 wt% salinity (0.5–3.3 wt% NaCl equivalent), at 174°C (155–211°C). Combining these physico‐chemical parameters with the mineral assemblage, the mineralization occurred under a reduced environment. Rock and soil assays indicate that elevated Au concentrations (up to 16.5 ppm over 1 m) occur along northeast‐trending zones and show a strong correlation with Pb, while Cu (up to 2.58% over 1 m), Zn, As, Sb, and Mo anomalies lie mostly at the periphery. The high‐grade mineralized veins correlate with moderate to high resistivity and chargeability zones, and the pseudosections of such geophysical signals are interpreted as reflecting coalesced or enlarged veins at depth, or inclined veins in other localities. The intermediate sulfidation affinity for Collins points to potential mineralization at depth as well as preservation of Au‐rich and sulfide‐poor zones in the less eroded areas. [ABSTRACT FROM AUTHOR]

The geochemical data from surface soils are often neglected or questioned when prospecting for ore deposits within active mining districts due to the “background noise” produced by anthropogenic pollution derived from mining activity. Large datasets on a national and international scale offer interesting possibilities to discover prospective zones. In the present work, data from the Geochemical Atlas of Castilla–La Mancha were treated in an area with an intense history of mining Hg, Pb, Zn, and Sb: the Almadén and Guadalmez synclines and the Alcudia Valley. The sampling grid was densified to adapt it to the scale of the main geological formations, and a cluster analysis was carried out to establish the relationships between the variables and a factor analysis to distinguish between geogenic and metallogenic factors. The results showed very high concentrations of some elements of prospective interest in local background areas: Hg (51 mg kg−1), Pb (1190 mg kg−1), and Sb (45 mg kg−1), with high variation coefficients. Cluster analysis unveiled a relationship between most of the local ore-forming metals (As, Sb, Hg, Pb, and Ag) with a clear correlation between Hg and organic matter, suggesting a notable contribution of Hg in soil. The factor analysis highlighted five factors, three geogenic and two ore-forming elements. Despite Hg being the main candidate to form a separate factor, its aerial deposition and a large number of outliers in the Almadén syncline contributed to integrating the element into a geogenic factor. Instead, factors F4 (Pb and Zn) and F5 (As and Sb) delimited the prospective areas in both synclines far from the known and the exploited mines. Some of these areas coincided with discovered mineralized zones, specifically in the area SE of a derelict Sb mine, confirming the usefulness of these datasets and statistical tools in areas with recent mining activity.

Geological and geochemical studies of gold mineralization in Bode-Saadu axis, Southwestern Basement Complex, Nigeria have been conducted in order to study their mode of occurrence, structural settings, pattern of distribution and potential. Geological studies reveal that granite and gneiss granite are the prominent rocks in the area and exist in the north-eastern, north-western and southwestern part of the area whereas mica and amphibole schist occur as low-lying exposure. Petrographic studies reveal spatial association between gold mineralization and the fractured zones. Geochemical studies show that the gold concentration in rocks and stream sediments from the region is low with the exception of a few areas with high values and is related to the occurrence of fissure in the northeast-west direction. The distribution pattern of gold in the region is skewed NE-SW, indicating that gold mineralization is structurally controlled. [ABSTRACT FROM AUTHOR]

As direct prospecting data, geochemical data play an important role in modelling prospect potential. Geochemical element assemblage anomalies are usually reflected by the correlation between elements. Correlation coefficients are computed from the values of two elements, which reflect only the correlation at a global level. Thus, the spatial details of the correlation structure are ignored. In fact, an element combination anomaly often exists in geological backgrounds, such as on a fault zone or within a lithological unit. This anomaly may cause some combination of anomalies that are submerged inside the overall area and thus cannot be effectively extracted. To address this problem, we propose a local correlation coefficient based on spatial neighbourhoods to reflect the global distribution of elements. In this method, the sampling area is first divided into a set of uniform grid cells. A moving window with a size of 3×3 is defined with an integer of 3 to represent the sampling unit. The local correlation in each unit is expressed by the Pearson correlation coefficient. The whole area is scanned by the moving window, which produces a correlation coefficient matrix, and the result is portrayed with a thermal diagram. The local correlation approach was tested on two selected geochemical soil survey sites in Xiao Mountain, Henan Province. The results show that the areas of high correlation are mainly distributed in the fault zone or the known mineral spots. Therefore, the local correlation method is effective in extracting geochemical element combination anomalies. [ABSTRACT FROM AUTHOR]

Mineral resources prediction and assessment is one of the most important tasks in geosciences. Geochemical anomalies, as direct indicators of the presence of mineralization, have played a significant role in the search of mineral deposits in the past several decades. In the near future, it may be possible to recognize subtle geochemical anomalies through the use of processing of geochemical exploration data using advanced approaches such as the spectrum-area multifractal model. In addition, negative geochemical anomalies can be used to locate mineralization. However, compared to positive geochemical anomalies, there has been limited research on negative geochemical anomalies in geochemical prospecting. In this study, two case studies are presented to demonstrate the identification of subtle geochemical anomalies and the significance of negative geochemical anomalies. Meanwhile, the opportunities and challenges in evaluating subtle geochemical anomalies associated with mineralization, and benefits of mapping of negative anomalies are discussed. [ABSTRACT FROM AUTHOR]

In Northeast Vietnam, Suoi Thau-Sang Than is considered as a high potential area of polymetallic deposits. 1,720 geochemical samples were used to investigate polymetallic mineralization; thereby polymetallic ore occurrences in this study region were discovered and the statistical and multivariate analysis helps to define geochemical anomalies in some northeastern regions, namely Suoi Thau, Sang Than, and Ban Kep. The statistical method and cluster analysis of geochemical data indicate that the Cu, Pb, and Zn elements are good indicators, and most of them comply with the lognormal or gamma distribution. Based on the third-order threshold, the geochemical anomalies of the content of the Cu, Pb, and Zn elements reflect the concentration of copper forming ore bodies in the mineralized zone, and clearly show the concentration in three distinct zones. The trend surface analysis which was employed to determine spatial variations and relationships among these good indicator elements and anomalous areas revealed relative changes in the content of the indicator elements, and they can be considered as regular. Moreover, the goodness of fit obtained trend functions of Pb and Zn, and Cu elements is a third-degree trend surface model. These results indicate that the models can be useful in studying geochemical anomalies and analyzing the tendency of the concentration of indicator elements in the Suoi Thau-Sang Than region. Additionally, it is suggested that the statistical analysis shows a remarkable potential to use the bottom river sediments in the region to investigate polymetallic mineralization. Moreover, geochemical data can help to evaluate geochemical anomalies of the pathfinder elements and potential mineral mapping of the Suoi Thau-Sang Than region in Northeast Vietnam. [ABSTRACT FROM AUTHOR]

Chromite deposits have long been reported and exploited in Northern Pakistan as a result of the ongoing convergence of Indian and Asian plates. This research work is a study of one such prospect. We used geophysical and geochemical tools such as magnetic susceptibility at seventy-seven observation stations along with fifteen rock samples collected for geochemical studies. Our geochemical analysis reveals a very high value of Fe, Mn, Cu, and Ni in regions of high magnetic susceptibility indicating the possibility of the presence of Magnetite, Chondrite, Copper-pyrites, and Pentlandite Ores. In addition, we also conducted the correlations analysis to investigate the potential association between various geochemical variables including trace elements to evaluate the potential of the ores for economic minerals others than chromite. Our PCs analysis result presents a clear picture that most of the minerals such as Fe, Ni, Co, Cd, Mg, Mn, and Pd are produced by the same source. Our various analyses are in perfect agreement with previous literature indicating the presence of economical mining of Chromite. [ABSTRACT FROM AUTHOR]

BACKGROUND: The contents of silver, tin, boron, molybdenum, and lead in geological samples are extremely important for studying the metallogenic regularity and for geochemical prospecting. Current analytical methods rarely determine silver, tin, boron, molybdenum, and lead simultaneously. OBJECTIVES: To establish a method to simultaneously determine silver, tin, boron, molybdenum and lead in geological samples. METHODS: To eliminate the matrix interference, first-class standard materials (rock, soil and water sediments) were used for linear fitting of the synthetic silicate standard materials curve. By setting analytical line conversion values, different analytical line can be used for samples with different contents. RESULTS: The detection limits of silver, tin, boron, molybdenum, and lead were 0.0077μg/g, 0.19μg/g, 0.68μg/g, 0.058μg/g, 0.49μg/g, respectively. The precisions of the method were 3.23%-9.39%. The measured value of national first class standard materials including soil, water sediments and rock by this method was in accordance with standard values, with an absolute value of ΔlogC<0.10. The qualified rates of actual sample were 92%-100%, and the qualified rate of the inspection sample was 100%. CONCLUSIONS: This method is easy to apply and can be used to analyze samples rapidly. It can also be used to avoid contamination during sample dilution. Compared with traditional atomic emission spectrometry that uses a single analytical spectrum line, this method can be used to obtain a value which is closer to the standard value of national standard materials. The detection limit of this method is much lower than the standard value of the specification of testing quality management for geological laboratories. [ABSTRACT FROM AUTHOR]

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