Geosystems and Geoenvironment最新文献_第8页

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 印度Cuddapah盆地~ 1.9 Ga Tadpatri组叠层石碳酸盐岩的地球化学和同位素证据：奥陶纪海洋氧化还原条件、溶质来源和生物地球化学循环

Geosystems and Geoenvironment

Pub Date : 2025-03-27 DOI: 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 εNd_1.9Ga 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.

古元古代中期的奥罗世是在大氧化事件的短暂氧化期后，大气氧含量下降，海洋减少的标志。本文通过对~ 1.9 Ga地层Tadpatri Carbonates (TC) CO、Nd-Sr同位素和微量元素地球化学的研究，了解了奥罗世海洋的氧化还原条件、溶质来源和碳循环。叠层石形态表现为潮间-潮下浅海条件下的沉积。富镁贫13c海盐流体在高温（140 ~ 200℃）和高液岩比（50 ~ 200）条件下对低mg方解石进行不同程度的白云化作用，显著改变了沉积CO同位素组成，低mg方解石的δ13C值（- 1.5‰~ - 2‰）可能最接近沉积值。与全球奥罗世记录相比，这些碳同位素值明显较低。TC中U/Th、V/Sc和Mo/Sc的低含量表明海水中氧化还原敏感元素的储量较小，同时高铁、锰浓度和ce异常的缺失表明海洋缺氧含铁。与古达瓦尔克拉通（- 9.6）相比，TC的高辐射成因εNd1.9Ga值（- 5.6 ~ - 3.9）表明溶质来源为幼年壳源或幔源热液。下Vempalle组较高的U/Th和V/Sc表明在大约1999 Ma的氧化条件下，中、上Vempalle组和Tadpatri组的U/Th和V/Sc逐渐上升到更低的水平表明大气pO2水平下降。

{"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}

引用次数: 0

Mapping of hematite ore deposits using multi-sensor data in the Sekota District, Northern Ethiopia 在埃塞俄比亚北部Sekota地区使用多传感器数据绘制赤铁矿矿床图

Geosystems and Geoenvironment

Pub Date : 2025-03-27 DOI: 10.1016/j.geogeo.2025.100385

Jerbaw Tiruneh Abejehu , Binyam Tesfaw Hailu , Worash Getaneh , Karuturi Venkata Suryabhagavan

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.

铁在推动一个国家的经济发展和技术进步方面发挥着至关重要的作用。尽管埃塞俄比亚各地蕴藏着大量铁矿石资源，但远景区的划分却不尽合理。因此，本研究旨在利用 ASTER 和 Sentinel-2A 卫星数据确定埃塞俄比亚 Sekota 地区的铁矿远景区，以便进一步进行现场勘探和测试。此外，还进行了粉末衍射分析（XRD），以确定主要矿物相。利用 ASTER 波段 2/波段 1（ASB2/B1）和 Sentinel-2A 波段 4/波段 2（S2B4/B2）波段比、主成分分析（PCA）和亚像素级绘图技术、混合调谐匹配滤波（MTMF）等图像处理技术绘制赤铁矿分布图。ASB2/B1 和 S2B4/B2 波段比绘制的赤铁矿面积分别为 102.50 平方公里和 97.68 平方公里。68 平方公里。所选的 ASTER PC4 划定的赤铁矿化区面积为 133.40 平方公里，哨兵 2 PC3 划定的赤铁矿化区面积为 110.70 平方公里。提取的赤铁矿内含物与 USGS 重新采样的赤铁矿光谱之间具有很高的光谱特征拟合度。ASTER 和 Sentinel-2 分别为 0.74 和 0.86。在研究区域的不同地方，利用这些内含物通过 MTMF 确定了赤铁矿异常区。粉末 X 射线衍射分析（XRD）显示，赤铁矿相占 Fe2O3 的 36.8%-85.5%。发现 S2B4/B2 和 S2B4/B2 （r = 0.83）、ASB2/B1 和 ASTER PC4 （r = 0.94）之间存在很强的正相关性。ASB2/B2、S2B4/B2（r = 0.44）、PCA（r = 0.44）、ASTER 和 Sentinel-2 MTMF（r = 0.36）之间的相关性中等。这两个数据集的结果显示出相似的区域覆盖率，并与现有的三个已知铁矿分布多边形重叠。由此可见，所采用的技术能有效缩小赤铁矿异常区，以便进一步进行现场地质勘探。

{"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}

引用次数: 0

Introduction: Special Issue on critical metals for clean energy transition 引言：清洁能源转型的关键金属特刊

Geosystems and Geoenvironment

Pub Date : 2025-03-24 DOI: 10.1016/j.geogeo.2025.100382

Jie Zhou , David I. Groves

引用次数: 0

Source-to-sink history of detrital garnet from coastal dune sands in SW Mexico 墨西哥西南部海岸沙丘砂中石榴石碎屑的源-汇历史

Geosystems and Geoenvironment

Pub Date : 2025-03-22 DOI: 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.

对碎屑石榴石进行了形态和地球化学研究，以评估其在理解墨西哥西南海岸风化有限侵蚀机制引起的海岸沙丘砂沉积过程中的效用。多种分析技术有助于阐明石榴石在源-汇沉积扩散过程中的物源、形态修饰和表面蚀变。电子探针分析仪（EMPA）（n = 89）的波长色散光谱（WDS）分析显示，瓦哈卡杂岩的准副长烃源岩主要矿物类型为almandine，西北方滨海沙丘砂露头的Xolapa杂岩贡献较小。扫描电子显微镜（SEM）通过绘制碎屑石榴石（n = 200）的轮廓，帮助评估形状描述符的密实度和凹凸度，并识别矿物表面的微观纹理。采用拉曼光谱（n = 17）测定氢氧化物或氧化氢氧化物涂层的存在，以量化稳定和浅埋条件引起的化学风化程度。结果表明，碎屑石榴石主要受风蚀作用，其次受河流水下和海洋侵蚀作用。前者得到了中高密实度和凹凸度值的量化，以及与大贝壳状断裂（>50µm）的水下微织构相比，风成力学微织构（如球根边缘、粘着颗粒和磨损疲劳）的SEM观察的支持。结果表明，低至中等化学溶蚀控制改变了碎屑石榴石的表面结构，主要表现为溶液坑、蚀刻坑、蚀刻特征、瓦叠楔形痕迹和丘状特征等化学显微结构。因此，碎屑石榴石的溶解主要由其化学组成、溶解速率的非化学计量特征和晶体形态决定。

{"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}

引用次数: 0

Biotite as a petrogenetic discriminator in the polymetamorphosed rocks: A case study from the Champaner supracrustal rocks, Western India 黑云母在多变质岩中的成岩鉴别作用：以印度西部Champaner上壳岩为例

Geosystems and Geoenvironment

Pub Date : 2025-03-19 DOI: 10.1016/j.geogeo.2025.100380

Parita K. Gorania , Gayatri N. Akolkar , Aditya U. Joshi , Manoj A. Limaye , Mahendra K. Singh

The mineral chemistry of Fe-Mg biotite has served as an aid to the petrogenesis of igneous rocks, especially for identifying the parent magma compositions. Though the interpretation of igneous and metamorphic processes utilizing biotite mineral chemistry is not upfront, it certainly provides preliminary insights into the petrogenetic characteristics of rocks. Apart from thermometry and chronology, studies emphasizing on the significance of biotite mineral chemistry for unveiling the protolith compositions, grade of metamorphism, origin, and P-T conditions of metamorphic rocks are poorly documented in the literature. Here we employ biotite mineral chemical compositions i.e., EPMA (electron probe micro-analyzer) data from the metapelitic rocks of the Meso-Neoproterozoic Champaner Group, exposed as an arcuate fold belt in western India to unravel the metamorphic rock record. This group of rocks display a complex deformational and polymetamorphic history, evident in distinct mineral assemblages that reflect regional, contact, and combined regional-contact metamorphism. The field observations, mesoscopic features of rocks, reaction textures, and biotite petrographic characteristics have revealed three distinct varieties of metapelitic rocks i.e., phyllites, spotted phyllites, and hornfelses. The mineral chemistry and cation substitution mechanisms of biotite selected from phyllite, spotted phyllite and hornfels suggests, the chemical composition of biotite in these rocks is a function of the bulk rock composition, co-existing minerals, type, and grade of metamorphism and thereby attesting to the pressure-temperature conditions of rock. Further, various compositional classification diagrams and Ti-in biotite thermometry demosntrate an increase in the grade of metamorphism from west to east of Champaner Group with intermittent as well as late-stage plutonic felsic intrusions. Thus, biotite being frequently the dominant or sometimes even sole Fe-Mg mineral with temperature-pressure driven substitutions in low-grade metamorphic rocks can offer a unique opportunity to unlock valuable insights into their metamorphic history.

铁镁黑云母的矿物化学特征对火成岩的成因，特别是母岩浆组成的鉴别具有重要的指导意义。虽然利用黑云母矿物化学对火成岩和变质过程的解释并不先进，但它确实为岩石的岩石成因特征提供了初步的见解。除了温度学和年代学外，强调黑云母矿物化学对揭示变质岩的原岩组成、变质程度、成因和P-T条件的重要性的研究文献很少。本文利用中-新元古代Champaner群变质岩的黑云母矿物化学成分，即电子探针微量分析仪（EPMA）数据，揭示了印度西部弧形褶皱带中-新元古代Champaner群变质岩记录。这组岩石显示出复杂的变形和多变质历史，其明显的矿物组合反映了区域、接触和区域-接触联合变质作用。通过野外观测、岩石介观特征、反应结构和黑云母岩石学特征，揭示出千粒岩、斑点千粒岩和角粒岩3种不同类型的变质长晶岩。从千层岩、点状千层岩和角砾岩中选取的黑云母的矿物化学和阳离子取代机制表明，这些岩石中的黑云母的化学组成与岩石的总体组成、共存矿物、变质作用类型和变质程度有关，从而证明了岩石的压力-温度条件。此外，各种成分分类图和钛-黑云母测温结果表明，Champaner群的变质程度由西向东递增，存在间歇性和晚期深成英质侵入。因此，在低品位变质岩中，黑云母往往是主导的，有时甚至是唯一的铁镁矿物，具有温度压力驱动的替代作用，这为揭示其变质历史提供了一个独特的机会。

{"title":"Biotite as a petrogenetic discriminator in the polymetamorphosed rocks: A case study from the Champaner supracrustal rocks, Western India","authors":"Parita K. Gorania , Gayatri N. Akolkar , Aditya U. Joshi , Manoj A. Limaye , Mahendra K. Singh","doi":"10.1016/j.geogeo.2025.100380","DOIUrl":"10.1016/j.geogeo.2025.100380","url":null,"abstract":"<div><div>The mineral chemistry of Fe-Mg biotite has served as an aid to the petrogenesis of igneous rocks, especially for identifying the parent magma compositions. Though the interpretation of igneous and metamorphic processes utilizing biotite mineral chemistry is not upfront, it certainly provides preliminary insights into the petrogenetic characteristics of rocks. Apart from thermometry and chronology, studies emphasizing on the significance of biotite mineral chemistry for unveiling the protolith compositions, grade of metamorphism, origin, and P-T conditions of metamorphic rocks are poorly documented in the literature. Here we employ biotite mineral chemical compositions i.e., EPMA (electron probe micro-analyzer) data from the metapelitic rocks of the Meso-Neoproterozoic Champaner Group, exposed as an arcuate fold belt in western India to unravel the metamorphic rock record. This group of rocks display a complex deformational and polymetamorphic history, evident in distinct mineral assemblages that reflect regional, contact, and combined regional-contact metamorphism. The field observations, mesoscopic features of rocks, reaction textures, and biotite petrographic characteristics have revealed three distinct varieties of metapelitic rocks i.e., phyllites, spotted phyllites, and hornfelses. The mineral chemistry and cation substitution mechanisms of biotite selected from phyllite, spotted phyllite and hornfels suggests, the chemical composition of biotite in these rocks is a function of the bulk rock composition, co-existing minerals, type, and grade of metamorphism and thereby attesting to the pressure-temperature conditions of rock. Further, various compositional classification diagrams and Ti-in biotite thermometry demosntrate an increase in the grade of metamorphism from west to east of Champaner Group with intermittent as well as late-stage plutonic felsic intrusions. Thus, biotite being frequently the dominant or sometimes even sole Fe-Mg mineral with temperature-pressure driven substitutions in low-grade metamorphic rocks can offer a unique opportunity to unlock valuable insights into their metamorphic history.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100380"},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715357","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}

引用次数: 0

Ozone patterns in Maceió: Insights into seasonal and geographic varibility Maceió中的臭氧模式：对季节和地理变化的洞察

Geosystems and Geoenvironment

Pub Date : 2025-03-13 DOI: 10.1016/j.geogeo.2025.100379

Amaury de Souza , Celina M. Takemura , Deniz Özonur , Elias Silva de Medeiros , Ivana Pobocikova , Janice F. Leivas , José Francisco de Oliveira-Júnior , Kelvy Rosalvo Alencar Cardoso , Marcel Carvalho Abreu , Wagner Alessandro Pansera , Jose Roberto Zenteno Jimenez , Sneha Gautam

This study analyzes the Total Ozone Column (TCO) over six cities in Alagoas, Brazil, aiming to evaluate their spatial and temporal homogeneity and identify seasonal and annual patterns from 2008 to 2016. TCO is a key indicator for monitoring the ozone layer and its implications for public health, given ozone's role in filtering ultraviolet radiation. The analysis utilized satellite-derived TCO data, with variance homogeneity assessed using the Bartlett test at a 95% significance level. Descriptive statistical analyses characterized the temporal distribution of TCO values, and probability density functions (PDFs) identified the best-fitting statistical distribution.

The findings indicate significant homogeneity in annual and seasonal TCO concentrations, with an annual mean of 263.24 ± 9.91 DU. A biannual TCO cycle was observed, with peaks in spring and lows in fall, influenced by Earth's orbit and ozone photochemistry. The data were best represented by a normal distribution, reflecting the role of the Brewer-Dobson Circulation in maintaining ozone uniformity and mitigating disruptions from phenomena like the Antarctic Polar Vortex.

These results emphasize the need for continuous monitoring of ozone variability, as fluctuations in TCO can affect ultraviolet radiation levels and, consequently, public health outcomes such as skin cancer and ocular diseases. The study underscores the importance of integrating TCO data into environmental policies and public health strategies, particularly in regions with high solar radiation exposure. The study's limited statistical sensitivity and geographic coverage highlight the necessity of further research on factors influencing ozone distribution and its broader environmental and health implications.

本研究分析了巴西阿拉戈斯州6个城市的总臭氧柱（TCO），旨在评估其时空均匀性，并确定2008 - 2016年的季节和年度模式。考虑到臭氧在过滤紫外线辐射方面的作用，总逸度是监测臭氧层及其对公众健康影响的关键指标。分析使用卫星衍生的TCO数据，方差同质性评估使用Bartlett检验在95%显著性水平。描述性统计分析表征了TCO值的时间分布，概率密度函数（pdf）确定了最适合的统计分布。结果表明，TCO浓度的年际和季节分布具有显著的均匀性，年平均值为263.24±9.91 DU。在地球轨道和臭氧光化学的影响下，观测到一年两次的TCO循环，春季达到峰值，秋季达到低点。正态分布最能代表数据，反映了布鲁尔-多布森环流在维持臭氧均匀性和减轻南极极地涡旋等现象造成的破坏方面的作用。这些结果强调需要持续监测臭氧变异性，因为总逸度的波动会影响紫外线辐射水平，从而影响皮肤癌和眼病等公共健康结果。该研究强调了将TCO数据纳入环境政策和公共卫生战略的重要性，特别是在太阳辐射高的区域。这项研究有限的统计敏感性和地理覆盖范围突出表明，有必要进一步研究影响臭氧分布的因素及其更广泛的环境和健康影响。

{"title":"Ozone patterns in Maceió: Insights into seasonal and geographic varibility","authors":"Amaury de Souza , Celina M. Takemura , Deniz Özonur , Elias Silva de Medeiros , Ivana Pobocikova , Janice F. Leivas , José Francisco de Oliveira-Júnior , Kelvy Rosalvo Alencar Cardoso , Marcel Carvalho Abreu , Wagner Alessandro Pansera , Jose Roberto Zenteno Jimenez , Sneha Gautam","doi":"10.1016/j.geogeo.2025.100379","DOIUrl":"10.1016/j.geogeo.2025.100379","url":null,"abstract":"<div><div>This study analyzes the Total Ozone Column (TCO) over six cities in Alagoas, Brazil, aiming to evaluate their spatial and temporal homogeneity and identify seasonal and annual patterns from 2008 to 2016. TCO is a key indicator for monitoring the ozone layer and its implications for public health, given ozone's role in filtering ultraviolet radiation. The analysis utilized satellite-derived TCO data, with variance homogeneity assessed using the Bartlett test at a 95% significance level. Descriptive statistical analyses characterized the temporal distribution of TCO values, and probability density functions (PDFs) identified the best-fitting statistical distribution.</div><div>The findings indicate significant homogeneity in annual and seasonal TCO concentrations, with an annual mean of 263.24 ± 9.91 DU. A biannual TCO cycle was observed, with peaks in spring and lows in fall, influenced by Earth's orbit and ozone photochemistry. The data were best represented by a normal distribution, reflecting the role of the Brewer-Dobson Circulation in maintaining ozone uniformity and mitigating disruptions from phenomena like the Antarctic Polar Vortex.</div><div>These results emphasize the need for continuous monitoring of ozone variability, as fluctuations in TCO can affect ultraviolet radiation levels and, consequently, public health outcomes such as skin cancer and ocular diseases. The study underscores the importance of integrating TCO data into environmental policies and public health strategies, particularly in regions with high solar radiation exposure. The study's limited statistical sensitivity and geographic coverage highlight the necessity of further research on factors influencing ozone distribution and its broader environmental and health implications.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100379"},"PeriodicalIF":0.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684300","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}

引用次数: 0

Assimilation of seismic attenuation model of NW Himalaya and its surrounding region 西北喜马拉雅及其周边地区地震衰减模式的同化

Geosystems and Geoenvironment

Pub Date : 2025-03-08 DOI: 10.1016/j.geogeo.2025.100378

Vandana, Naresh Kumar

In this study, we analyze the seismic attenuation characteristics of the Northwest Himalaya and adjacent regions using a dataset of 2,716 earthquakes (2.5 ≤ Mw ≤ 5.0) recorded from 2008 to 2015 by a network of 30 broadband seismographs. The single backscattering model was applied to estimate the quality factor of coda waves (Q_c) across three lapse time windows (LTWs) at varying frequencies. Our results reveal that Q_c increases with both frequency and LTW, suggesting a depth-dependent nature of seismic attenuation in the region. The average attenuation relationships for Q_c, Q_α and Q_β across the Northwest Himalaya are determined as follows for LTWs of 20, 30, and 40 s, respectively: Q_c = (74 ± 14)f ^(1.27±0.06), Q_c = (103 ± 26)f ^(1.16±0.08), and Q_c = (140 ± 41)f ^(1.10±0.09). Our findings reveal significant variability in Q_c, Q_α and Q_β across the Tethys (TH), High (HH), Lesser (LH), and Shiwalik (SH) Himalaya regions, as well as the adjacent Indo-Gangetic Plains (IGP), with this variability strongly linked to structural heterogeneity and seismogenic processes in each region. We further establish attenuation relations for distinct tectonic units, observing the following hierarchy: [Q_α,β,c⁻¹(HH) < Q_α,β,c⁻¹(SH) < Q_α,β,c⁻¹(IGP) < Q_α,β,c⁻¹(LH) < Q_α,β,c⁻¹(TH)]. The Tethys Himalaya exhibits the high attenuation, likely due to its sedimentary structure, while the Higher Himalaya shows the low attenuation. These insights into attenuation characteristics across geotectonic segments in the Northwest Himalaya contribute to a more comprehensive seismic hazard assessment for the region.

本文利用30台宽带地震仪在2008 - 2015年间记录的2716次地震（2.5≤Mw≤5.0）数据，分析了喜马拉雅西北部及邻近地区的地震衰减特征。采用单后向散射模型估计了不同频率下尾波在三个时间窗（LTWs）上的质量因子。我们的研究结果表明，Qc随频率和LTW的增加而增加，表明该地区地震衰减具有深度依赖性质。在20、30和40 s的ltw下，喜马拉雅西北地区Qc、Qα和Qβ的平均衰减关系分别为：Qc =(74±14)f（1.27±0.06）、Qc =(103±26)f（1.16±0.08）和Qc =(140±41)f（1.10±0.09）。我们的研究结果揭示了Qc、Qα和Qβ在Tethys （TH）、High （HH）、Lesser （LH）和Shiwalik （SH）喜马拉雅地区以及邻近的印度-恒河平原（IGP）的显著变化，这种变化与每个地区的结构非均质性和孕震过程密切相关。我们进一步建立了不同构造单元的衰减关系，观察到以下层次：[Qα，β,c−1(HH) <；问α,β,c−1 (SH) & lt;问α,β,c−1(显卡)& lt;问α,β,c−1 (LH) & lt;问α,β,c−1 (TH)]。特提斯-喜马拉雅的衰减程度较高，可能与沉积构造有关，而上喜马拉雅的衰减程度较低。这些对喜马拉雅西北部大地构造段衰减特征的了解有助于对该地区进行更全面的地震危险性评估。

{"title":"Assimilation of seismic attenuation model of NW Himalaya and its surrounding region","authors":"Vandana, Naresh Kumar","doi":"10.1016/j.geogeo.2025.100378","DOIUrl":"10.1016/j.geogeo.2025.100378","url":null,"abstract":"<div><div>In this study, we analyze the seismic attenuation characteristics of the Northwest Himalaya and adjacent regions using a dataset of 2,716 earthquakes (2.5 ≤ Mw ≤ 5.0) recorded from 2008 to 2015 by a network of 30 broadband seismographs. The single backscattering model was applied to estimate the quality factor of coda waves (<em>Q<sub>c</sub></em>) across three lapse time windows (LTWs) at varying frequencies. Our results reveal that <em>Q<sub>c</sub></em> increases with both frequency and LTW, suggesting a depth-dependent nature of seismic attenuation in the region. The average attenuation relationships for <em>Q<sub>c</sub>, Q<sub>α</sub></em> and <em>Q<sub>β</sub></em> across the Northwest Himalaya are determined as follows for LTWs of 20, 30, and 40 s, respectively: <em>Q<sub>c</sub></em> = (74 ± 14)<em>f</em> <sup>(1.27±0.06)</sup>, <em>Q<sub>c</sub></em> = (103 ± 26)<em>f</em> <sup>(1.16±0.08)</sup>, and <em>Q<sub>c</sub></em> = (140 ± 41)<em>f</em> <sup>(1.10±0.09)</sup>. Our findings reveal significant variability in <em>Q<sub>c</sub>, Q<sub>α</sub></em> and <em>Q<sub>β</sub></em> across the Tethys (TH), High (HH), Lesser (LH), and Shiwalik (SH) Himalaya regions, as well as the adjacent Indo-Gangetic Plains (IGP), with this variability strongly linked to structural heterogeneity and seismogenic processes in each region. We further establish attenuation relations for distinct tectonic units, observing the following hierarchy: [<em>Q<sub>α,β,c</sub></em><sup>−1</sup>(HH) < <em>Q<sub>α,β,c</sub></em><sup>−1</sup>(SH) < <em>Q<sub>α,β,c</sub></em><sup>−1</sup>(IGP) < <em>Q<sub>α,β,c</sub></em><sup>−1</sup>(LH) < <em>Q<sub>α,β,c</sub></em><sup>−1</sup>(TH)]. The Tethys Himalaya exhibits the high attenuation, likely due to its sedimentary structure, while the Higher Himalaya shows the low attenuation. These insights into attenuation characteristics across geotectonic segments in the Northwest Himalaya contribute to a more comprehensive seismic hazard assessment for the region.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100378"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684299","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}

引用次数: 0

Geohazard impact and gas reservoir pressure dynamics in the Zagros Fold-Thrust Belt: An environmental perspective 扎格罗斯褶皱冲断带地质灾害影响与气藏压力动态：环境视角

Geosystems and Geoenvironment

Pub Date : 2025-03-07 DOI: 10.1016/j.geogeo.2025.100362

Mahsa Asghari , Zahra Maleki , Ali Solgi , Mohammad Ali Ganjavian , Pooria Kianoush

The Zagros Fold-Thrust Belt (ZFTB) presents a unique intersection of geohazards and gas reservoir dynamics, shaped by the ongoing tectonic activity resulting from the collision of the Arabian and Eurasian plates. This study aims to assess the risk of earthquake-induced landslides and their impact on gas reservoir pressure dynamics – with a particular focus on the Kabir Kuh gas field – identified as a critical area for monitoring due to its vulnerability to seismic events. A novel hybrid model is introduced that integrates geographic information system (GIS) mapping, decision support system (DSS) modeling, and machine learning algorithms. By analyzing a century's worth of seismic data alongside real-time environmental parameters, the model demonstrates a predictive accuracy of 92% using Random Forest algorithms, significantly outperforming traditional methods. The findings reveal a strong correlation between seismic activity and fluctuations in gas reservoir pressure, with an average pressure change of ±150 psi observed during significant seismic events. A landslide susceptibility map was generated, pinpointing regions that require proactive management strategies, particularly where significant landslide potential threatens gas field stability. Identifying the Seymareh landslide as a monumental geological event underscores the impact of landslide hazards on gas field integrity. This research emphasizes the integration of advanced predictive techniques into seismic risk assessments, providing actionable insights for the sustainable gas reservoir management in seismically active regions. The necessity for continuous monitoring and the implementation of advanced geotechnical measures are highlighted as essential components of effective geohazard management. This study contributes to understanding the interplay between seismic hazards and gas reservoir dynamics, offering a comprehensive framework for future research and practical applications in risk management and environmental sustainability.

扎格罗斯褶皱冲断带（ZFTB）呈现出独特的地质灾害和天然气储层动力学的交叉点，由阿拉伯板块和欧亚板块碰撞引起的持续构造活动形成。这项研究的目的是评估地震诱发滑坡的风险及其对气藏压力动态的影响——特别关注Kabir Kuh气田——由于容易受到地震事件的影响，该气田被确定为一个需要监测的关键区域。提出了一种融合地理信息系统（GIS）制图、决策支持系统（DSS）建模和机器学习算法的新型混合模型。通过分析一个世纪以来的地震数据和实时环境参数，该模型使用随机森林算法的预测精度达到92%，显著优于传统方法。研究结果表明，地震活动与气藏压力波动之间存在很强的相关性，在重大地震事件期间观察到的平均压力变化为±150 psi。生成了滑坡易感性图，确定了需要采取主动管理策略的区域，特别是那些严重滑坡潜在威胁气田稳定的区域。将Seymareh滑坡确定为重大地质事件，凸显了滑坡灾害对气田完整性的影响。本研究强调将先进的预测技术整合到地震风险评估中，为地震活跃地区的可持续气藏管理提供可操作的见解。持续监测和实施先进岩土技术措施的必要性被强调为有效的地质灾害管理的重要组成部分。这项研究有助于理解地震灾害与气藏动态之间的相互作用，为未来的研究和风险管理和环境可持续性的实际应用提供了一个全面的框架。

{"title":"Geohazard impact and gas reservoir pressure dynamics in the Zagros Fold-Thrust Belt: An environmental perspective","authors":"Mahsa Asghari , Zahra Maleki , Ali Solgi , Mohammad Ali Ganjavian , Pooria Kianoush","doi":"10.1016/j.geogeo.2025.100362","DOIUrl":"10.1016/j.geogeo.2025.100362","url":null,"abstract":"<div><div>The Zagros Fold-Thrust Belt (ZFTB) presents a unique intersection of geohazards and gas reservoir dynamics, shaped by the ongoing tectonic activity resulting from the collision of the Arabian and Eurasian plates. This study aims to assess the risk of earthquake-induced landslides and their impact on gas reservoir pressure dynamics – with a particular focus on the Kabir Kuh gas field – identified as a critical area for monitoring due to its vulnerability to seismic events. A novel hybrid model is introduced that integrates geographic information system (GIS) mapping, decision support system (DSS) modeling, and machine learning algorithms. By analyzing a century's worth of seismic data alongside real-time environmental parameters, the model demonstrates a predictive accuracy of 92% using Random Forest algorithms, significantly outperforming traditional methods. The findings reveal a strong correlation between seismic activity and fluctuations in gas reservoir pressure, with an average pressure change of ±150 psi observed during significant seismic events. A landslide susceptibility map was generated, pinpointing regions that require proactive management strategies, particularly where significant landslide potential threatens gas field stability. Identifying the Seymareh landslide as a monumental geological event underscores the impact of landslide hazards on gas field integrity. This research emphasizes the integration of advanced predictive techniques into seismic risk assessments, providing actionable insights for the sustainable gas reservoir management in seismically active regions. The necessity for continuous monitoring and the implementation of advanced geotechnical measures are highlighted as essential components of effective geohazard management. This study contributes to understanding the interplay between seismic hazards and gas reservoir dynamics, offering a comprehensive framework for future research and practical applications in risk management and environmental sustainability.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100362"},"PeriodicalIF":0.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562425","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}

引用次数: 0

Petrogenesis of gneisses and granitoids from Southern Bastar Craton, India: A geochemical insight to crustal evolution 印度南巴斯塔克拉通的片麻岩和花岗岩类岩石成因：地壳演化的地球化学视角

Geosystems and Geoenvironment

Pub Date : 2025-03-04 DOI: 10.1016/j.geogeo.2025.100377

Soumya Mitra , Santa Dolui , Asutosh K Tripathy

This study investigates the geochemical evolution and petrogenesis of gneisses and granitoids from the southern part of the Bastar Craton, India, to understand the crustal evolution. The study incorporates the result on major, minor, trace and rare earth elements (REE) interpretation. The gneisses, classified as high alumina granodiorite to granite, peraluminous and exhibit geochemical signatures typical of Archaean TTGs, including enrichment in large ion lithophile elements (LILE) and depletion in high field strength elements (HFSE) with notable negative anomalies in elements like Nb, P, and Ti. In contrast, the granitoids show a meta-aluminous to per-aluminous composition, with higher K₂O/Na₂O ratios and pronounced enrichment in LILE with higher Sr, Ba, Zr, Nb, Y and Yb contents than the gneisses. These patterns suggest a progressive geochemical evolution from gneiss to granitoids. The study put forward two distinct subduction phases contributing to the formation of these rocks. The initial phase associated with a pre- to syn-collisional tectonic setting in a flat low-angle subduction at shallower depth and minimal interaction between slab melts and the mantle wedge. Whereas, the later one is characterized by a collision to subduction transition in a post-collisional setting with gradual increase in mantle-wedge interaction at a relatively greater depth, involving a steeply dipping subduction process. This dual-phase subduction model highlights the tectonic shift in the region over time and provides a comprehensive understanding of the geological evolution of the Bastar Craton.

本文研究了印度巴斯塔尔克拉通南部片麻岩和花岗岩类的地球化学演化和岩石成因，以了解地壳演化。该研究结合了主要、次要、微量和稀土元素（REE）的解释结果。片麻岩类型为高铝花岗闪长岩-过铝质花岗岩，具有太古宙TTGs的地球化学特征，主要表现为大离子亲石元素（LILE）富集和高场强元素（HFSE）亏缺，Nb、P、Ti等元素呈显著负异常。花岗岩类呈准铝-准铝组成，K2O/Na2O比值较高，LILE富集明显，Sr、Ba、Zr、Nb、Y、Yb含量高于片麻岩。这些模式表明地球化学从片麻岩到花岗质是一个渐进的演化过程。研究提出了两个不同的俯冲阶段对这些岩石的形成有贡献。初始阶段与前-同碰撞构造环境有关，在较浅深度处于低角度俯冲的平坦状态，板块熔体与地幔楔体之间的相互作用最小。后者的特点是在碰撞后的背景下由碰撞向俯冲转变，在相对较深的深度上，幔楔相互作用逐渐增加，涉及陡倾俯冲过程。这种双相俯冲模式突出了该地区随时间的构造转移，并提供了对巴斯塔克拉通地质演化的全面理解。

{"title":"Petrogenesis of gneisses and granitoids from Southern Bastar Craton, India: A geochemical insight to crustal evolution","authors":"Soumya Mitra , Santa Dolui , Asutosh K Tripathy","doi":"10.1016/j.geogeo.2025.100377","DOIUrl":"10.1016/j.geogeo.2025.100377","url":null,"abstract":"<div><div>This study investigates the geochemical evolution and petrogenesis of gneisses and granitoids from the southern part of the Bastar Craton, India, to understand the crustal evolution. The study incorporates the result on major, minor, trace and rare earth elements (REE) interpretation. The gneisses, classified as high alumina granodiorite to granite, peraluminous and exhibit geochemical signatures typical of Archaean TTGs, including enrichment in large ion lithophile elements (LILE) and depletion in high field strength elements (HFSE) with notable negative anomalies in elements like Nb, P, and Ti. In contrast, the granitoids show a meta-aluminous to per-aluminous composition, with higher K<sub>2</sub>O/Na<sub>2</sub>O ratios and pronounced enrichment in LILE with higher Sr, Ba, Zr, Nb, Y and Yb contents than the gneisses. These patterns suggest a progressive geochemical evolution from gneiss to granitoids. The study put forward two distinct subduction phases contributing to the formation of these rocks. The initial phase associated with a pre- to syn-collisional tectonic setting in a flat low-angle subduction at shallower depth and minimal interaction between slab melts and the mantle wedge. Whereas, the later one is characterized by a collision to subduction transition in a post-collisional setting with gradual increase in mantle-wedge interaction at a relatively greater depth, involving a steeply dipping subduction process. This dual-phase subduction model highlights the tectonic shift in the region over time and provides a comprehensive understanding of the geological evolution of the Bastar Craton.</div></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"4 2","pages":"Article 100377"},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636765","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}

引用次数: 0

The future of recycling for critical metals: The example of EV batteries 关键金属回收的未来：以电动汽车电池为例

Geosystems and Geoenvironment

Pub Date : 2025-03-03 DOI: 10.1016/j.geogeo.2025.100376

Yanyan Zhao, Gurpreet Kaur

Across the globe, the uptake of electric vehicles (EVs) has grown rapidly in recent years. With most EVs using lithium-ion batteries, there is a keen focus on the recovery of key battery metals: lithium (Li), nickel (Ni) and cobalt (Co), as well as graphite for the sustainable growth of the electric vehicle industry. This short review briefly introduces EV batteries, discusses EV battery recycling status and market outlook, recent technology advancement, challenges and opportunities and current government initiatives.

近年来，全球范围内电动汽车（EV）的使用率迅速增长。由于大多数电动汽车使用锂离子电池，因此人们非常关注关键电池金属：锂（Li）、镍（Ni）和钴（Co）以及石墨的回收，以促进电动汽车行业的可持续发展。本短评简要介绍了电动汽车电池，讨论了电动汽车电池回收现状和市场前景、最新技术进展、挑战和机遇以及当前的政府举措。

引用次数: 0