Evolving Earth最新文献

Groundwater quality assessments of phreatic and deeper aquifers of the eastern Palghat, Kerala, Southern India 印度南部喀拉拉邦帕尔加特东部深层含水层的地下水质量评估

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2025-12-24 DOI: 10.1016/j.eve.2025.100104

K.V. Sarath , E. Shaji , M. Thirumurugan , S.G. Dhanil Dev , G. Indu , Ashitha , Keerthana

Identification and management of groundwater quality is crucial for maintaining the resources of over-exploited areas in the rain shadow region of the hard rock aquifer, which is essential for sustainable development. This research aims to identify water quality analysis for drinking and agricultural harvest in the crystalline aquifer, located in the eastern Palghat, Kerala, southern India. A groundwater compatibility study was conducted by analysing in situ parameters, major cations, anions, macronutrients, and fluorine in groundwater. Irrigational water quality parameters like Soluble Sodium Percentage (SSP), Sodium Adsorption Ratio (SAR), and Kelly's Ratio (KR), Permeability Index (PI) and Magnesium Hazard were obtained from 48 samples, 24 from excavated wells and 24 from tube wells (TW) in the exact location. The Water Quality Index (WQI) and irrigation water quality (IWQ) index are utilised due to their high importance in identifying the quality of water resources for irrigation and drinking purposes. Groundwater is the essential source for domestic, agricultural, and industrial purposes in the eastern Palghat, Kerala, southern India. This paper presents geochemical analyses of groundwater collected from phreatic and deeper aquifers of the area. Groundwater quality analyses show a considerable difference in the groundwater chemistry of phreatic and deeper aquifers. Excess fluoride is noted in a few samples. Rainwater harvesting, nanotechnology-based filters and awareness programs are recommended for reliable groundwater management in the study area.

地下水质量的识别和管理对维持硬岩含水层雨影区过度开发地区的资源至关重要，对可持续发展至关重要。本研究旨在确定位于印度南部喀拉拉邦帕尔加特东部的结晶含水层的饮用水和农业收获水质分析。通过分析地下水中的原位参数、主要阳离子、阴离子、常量营养素和氟，进行了地下水相容性研究。选取48个样品，其中开挖井24个，管井24个，获得了灌溉水的可溶性钠含量（SSP）、钠吸附比（SAR）、凯利比（KR）、渗透率指数（PI）、镁危害等水质参数。使用水质指数（WQI）和灌溉水质指数（IWQ）是因为它们在确定用于灌溉和饮用的水资源质量方面非常重要。地下水是印度南部喀拉拉邦东部帕尔加特地区家庭、农业和工业的重要水源。本文介绍了从该地区的深层和深层含水层收集的地下水的地球化学分析。地下水水质分析表明，深层含水层和深层含水层的地下水化学成分有相当大的差异。在一些样品中发现了过量的氟化物。雨水收集、基于纳米技术的过滤器和意识项目被推荐用于研究区域可靠的地下水管理。

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引用次数: 0

Impacts of flooding on agricultural practices in Bunkure Local Government Area, Kano State, Nigeria 洪水对尼日利亚卡诺州邦库尔地方政府地区农业生产的影响

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-01-23 DOI: 10.1016/j.eve.2026.100110

Inuwa Sani Sani, Adi Wibowo

Flooding has become one of the key environmental issues that have impacted agricultural productivity in northern Nigeria. This study examines the impacts of recurrent flooding on agricultural practices in Bunkure Local Government Area, Kano State, integrating multi-year satellite-derived Land Use/Land Cover (LULC) analysis, Digital Elevation Model (DEM) terrain assessment, and household survey data. The LULC classifications (2019–2023) based on Landsat data show the presence of considerable Spatio temporal changes in agricultural land, vegetation, bare land and water bodies, which are highly affected by seasonal floods. Terrain analysis also indicates that hydromorphic lowlands in the southern and central parts of the LGA are highly prone to inundation, resulting in prolonged waterlogging of farmlands. The outcomes of the surveys conducted on 346 farmers affirm the prevalence of the effects such as delayed growth of crops, untimely death of crops, changed planting time and low quality of harvests. The findings align with recent studies showing increasing flood frequency and rainfall intensity across northern Nigeria linked to climate variability. In general, flooding has led to massive loss of crops, soil erosion and economic distress particularly to smallholders and vulnerable farmers. The combined spatial and socio-economic analysis indicates evidence that there are changes in the agricultural land availability and productivity in response to the annual floods. The research recommends that flood resistant crop varieties, better drainage systems, and land-use planning should be adopted in minimizing the exposure of farmlands to flooding. Enhancing the early warning system and incorporating local knowledge in line with the contemporary farming practices will boost resiliency in the communities. The study provides context-related observations to enable policy intervention in the case of sustainable agricultural and disaster-risk management in flood-prone rural LGAs.

洪水已经成为影响尼日利亚北部农业生产力的关键环境问题之一。本研究综合了多年卫星土地利用/土地覆盖（LULC）分析、数字高程模型（DEM）地形评估和住户调查数据，研究了卡诺州邦库尔地方政府地区经常性洪水对农业生产的影响。基于Landsat数据的lucc分类（2019-2023年）显示，受季节性洪水影响较大的农用地、植被、裸地和水体存在较大的时空变化。地形分析还表明，LGA南部和中部的水形低地极易被淹没，导致农田涝渍时间延长。对346名农民进行的调查结果证实，诸如作物生长延迟、作物过早死亡、种植时间改变和收成质量低下等影响普遍存在。这些发现与最近的研究结果一致，这些研究表明，尼日利亚北部洪水频率和降雨强度的增加与气候变化有关。总的来说，洪水造成了大量的作物损失、土壤侵蚀和经济困境，特别是对小农和脆弱的农民。综合空间和社会经济分析表明，农业用地可利用性和生产力在响应年度洪水时发生了变化。该研究建议，应该采用抗洪作物品种、更好的排水系统和土地利用规划，以尽量减少农田遭受洪水的风险。加强早期预警系统，结合符合当代农业实践的当地知识，将提高社区的复原力。该研究提供了与环境相关的观察结果，以便在易发洪水的农村地方政府可持续农业和灾害风险管理的情况下进行政策干预。

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引用次数: 0

Heavy metal contamination in water and sediment of a tropical urbanizing landscape: Insights from Akkulam–Veli Lake, southwest coast, India 热带城市化景观中水和沉积物中的重金属污染：来自印度西南海岸阿库拉姆-维利湖的见解

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-01-27 DOI: 10.1016/j.eve.2026.100112

Arsha , Pooja Pradeep , S.G. Dhanil Dev , E. Shaji , P.K. Krishna Prasad , S. Swetha , S. Arya , V. Deepchand , Mohammed Noohu Nazeer

A comprehensive hydrogeological investigation was conducted to evaluate heavy metal contamination in water and sediments of the Akkulam–Veli Lake system, a rapidly urbanizing coastal landscape in Thiruvananthapuram, Kerala, southwest India. Decadal land use/land cover (LULC) analysis (2014–2023) over a 7.05 km² area revealed extensive urban expansion, with built-up areas increasing sharply at the expense of vegetation and wetlands, reflecting intense anthropogenic pressure. Water and sediment samples were analyzed for physicochemical parameters and heavy metals using Microwave Plasma Atomic Emission Spectroscopy and Atomic Absorption Spectrophotometry, integrated with GIS-based spatial analysis. Sediments exhibited elevated concentrations of Zn (up to 285 mg/kg), Ni (113 mg/kg), Cu (74 mg/kg), Pb (66–260 mg/kg), Cd (1.14–8.21 mg/kg), Fe (255–1755 mg/kg), and Cr (86–241 mg/kg), with lead exceeding permissible limits by up to 6.5 times. Water samples showed Zn concentrations up to 5.6 mg/L, Cd up to 0.24 mg/L, Fe up to 0.37 mg/L, and Cr up to 0.09 mg/L, frequently surpassing drinking-water standards. Pollution indices identified severe contamination hotspots near Parvathy Puthanaar and Kochuveli, closely associated with unplanned urban development, dredging activities, and untreated effluent discharge. Comparison with earlier studies (2012–2014) indicates a marked escalation in heavy metal concentrations, particularly Pb, Cd, and Cr, highlighting intensifying anthropogenic influence. The findings underscore the need for continuous monitoring, stricter regulation of urban discharges, and future studies integrating seasonal variability, contaminant source apportionment, and ecological risk assessment to support sustainable management of tropical urban lake systems.

本文对印度西南部喀拉拉邦蒂鲁凡南得普拉姆（Thiruvananthapuram）快速城市化的沿海景观Akkulam-Veli湖系统的水和沉积物中的重金属污染进行了全面的水文地质调查。2014-2023年7.05 km2区域的年代际土地利用/土地覆盖（LULC）分析显示，城市扩张范围广泛，建成区急剧增加，植被和湿地受到损害，反映出强烈的人为压力。采用微波等离子体原子发射光谱法和原子吸收分光光度法，结合基于gis的空间分析技术，对水和沉积物样品的理化参数和重金属进行了分析。沉积物中Zn（高达285 mg/kg）、Ni （113 mg/kg）、Cu （74 mg/kg）、Pb （66 ~ 260 mg/kg）、Cd （1.14 ~ 8.21 mg/kg）、Fe （255 ~ 1755 mg/kg）、Cr （86 ~ 241 mg/kg）的浓度均有所升高，其中铅的浓度最高超标6.5倍。水样中锌含量高达5.6 mg/L，镉含量高达0.24 mg/L，铁含量高达0.37 mg/L，铬含量高达0.09 mg/L，经常超过饮用水标准。污染指数确定了Parvathy Puthanaar和Kochuveli附近的严重污染热点，与无计划的城市发展、疏浚活动和未经处理的污水排放密切相关。与早期研究（2012-2014）相比，重金属浓度显著上升，尤其是Pb、Cd和Cr，凸显了人为影响的加剧。研究结果强调，需要对城市排放进行持续监测和更严格的监管，并在未来的研究中整合季节变化、污染源分配和生态风险评估，以支持热带城市湖泊系统的可持续管理。

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引用次数: 0

Threshold dynamics of mass extinctions and human famine risk 大规模物种灭绝和人类饥荒风险的阈值动态

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-02-18 DOI: 10.1016/j.eve.2026.100114

Kunio Kaiho

Large-scale continental volcanism, meteoroid impacts, and nuclear war can inject massive amounts of sulfur dioxide or soot into the stratosphere, causing solar dimming, global cooling, reduced rainfall, and—at extremes—global famine and mass extinction. Using Phanerozoic data, this study quantifies animal extinction magnitudes and human famine risk under such scenarios. We find a nonlinear threshold: species loss surges from a few percent to 20–40% when soot exceeds 100–120 Tg or volcanic ejecta surpasses 500,000–700,000 km³. Human population loss from food shortages increases more gradually, reaching 50–80% beyond these thresholds. These tipping points may be exceeded by massive eruptions, large asteroid impacts, or full-scale nuclear war. Our results offer a unified model for extinction mechanisms and underscore the grave risks these events pose to biodiversity and human survival.

大规模的大陆火山活动、流星体撞击和核战争会将大量的二氧化硫或烟尘注入平流层，导致太阳变暗、全球变冷、降雨量减少，在极端情况下，还会导致全球饥荒和大规模物种灭绝。利用显生宙的数据，本研究量化了这种情景下动物灭绝的程度和人类饥荒的风险。我们发现了一个非线性阈值：当烟尘超过100-120 Tg或火山喷出物超过50 - 700,000 km3时，物种损失从几个百分点激增到20-40%。粮食短缺造成的人口损失增加更为缓慢，超过这些阈值的50% - 80%。这些临界点可能会被大规模火山喷发、大型小行星撞击或全面核战争所超越。我们的研究结果为灭绝机制提供了一个统一的模型，并强调了这些事件对生物多样性和人类生存构成的严重风险。

引用次数: 0

Investigating size-asymmetric feeding among tyrannosaurids using tooth marks on a metatarsal from the Judith River Formation, Montana, USA 利用在美国蒙大拿州朱迪思河地层发现的跖骨上的牙印来研究暴龙的大小不对称摄食

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-01-22 DOI: 10.1016/j.eve.2026.100107

Josephine Nielsen , Denver Fowler , Taia Wyenberg-Henzler , Aase Roland Jacobsen , Christof Pearce

The Judith River Formation in Montana, USA, is a key Campanian-aged sedimentary package, with a rich fossil assemblage, including multiple tyrannosaurid taxa. This study documents BDM 124, a partial left metatarsal II exhibiting multiple tooth marks consistent with tyrannosaurid feeding activity. Using the Category-Modifier (CM) classification system and high-resolution 3D surface scanning, 16 distinct marks were systematically characterized. Morphometric analyses and Non-metric Multidimensional Scaling (NMDS) revealed grouping patterns suggestive of size-asymmetric feeding behavior. The small size and spacing of the marks indicate that they were produced by a small tyrannosaurid, most likely scavenging on the carcass of a significantly larger conspecific or closely related taxon. The absence of healing, mark placement on the metatarsal, and their morphology collectively suggest late-stage carcass consumption. The study contributes a new data point to our understanding of trophic dynamics and interactions among Late Cretaceous tyrannosaurids, highlighting the value of systematic methodologies for interpreting tooth marks.

美国蒙大拿州朱迪思河组是坎帕尼亚期重要的沉积包系，化石组合丰富，包括多个暴龙类群。本研究记录了BDM 124，一个局部左跖II，显示出与暴龙进食活动一致的多齿印。利用CM分类系统和高分辨率三维表面扫描，系统表征了16个明显的标记。形态计量学分析和非度量多维尺度（NMDS）揭示了提示尺寸不对称摄食行为的分组模式。这些标记的小尺寸和间距表明，它们是由一只小型暴龙留下的，很可能是在一个明显更大的同种或密切相关的分类单元的尸体上觅食。愈合的缺失，跖骨上的标记，以及它们的形态都表明尸体是在后期被消耗的。该研究为我们了解晚白垩世暴龙之间的营养动力学和相互作用提供了新的数据点，突出了系统方法解释牙印的价值。

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引用次数: 0

Variability in Indian monsoon onset: Delays, advances, and regional disruptions 印度季风发生的变异性：延迟、提前和区域中断

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2025-12-19 DOI: 10.1016/j.eve.2025.100103

Hemalatha Kapa , Kandula Bharghavi , Thotli Lokeswara Reddy

The Indian Summer Monsoon is a critical climatic phenomenon that sustains agriculture, water resources, and economic stability across South Asia. Accurate prediction of monsoon onset timing is essential, as delays can severely disrupt agricultural cycles, reduce crop yields, and strain water availability. This review examines the factors driving monsoon onset variability, with particular emphasis on delayed onset patterns and their regional impacts. The ISM onset is governed by complex atmospheric transitions including the weakening of westerlies, strengthening of easterlies, and formation of onset vortices that are modulated by large-scale climate drivers. El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), and Madden–Julian Oscillation (MJO) phases play dominant roles in determining onset timing. Climate change has intensified these interactions by amplifying ENSO variability, altering IOD behavior, and weakening atmospheric circulation responses, thereby increasing the complexity of monsoon dynamics. Additionally, rising Land Surface Temperatures (LST) driven by global warming and land use changes have further contributed to onset variability. Historical analysis reveals that late-onset events were particularly frequent during 1900–1925 and 1970–1990, though some regions now experience earlier onsets, reflecting spatiotemporal heterogeneity in monsoon behavior. Advances in forecasting particularly through Artificial Neural Networks (ANNs) and Multi-Model Ensemble (MME) approaches—have enhanced prediction accuracy by capturing both deterministic and stochastic rainfall patterns while reducing model uncertainties. Integration of indigenous knowledge into forecasting frameworks offers valuable localized insights for climate adaptation. Agricultural resilience strategies, including climate-smart practices such as integrated soil fertility management, agroforestry, resource conservation techniques, and community-based adaptation programs, are crucial for mitigating the impacts of monsoon variability while simultaneously contributing to greenhouse gas mitigation. Given the escalating complexities introduced by climate change, a synergistic approach combining improved forecasting models with adaptive agricultural practices is essential to enhance preparedness, optimize resource management, and mitigate the socioeconomic and environmental risks associated with monsoon variability.

印度夏季风是维持南亚农业、水资源和经济稳定的关键气候现象。准确预测季风发生的时间至关重要，因为延迟会严重破坏农业周期，降低作物产量，并使水资源供应紧张。本文审查了驱动季风开始变率的因素，特别强调延迟开始模式及其区域影响。ISM的开始是由复杂的大气转变控制的，包括西风带的减弱，东风带的加强，以及由大尺度气候驱动因素调节的开始旋涡的形成。El Niño-Southern涛动（ENSO）相、印度洋偶极子（IOD）相和Madden-Julian涛动（MJO）相是决定发生时间的主要因素。气候变化通过放大ENSO变率、改变IOD行为和减弱大气环流响应而加剧了这些相互作用，从而增加了季风动力学的复杂性。此外，全球变暖和土地利用变化导致的地表温度上升进一步加剧了初始变率。历史分析表明，晚发事件在1900-1925年和1970-1990年尤为频繁，尽管一些地区现在经历了早发事件，反映了季风行为的时空异质性。预测技术的进步，特别是通过人工神经网络（ann）和多模型集成（MME）方法，通过捕获确定性和随机降雨模式，同时减少模型的不确定性，提高了预测精度。将本土知识整合到预测框架中为气候适应提供了宝贵的本地化见解。农业抗灾能力战略，包括土壤肥力综合管理、农林业、资源保护技术和基于社区的适应方案等气候智能型做法，对于减轻季风变率的影响，同时促进温室气体减排至关重要。鉴于气候变化带来的复杂性不断升级，将改进的预报模型与适应性农业实践相结合的协同方法对于加强防范、优化资源管理以及减轻与季风变率相关的社会经济和环境风险至关重要。

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引用次数: 0

Machine learning & geospatial approach for analysing the groundwater quality of J&K region, NW Himalaya 机器学习和地理空间方法用于分析喜马拉雅西北部查谟克什米尔地区的地下水质量

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-03-05 DOI: 10.1016/j.eve.2026.100118

Avtar Singh Jasrotia , Amit Sharma , Mohinder Lal Angurala , Komal Kumar Singh , Upasna Andotra , Rajesh Kumar

The hydrochemical characteristics of groundwater in the Jammu & Kashmir (J&K) region were investigated using integrated machine learning and geospatial approaches. The major groundwater cations (Ca²⁺, Mg²⁺, Na⁺, K⁺) and anions (HCO₃⁻, SO₄²⁻, Cl⁻, NO₃⁻) were analysed. The ionic dominance followed the order Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and HCO₃⁻ > SO₄²⁻ > Cl⁻ > NO₃⁻. Total dissolved solids ranged from 4 to 2555 mg L⁻¹ (mean: 332.74 mg L⁻¹), while electrical conductivity varied between 150 and 4820 μS cm⁻¹. Gibbs and Piper diagrams indicate that groundwater chemistry is primarily governed by carbonate and silicate weathering processes, with silicate weathering contributing significantly to Na⁺ enrichment. Water Quality Index (WQI) values ranged from 23.11 to 429.23, classifying 85% of samples as excellent to good for drinking, while 22% were identified as poor to unsuitable. Statistical analysis revealed non-normal distribution of all variables (Shapiro–Wilk test), and Spearman's rank correlation indicated significant interrelationships among major ions. Machine learning models- Artificial Neural Network (ANN), Support Vector Regression (SVR), and Random Forest (RF) were applied for WQI prediction, with SVR outperforming other models (R² = 0.99, MSE = 15.51) and achieving an overall prediction accuracy of approximately 80%. The results demonstrate that coupling hydrochemical process interpretation with machine learning–based prediction provides a scalable and transferable framework for regional groundwater quality assessment across data-rich Himalayan terrains.

利用综合机器学习和地理空间方法研究了查谟克什米尔地区地下水的水化学特征。分析了地下水的主要阳离子（Ca2+、Mg2+、Na+、K+）和阴离子（HCO3−、SO42−、Cl−、NO3−）。离子优势度依次为Na+ >； Ca2+ > Mg2+ >； K+和HCO3−>； SO42−> Cl−> NO3−。溶解固体总量为4 ~ 2555 mg L−1（平均为332.74 mg L−1），电导率为150 ~ 4820 μS cm−1。Gibbs和Piper图表明，地下水化学主要受碳酸盐和硅酸盐风化过程控制，其中硅酸盐风化对Na+富集有显著贡献。水质指数（WQI）值在23.11 ~ 429.23之间，85%的样本为优至好，22%的样本为差至不适合饮用。统计分析显示各变量呈非正态分布（Shapiro-Wilk检验），Spearman秩相关表明各主要离子之间存在显著的相互关系。应用机器学习模型——人工神经网络（ANN）、支持向量回归（SVR）和随机森林（RF）进行WQI预测，其中SVR优于其他模型（R2 = 0.99, MSE = 15.51），总体预测精度约为80%。结果表明，将水化学过程解释与基于机器学习的预测相结合，为数据丰富的喜马拉雅地区的区域地下水质量评估提供了一个可扩展和可转移的框架。

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引用次数: 0

Streptichnus ichnofossils from the Marwar Supergroup: Tracing early Cambrian shallow-marine ecosystems 来自马尔瓦尔超群的链甲鱼化石：追踪早寒武纪浅海生态系统

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2025-12-16 DOI: 10.1016/j.eve.2025.100102

S. Ahmad

The ichnogenus Streptichnus is a key component of Early Cambrian ichnofaunas, reflecting the increasing complexity of benthic behavior and animal substrate interactions during this evolutionary interval. In the Cambrian Nagaur Sandstone (Marwar Supergroup) of western India, Streptichnus occurs abundantly within shallow-marine siliciclastic facies, providing important evidence for the nature of the Early Cambrian biosphere in the Indian subcontinent. In this study, Streptichnus burrows from the Nagaur Sandstone, Marwar Supergroup are described and compared with occurrences from the Shibantan Member of the Dengying Formation in South China. Their morphology, distribution, and global significance highlight the role of tracemakers in substrate destabilization and ecospace expansion during the Early Cambrian.

链链鱼属是早寒武纪鱼动物群的重要组成部分，反映了这一进化时期底栖动物行为和动物与底物相互作用的复杂性。在印度西部寒武系纳戈尔砂岩（马尔瓦尔超群）中，链甲虫大量分布于浅海硅酸岩相中，为研究印度次大陆早寒武世生物圈的性质提供了重要证据。本文对中国南方马尔瓦尔超群纳戈尔砂岩中的链链菌洞进行了描述，并与灯影组十板滩段的产状进行了比较。它们的形态、分布和全球意义突出了在早寒武纪基底不稳定和生态空间扩张中示踪者的作用。

引用次数: 0

Source terranes, humid-weathering diagenesis, and fluvial deposition in the cretaceous Garoua Basin: Implications for correlation with the upper Benue (Bima) system Garoua盆地白垩系烃源体、湿风化成岩作用和河流沉积：与上贝努埃（Bima）体系的对比意义

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-01-22 DOI: 10.1016/j.eve.2026.100109

Hermann Nyochembeng Akateh , Olugbenga A. Boboye , Edwin Ayuk Ndip , Shivanjali Sharma , Darshan Halari , Andre Mbabi Bitchong , Raoul Gake Belle

The Cretaceous Garoua Rift Basin, an eastern extension of the Upper Benue Basin in West Africa, preserves a fluvial succession essential for understanding the syn-rift sediment deposition of the West and Central African Rift System (WCARS). This study provides a comprehensive analysis of the clastic fill of the basin, combining grain size statistics, thin section petrology, heavy-mineral analysis, X-ray diffraction, and scanning electron microscopy to elucidate the provenance, diagenesis, and depositional processes. The results reveal that the sediments consist primarily of medium-to coarse-grained, moderately to moderately well-sorted, arkose to subarkose, characterized by approximately leptokurtic and near-symmetrical grain size distributions. These textural attributes indicate deposition by bedload-dominated, braided to low-sinuosity fluvial systems under high-energy conditions. The signatures of provenance, characterised by a framework dominated by quartz, feldspar and a group of heavy minerals abundant in zircon, tourmaline and rutile (ZTR) alongside prominent garnet and staurolite (GZi = 23–59 %), clearly indicate a source from nearly granitoid and gneissic basement rock throughout Pan-African. Diagenesis was primarily influenced by humid-weathering processes, as evidenced by the high kaolinite content of feldspar (up to 43 wt%) and widespread hematite cementation, which together governed the development of the reservoir quality. The striking similarity in composition, texture, and diagenetic overprint between the Garoua Succession and the upper Bima Member of the Nigerian Benue Trough confirm their stratigraphic equivalence. This correlation defines a coherent Cretaceous river system within the Yola-Garoua rift arm, providing an improved model for source-to-basin dynamics and reservoir characterisation in humid climate rift basins.

白垩纪Garoua裂谷盆地是西非上贝努埃盆地的东部延伸，保留了对了解西非和中非裂谷系（WCARS）同裂谷沉积至关重要的河流演替。结合粒度统计、薄片岩石学、重矿物分析、x射线衍射、扫描电镜等综合分析盆地碎屑充填物，阐明物源、成岩作用和沉积过程。结果表明，沉积物主要由中~粗粒、中等~中等分选良好、粗粒~次粗粒组成，粒度分布呈近似细峰状，接近对称；这些结构属性表明，在高能条件下，沉积以层状物为主，编织成低弯曲度的河流体系。物源特征以石英、长石为主，以锆石、电气石和金红石（ZTR）为主的一组重矿物为特征，并伴有显著的石榴石和橄榄石（GZi = 23 - 59%），表明其物源来自泛非洲地区的近花岗质和片麻岩基岩。成岩作用主要受湿风化作用的影响，长石高岭石含量高（高达43%），赤铁矿胶结作用广泛存在，两者共同决定了储层质量的发展。Garoua演替与尼日利亚Benue海槽上Bima段在组成、结构和成岩叠印上的惊人相似性证实了它们的地层等效性。这种对比定义了Yola-Garoua裂谷臂内连贯的白垩纪河流系统，为湿润气候裂谷盆地的源-盆地动力学和储层特征提供了改进的模型。

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引用次数: 0

Enhancing paleoclimate reconstructions in the late Aptian North-Northeast Brazil using clay mineralogy 利用粘土矿物学加强阿普tian晚期巴西东北北部古气候重建

Evolving Earth

Pub Date : 2026-01-01 Epub Date: 2026-01-27 DOI: 10.1016/j.eve.2026.100111

Victor Matheus Joaquim Salgado-Campos , Luiz Carlos Bertolino , Leonardo Borghi , Aristóteles de Moraes Rios-Netto , Bruno Cesar Araújo , Danielle Cardoso de Souza , Laís de Oliveira Ferreira , Fabia Emanuela Rafaloski Bobco , Jéssica de Souza Gabi Barcellos , Ismar de Souza Carvalho

Paleoclimate changes are commonly analyzed on three distinct scales: small-scale (20–500 kyr), linked to Milankovitch cycles; medium-scale events (∼30 Myr), associated with sea-level changes and tectonic activity; and large-scale (∼300 Myr), related to icehouse-greenhouse transitions. Different methods are used in paleoclimatology, with clay mineralogy emerging as a particularly effective tool. This study presents an approach to understanding late Aptian paleoclimate variations in North-Northeastern Brazil using clay mineralogy. To achieve this, fifty-two mudrock samples from the late Aptian Codó and Itapecuru formations were analyzed in the Parnaíba Basin (Northeastern Brazil) using clay and bulk mineralogy, major element chemical analysis, and scanning electron microscopy. These new data were integrated with a compiled dataset and evaluated using climofunctions to reconstruct paleoprecipitation and paleotemperature conditions, which were subsequently compared with patterns observed in modern lacustrine environments. Three paleoclimate stages were identified in North-Northeastern Brazil during the late Aptian, characterized by four distinct clay mineral assemblages. From the older to the younger stages, the first one indicates paleoprecipitation values ranging from 800 to 1000 mm/yr and paleotemperatures of approximately 15 °C. The second stage indicates paleoprecipitation values of up to 200 mm/yr and paleotemperature values of approximately 22 °C. The third stage suggests paleoprecipitation values between 600 and 800 mm/yr and paleotemperature conditions of approximately 20 °C. These paleoclimate stages indicate an aridification followed by a humidification process during the late Aptian in North-Northeastern Brazil. The latter humidification is likely linked to the Gondwana break-up and the potential onset of Oceanic Anoxic Event 1b, which marks the transition from the Aptian to the Albian. This study contributes to the use of clay minerals in reconstructing past climates and enhances our understanding of late Aptian climate changes in North-Northeastern Brazil.

古气候变化通常在三个不同的尺度上进行分析：小尺度（20-500 kyr），与米兰科维奇旋回有关；与海平面变化和构造活动有关的中等尺度事件（~ 30 Myr）；大尺度（~ 300 Myr），与冰-温室过渡有关。在古气候学中使用了不同的方法，粘土矿物学是一种特别有效的工具。本研究提出了一种利用粘土矿物学来理解巴西东北北部晚阿普提古气候变化的方法。为了实现这一目标，研究人员在Parnaíba盆地（巴西东北部）对来自晚Aptian Codó和Itapecuru地层的52个泥岩样本进行了粘土和大块矿物学、主要元素化学分析和扫描电子显微镜分析。将这些新数据与已编制的数据集相结合，利用气候函数进行评估，重建古降水和古温度条件，并将其与现代湖泊环境的模式进行比较。巴西东北部北部在阿普tian晚期确定了3个古气候阶段，其特征是4种不同的粘土矿物组合。从较老阶段到较年轻阶段，第一个阶段表明古降水值在800 ~ 1000 mm/yr之间，古温度约为15℃。第二阶段表明古降水量高达200 mm/yr，古温度值约为22°C。第三阶段表明古降水值在600 ~ 800 mm/yr之间，古温度条件约为20℃。这些古气候阶段表明，在巴西东北部北部的阿普tian晚期，一个干旱化之后是一个湿化过程。后者的湿化可能与冈瓦纳破裂和海洋缺氧事件1b的潜在开始有关，这标志着从阿普tian到Albian的过渡。该研究有助于利用粘土矿物重建过去的气候，并提高我们对巴西东北北部阿普提亚晚期气候变化的认识。

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