Pub Date : 2025-04-10DOI: 10.1016/j.geogeo.2025.100393
Gang Fu , Yihong Duan
Meteorology is a science which has long time history and significant impacts on the lives of people globally, attracting worldwide attention. Qingdao Observatory, known as one of “three major observatories in the far east” built by Germany in 1898, had remarkable influences on the evolution of marine meteorology in China. Chinese Meteorological Society (CMS) was established on 10 October 1924 in Qingdao Observatory, which is widely regarded as the birthplace of modern meteorology in China. During the childhood of modern meteorology in China, quite some pioneers had made significant contributions. Based on widely-published Chinese and English books and papers, this article tells unusual stories behind two pioneers, Dr. Pingjan Tsiang (蒋丙然) and his student Binhua Wang (王彬华), who both served as the directors of Qingdao Observatory successively, and played vital roles in promoting the development of marine meteorology in China. However, due to the complex reasons like the influence of wars and the limitation of papers being published in non-English journals, their names and academic contributions were rarely recognized by the international academic community, beyond their home country – China. This paper may provide multiple-angle insights for understanding of the history of marine meteorology in China.
{"title":"Initial development of marine meteorology in China: Insights from two pioneers Prof. Pingjan Tsiang and Prof. Binhua Wang","authors":"Gang Fu , Yihong Duan","doi":"10.1016/j.geogeo.2025.100393","DOIUrl":"10.1016/j.geogeo.2025.100393","url":null,"abstract":"<div><div>Meteorology is a science which has long time history and significant impacts on the lives of people globally, attracting worldwide attention. Qingdao Observatory, known as one of “three major observatories in the far east” built by Germany in 1898, had remarkable influences on the evolution of marine meteorology in China. Chinese Meteorological Society (CMS) was established on 10 October 1924 in Qingdao Observatory, which is widely regarded as the birthplace of modern meteorology in China. During the childhood of modern meteorology in China, quite some pioneers had made significant contributions. Based on widely-published Chinese and English books and papers, this article tells unusual stories behind two pioneers, Dr. Pingjan Tsiang (蒋丙然) and his student Binhua Wang (王彬华), who both served as the directors of Qingdao Observatory successively, and played vital roles in promoting the development of marine meteorology in China. However, due to the complex reasons like the influence of wars and the limitation of papers being published in non-English journals, their names and academic contributions were rarely recognized by the international academic community, beyond their home country – China. This paper may provide multiple-angle insights for understanding of the history of marine meteorology in China.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 3","pages":"Article 100393"},"PeriodicalIF":0.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent times, biostratigraphy, apart from its primary roles in age dating, paleoenvironmental reconstruction and correlation now constitutes a significant aspect of sequence stratigraphy applicable in exploration and production activities. Unfortunately, published biostratigraphic and biochronostratigraphic records of Niger Delta Eocene –Oligocene sediments are scanty. This integrated study of the H1-P well (1250–3931 m) from the Central Niger Delta revealed two lithostratigraphic units, the continental Benin Formation (1250–2384 m) and the Upper Agbada Formation (2384–3931 m) composed of alternating sand and shale intervals. The uppermost section (1250–2384 m), which is within the continental Benin Formation was barren of foraminifera. However, it was dated Early to Middle Oligocene (P520-P560) based on diagnostic palynomorphs. Conversely, the lowermost part (3931–2384 m), consisting moderate numbers of foraminifera species, was dated Late Eocene (P480). The paleoenvironments, which fluctuated between Coastal Deltaic to Middle Neritic, were subdivided into four highstand and four transgressive systems tracts. The 39.4 Ma, 38.0Ma, 36.8 Ma and 35.9 Ma maximum flooding surfaces, and three sequence boundaries were inferred. The youngest maximum flooding surface dated 35.9 Ma at 2385 m, was defined by the FDO Nonion oyae, FDO Brizalina ihuoensis (2402 m), presence of Globigerina yeguaensis and FDO Uvigerinella sparsicostata at 2713 m, the FDO of the diagnostic palynomorphs Grimsdalea polygonalis, Doualaidites laevigatus, at 2414 m / 2792 m respectively indicated the penetration of Late Eocene. The FDO Uvigerina hourqi delineated the Middle/Late Eocene boundary at 3121 m. The Middle Eocene is further characterized by Acme Uvigerinella sparsicostata and occurrence of Chiloguembelina martini. The sequence stratigraphic interpretation permitted age dating of the maximum flooding surfaces and the sequence boundaries within the well section.
{"title":"Biostratigraphy, stratigraphy and paleoenvironments of middle Eocene – middle Oligocene sediments from Onshore Niger Delta, Nigeria: Insights from foraminifera and palynomorphs","authors":"Moshood Adegboyega Olayiwola , Olugbenga Temitope Fajemila","doi":"10.1016/j.geogeo.2025.100391","DOIUrl":"10.1016/j.geogeo.2025.100391","url":null,"abstract":"<div><div>In recent times, biostratigraphy, apart from its primary roles in age dating, paleoenvironmental reconstruction and correlation now constitutes a significant aspect of sequence stratigraphy applicable in exploration and production activities. Unfortunately, published biostratigraphic and biochronostratigraphic records of Niger Delta Eocene –Oligocene sediments are scanty. This integrated study of the H1-P well (1250–3931 m) from the Central Niger Delta revealed two lithostratigraphic units, the continental Benin Formation (1250–2384 m) and the Upper Agbada Formation (2384–3931 m) composed of alternating sand and shale intervals. The uppermost section (1250–2384 m), which is within the continental Benin Formation was barren of foraminifera. However, it was dated Early to Middle Oligocene (P520-P560) based on diagnostic palynomorphs. Conversely, the lowermost part (3931–2384 m), consisting moderate numbers of foraminifera species, was dated Late Eocene (P480). The paleoenvironments, which fluctuated between Coastal Deltaic to Middle Neritic, were subdivided into four highstand and four transgressive systems tracts. The 39.4 Ma, 38.0Ma, 36.8 Ma and 35.9 Ma maximum flooding surfaces, and three sequence boundaries were inferred. The youngest maximum flooding surface dated 35.9 Ma at 2385 m, was defined by the FDO <em>Nonion oyae</em>, FDO <em>Brizalina ihuoensis</em> (2402 m), presence of <em>Globigerina yeguaensis</em> and FDO <em>Uvigerinella sparsicostata</em> at 2713 m, the FDO of the diagnostic palynomorphs <em>Grimsdalea polygonalis, Doualaidites laevigatus,</em> at 2414 m / 2792 m respectively indicated the penetration of Late Eocene. The FDO <em>Uvigerina hourqi</em> delineated the Middle/Late Eocene boundary at 3121 m. The Middle Eocene is further characterized by Acme <em>Uvigerinella sparsicostata</em> and occurrence of <em>Chiloguembelina martini</em>. The sequence stratigraphic interpretation permitted age dating of the maximum flooding surfaces and the sequence boundaries within the well section.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 3","pages":"Article 100391"},"PeriodicalIF":0.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-04DOI: 10.1016/j.geogeo.2025.100389
Khalid Ziadi , Ahmed Barakat , Abdenbi El Aloui , Mustapha Ouayah , Mustapha Namous
Identifying areas vulnerable to soil erosion is essential for the sustainable management of natural resources and the implementation of effective prevention strategies. This study proposes a robust multi-criteria decision analysis (MCDA)framework integrated with geographic information system (GIS) technology to evaluate susceptibility to water erosion in the upstream watershed of Tassaoute (Central High Atlas, Morocco). Elevation, slope, SPI, TWI, NDVI, LULC, lithology, rainfall, distance from river, and drainage density were the ten factors we employed to establish the soil erosion vulnerability map. Criteria weights were measured using the AHP method based on suggestions from different studies and research that ensured an effective way of soil erosion control. The final susceptibility map, created from GIS data and a classification of natural phenomena, identified five distinct levels: very low, low, moderate, high and very high. It reveals a significant erosion threat, with around 60 % of the study area showing moderate to very high levels of erosion. On the other hand, 40 % of the area studied is considered to be at low risk of erosion. Areas at high risk of erosion are more common on steep slopes, with high rainfall and rocks of the marl and clay formation. The accuracy of the results is assessed using the ROC (receiver operating characteristic) curve. The area under the curve (AUC) is 0.782, equivalent to a prediction accuracy of 78.2 %. In conclusion, this model is proving to be a valuable tool for effectively guiding future planning with regard to sustainable soil and water management, in particular by addressing the problem of soil erosion.
确定易受土壤侵蚀影响的地区对于自然资源的可持续管理和有效预防战略的执行至关重要。本研究提出了一个强大的多标准决策分析（MCDA）框架，结合地理信息系统（GIS）技术来评估Tassaoute上游流域（Central High Atlas，摩洛哥）对水侵蚀的敏感性。利用高程、坡度、SPI、TWI、NDVI、LULC、岩性、降雨量、离河距离和排水密度等10个因子建立土壤侵蚀脆弱性图。根据不同研究的建议，采用层次分析法测算各指标权重，确保土壤侵蚀治理的有效途径。根据地理信息系统数据和自然现象分类绘制的最终敏感性图确定了五个不同的级别：极低、低、中等、高和极高。它揭示了严重的侵蚀威胁，大约60%的研究区域显示出中度到非常严重的侵蚀。另一方面，研究区域的40%被认为处于低侵蚀风险。受侵蚀风险高的地区多在陡峭的山坡上，那里降雨量大，岩石由泥灰岩和粘土组成。使用ROC（受试者工作特征）曲线评估结果的准确性。曲线下面积（AUC）为0.782，预测精度为78.2%。总之，这一模式证明是有效指导关于可持续水土管理的未来规划的宝贵工具，特别是通过解决土壤侵蚀问题。
{"title":"Prioritization of the Tassaoute Watershed (Morocco) for soil erosion using analytical hierarchy process (AHP) and geospatial techniques","authors":"Khalid Ziadi , Ahmed Barakat , Abdenbi El Aloui , Mustapha Ouayah , Mustapha Namous","doi":"10.1016/j.geogeo.2025.100389","DOIUrl":"10.1016/j.geogeo.2025.100389","url":null,"abstract":"<div><div>Identifying areas vulnerable to soil erosion is essential for the sustainable management of natural resources and the implementation of effective prevention strategies. This study proposes a robust multi-criteria decision analysis (MCDA)framework integrated with geographic information system (GIS) technology to evaluate susceptibility to water erosion in the upstream watershed of Tassaoute (Central High Atlas, Morocco). Elevation, slope, SPI, TWI, NDVI, LULC, lithology, rainfall, distance from river, and drainage density were the ten factors we employed to establish the soil erosion vulnerability map. Criteria weights were measured using the AHP method based on suggestions from different studies and research that ensured an effective way of soil erosion control. The final susceptibility map, created from GIS data and a classification of natural phenomena, identified five distinct levels: very low, low, moderate, high and very high. It reveals a significant erosion threat, with around 60 % of the study area showing moderate to very high levels of erosion. On the other hand, 40 % of the area studied is considered to be at low risk of erosion. Areas at high risk of erosion are more common on steep slopes, with high rainfall and rocks of the marl and clay formation. The accuracy of the results is assessed using the ROC (receiver operating characteristic) curve. The area under the curve (AUC) is 0.782, equivalent to a prediction accuracy of 78.2 %. In conclusion, this model is proving to be a valuable tool for effectively guiding future planning with regard to sustainable soil and water management, in particular by addressing the problem of soil erosion.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100389"},"PeriodicalIF":0.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1016/j.geogeo.2025.100390
Barnita Banerjee , Monalisa Mallick , Mohd Amir , Abdul Hameed , Luan Ozelim , Nihar Ranjan Kar , E.V.S.S.K. Babu , K. Venkatesham , M. Venkateshwarlu , Tanveer Hassan , Vireswar Samanta , Prem Chand Kisku , Debajyoti Paul , Pankaj Kumar , Aurovinda Panda
Coastal lagoons, acting as a link between land and sea, serve as valuable archives for past climate variations, human activities, and paleo-cyclonic events. In this study, we employ a multi-proxy approach to analyze sedimentary records and uncover climatic shifts influenced by both monsoonal and non-monsoonal factors. Our analysis incorporates sediment characteristics such as grain size, magnetic susceptibility (MS), and clay mineralogy to infer high-energy conditions within the Chilika Lagoon. Additionally, we utilize Rock-Eval pyrolysis and deconvolution of flame ionization detector (FID) signals to determine the type of organic matter (OM) present.
Findings reveal that during the Early Holocene, a high sand percentage and elevated MS indicate an intensified monsoon, coinciding with a dominance of terrestrial OM. However, as monsoonal intensity declined after the Early Holocene, marine OM became more prevalent, likely linked to the formation of an estuary around ∼7.7 Ka. Despite a weakening monsoon around ∼4 Ka, MS values remained high, possibly due to increased aeolian input, which transported titanomagnetite, contributing to elevated MS in the sediment record. After ∼4 Ka, the sedimentary record indicates a greater influx of terrestrial OM, likely due to the formation of a barrier spit that limited marine influence. From this period onward, monsoonal intensity gradually increased, peaking around ∼1.1 Ka, coinciding with the Medieval Warm Period. Following ∼1.1 Ka, sedimentation rates rose, accompanied by low magnetic susceptibility (MS) and high sand content. This phase also shows an increase in both terrestrial and marine OM, along with higher CaCO₃ and illite concentrations, suggesting the impact of high-energy events, possibly cyclones. The intensification of cyclonic activity after ∼1.1 Ka may be associated with a weakening of El Niño–Southern Oscillation (ENSO) intensity during this period.
{"title":"Holocene climate variability deciphered from Chilika Lagoon sediments: Implication for anthropogenic activity or paleocyclones?","authors":"Barnita Banerjee , Monalisa Mallick , Mohd Amir , Abdul Hameed , Luan Ozelim , Nihar Ranjan Kar , E.V.S.S.K. Babu , K. Venkatesham , M. Venkateshwarlu , Tanveer Hassan , Vireswar Samanta , Prem Chand Kisku , Debajyoti Paul , Pankaj Kumar , Aurovinda Panda","doi":"10.1016/j.geogeo.2025.100390","DOIUrl":"10.1016/j.geogeo.2025.100390","url":null,"abstract":"<div><div>Coastal lagoons, acting as a link between land and sea, serve as valuable archives for past climate variations, human activities, and paleo-cyclonic events. In this study, we employ a multi-proxy approach to analyze sedimentary records and uncover climatic shifts influenced by both monsoonal and non-monsoonal factors. Our analysis incorporates sediment characteristics such as grain size, magnetic susceptibility (MS), and clay mineralogy to infer high-energy conditions within the Chilika Lagoon. Additionally, we utilize Rock-Eval pyrolysis and deconvolution of flame ionization detector (FID) signals to determine the type of organic matter (OM) present.</div><div>Findings reveal that during the Early Holocene, a high sand percentage and elevated MS indicate an intensified monsoon, coinciding with a dominance of terrestrial OM. However, as monsoonal intensity declined after the Early Holocene, marine OM became more prevalent, likely linked to the formation of an estuary around ∼7.7 Ka. Despite a weakening monsoon around ∼4 Ka, MS values remained high, possibly due to increased aeolian input, which transported titanomagnetite, contributing to elevated MS in the sediment record. After ∼4 Ka, the sedimentary record indicates a greater influx of terrestrial OM, likely due to the formation of a barrier spit that limited marine influence. From this period onward, monsoonal intensity gradually increased, peaking around ∼1.1 Ka, coinciding with the Medieval Warm Period. Following ∼1.1 Ka, sedimentation rates rose, accompanied by low magnetic susceptibility (MS) and high sand content. This phase also shows an increase in both terrestrial and marine OM, along with higher CaCO₃ and illite concentrations, suggesting the impact of high-energy events, possibly cyclones. The intensification of cyclonic activity after ∼1.1 Ka may be associated with a weakening of El Niño–Southern Oscillation (ENSO) intensity during this period.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 3","pages":"Article 100390"},"PeriodicalIF":0.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-30DOI: 10.1016/j.geogeo.2025.100387
Kedir Kemal Hajisheko , Karuturi Venkata Suryabhagavan , Karuturi Soumya
Soil erosion is a crucial environmental issue affecting agricultural productivity, water quality, and ecosystem sustainability. Deforestation and human activities have led to excessive soil erosion. A webGIS-based decision support system (DSS) was developed to provide complete information on soil erosion in the Guder watershed forming a part of the Abay River Basin in Ethiopia. The parameters employed were estimated using remote sensing data. Sub-watersheds were prioritised based on soil erosion risk through a revised universal soil loss equation (RUSLE) integrated with geographic information system (GIS). The study employed high-resolution spatial data, including rainfall, soil properties, and topography, to model erosion rates across the watershed. Results indicate that the annual soil loss in the watershed varied significantly from 0 to 8021 t ha−1 yr−1, with an average loss of 97.5 t ha−1 yr−1. About 33.3% of the watershed experienced very high soil loss (>50 t ha−1 yr−1), accounting for 91.3% of the total eroded. In contrast, 25.5% of the area exhibited medium soil erosion rates (<5 t ha⁻¹ yr⁻¹). The WebGIS tool developed is powerful and user-friendly portal that enables non-technical users to access real-time soil erosion data and better understand soil conservation programs, helping them identify measures to reduce soil erosion in the watershed. Moreover, this information also supports land managers, policymakers, and farmers in adopting targeted soil erosion control measures, promoting sustainable land management in the region.
土壤侵蚀是影响农业生产力、水质和生态系统可持续性的重要环境问题。森林砍伐和人类活动导致了过度的土壤侵蚀。开发了一个基于网络地理信息系统的决策支持系统（DSS），以提供关于构成埃塞俄比亚阿贝河流域一部分的古德流域土壤侵蚀的完整信息。所采用的参数是利用遥感数据估计的。通过与地理信息系统（GIS）相结合的修正通用土壤流失方程（RUSLE），基于土壤侵蚀风险对子流域进行优先排序。这项研究采用了高分辨率的空间数据，包括降雨、土壤性质和地形，来模拟整个流域的侵蚀率。结果表明，流域年土壤流失量在0 ~ 8021 tha−1 yr−1之间变化显著，平均流失量为97.5 tha−1 yr−1。约33.3%的流域土壤流失非常严重（50 t / h - 1年- 1年），占侵蚀总量的91.3%。相比之下，25.5%的地区表现出中等的土壤侵蚀率（<5(1 - 1)）。开发的WebGIS工具是一个功能强大且用户友好的门户，使非技术用户能够访问实时土壤侵蚀数据，更好地了解土壤保持计划，帮助他们确定减少流域土壤侵蚀的措施。此外，这些信息还有助于土地管理者、政策制定者和农民采取有针对性的水土流失控制措施，促进该地区的可持续土地管理。
{"title":"WebGIS-based decision support system for soil erosion risk assessment for Guder River catchment, Ethiopia","authors":"Kedir Kemal Hajisheko , Karuturi Venkata Suryabhagavan , Karuturi Soumya","doi":"10.1016/j.geogeo.2025.100387","DOIUrl":"10.1016/j.geogeo.2025.100387","url":null,"abstract":"<div><div>Soil erosion is a crucial environmental issue affecting agricultural productivity, water quality, and ecosystem sustainability. Deforestation and human activities have led to excessive soil erosion. A webGIS-based decision support system (DSS) was developed to provide complete information on soil erosion in the Guder watershed forming a part of the Abay River Basin in Ethiopia. The parameters employed were estimated using remote sensing data. Sub-watersheds were prioritised based on soil erosion risk through a revised universal soil loss equation (RUSLE) integrated with geographic information system (GIS). The study employed high-resolution spatial data, including rainfall, soil properties, and topography, to model erosion rates across the watershed. Results indicate that the annual soil loss in the watershed varied significantly from 0 to 8021 t ha<sup>−1</sup> yr<sup>−1</sup>, with an average loss of 97.5 t ha<sup>−1</sup> yr<sup>−1</sup>. About 33.3% of the watershed experienced very high soil loss (>50 t ha<sup>−1</sup> yr<sup>−1</sup>), accounting for 91.3% of the total eroded. In contrast, 25.5% of the area exhibited medium soil erosion rates (<5 t ha⁻¹ yr⁻¹). The WebGIS tool developed is powerful and user-friendly portal that enables non-technical users to access real-time soil erosion data and better understand soil conservation programs, helping them identify measures to reduce soil erosion in the watershed. Moreover, this information also supports land managers, policymakers, and farmers in adopting targeted soil erosion control measures, promoting sustainable land management in the region.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100387"},"PeriodicalIF":0.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-30DOI: 10.1016/j.geogeo.2025.100384
Xiao Wang , Jin Liu , Hai Zhou , Xiaoguang Liu , Chenying Yu , Shuhui Zhang , Jian Zhang
K-rich granitoids are considered as an indicator of the maturation of the continental crust, particularly in correlation to the significant crustal evolution during the Neoarchean Eon. The Yinshan Block, a typical Neoarchean microcontinental block of the western North China Craton (NCC), preserves several typical K-rich granites (monzogranitic gneisses). However, their petrogenesis and tectonic background of these remain unclear, hindering our understanding of the late Neoarchean crustal evolution of the NCC. This study presents new geochronological, geochemical, and Sr-Nd-Pb-Hf isotopic data on the K-rich granites exposed in the Zhulagou area, a key exposure of the Yinshan Block. Zircon U–Pb dating results suggest that the K-rich granites were emplaced at 2.52–2.50 Ga. The K-rich granites exhibit high SiO2 (68.70–74.10 wt. %) and K2O (3.40–7.79 wt. %) and lower MgO (0.24–1.04 wt. %) content. They also have high Sr/Y and (La/Yb)N ratios, as well as low Y and Yb contents. Furthermore, they display variable εHf(t) (–1.1 to +2.5) and εNd(t) (–6.05 to +1.64) values, with relatively low Pb isotopes (206Pb/204Pb(t) = (13.910485–15.241164), 207Pb/204Pb(t) = (14.806723–15.259938), and 208Pb/204Pb(t) = (33.758621–35.592727)), indicating that their parental magmas may have originated from the partial melting of a thickened lower crust with heterogeneous sources. Combined with previous data, we suggest that a pulse or stage of mantle plume may have been operating under the Yinshan Block during late Neoarchean period. The pre-existing thickened (mafic) lower crust was partially melted to generate these K-rich granites at 2.52–2.50 Ga, resulting in a mature and stable continental crust.
{"title":"Petrogenesis and tectonic setting of Neoarchean K-rich granitoids in the Zhulagou area: Implications for the crustal maturation of Yinshan Block, western North China Craton","authors":"Xiao Wang , Jin Liu , Hai Zhou , Xiaoguang Liu , Chenying Yu , Shuhui Zhang , Jian Zhang","doi":"10.1016/j.geogeo.2025.100384","DOIUrl":"10.1016/j.geogeo.2025.100384","url":null,"abstract":"<div><div>K-rich granitoids are considered as an indicator of the maturation of the continental crust, particularly in correlation to the significant crustal evolution during the Neoarchean Eon. The Yinshan Block, a typical Neoarchean microcontinental block of the western North China Craton (NCC), preserves several typical K-rich granites (monzogranitic gneisses). However, their petrogenesis and tectonic background of these remain unclear, hindering our understanding of the late Neoarchean crustal evolution of the NCC. This study presents new geochronological, geochemical, and Sr-Nd-Pb-Hf isotopic data on the K-rich granites exposed in the Zhulagou area, a key exposure of the Yinshan Block. Zircon U–Pb dating results suggest that the K-rich granites were emplaced at 2.52–2.50 Ga. The K-rich granites exhibit high SiO<sub>2</sub> (68.70–74.10 wt. %) and K<sub>2</sub>O (3.40–7.79 wt. %) and lower MgO (0.24–1.04 wt. %) content. They also have high Sr/Y and (La/Yb)<sub>N</sub> ratios, as well as low Y and Yb contents. Furthermore, they display variable <em>ε</em><sub>Hf</sub>(<em>t</em>) (–1.1 to +2.5) and <em>ε</em><sub>Nd</sub>(<em>t</em>) (–6.05 to +1.64) values, with relatively low Pb isotopes (<sup>206</sup>Pb/<sup>204</sup>Pb<sub>(t)</sub> = (13.910485–15.241164), <sup>207</sup>Pb/<sup>204</sup>Pb<sub>(t)</sub> = (14.806723–15.259938), and <sup>208</sup>Pb/<sup>204</sup>Pb<sub>(t)</sub> = (33.758621–35.592727)), indicating that their parental magmas may have originated from the partial melting of a thickened lower crust with heterogeneous sources. Combined with previous data, we suggest that a pulse or stage of mantle plume may have been operating under the Yinshan Block during late Neoarchean period. The pre-existing thickened (mafic) lower crust was partially melted to generate these K-rich granites at 2.52–2.50 Ga, resulting in a mature and stable continental crust.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100384"},"PeriodicalIF":0.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-27DOI: 10.1016/j.geogeo.2025.100386
M. Ashok, Nurul Absar
The Orosirian Period of the middle Paleoproterozoic Era was marked by a decline in atmospheric oxygen and a reducing ocean after a brief oxidized interval of the preceding Great Oxidation Event. Here, we present CO, Nd-Sr isotopic and trace element geochemistry of ∼1.9 Ga stromatolitic Tadpatri Carbonates (TC) to understand the redox condition, solute sources and carbon cycling in the Orosirian ocean. The stromatolite morphology shows deposition under inter-tidal to sub-tidal shallow marine conditions. Varying degrees of dolomitization of low-Mg calcites by an Mg-rich and 13C-depleted saline marine fluid at elevated temperature (140–200ºC) and high fluid-to-rock ratios (50–200) significantly modified the depositional CO isotopic composition, and δ13C values (–1.5‰ - –2‰) recorded in low-Mg calcite are likely closest to the depositional values. These carbon isotopic values are significantly lower compared to the global Orosirian records. Low U/Th, V/Sc, and Mo/Sc in TC suggest a small seawater inventory of redox-sensitive elements, and in conjunction with high Fe-, Mn- concentrations and absence of Ce-anomaly indicates an anoxic- ferruginous ocean. High radiogenic εNd1.9Ga values (–5.6 - –3.9) of TC compared to the older Dharwar Craton (–9.6) suggest solute sources from a juvenile crust or mantle-derived hydrothermal fluids. Very high U/Th and V/Sc in the Lower Vempalle Formation suggest oxidized conditions at ca. 1999 Ma, and progressive upward decrease of U/Th and V/Sc in the Middle-, Upper-Vempalle and Tadpatri Formations to much lower levels indicate a drawdown in atmospheric pO2 level.
{"title":"Redox conditions, solute sources and biogeochemical cycling in the Orosirian ocean: Geochemical and isotopic evidence from stromatolitic carbonates of ∼1.9 Ga Tadpatri Formation, Cuddapah Basin, India","authors":"M. Ashok, Nurul Absar","doi":"10.1016/j.geogeo.2025.100386","DOIUrl":"10.1016/j.geogeo.2025.100386","url":null,"abstract":"<div><div>The Orosirian Period of the middle Paleoproterozoic Era was marked by a decline in atmospheric oxygen and a reducing ocean after a brief oxidized interval of the preceding Great Oxidation Event. Here, we present C<img>O, Nd-Sr isotopic and trace element geochemistry of ∼1.9 Ga stromatolitic Tadpatri Carbonates (TC) to understand the redox condition, solute sources and carbon cycling in the Orosirian ocean. The stromatolite morphology shows deposition under inter-tidal to sub-tidal shallow marine conditions. Varying degrees of dolomitization of low-Mg calcites by an Mg-rich and <sup>13</sup>C-depleted saline marine fluid at elevated temperature (140–200ºC) and high fluid-to-rock ratios (50–200) significantly modified the depositional C<img>O isotopic composition, and δ<sup>13</sup>C values (–1.5‰ - –2‰) recorded in low-Mg calcite are likely closest to the depositional values. These carbon isotopic values are significantly lower compared to the global Orosirian records. Low U/Th, V/<em>Sc</em>, and Mo/<em>Sc</em> in TC suggest a small seawater inventory of redox-sensitive elements, and in conjunction with high Fe-, Mn- concentrations and absence of Ce-anomaly indicates an anoxic- ferruginous ocean. High radiogenic εNd<sub>1.9Ga</sub> values (–5.6 - –3.9) of TC compared to the older Dharwar Craton (–9.6) suggest solute sources from a juvenile crust or mantle-derived hydrothermal fluids. Very high U/Th and V/<em>Sc</em> in the Lower Vempalle Formation suggest oxidized conditions at ca. 1999 Ma, and progressive upward decrease of U/Th and V/<em>Sc</em> in the Middle-, Upper-Vempalle and Tadpatri Formations to much lower levels indicate a drawdown in atmospheric <em>p</em>O<sub>2</sub> level.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 3","pages":"Article 100386"},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iron plays a vital role in fueling the economic development and technological advancement of a country. Despite Ethiopia, being endowed with a large amount of iron ore resources in different parts of the country, prospective zones are not delineated properly. Therefore, this study aims to identify the iron ore prospective zones in the Sekota district of Ethiopia utilizing ASTER and Sentinel−2A satellite data for further onsite exploration and testing. In addition, powder diffraction analysis (XRD) was conducted to determine the dominant mineralogical phases. The image processing techniques such as ASTER band 2/band 1 (ASB2/B1) and Sentinel−2A band 4/band 2 (S2B4/B2) band ratios, principal component analysis (PCA), and subpixel level mapping technique, mixture-tuned matched filtering (MTMF) were used to map the distribution of hematite. ASB2/B1 and S2B4/B2 band ratios mapped hematite iron ore covering an area of 102.50 and 97. 68 km2. The selected PC4 of ASTER delineated hematite mineralized zones covering 133.40 km2 and Sentinel 2 PC3 of 110.70 km2 area. A very high spectral feature fit was found between the extracted hematite endmember and USGS resampled hematite spectra. The spectral fit of the endmember was 0.74 for ASTER and 0.86 for Sentinel−2. Hematite anomaly zones were identified with MTMF using these endmembers in different parts of the study area. Powder X-ray diffraction analysis (XRD) revealed high hematite phases ranging from 36.8%−85.5% of Fe2O3. A strong positive correlation was found between S2B4/B2 and S2B4/B2 (r = 0.83), ASB2/B1 and ASTER PC4 (r = 0.94). Moderate correlations for ASB2/B2, S2B4/B2 (r = 0.44), PCA (r = 0.44), ASTER and Sentinel−2 MTMF (r = 0.36). Results of both datasets show comparable areal coverage and overlay with three of the existing known iron occurrence polygons. Thus, it is evident that techniques employed are effective in narrowing hematite anomalies zones for further onsite gological exploration.
{"title":"Mapping of hematite ore deposits using multi-sensor data in the Sekota District, Northern Ethiopia","authors":"Jerbaw Tiruneh Abejehu , Binyam Tesfaw Hailu , Worash Getaneh , Karuturi Venkata Suryabhagavan","doi":"10.1016/j.geogeo.2025.100385","DOIUrl":"10.1016/j.geogeo.2025.100385","url":null,"abstract":"<div><div>Iron plays a vital role in fueling the economic development and technological advancement of a country. Despite Ethiopia, being endowed with a large amount of iron ore resources in different parts of the country, prospective zones are not delineated properly. Therefore, this study aims to identify the iron ore prospective zones in the Sekota district of Ethiopia utilizing ASTER and Sentinel−2A satellite data for further onsite exploration and testing. In addition, powder diffraction analysis (XRD) was conducted to determine the dominant mineralogical phases. The image processing techniques such as ASTER band 2/band 1 (ASB2/B1) and Sentinel−2A band 4/band 2 (S2B4/B2) band ratios, principal component analysis (PCA), and subpixel level mapping technique, mixture-tuned matched filtering (MTMF) were used to map the distribution of hematite. ASB2/B1 and S2B4/B2 band ratios mapped hematite iron ore covering an area of 102.50 and 97. 68 km<sup>2</sup>. The selected PC4 of ASTER delineated hematite mineralized zones covering 133.40 km<sup>2</sup> and Sentinel 2 PC3 of 110.70 km<sup>2</sup> area. A very high spectral feature fit was found between the extracted hematite endmember and USGS resampled hematite spectra. The spectral fit of the endmember was 0.74 for ASTER and 0.86 for Sentinel−2. Hematite anomaly zones were identified with MTMF using these endmembers in different parts of the study area. Powder X-ray diffraction analysis (XRD) revealed high hematite phases ranging from 36.8%−85.5% of Fe<sub>2</sub>O<sub>3</sub>. A strong positive correlation was found between S2B4/B2 and S2B4/B2 (<em>r</em> = 0.83), ASB2/B1 and ASTER PC4 (<em>r</em> = 0.94). Moderate correlations for ASB2/B2, S2B4/B2 (<em>r</em> = 0.44), PCA (<em>r</em> = 0.44), ASTER and Sentinel−2 MTMF (<em>r</em> = 0.36). Results of both datasets show comparable areal coverage and overlay with three of the existing known iron occurrence polygons. Thus, it is evident that techniques employed are effective in narrowing hematite anomalies zones for further onsite gological exploration.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100385"},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-24DOI: 10.1016/j.geogeo.2025.100382
Jie Zhou , David I. Groves
{"title":"Introduction: Special Issue on critical metals for clean energy transition","authors":"Jie Zhou , David I. Groves","doi":"10.1016/j.geogeo.2025.100382","DOIUrl":"10.1016/j.geogeo.2025.100382","url":null,"abstract":"","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100382"},"PeriodicalIF":0.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.geogeo.2025.100381
Lizeth Carlos Delgado , Juan J. Kasper-Zubillaga , Raymundo G. Martínez-Serrano , Mayumy Amparo Cabrera Ramírez , Elsa Arellano-Torres , José Luis Sánchez Zavala
A morphological and geochemical study of detrital garnet was conducted to assess its utility in understanding sedimentary processes in coastal dune sands caused by in a weathering-limited erosion regime along the southwestern coast of Mexico. Multiple analytical techniques helped to elucidate the garnet's provenance, shape modification and surface alteration during its source-to-sink sedimentary dispersal. A Wavelength Dispersive Spectrometry (WDS) in an Electron Microprobe Analyzer (EMPA) (n = 89) revealed the dominance of almandine as the main mineral type related to the ortho-paragneiss source rocks from the Oaxacan Complex with a lesser contribution from the Xolapa Complex, outcropping in northwestern of the coastal dune sands. Scanning Electron Microscopy (SEM) helped to assess the compactness and convexity of shape descriptors by contouring the outline of detrital garnet (n = 200) and to identify the microtextures of the mineral's surface. A Raman Spectroscopy (n = 17) was employed to determine the presence of hydroxide or oxyhydroxide coatings to quantify the chemical weathering degree caused by steady and shallow burial conditions. Results show that the detrital garnet mainly underwent aeolian abrasion followed by fluvial subaqueous and marine controls. The former was supported by the quantification of moderate to high compactness and convexity values and the SEM observation of aeolian mechanical microtextures like bulbous edges, adhering particles and abrasion fatigue compared to the subaqueous microtextures as large conchoidal fractures (>50 µm). Finally, we found that low to moderate chemical dissolution control modified the detrital garnet's surficial texture, evidenced by chemical microtextures like solution pits, etch pits, etch features, imbricate wedge marks and mound features. Hence, detrital garnet dissolution was dominated by its chemical composition, the nonstoichiometric character of the dissolution rate and its crystallographic forms.
{"title":"Source-to-sink history of detrital garnet from coastal dune sands in SW Mexico","authors":"Lizeth Carlos Delgado , Juan J. Kasper-Zubillaga , Raymundo G. Martínez-Serrano , Mayumy Amparo Cabrera Ramírez , Elsa Arellano-Torres , José Luis Sánchez Zavala","doi":"10.1016/j.geogeo.2025.100381","DOIUrl":"10.1016/j.geogeo.2025.100381","url":null,"abstract":"<div><div>A morphological and geochemical study of detrital garnet was conducted to assess its utility in understanding sedimentary processes in coastal dune sands caused by in a weathering-limited erosion regime along the southwestern coast of Mexico. Multiple analytical techniques helped to elucidate the garnet's provenance, shape modification and surface alteration during its source-to-sink sedimentary dispersal. A Wavelength Dispersive Spectrometry (WDS) in an Electron Microprobe Analyzer (EMPA) (n = 89) revealed the dominance of almandine as the main mineral type related to the ortho-paragneiss source rocks from the Oaxacan Complex with a lesser contribution from the Xolapa Complex, outcropping in northwestern of the coastal dune sands. Scanning Electron Microscopy (SEM) helped to assess the compactness and convexity of shape descriptors by contouring the outline of detrital garnet (n = 200) and to identify the microtextures of the mineral's surface. A Raman Spectroscopy (n = 17) was employed to determine the presence of hydroxide or oxyhydroxide coatings to quantify the chemical weathering degree caused by steady and shallow burial conditions. Results show that the detrital garnet mainly underwent aeolian abrasion followed by fluvial subaqueous and marine controls. The former was supported by the quantification of moderate to high compactness and convexity values and the SEM observation of aeolian mechanical microtextures like bulbous edges, adhering particles and abrasion fatigue compared to the subaqueous microtextures as large conchoidal fractures (>50 µm). Finally, we found that low to moderate chemical dissolution control modified the detrital garnet's surficial texture, evidenced by chemical microtextures like solution pits, etch pits, etch features, imbricate wedge marks and mound features. Hence, detrital garnet dissolution was dominated by its chemical composition, the nonstoichiometric character of the dissolution rate and its crystallographic forms.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100381"},"PeriodicalIF":0.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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