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The objective of this study was to analyse the characteristics of highly cited papers (HCPs) in the research field of geosciences based on the Essential Science Indicators database, which is widely used to evaluate institutions and researchers. Multi-aspects, including country/region's productivity distribution, organizations, authors, detailed categories and hot topics, journals and implications of collaboration networks have been explored in this study. The main findings are: (1) USA ranks first in geosciences research with over 60% global share, with most of the leading organizations (12 out of 15) also from that country. (2) The percentage of international collaborations is high in this research field; the collaboration shows tangled networks among countries/regions (organizations) and also indicates close connections worldwide. (3) Despite the dominance of USA in productivity, only 5 of the top 15 authors are from that country, and relatively tight collaboration networks are found among the top authors. (4) The current high-level researches in geosciences focus on meteorology, geochemistry, geophysics, remote sensing and oceanography, and topics involving climate change draw most of the attention. [ABSTRACT FROM AUTHOR]

I thank the discussors for their critique of the above paper. In geology there are rarely any absolute models but working hypotheses, which will be modified with new data. The paper under discussion, Charrach (Carbonates Evaporites 33:727–766, 2018a), presents a very new large data set, which is multi-disciplinary and integrated the most recent research. The critique by Möller et al. (Carbonates Evaporites 10.1007/s13146-019-00486-3, 2019) and their paper of 2018 (Int J Earth Sci 107:2409–2431, 2018), presents a computer simulation, which must be validated with field evidence and recent research in the area, and not based on assumptions, which have turned into facts over time. The discussors may be unfamiliar with the geological research that has been published over the last 20 years in the areas under consideration. Furthermore, the research on marine–non-marine evaporite formations is hardly considered in their discussion, yet much has been published. [ABSTRACT FROM AUTHOR]

Based on a compilation of published sources, rocks referred to as adakites show the following geochemical and isotopic characteristics: SiQ2 ≥56 wt percent, Al2O3 ≥15 wt percent, MgO normally <3 wt percent, Mg number ≈0.5, Sr ≥400 ppm, Y ≤18 ppm, Yb ≤1.9 ppm, Ni ≥20 ppm, Cr ≥30 ppm, Sr/Y ≥20, La/Yb ≥20, and 87Sr/86Sr ≤0.7045. Rocks with such compositions have been interpreted to be the products of hybridization of felsic partial melts from subducting oceanic crust with the peridotitic mantle wedge during ascent and are not primary magmas. High Mg andesites have been interpreted to be related to adakites by partial melting of asthenospheric peridotite contaminated by slab melts. The case for these petrogenetic models for adakites and high Mg andesites is best made in the Archean, when higher mantle geotherms resulted in subducting slabs potentially reaching partial melting temperatures at shallow depths before dehydration rendered the slab infusible. In the Phanerozoic these conditions were likely only met under certain special tectonic conditions, such as subduction of young (≤25-m.y.-old) oceanic crust. Key adakitic geochemical signatures, such as low Y and Yb concentrations and high Sr/Y and La/Yb ratios, can be generated in normal asthenosphere-derived tholeiitic to calc-alkaline are magmas by common upper plate crustal interaction and crystal fractionation processes and do not require slab melting. An assessment of several are volcanic suites from around the world shows that most adakite-like compositions are generated in this way mad do not reflect source processes. Similarly, rare adakite-like intrusive rocks associated with some porphyry Cu deposits are the evolved products of extensive crustal-level processing of calc-alkaline basalt-andesite-dacite-rhyolite series magmas. If slab melts contribute to such magmas, their geochemical signatures would have been obliterated or rendered ambiguous by subsequent extensive open-system processes. In Archean terranes, where adakitic and high Al tonalite-trondhjemite-granodiorite (TTG) magma series rocks are more common, porphyry Cu deposits are rare and, where found, are associated with normal calc-alkaline suites rather than adakites. The two different magma series are compositionally distinct in terms of several major and trace element parameters. Common upper plate magmatic processes such as melting-assimilation-storage-homogenization (MASH) and assimilation-fractional-crystallization (AFC) affecting normal are magmas can be demonstrated to explain the distinctive compositions of most adakite-like are rocks, including high Mg andesites and especially those rare examples associated with porphyry Cu deposits. In contrast, slab melting can in most cases neither be proved nor disproved mad is therefore unsatisfactory as a unique factor in porphyry Cu genesis. [ABSTRACT FROM AUTHOR]

The section presents a list of articles in periodicals including "Acta Geologica Polonica," "American Mineralist," "Applied Earth Science," "Applied Geochemistry," 'Australian Journal of Earth Sciences" and "Canadian Mineralogist."

Presents partial tables of contents of different journals with research articles related to geology. "Acta Geologica Sinica"; "American Mineralogist"; "Applied Geochemistry."

Abstract: We appreciate that our attempt to document deformation pattern within the Mesoproterozoic Singhora Group, India, and to resolve some key stratigraphic issues in Chhattisgarh geology (Patranabis-Deb and Chaudhuri, 2008; Dhang and Patranabis-Deb, 2012), in recent times, has attracted the attention of Deb. We whole heartedly welcome the keen interest shown by Deb in our paper and discussions attempted by him on different aspects of the paper. Here we offer our strong rebuttal of his imaginative discussions, principally because the claims made by Deb are neither supported by outcrop-based field data nor through any available subsurface geophysical data. It appears that the key concern of Deb (2013) was to force-fit the structural grains of the Sonakhan greenstone belt within the deformation pattern of Singhora cover sediments, upholding an unsubstantiated assumption that the Sonakhan greenstones belt constitutes the basement for the Singhora basin. Without citing any evidence (outcrop, geophysical or bore hole) showing Sonakhan metamorphics in the basement of the Singhora basin, he plotted the structural data of the Sonakhan Greenstone Belt and attempted comparison of those with the bedding attitudes of the Singhora cover sediments, and claimed that the possible rejuvenation of basement faults triggered folding in the Singhora cover sediments. Leaving aside the issues of lack of any field support, available geophysical results (3 layer gravity survey by Srinivas et al. (2000); magnetic survey by Srinivas et al. (2004)) and short borehole observations (pers. comm., Mukherjee, A., 2012) – all clearly demonstrates unclassified Archean/Paleoproterozoic granites and gneisses of the Bastar craton as basement for the Singhora Basin, not the Sonakhan Greenstones. Neither is the presence of any basin-scale fault inferred from the basement of the Singhora basin in any geophysical model. The result of magnetic survey along the Basna–Sohela transect carried out by Srinivas et al. (2004), which represents the Singhora basement in particular, clearly shows granites as immediate basement for the Singhora. As the very assumption of Deb (2013) i.e., that the Sonakhan represents the basement to the Singhora basin, does not stand either on his own field data or on any strong reasoning, we refrain from any further discussion on this topic. Instead, we frame our reply on the doubts raised by Deb (2013) on the mapping, field analysis and concepts used in our paper (Saha et al., 2013). [Copyright &y& Elsevier]

Many of the commonly used analytical techniques for assessing the properties of fluvial suspended particulate matter (SPM) are neither cost effective nor time efficient, making them prohibitive to long-term high-resolution monitoring. We present an in-depth methodology utilizing two types of spectroscopy which, when combined with automatic water samplers, can generate accurate, high-temporal resolution SPM geochemistry data, inexpensively and semi-destructively, directly from sediment covered filter papers. A combined X-ray fluorescence spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy approach is developed to estimate concentrations for a range of elements (Al, Ca, Ce, Fe, K, Mg, Mn, Na, P, Si, Ti) and compounds (organic carbon, Aldithionate, Aloxalate, Fedithionate, and Feoxalate) within SPM trapped on quartz fibre filters at masses as low as 3 mg. Calibration models with small prediction errors are derived, along with mass correction factor models to account for variations in retained SPM mass. Spectral pre-processing methods are shown to enhance the reproducibility of results for some compounds, and the importance of filter paper selection and homogeneous sample preparation in minimizing spectral interference is emphasized. The geochemical signal from sediment covered filter papers is demonstrated to be time stable enabling samples to be stored for several weeks prior to analysis. Example results obtained during a heavy precipitation event in October 2012 demonstrate the methodology presented here has considerable potential to be utilized for high-resolution monitoring of SPM geochemistry under a range of in-stream hydrological conditions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Presents a list of journals related to geology. "Acta Geologica Sinica," vol. 78, no. 3, 2004; "American Mineralogist," vol. 89, no. 10, 2004; "Atlantic Geology," vol. 39, no. 12, 2004.

Presents a list of journals and table of contents of other journals with topics related to geology. "American Journal of Science"; "Applied Geochemistry"; "Bulletin of Geoscience."

Abstract: The paper “A crustal-upper mantle model for southeastern Sicily (Italy) from the integration of petrologic and geophysical data” by Manuella et al. (2013) speculatively proposes that the basement beneath southeastern Sicily is made up of a fossil oceanic crust of Permo-Triassic age. The Authors support their hypothesis discussing the geochemical features of Cenozoic basic lavas and entrained xenoliths. Unfortunately, the paper does not include fundamental references on the subject, and these omissions limit the discussion of alternative hypotheses. In this reply we highlight that the new model proposed by the Authors is poorly constrained and that their argumentations are weak and sometimes wrongly founded. [Copyright &y& Elsevier]

Aiming to address whether coal-bed methane and shale gas can form helium-rich gas reservoirs, this paper employs geochemical research methods to analyze the content of uranium (U) and thorium (Th) in coal and shale, as well as the helium content in coal-bed and shale gas reservoirs. An objective evaluation of the helium-generating potential and helium-bearing properties of coal and shale is provided. It is observed that although the content of U and Th in coal and shale is significantly higher than in other rocks, resulting in relatively more helium production from radioactive decay, the large amount of natural gas generated by coal and shale exerts a serious dilution effect on helium, making it difficult for coal beds and shale to enrich helium. The organic carbon content of coal is much higher than that of shale, leading to a greater generation of natural gas from coal beds compared to shale. Consequently, the helium content of coal-bed gas is much lower than that of shale gas. The helium rich shale gas and coal bed gas found in a few areas are attributed to the helium supply from other rocks in the gas reservoir, which is mostly distributed on or near the old granite masses, or in the tectonic active zones. In addition to capturing some of the helium produced by the coal beds and shales themselves, helium from other rocks, particularly from ancient basement rocks, is also captured, though this is not common. [ABSTRACT FROM AUTHOR]

The 9th national conference on applied geochemistry in China will be held in Chengdu, Sichuan province, in October 2023, hosted by the committee of applied geochemistry, the Chinese Society for Mineralogy, Petrology and Geochemistry (CSMPG). Sediment provenance is a main topic in research on soils, sediments, and sedimentary rocks. [Extracted from the article]

In its 26 years of existence, the journal of Natural Resources Research (NRR) has published and continues to publish papers on geochemical anomaly and mineral potential mapping. This is consistent with its aims and scope to publish quantitative studies of natural (mainly but not limited to mineral) resources exploration, evaluation and exploitation, including environmental and risk-related aspects. Over the years, NRR has contributed significantly more to the publication of developments in mineral potential mapping and notably less to the publication of developments in geochemical anomaly mapping. In more detail, NRR has contributed significantly more to the publication of research on development of robust quantitative methods for analysis and synthesis of spatial evidence of mineral potential but notably less to the publication of research on development of geologically focused models of mineral potential. The editorship of NRR recognizes the latter as a challenge to promote further research on development of numerically robust as well as geologically focused mineral potential models, and this special issue is a major initiative in response to that challenge. The recent inclusion of Natural Resources Research for coverage by the Clarivate Analytics (formerly the Institute for Scientific Information) in the Science Citation Index Expanded™ and Journal Citation Reports (JCR) Science Edition will help make Natural Resources Research meet that challenge. [ABSTRACT FROM AUTHOR]

Kaloko-Honokōhau National Historical Park (KAHO) is a coastal sanctuary on the western side of the Island of Hawai‘i that was established in 1978 to preserve, interpret, and perpetuate traditional Native Hawaiian culture and activities. KAHO contains a variety of culturally and ecologically significant water resources and water-related habitat for species that have been declared as threatened or endangered by the U.S. Fish and Wildlife Service, or are candidate threatened or endangered species. These habitats are dependent on coastal unconfined groundwater in a freshwater-lens system. The coastal unconfined-groundwater system is recharged by local infiltration of rainfall but also may receive recharge from an inland groundwater system containing groundwater impounded to high altitudes. The area inland of and near KAHO is being rapidly urbanized and increased groundwater withdrawals from the inland impounded-groundwater system may affect habitat and water quality in KAHO, depending on the extent of connection between the coastal unconfined groundwater and inland impounded-groundwater. An investigation of the geochemistry of surface-water and groundwater samples in and near KAHO was performed to evaluate the presence or absence of a connection between the inland impounded- and coastal unconfined-groundwater systems in the area. Analyses of major ions, selected trace elements, rare-earth elements, and strontium-isotope ratio results from ocean, fishpond, anchialine pool, and groundwater samples were consistent with a linear mixing process between the inland impounded and coastal unconfined-groundwater systems. Stable isotopes of water in many samples from the coastal unconfined-groundwater system require an aggregate recharge altitude that is substantially higher than the boundary between the coastal unconfined and inland impounded systems, a further indication of a hydrologic connection between the two systems. The stable isotope composition of the freshwater component of water samples from KAHO indicates that about 25–70% of the freshwater is derived from the inland impounded system. [ABSTRACT FROM AUTHOR]

EGAH has published SEGH conference proceedings, as papers or extended abstracts, and their titles bear testimony to the success of SEGH in highlighting those concerns over the years. SEGH 2018 Vic Falls: Geochemistry for sustainable development, July 17, 2018 http://www.segh.net/articles/segh 2018 vic%20Falls geochemistry for sustainable development/ 7 Watts MJ, An TC, Argyraki A. The society for environmental geochemistry and health (SEGH): building for the future. Evolve the relevance of SEGH goals to include the United Nations Sustainable Development Goals to reinforce relevance to policy impact - whilst the wider SEGH community is probably making good progress on this point, SEGH needs to evidence its role in SDGs through an evaluation and monitoring process. [Extracted from the article]

The article presents a commentary on a paper concerning the petrology and geochemistry of the granitoid rocks of the Johannesburg Dome in Central Kaapvaal Craton, South Africa. It examines the subdivision of the Johannesburg Dome (JD) granitoids into three main suites by the authors of the article. It also suggests that there is not justification for invoking a separate sanukitoid magmatic intrusive event anywhere on the JD.

In historical architecture, which includes many types of monuments and ancient buildings, natural stone was used as the main building material because of its natural beauty, availability and durability. The results reported in the papers published in this Special Issue highlight the importance of a multidisciplinary approach to the study of stones in order to obtain information on composition, and physical and mechanical properties. 10.3390/app12094588 4 Santo A.P., Agostini B., Garzonio C.A., Pecchioni E., Salvatici T. Decay Process of Serpentinite: The Case of the San Giovanni Baptistery (Florence, Italy) Pavement. [Extracted from the article]

With the rapid development of modern geochemical analysis techniques, massive volumes of data are being generated from various sources and forms, and geochemical data acquisition and analysis have become important tools for studying geochemical processes and environmental changes. However, geochemical data have high-dimensional, nonlinear characteristics, and traditional geochemical data analysis methods have struggled to meet the demands of modern science. Nowadays, the development of big data and artificial intelligence technologies has provided new ideas and methods for geochemical data analysis. However, geochemical research involves numerous fields such as petrology, ore deposit, mineralogy, and others, each with its specific research methods and objectives, making it difficult to strike a balance between depth and breadth of investigation. Additionally, due to limitations in data sources and collection methods, existing studies often focus on a specific discipline or issue, lacking a comprehensive understanding of the bigger picture and foresight for the future. To assist geochemists in identifying research hotspots in the field and exploring solutions to the aforementioned issues, this article comprehensively reviews related studies in recent years, elaborates on the necessity and challenges of combining geochemistry and artificial intelligence, and analyzes the characteristics and research hotspots of the global collaboration network in this field. The study reveals that the investigation into artificial intelligence techniques to address geochemical issues is progressing swiftly. Joint research papers serve as the primary means of contact within a worldwide collaborative network. The primary areas of focus in the ongoing research on the integration of geochemistry and artificial intelligence include methodologies for analyzing geochemical data, environmental modifications, and mineral prospectivity mapping. Geochemical data analysis is currently a significant focus of research, encompassing a range of methods including machine learning and deep learning. Predicting mineral resources for deep space, deep Earth, and deep sea is also a pressing topic in contemporary research. This paper explores the factors driving research interest and future trends, identifies current research challenges, and considers opportunities for future research. [ABSTRACT FROM AUTHOR]

A PM1 geochemical and mineralogical study using Scanning Electron Microscopy (SEM) was performed on a pilot site in the Agri Valley which is close to the oil pretreatment plant (C.O.V.A) of the Europe's largest on-shore hydrocarbon reservoir. The study identified PM1 geochemical and mineralogical characters in a period before, during and immediately after a burning torch flare event. The finer fraction (DFe <0.7 µm) consisted mainly of secondary particles and soot. In the coarser fraction (DFe ≥0.7 µm), natural particles originating from crustal erosion and soot were abundant. Fine quartz particles and lower Al=Si ratios are markers for desert dust origin, proving that a Saha ran dust episode which occurred during the observation period played a significant role in supplying geogenic aerosol components to the PM1. Largest amounts of ≥0.7 µm fraction particles observed on the day of flare event may be due to a greater supply of Saharan geogenic particles. Soot had been significantly increasing long before the flare event, suggesting that this increase is also related to other causes, although we cannot exclude a contribution from flaring. S-rich aerosol consisted mainly of mixed particles originating from deposition and heterogeneous nucleation of secondary sulfates on mineral dust. Only-S particles were identified in the 0.7 µm fraction following the flare event. These particles may be indicators of larger amounts of sulphur in the atmosphere. [ABSTRACT FROM AUTHOR]

Kaolin-group minerals occur in nature as the result of high-sulfidation acid sulfate, sulfur-poor HCl-, HF- and H2CO3-rich acidic fluid-related hydrothermal alterations and in situ geochemical weathering. These minerals possess different crystallographic and chemical properties that determine their application areas, mainly in the ceramic and paper industries, and as nanocomposite materials. The physicochemical properties of hydrothermal kaolin deposits are the result of the type of parent rock, the effect of the regional tectonism-associated magmatism, and the chemical features of hydrothermal fluids that interact with the deep basement rocks. However, understanding these geothermal systems is one of the most challenging issues due to the rich mineralogical assemblages, complex geochemistry and isotopic data of hydrothermal alteration zones. This study evaluates the formation of hydrothermal-origin kaolin-group minerals by considering their characteristics of hydrothermal alteration, isotopic compositions and differences in characteristic properties of low- and high-sulfidation occurrences; this paper also addresses mineralogical and structural differences between hypogene and supergene kaolin formations, and kaolin–alunite–pyrophyllite association, and it provides examples of worldwide occurrences. The study of the mineralogical assemblages, geochemistry and isotopic data of the hydrothermal alteration zones is one of the most challenging subjects in terms of gaining a detailed understanding of the geothermal systems. Silicification processes are subsequent to late-stage alteration after the completion of kaolinization processes, erasing existing hydrothermal mineralogical and geochemical traces and making interpretation difficult. In the early stages involving magmatic–hydrothermal-origin acidic geothermal fluids, the latter comes from the disproportionation of SO2 (+H2O) and H2S oxidation to H2SO4 in hydrothermal environments. In the later stages, due to spatial and temporal changes over time in the chemistry of geothermal fluids, the system comes to have a more alkali–chloride composition, with neutral pH waters frequently saturated with amorphous silica which characteristically precipitate as siliceous sinter deposits containing large amounts of opal-A. [ABSTRACT FROM AUTHOR]

The Lesser Xing'an—Zhangguangcai Range of northeast China is located in the eastern segment of the Central Asian Orogenic Belt (CAOB), which records intense magmatism during the Mesozoic. The petrogenesis and geodynamic setting of the Early Jurassic intrusive rocks in this region are unclear. In this paper, we present new zircon U–Pb age and whole-rock geochemical data for these intrusive rocks to investigate their origins and tectonic setting. Zircon U–Pb dating suggests these intrusive rocks were emplaced during the Early Jurassic (197–187 Ma). The granites are enriched in silica and alkali, and depleted in MgO and CaO. They are metaluminous to weakly peraluminous, and have high A/CNK values and low zircon saturation temperatures (TZr ~ 779°C), suggesting they are highly fractionated I-type granites derived by partial melting of lower crustal materials. The granites exhibit negative Nb, Ta, P, Eu, and Ti anomalies due to fractional crystallization. The diorites and gabbros have low SiO2 contents and high Mg# values, and are enriched in light rare earth and large-ion lithophile (Ba, K, and Sr) elements, and depleted in heavy rare earth and high field strength (Nb, Ta, and Ti) elements. The geochemical characteristics show that the mafic magmas were derived by partial melting of mantle that had been metasomatized by subduction-related fluids. Based on the geochemical characteristics of coeval intrusive rocks and the regional geological setting, we suggest the Early Jurassic intrusive rocks in the Lesser Xing'an—Zhangguangcai Range were formed along an active continental margin, possibly as a result of bidirectional subduction of the Mudanjiang Oceanic plate between the Jiamusi and Songnen—Zhangguangcai Range massifs. [ABSTRACT FROM AUTHOR]

The Uhelchulu quartz diorite-granodiorite intrusions in Xiwuqi, Inner Mongolia, are exposed along the northwestern margin of the Xilinhot microcontinental block, located within the central and eastern parts of the southeastern Hegenshan suture zone. LA-ICP-MS zircon U-Pb dating yielded crystallization ages of (396 ± 8) Ma for the quartz diorite and (385 ± 5) Ma for the granodiorite, indicating an Early-Middle Devonian magmatic event. The quartz diorite exhibits I-type granite features, characterized by elevated Al2O3 (14.33–15.43 wt%), MgO (3.73–5.62 wt%), and Na (Na2O/K2O = 1.04–1.44), coupled with low P2O5 (0.15–0.20 wt%) and TiO2 (0.73–0.99 wt%). Trace element patterns show relative enrichments in Rb, Th, U, and Pb, while Nb, Ta, Sr and Ti are relatively depleted. Total REE contents are relatively low (123–178 ppm), with significant LREE enrichment (ΣLREE/ΣHREE = 4.75–5.20), and a non-obvious Eu anomaly (δEu = 0.75–0.84). In contrast, the granodiorite displays S-type granite characteristics, with high SiO2 (70.48–73.01 wt%), K (K2O/Na2O = 1.35–1.83), Al2O3 (A/CNK = 1.16–1.31), and a high differentiation index (DI = 76–82). Notably, MgO (1.44–2.24 wt%) contents are low, and significant depletions of Ba, Sr, Ti, and Eu are observed, while Rb, Pb, Th, U, Zr, and Hf are significantly enriched. Total REE contents are relatively low (178–314 ppm), exhibiting significant LREE enrichment (LREE/HREE = 6.17–8.36) and a pronounced negative Eu anomaly (δEu = 0.34–0.49). The overall characteristics point towards an active continental margin arc background for the Uhelchulu intrusions. Previous studies have suggested that the Hegenshan ocean continuously subducted northward from the Early Carboniferous to the Late Permian, but there is a lack of evidence for its geological evolution during the pre-Early Carboniferous. Therefore, this paper provides a certain basis for studying the geological evolution during the pre-Early Carboniferous in the Hegenshan ocean. We preliminarily believed that the Hegenshan ocean underwent a southward subduction towards the Xilinhot microcontinental block in the Xiwuqi area, at least from the Early Devonian to the Middle Devonian and the Hegenshan ocean may might have undergone a shift in subduction mechanism during the Late Devonian or Early Carboniferous. [ABSTRACT FROM AUTHOR]

This editorial titled "Evolution of subcontinental and oceanic lithospheric mantle" discusses the significance of studying the history of the lithospheric mantle beneath continents and ocean floors to gain insights into plate tectonics. The editorial highlights the use of petrology, geochemistry, and geophysics to investigate the composition, attributes, and structure of the lithospheric mantle. It also mentions a compilation of six papers included in the Research Topic, which analyze various types of rocks and investigate the internal structure and dynamics of the lithospheric mantle using seismic wave analysis. The document specifically focuses on the analysis of seismic anisotropy in the Tibetan plateau, revealing crust-mantle coupling deformation in the northeastern Tibet and crust-mantle decoupling deformation in the southeastern Tibet. The authors emphasize the importance of these findings in understanding the structure and evolution of the lithosphere. It is important to note that the claims expressed in this document are solely those of the authors and do not necessarily represent the views of their affiliated organizations or the publisher. [Extracted from the article]

This study attempts to determine the impact of industries such as paper mills and ferro-alloy units and mining of Mn ore deposits on soil and river geochemistry in a monsoon-dominated area on the southwest coast of India. Soils, suspended particulate matter (SPM), andbottom sediments from the Kali River are all enriched with Al, Fe, Ni and Co, but strongly depleted in Na, Ca, K, Mg, Rb and Sr due to intense chemical weathering. However, even in river water the concentrations of dissolved alkaline and alkaline earth elements are low. Manganese, in particular, is anomalously high in bottom sediments and suspended particles by factors of 2.3 to 20.76 in relation to average shale and world river SPM. This enrichment is attributable to mining of Mn ore deposits in the riverdrainage area. The concentration of dissolved Pb, Co and Cd in Kali River water is much higher (by factors of 2 to 13) in comparison to the world's major rivers, implying anthropogenic inputs of these metals through localized discharge of sewage and industrial effluents. Assessment of heavy metal pollution determined by the element enrichment factor (EF) and the index of geo-accumulation (Igeo) suggests that most of the hazardous heavy metals studied are within the background level. However, Al, Fe, Co andNi are enriched due to their immobility during chemical weathering and their adsorption subsequently by Al and Fe oxides. These studies show that, although there are major industries in the study area, their impact is not yet visible due to the large input of pristine sediments from the catchment. [ABSTRACT FROM AUTHOR]

Calcitic speleothems in caves can form through abiogenic, biogenic, or a combination of both processes. Many issues conspire to make the assessment of biogenicity difficult, especially when focusing on old speleothem deposits. This study reports a multi-proxy analysis of a Siberian stalactite, combining high-resolution microscopy, isotope geochemistry and microbially enhanced mineral precipitation laboratory experiments. The contact between growth layers in a stalactite exhibits a biogenic isotopic signature; coupled with morphological evidence this supports a microbial origin of calcite crystals. SIMS δ13C data suggest that microbially mediated speleothem formation occurred repeatedly for short intervals before abiotic precipitation took over. The studied stalactite also contains iron and manganese oxides that have been mediated by microbial activity through extracellular polymeric substances (EPS)-influenced organomineralization processes. The latter reflect palaeoenvironmental changes that occurred more than 500 000 yr ago, possibly related to the presence of a peat bog above the cave at that time. Microbial activity can initiate calcite deposition in the aphotic zone of caves before inorganic precipitation of speleothem carbonates. This study highlights the importance of microbially induced fractionation that can result in large negative δ13C excursions. The micro-scale biogeochemical processes imply that microbial activity has only negligible effects on the bulk δ13C signature in speleothems, which is more strongly affected by CO2 degassing and the hostrock signature [ABSTRACT FROM AUTHOR]

A new approach is presented in this paper for the dynamic modeling of the chemical and isotopic evolution of C1–3 during the hydrocarbon generation process. Based on systematic data obtained from published papers for the pyrolysis of various hydrocarbon sources (type I kerogen/source rock, type II kerogen/source rock, type III kerogen/source rock, crude oil, and asphalt, etc.), the empirical evolution framework of the chemical and isotopic composition of C1–3 during the hydrocarbon generation process was built. Although the empirical framework was built only by fitting a large amount of pyrolysis data, the chemical and isotopic composition of C1–3 derived from the pyrolysis experiments all follow evolution laws, convincing us that it is applicable to the thermal evolution process of various hydrocarbon sources. Based on the simplified formula of the isotopic composition of mixed natural gas at different maturities (δ13Cmixed), δ13Cmixed = X × n i A × δ 13 C i A + Y × n i B × δ 13 C i B X × n i A + Y × n i B , it can be derived that the cumulative isotopic composition of alkane generated in a certain maturity interval can be expressed by the integral of the product of the instantaneous isotopic composition and instantaneous yield at a certain maturity point, and then divided by the cumulative yield of alkane generated in the corresponding maturity interval. Thus, the cumulative isotopic composition (A(X)), cumulative yield (B(X)), instantaneous isotope (C(X)), and instantaneous yield (D(x)) in the dynamic model, comply with the following formula during the maturity interval of (X0~X). A(X) = ∫ X 0 X C X × D X d x B (X) , where A(X) and B(X) can be obtained by the fitting of pyrolysis data, and D(x) can also be obtained from the derivation of B(X). The dynamic model was applied on the pyrolysis data of Pingliang Shale to illustrate the quantitative evolution of the cumulative yield, instantaneous yield, cumulative isotope, and instantaneous isotope of C1–3 with increasing maturity. The dynamic model can quantify the yield of methane, ethane, and propane, as well as δ13C1, δ13C2, and δ13C3, respectively, during the hydrocarbon generation process. This model is of great significance for evaluating the natural gas resources of hydrocarbon source rock of different maturities and for identifying the origin and evolutionary process of hydrocarbons by chemical and isotopic data. Moreover, this model provides an approach to study the dynamic evolution of the isotope series of C1–3 (including reversed isotopic series), which is promising for revealing the mechanism responsible for isotopic reversal when combined with post-generation studies. [ABSTRACT FROM AUTHOR]

This special issue (Volume 3) belongs to the special issues on the orogens along the Silk Road. We selected 34 papers to focus on the mineral deposits, orogeny‐links, geochemistry, geochronology, and environments related to the Tianshan Orogen of the Silk Road. We hope that these papers will highlight more geological research along the Silk Road to promote the construction and development of the Road and Belt. [ABSTRACT FROM AUTHOR]

It has been suggested that eroding landscapes can form C sinks or sources, but the underlying mechanisms are not fully understood. Our analysis aims to clarify the effects of soil redistribution on physical and biogeochemical soil organic carbon (SOC) stabilization mechanisms along a hillslope transect. The observed mineralogical differences seem partly responsible for the effectiveness of geochemical and physical SOC stabilization mechanisms as the mineral environment along the transect is highly variable and dynamic. The abundance of primary and secondary minerals and the weathering status of the investigated soils differ drastically along this transect. Extractable iron and aluminum components are largely abundant in aggregates, but show no strong correlation to SOC, indicating their importance for aggregate stability but not for SOC retention. We further show that pyrophosphate extractable soil components, especially manganese, play a role in stabilizing SOC within non-aggregated mineral fractions. The abundance of microbial residues and measured 14C ages for aggregated and non-aggregated SOC fractions demonstrate the importance of the combined effect of geochemical and physical protection to stabilize SOC after burial at the depositional site. Mineral alteration and the breakdown of aggregates limit the protection of C by minerals and within aggregates temporally. The 14C ages of buried soil indicate that C in aggregated fractions seem to be preserved more efficiently while C in non-aggregated fractions is released, allowing a re-sequestration of younger C with this fraction. Old 14C ages and at the same time high contents of microbial residues in aggregates suggest that microorganisms either feed on old carbon to build up microbial biomass, or that these environments consisting of considerable amounts of old C are proper habitats for microorganisms and preserve their residues. Due to continuous soil weathering and, hence, weakening of protection mechanisms, a potential C sink through soil burial is finally temporally limited. [ABSTRACT FROM AUTHOR]

Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin (Western Desert, Egypt) necessitate a thorough oil-source correlation investigation. This objective is achieved through a meticulous analysis of well-log responses, Rock-Eval pyrolysis, and biomarker data. The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt% to 2.04 wt%, thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen. Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter. Notably, a significant contribution from more oxidized residual organic matter and gasprone Type III kerogen is observed. Contrarily, the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment, and thus featuring a pronounced marine influence within a more reducing setting, which is associated with Type II kerogen. Through analysis of five oil samples from different wellsdSIWA L-1X, SIWA R-3X, SIWA D-1X, PTAH 5X, and PTAH 6X, it is evident that terrestrial organic matter, augmented by considerable marine input, was deposited in an oxidizing environment, and contains Type III kerogen. Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments. Noteworthy is the uniformity of identified kerogen Types II and III across all samples, known to have potential for hydrocarbon generation. The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir, suggesting potential links to Paleozoic sources or even originating from the Safa Member itself. These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin. By illuminating the processes of hydrocarbon genesis in the region, this study significantly enriches our knowledge base. [ABSTRACT FROM AUTHOR]

This paper presents a detailed study including LA-ICP-MS zircon U-Pb dating, geochemical, zircon Hf isotope, and whole rock Sr-Nd isotope analysis of magmatic rocks from the Yitong County, Jilin Province, NE China. These data are used to better constrain the Middle Silurian–Middle Devonian tectonic evolution in the eastern segment of the northern margin of the North China Craton (NCC). Zircon U-Pb dating results show that the Ximangzhang tonalite formed in the Late Silurian (425 ± 6 Ma); the basalt, andesite, and metamorphic olivine-bearing basalt in the Fangniugou volcanic rocks formed in the Middle Silurian (428 ± 6.6 Ma) and Middle Devonian (388.4 ± 3.9 Ma, and 384.1 ± 4.9 Ma). The Late Silurian tonalites are characterized by high SiO2 and Na2O and low K2O, MgO, FeOT, and TiO2, with an A/CNK ratio of 0.91–1.00, characteristic of calc-alkaline I-type granite. They are enriched in Rb, Ba, Th, U, and K, and depleted in Nb, Sr, P, and Ti, with positive εNd(t) (+0.35) and εHf(t) (+0.44 to +6.31) values, suggesting that they mainly originated from the partial melting of Meso–Neoproterozoic accretionary lower crustal material (basalt). The Middle Silurian basalts are characterized by low SiO2, P2O5, TiO2, and Na2O and high Al2O3, FeOT, and K2O, enriched in Rb, Ba, Th, U, and K and depleted in Nb, Ta, Sr, P, and Ti, indicative of shoshonitic basalt. The Late Silurian tonalites have positive εNd(t) (+4.91 to +6.18) values and primarily originated from depleted mantle magmas metasomatized by subduction fluids, supplemented by a small amount of subducted sediments and crustal materials. The Middle Devonian volcanic rocks exhibit low SiO2, TiO2, and Na2O and high K2O, and MgO, enriched in Rb, K, and LREEs and depleted in Nb, Ta, Sr, and HREEs, characteristic of shoshonitic volcanic rocks. Their εNd(t) (+2.11 to +3.77) and εHf(t) (+5.90 to +11.73) values are positive. These characteristics indicate that the Middle Devonian volcanic rocks primarily originated from depleted mantle magmas metasomatized by subduction fluids, with the addition of crustal materials or subducted sediments during their formation. Based on regional geological data, it is believed that the study area underwent the following evolutionary stages during the Silurian–Devonian period: (1) active continental margin stage of southward subduction of the Paleo–Asian Ocean (PAO) (443–419 Ma); (2) arc-continent collision stage (419–405 Ma); (3) post-collision extension stage (404–375 Ma); (4) active continental margin stage, with the PAO plate subducting southward once again (375–360 Ma). [ABSTRACT FROM AUTHOR]

We investigated the distribution patterns and evaluated the average contents of trace elements in the k7 seam of the Karaganda coal basin in Central Kazakhstan. This paper presents the results of studying the geochemistry of 34 elements in 85 samples of the k7 seam. The study employed a suite of advanced high-resolution analytical methods, including atomic emission spectrometry with inductively coupled plasma (ICP–OES) and mass spectrometry with inductively coupled plasma (ICP–MS), along with their processing and interpretation. It was determined that the concentrations of trace elements in the k7 seam are primarily associated with lithophile elements, revealing high concentrations of Li, V, Sc, Zr, Hf, and Ba. Additionally, increased concentrations of Nb, Ta, Se, Te, Ag, and Th were observed compared to the coal Clarke. Specific Nb(Ta)–Zr(Hf)–Li mineralization accompanied by a group of associated metals (Ba, V, Sc, etc.) was identified. The study revealed lateral and vertical heterogeneity of the rare elements' distributions in coals, attributed to the formation dynamics of the coal basin. A correlation between Li and Al2O3 with a less positive relationship with K2O suggests the affinity of certain elements (Li, Ta, Nb, and Ba) to kaolinite. Clay layers showed increased radioactivity, with Th—13.2 ppm and U—2.6 ppm, indicating the possible presence of volcanogenic pyroclastic rocks characterized by radioactivity. Taken together, these data reveal the features of the rock composition of the source area, which is considered a mineralization source. According to geochemical data, it was found that the source area mainly consists of igneous felsic rocks, indicating that the formation occurred under conditions of a volcanic arc. This study's novelty lies in estimating the average trace elements in the k7 seam, with elevated concentrations of certain elements that suggest promising prospects for industrial extraction from coals and coal wastes. These findings offer insights into considering coal as a potential source of raw material for rare metal production, guiding the industrial processing of key elements within coal. The potential extraction of metals from coal deposits, including from dumps, holds significance for industrial and commercial technologies, as processing critical coal elements can reduce disposal costs and mitigate their environmental impact. [ABSTRACT FROM AUTHOR]

Strontium isotope ratios (87Sr/86Sr) are a key geochemical tracer used in a wide range of fields including archaeology, ecology, food and forensic sciences. These applications are based on the principle that the Sr isotopic ratios of natural materials reflect the sources of strontium available during their formation. A major constraint for current studies is the lack of robust reference maps to evaluate the source of strontium isotope ratios measured in the samples. Here we provide a new dataset of bioavailable Sr isotope ratios for the major geologic units of France, based on plant and soil samples (Pangaea data repository doi:10.1594/PANGAEA.819142). The IRHUM (Isotopic Reconstruction of Human Migration) database is a web platform to access, explore and map our dataset. The database provides the spatial context and metadata for each sample, allowing the user to evaluate the suitability of the sample for their specific study. In addition, it allows users to upload and share their own datasets and data products, which will enhance collaboration across the different research fields. This article describes the sampling and analytical methods used to generate the dataset and how to use and access of the dataset through the IRHUM database. Any interpretation of the isotope dataset is outside the scope of this publication. [ABSTRACT FROM AUTHOR]

Interest in seamount research has gathered momentum over the past five years in an effort to understand the physical, geochemical and biological characteristics as well as the interconnectedness of seamount ecosystems. The majority of biological seamount research has concentrated upon the rich and diverse suspension feeding organisms that dominate the megafauna, such as gorgonians and antipatharian corals; by comparison there have been few studies that have investigated the no less enigmatic, but possibly just as important infauna. To help fill this knowledge gap, the macrofaunal community was sampled from a total of five stations along a northerly transect (capturing water depths from ~130m to ~3300m), on Senghor Seamount (NE Atlantic). The focus of this study is on the polychaete communities. Polychaete abundance peaked at the summit and a mid-slope station (~1500m), a pattern mirrored by the biomass values. The polychaete community along the transect appeared to be particularly diverse, with 135 species nominally identified to putative species from a total of 954 individuals. A diversity maximum was identified on the upper slope at ~800m depth, with species diversity, richness and evenness also all peaking at this station. Depth is likely to be a significant factor in determining levels of similarity between stations. [ABSTRACT FROM AUTHOR]

The country of the Republic of Kosovo is situated in the central part of the Balkan Peninsula. In the Southwest, it is bordered by Albania, in the West by Montenegro, in the North and East by Serbia and in the Southeast by North Macedonia. In this scientific paper was done the identification detailed for rocks found on the researched region. it was done the identification detailed for rocks found in the researched region. The region research it's done scale by 1:25 000 for comparison map of geology scale by 1:200 000 and paper will be treated the mineralogical content, petrography microscope preparation, and geochemistry. For the region of Gjilan, the analysis was performed: for large elements, for small elements and traces, and for rare soils. The processing of the analysis of large elements, traces, and sub-traces was performed in the geochemical-petrological software MINPET. Constructed diagrams show that we are dealing with rocks generated in differentiated geodynamic environments. Most of the rocks analyzed fall in the field of basic and acid rocks, and only a small part of them belong to the medium and ultrabasic rocks. Acid rocks are represented mainly by their Metamorphism types - gneiss and less of those ages with them younger - granite. They generally show geochemical features of volcanic type than orogenic in acid magmatism. The purpose of the paper it the proposal of the paper is the identification rocks in the exploration zone for the preparation petrographic of microscope and processing of the analysis of large elements, traces, and sub-traces was performed in the geochemical-petrological software MINPET. It was done by the evidencing and detailed description of all the types of rocks found in the researched region. The samples were taken from those rocks for the preparation of petrography microscope preparation. The analyses were completed at the certified laboratory of Geology-Mining Faculty (Polytechnic University of Tirana) - Geosciences Institute. [ABSTRACT FROM AUTHOR]

Two sediment cores from the Changjiang (Yangtze) River estuary and its adjacent East China Sea were collected and studied for eutrophication history using paleoecological records of environmental changes over the last century. A multiproxy approach by using biological and geochemical analyses revealed changes in diatom assemblages, total organic carbon (TOC), total nitrogen (TN) and biogenic silica (BSi) and give an indication of nutrient in status and trends in Changjiang River estuary and its adjacent East China Sea. The diatom assemblages in the two cores generally increased gradually from the 1970s, and accelerated from the 1990s until now, reflecting the increased eutrophication and causing large algae blooms/red tides. The TOC, TN and BSi showing the similar trends, supported the interpretation of the eutrophication process indicated by diatom analyses. The two cores were located in different sea areas of the East China Sea, and we discuss their relative changes based on their environment characteristics. We also discuss the potential effect of anthropogenic influences and ongoing projects on eutrophication in the Changjiang River and its adjacent East China Sea. [ABSTRACT FROM AUTHOR]

The article discusses a research study which introduces the new aerosol microphysics submodel MADE-IN with the ECHAM5/MESSy Atmospheric Chemistry global model (EMAC). The said approach describes three classes of particles and predicts the size distribution and chemical composition of these classes. Findings reveal that the model is an efficient tool for the study of concentration and composition of potential atmospheric ice nuclei.

We describe a new 4D-Var inversion framework for N2O based on the GEOS-Chem chemical transport model and its adjoint, and apply this framework in a series of observing system simulation experiments to assess how well N2O sources and sinks can be constrained by the current global observing network. The employed measurement ensemble includes approximately weekly and quasi-continuous N2O measurements (hourly averages used) from several long-term monitoring networks, N2O measurements collected from discrete air samples aboard a commercial aircraft (CARIBIC), and quasi-continuous measurements from an airborne pole-to-pole sampling campaign (HIPPO). For a two-year inversion, we find that the surface and HIPPO observations can accurately resolve a uniform bias in emissions during the first year; CARIBIC data provide a somewhat weaker constraint. Variable emission errors are much more difficult to resolve given the long lifetime of N2O, and major parts of the world lack significant constraints on the seasonal cycle of fluxes. Current observations can largely correct a global bias in the stratospheric sink of N2O if emissions are known, but do not provide information on the temporal and spatial distribution of the sink. However, for the more realistic scenario where source and sink are both uncertain, we find that simultaneously optimizing both would require unrealistically small errors in model transport. Regardless, a bias in the magnitude of the N2O sink would not affect the a posteriori N2O emissions for the two-year timescale used here, given realistic initial conditions, due to the timescale required for stratosphere-troposphere exchange (STE). The same does not apply to model errors in the rate of STE itself, which we show exerts a larger influence on the tropospheric burden of N2O than does the chemical loss rate over short (< 3 year) timescales. We use a stochastic estimate of the inverse Hessian for the inversion to evaluate the spatial resolution of emission constraints provided by the observations, and find that significant, spatially explicit constraints can be achieved in locations near and immediately upwind of surface measurements and the HIPPO flight tracks; however, these are mostly confined to North America, Europe, and Australia. None of the current observing networks are able to provide significant spatial information on tropical N2O emissions. There, averaging kernels are highly smeared spatially and extend even to the midlatitudes, so that tropical emissions risk being conflated with those elsewhere. For global inversions, therefore, the current lack of constraints on the tropics also places an important limit on our ability to understand extratropical emissions. Based on the error reduction statistics from the inverse Hessian, we characterize the atmospheric distribution of unconstrained N2O, and identify regions in and downwind of South America, Central Africa, and Southeast Asia where new surface or profile measurements would have the most value for reducing present uncertainty in the global N2O budget. [ABSTRACT FROM AUTHOR]

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Mesozoic igneous rocks are widely distributed in the South China Sea (SCS) and its adjacent areas and are exposed in the SCS, South China, Hainan, Indochina, Taiwan, the Philippines, and Borneo; these rocks are mostly dominated by granitoids. This paper presents a complete map of the Mesozoic igneous rocks of the SCS and its adjacent areas. This paper also presents an analysis of geological survey and published data in terms of seismic profiles, ages, geochemistry and isotopic systematics of the Mesozoic igneous complexes of the SCS and its adjacent areas. Three periods of igneous activity can be distinguished: (1) Permian – Triassic that spans from 250–201 Ma; (2) Jurassic (201–145 Ma); and (3) Latest Jurassic/Cretaceous to Maastrichtian (145–66 Ma), of which the Cretaceous is the best preserved and could possibly be the most widespread. Triassic igneous rocks are distributed in the northwestern and southern SCS (Qiongdongnan Basin, Yinggehai-Song Hong Basin, Beibu Gulf Basin, the Dangerous Grounds, and the Reed Bank); Jurassic igneous rocks are distributed in the northern and southern SCS (Pearl River Mouth Basin, Qiongdongnan Basin, Yinggehai-Song Hong Basin, Beibu Gulf Basin, and the Reed Bank); and Cretaceous igneous rocks are distributed in the northern, western and southern SCS. The igneous activity of the SCS is mostly distributed in the continent slope. Mesozoic igneous rocks of the SCS include at least 350 rock masses: the smallest being 0.182 km2, the largest being 5,5,502 km2, and the total area covering 688,539 km2. Mesozoic magmatism in the SCS and its adjacent areas migrated oceanward (southeastward). Our new seismic profiles and the wells from the literature highlight that Jurassic granites occur not only inland of South China but also in coastal South China and the northern and southern SCS. The YING6 well in the northern SCS encountered andesite with an age of 68.24 Ma, which is the youngest age found for the SCS Mesozoic volcanic rocks. The XY1 well in the western SCS encountered granite with an age of 68.9 Ma, which is the youngest age found for the SCS Mesozoic intrusive rocks. The WZ12-3-1 well in the northern SCS encountered granite with an age of 243.3 Ma, which is the oldest age found for the SCS Mesozoic intrusive rocks. The encountered dacite ages (219.1 ± 1.4 Ma) of the NK-1 well in the southern SCS were the oldest ages found for the SCS Mesozoic volcanic rocks. The thickest Mesozoic igneous rocks (>1022.5 m) were encountered in the NK-1 well. Igneous rocks in the SCS and its adjacent areas are closely related to tectonic movements such as faults, plate movement, and mantle-derived igneous fluid ascent. They are controlled by the subduction of the Tethys lithospheric and Paleo-Pacific domains. [ABSTRACT FROM AUTHOR]

Within the Himalayan collisional belt, granites occur along two subparallel belts, namely, the Tethyan Himalayan Sequence (THS) and the Greater Himalayan Crystalline Complex (GHC). In this study, Eocene adakitic rocks and leucogranite are found only in the northern Himalayas, so further research is required to constrain their origin. Here, we present zircon U–Pb and monazite U–Th–Pb ages, Sr–Nd–Pb and Hf isotopes, and whole-rock major and trace elements for Liemai muscovite granite in the eastern Himalayan region. The U–(Th)–Pb results show that Liemai muscovite granite was emplaced at 43 Ma, and that its geochemical characteristics are similar to those of adakitic rocks of the same age (Dala, Quedang, Ridang, etc.). Combined with previous studies, both Eocene adakitic rocks and leucogranite are high-potassium calc-alkaline peraluminous granites. The former is relatively rich in large-ion lithophile elements (LILEs), such as Ba and Sr, and relatively deficient in high-field-strength elements (HFSEs), such as Nb, Ta, Zr, and Y, with weak or no Eu anomalies, and the average light rare earth element (LREE)/heavy rare earth element (HREE) ratio is 17.8. The latter is enriched in LILEs (such as Rb) and U, Ta, and Pb, and depleted in HFSEs (such as Nb and Zr), La, and Nd, with obvious negative Sr, Ba, and Eu anomalies and a mean LREE/HREE ratio of 10.7. The 87Sr/86Sr of the former is in the range of 0.707517–0.725100, εNd (t) ranged from −1.2 to −14.7, the average is −11.6, εHf (t) ranged from −0.5 to −65, the average is −12.2. The average values of (206Pb/204Pb) i, (207Pb/204Pb) i and (208Pb/204Pb) i are 18.788, 15.712 and 39.221, respectively; The 87Sr/86Sr of the latter is in the range of 0.711049~0.720429, εNd (t) ranged from −9.8 to −13.8, the average is −12.3, εHf (t) ranged from −4.2 to −10, the average is −6.7. The isotopic characteristics indicate that adakitic rocks and leucogranites are derived from the ancient lower crust, and both may be derived from metamorphic rocks of the GHC. In this paper, the origin of the two is associated with the transformation of the Himalayan tectonic system during the Eocene, and it is inferred that the deep crust may have altered the tectonic environment (temperature and pressure), resulting in an obvious episodic growth trend of leucogranite and significant development of adakitic rocks from 51 to 40 Ma. From 40 to 35 Ma, the development of Eocene magmatic rocks was hindered, and adakitic rocks disappeared. It is proposed that the genetic difference is related to the transition from high to low angles of the subducting plate in the crustal thickening process. [ABSTRACT FROM AUTHOR]

In recent decades, the development of different analytical procedures applied to the study of archaeological lithic remains has allowed us to approach the territoriality of past societies. The application of geochemical tools has improved the study of lithic raw materials, allowing direct connections between archaeological samples and specific geological formations. In a similar way, the incorporation of GIS tools to the study of past mobility and territoriality has allowed to define which could have been the most probable routes used by past groups to stock up on rocks. In this paper, we present the results obtained after the geochemical study by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) of lithic cherts found at Upper Palaeolithic human occupations at Cueva del Gato 2 (Épila, Zaragoza, Spain) as well as the least cost path routes obtained after GIS analyses. The Cueva del Gato 2 archaeological site is a large cave placed in the first foothills of the Iberian System, close to the Middle Ebro Basin, in Eastern Iberia. The archaeological work has revealed a long sequence of occupation with archaeological levels from the Bronze Age, the Ancient Neolithic and the Upper Palaeolithic. In this paper, we have focused on the study of level II, which has been dated in the range 21,000–23,000 cal BP. Results have demonstrated that past human groups from the Last Glacial Maximum knew and frequented the Sierra de Lanaja – Montes de Castejón lacustrine chert sources, outcropping in the Middle Ebro Basin. [ABSTRACT FROM AUTHOR]