Pub Date : 2025-01-01DOI: 10.1016/j.eve.2025.100060
A.E. Bernardini , O. Bertolami , F. Francisco
It is shown that the Earth System (ES) can, due to the impact of human activities, behave in a chaotic fashion. Our arguments are based on the assumption that the ES can be described by a Landau–Ginzburg model, which on its own allows for predicting that the ES evolves, through regular trajectories in the phase space, towards a Hothouse Earth scenario for a finite amount of human-driven impact. Furthermore, we find that the equilibrium point for temperature fluctuations can exhibit bifurcations and a chaotic pattern if the human impact follows a logistic map. Our final analysis includes interactions between different terms of the planetary boundaries (PB) in order to gauge the predictability of our model.
{"title":"Chaotic behaviour of the Earth System in the Anthropocene","authors":"A.E. Bernardini , O. Bertolami , F. Francisco","doi":"10.1016/j.eve.2025.100060","DOIUrl":"10.1016/j.eve.2025.100060","url":null,"abstract":"<div><div>It is shown that the Earth System (ES) can, due to the impact of human activities, behave in a chaotic fashion. Our arguments are based on the assumption that the ES can be described by a Landau–Ginzburg model, which on its own allows for predicting that the ES evolves, through regular trajectories in the phase space, towards a Hothouse Earth scenario for a finite amount of human-driven impact. Furthermore, we find that the equilibrium point for temperature fluctuations can exhibit bifurcations and a chaotic pattern if the human impact follows a logistic map. Our final analysis includes interactions between different terms of the planetary boundaries (PB) in order to gauge the predictability of our model.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100060"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097916","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}
Reconstructing the sedimentary environment and comprehension of the process of mineral enrichment rely significantly on lithofacies, which can be considered a proxy for the paleoenvironment. This study investigates the lithostratigraphic characteristics of the Late Cretaceous to Early Paleocene period, spanning the pivotal Cretaceous-Paleogene (K-Pg) boundary, in the Mannar Basin. Utilizing 25 drill cutting samples from the Dorado exploration well at intervals of 10 m, ranging from 2800 m to 3040 m in depth, various lithofacies were identified using Scanning Electron Microscope (SEM), polarizing microscope, and X-ray diffraction (XRD) analysis. Petrographic examinations revealed a diverse mineral arrangement, ranging from very fine to coarse-grained textures. Dominant minerals identified through XRD analysis include Quartz, Feldspar, Carbonate, and various clay minerals, facilitating shale classification. Five distinct lithofacies were delineated, encompassing calcareous, clayey, calcareous siliceous mixed, calcareous clayey mixed shales, and siliceous rocks. Noteworthy mineralogical compositions include abundant kaolinite, chlorite, and hematite minerals in the Maastrichtian succession, transitioning to montmorillonite, illite, and pyrite dominance in the Early Maastrichtian succession. Through clay mineralogy, this study discerns significant shifts in paleoenvironmental conditions, ranging from anoxic, arid to semi-arid climates during the Campanian to warm/wet, oxidizing environments during Maastrichtian, and finally to arid/semi-arid conditions during the early Paleocene. Additionally, evidence of early burial diagenesis and Late Maastrichtian sea-level regression is identified, contributing to a comprehensive understanding of environmental dynamics during this critical geological period in the Mannar Basin in the Equatorial Margin of the Northern Indian Ocean.
{"title":"Unravelling paleoenvironmental dynamics across the cretaceous-paleogene (K-Pg) boundary in the offshore Mannar Basin of the Northern Indian Ocean","authors":"S.S. Nawarathna , P.L. Dharmapriya , A.U. Wijenayake , E.K.C.W. Kularathna","doi":"10.1016/j.eve.2025.100062","DOIUrl":"10.1016/j.eve.2025.100062","url":null,"abstract":"<div><div>Reconstructing the sedimentary environment and comprehension of the process of mineral enrichment rely significantly on lithofacies, which can be considered a proxy for the paleoenvironment. This study investigates the lithostratigraphic characteristics of the Late Cretaceous to Early Paleocene period, spanning the pivotal Cretaceous-Paleogene (K-Pg) boundary, in the Mannar Basin. Utilizing 25 drill cutting samples from the Dorado exploration well at intervals of 10 m, ranging from 2800 m to 3040 m in depth, various lithofacies were identified using Scanning Electron Microscope (SEM), polarizing microscope, and X-ray diffraction (XRD) analysis. Petrographic examinations revealed a diverse mineral arrangement, ranging from very fine to coarse-grained textures. Dominant minerals identified through XRD analysis include Quartz, Feldspar, Carbonate, and various clay minerals, facilitating shale classification. Five distinct lithofacies were delineated, encompassing calcareous, clayey, calcareous siliceous mixed, calcareous clayey mixed shales, and siliceous rocks. Noteworthy mineralogical compositions include abundant kaolinite, chlorite, and hematite minerals in the Maastrichtian succession, transitioning to montmorillonite, illite, and pyrite dominance in the Early Maastrichtian succession. Through clay mineralogy, this study discerns significant shifts in paleoenvironmental conditions, ranging from anoxic, arid to semi-arid climates during the Campanian to warm/wet, oxidizing environments during Maastrichtian, and finally to arid/semi-arid conditions during the early Paleocene. Additionally, evidence of early burial diagenesis and Late Maastrichtian sea-level regression is identified, contributing to a comprehensive understanding of environmental dynamics during this critical geological period in the Mannar Basin in the Equatorial Margin of the Northern Indian Ocean.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100062"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427852","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 : 2025-01-01DOI: 10.1016/j.eve.2025.100061
Sarvendra Pratap Singh , Mohammad Arif , Arvind Kumar Singh , Shreya Mishra , Vivesh Vir Kapur , Vandana Prasad , Mamilla Venkateshwarlu , Amiya Shankar Naik
The present study examines a composite section representing four basaltic and three intertrappean successions at Gujri locality, Malwa subprovince, Central India. An integrated palaeomagnetic, sedimentological, mineralogical, and palaeontological approach has been utilized to understand the palaeoenvironmental changes in a stratigraphic context. The palaeomagnetic results reveal the presence of C30n/C29r and C29r/C29n magnetic reversals providing the C30n-C29r-C29n magnetostratigraphy for the region that spans almost the entire eruption history of the Deccan volcanism. As the Malwa lava flows contain C30n magnetochron, it represents the earliest basalt flows of Deccan volcanism compared to the Western Ghats sequences. Additionally, the record of the younger C29n magnetochron suggests that the Malwa and Mandla lava flows are magnetostratigraphically correlatable and experienced synchronous volcanic activity with the Western Ghats sequences during the main (C29r) and late (C29n) phases of Deccan volcanic eruption. Sedimentological and palaeontological data support that the intertrappean sediments at the Gujri locality were deposited in a dominantly low to moderate-energy freshwater palustrine-lacustrine environment under tropical to sub-tropical humid conditions with seasonal precipitation. However, data from the topmost intertrappean unit at Gujri possibly hints at ‘Mock’ aridity across the C29r/C29n transition.
{"title":"Magnetostratigraphic perspectives and palaeoenvironmental implications of Deccan volcano-sedimentary succession within the Malwa subprovince, Central India","authors":"Sarvendra Pratap Singh , Mohammad Arif , Arvind Kumar Singh , Shreya Mishra , Vivesh Vir Kapur , Vandana Prasad , Mamilla Venkateshwarlu , Amiya Shankar Naik","doi":"10.1016/j.eve.2025.100061","DOIUrl":"10.1016/j.eve.2025.100061","url":null,"abstract":"<div><div>The present study examines a composite section representing four basaltic and three intertrappean successions at Gujri locality, Malwa subprovince, Central India. An integrated palaeomagnetic, sedimentological, mineralogical, and palaeontological approach has been utilized to understand the palaeoenvironmental changes in a stratigraphic context. The palaeomagnetic results reveal the presence of C30n/C29r and C29r/C29n magnetic reversals providing the C30n-C29r-C29n magnetostratigraphy for the region that spans almost the entire eruption history of the Deccan volcanism. As the Malwa lava flows contain C30n magnetochron, it represents the earliest basalt flows of Deccan volcanism compared to the Western Ghats sequences. Additionally, the record of the younger C29n magnetochron suggests that the Malwa and Mandla lava flows are magnetostratigraphically correlatable and experienced synchronous volcanic activity with the Western Ghats sequences during the main (C29r) and late (C29n) phases of Deccan volcanic eruption. Sedimentological and palaeontological data support that the intertrappean sediments at the Gujri locality were deposited in a dominantly low to moderate-energy freshwater palustrine-lacustrine environment under tropical to sub-tropical humid conditions with seasonal precipitation. However, data from the topmost intertrappean unit at Gujri possibly hints at ‘Mock’ aridity across the C29r/C29n transition.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100061"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437555","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 : 2025-01-01DOI: 10.1016/j.eve.2025.100057
Krishna Kumar S , S.A. Ahmed , Jyothika Karkala , Sanjay Kumar
In recent years, human activities and uneven development have significantly reduced groundwater recharge, which is a crucial resource. Understanding the potential for groundwater is essential for managing and extending research areas. Designing and implementing structures to correct groundwater replenishment requires this knowledge. The Vedavathi River basin shows that groundwater availability varies over time and geography, necessitating a comprehensive assessment. Using a weighted overlay method, the Vedavathi River basin has been categorized into Groundwater Potential Zone (GWPZ): extremely high (1849.912 km2), high (7320.034 km2), moderate (9038.448 km2), low (4804.256 km2), and very low (283.6686 km2). The graphic illustrates that the basin's midland has significant groundwater potential, with substantial groundwater zones found in areas of heavy rainfall and significant infiltration. Our study's GWPZ were cross-validated using data from the Central Groundwater Board (CGWB) observation wells. The map's accuracy was confirmed by matching it with well-yield data. The model's performance was assessed using the Receiver-operation characteristics (ROC) curve, revealing that the Analytical Hierarchy Process (AHP)-based map achieved an 89% accuracy. This result aligns well with the predicted potential zones and well-yield data. The application of GIS and AHP methods to delineate GWPZ is relevant for river basin planning and development in tropical and subtropical regions with varied geological environments.
{"title":"Assessing the potential of hard rock terrain to store groundwater using AHP techniques in the Vedavathi River Basin, India","authors":"Krishna Kumar S , S.A. Ahmed , Jyothika Karkala , Sanjay Kumar","doi":"10.1016/j.eve.2025.100057","DOIUrl":"10.1016/j.eve.2025.100057","url":null,"abstract":"<div><div>In recent years, human activities and uneven development have significantly reduced groundwater recharge, which is a crucial resource. Understanding the potential for groundwater is essential for managing and extending research areas. Designing and implementing structures to correct groundwater replenishment requires this knowledge. The Vedavathi River basin shows that groundwater availability varies over time and geography, necessitating a comprehensive assessment. Using a weighted overlay method, the Vedavathi River basin has been categorized into Groundwater Potential Zone (GWPZ): extremely high (1849.912 km<sup>2</sup>), high (7320.034 km<sup>2</sup>), moderate (9038.448 km<sup>2</sup>), low (4804.256 km<sup>2</sup>), and very low (283.6686 km<sup>2</sup>). The graphic illustrates that the basin's midland has significant groundwater potential, with substantial groundwater zones found in areas of heavy rainfall and significant infiltration. Our study's GWPZ were cross-validated using data from the Central Groundwater Board (CGWB) observation wells. The map's accuracy was confirmed by matching it with well-yield data. The model's performance was assessed using the Receiver-operation characteristics (ROC) curve, revealing that the Analytical Hierarchy Process (AHP)-based map achieved an 89% accuracy. This result aligns well with the predicted potential zones and well-yield data. The application of GIS and AHP methods to delineate GWPZ is relevant for river basin planning and development in tropical and subtropical regions with varied geological environments.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100057"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140577","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 : 2025-01-01DOI: 10.1016/j.eve.2024.100055
Alan Cannell , Federico J. Degrange
Four genera of distantly phylogenetically very large volant birds existed for most of the Pliocene: Pelagornithidae seabirds; the large North American Teratornithidae, the stork Leptoptilos falconeri in Africa and Asia, and the gigantic vulture Dryornis pampeanus in Argentina. All became extinct around 2 to 3 Ma. The reasons for their demise are puzzling, as the Pelagornithidae had a world-wide evolutionary history of more than 50 Ma, smaller teratorns were still extant in the Holocene, and smaller stork and vulture species continue to be successful today. Extant large birds have a common critical takeoff airspeed suggesting biomechanical constraints in terms of power, risk and launch speed. Atmospheric mass is not constant over time and estimates for Late Pliocene atmospheric density, based on the difference between marine and terrestrial derived pCO2 and isotopes in amber, suggest a value equivalent to about 1.2 bar that dropped to the present level over the period from ∼3.3 to 2.0 Ma. Simulations of the flight of these extinct species suggest that in the present atmosphere at sea level (∼1) bar their takeoff airspeeds would have exceeded critical values; however, at 1.2 bar all the extinct species present takeoff airspeeds similar to those of large extant volant birds and which are within their muscle power and kinetic energy limits. A loss in atmospheric density may therefore have caused biomechanical and ecological stress contributing to their extinction and/or evolution of smaller forms.
{"title":"Into thin air: The loss of the pliocene giant volant birds","authors":"Alan Cannell , Federico J. Degrange","doi":"10.1016/j.eve.2024.100055","DOIUrl":"10.1016/j.eve.2024.100055","url":null,"abstract":"<div><div>Four genera of distantly phylogenetically very large volant birds existed for most of the Pliocene: Pelagornithidae seabirds; the large North American Teratornithidae, the stork <em>Leptoptilos falconeri</em> in Africa and Asia, and the gigantic vulture <em>Dryornis pampeanus</em> in Argentina. All became extinct around 2 to 3 Ma. The reasons for their demise are puzzling, as the Pelagornithidae had a world-wide evolutionary history of more than 50 Ma, smaller teratorns were still extant in the Holocene, and smaller stork and vulture species continue to be successful today. Extant large birds have a common critical takeoff airspeed suggesting biomechanical constraints in terms of power, risk and launch speed. Atmospheric mass is not constant over time and estimates for Late Pliocene atmospheric density, based on the difference between marine and terrestrial derived pCO<sub>2</sub> and isotopes in amber, suggest a value equivalent to about 1.2 bar that dropped to the present level over the period from ∼3.3 to 2.0 Ma. Simulations of the flight of these extinct species suggest that in the present atmosphere at sea level (∼1) bar their takeoff airspeeds would have exceeded critical values; however, at 1.2 bar all the extinct species present takeoff airspeeds similar to those of large extant volant birds and which are within their muscle power and kinetic energy limits. A loss in atmospheric density may therefore have caused biomechanical and ecological stress contributing to their extinction and/or evolution of smaller forms.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100055"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097472","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 : 2025-01-01DOI: 10.1016/j.eve.2025.100058
Tammo Reichgelt , Christopher K. West
Leaf megafloras represent a snapshot of local environmental conditions in Earth's history. As such, they are an important way to understand terrestrial climate analogues for future warmer climate scenarios. Here, we present paleoclimate, productivity, and biome reconstructions of 108 globally distributed Miocene leaf megafloras using a standardized method based on leaf physiognomy. Our results show that the Miocene had higher than modern zonal temperature, precipitation and net primary productivity (NPP) averages, especially for precipitation at latitudes >30°N/°S, suggesting enhanced poleward moisture transport in both hemispheres and a greener biosphere. There is a dearth of Miocene data in the tropics and notably an absence of data points in equatorial localities that have high modern NPP (rainforests), which makes a direct comparison complicated. 89% of investigated sites underwent a precipitation decrease from the Miocene to modern, whereas 66% underwent a temperature decrease, and 60% underwent both a precipitation and a temperature decrease. 67% of sites had more productive biomes during the Miocene than today. Most notably, forested biomes were replaced by more open woodland/shrubland or grassland biomes. Correspondingly, the average NPP decrease from the Miocene to today of our investigated localities was conservatively ∼250 gC m−2 yr−1 or ∼450 gC m−2 yr−1 by comparison of zonal averages. Considered collectively, leaf megafloras reveal an overall greener Miocene world that appears to be largely driven by greater moisture availability.
{"title":"Insights into greener Miocene biomes and globally enhanced terrestrial productivity from fossil leaves","authors":"Tammo Reichgelt , Christopher K. West","doi":"10.1016/j.eve.2025.100058","DOIUrl":"10.1016/j.eve.2025.100058","url":null,"abstract":"<div><div>Leaf megafloras represent a snapshot of local environmental conditions in Earth's history. As such, they are an important way to understand terrestrial climate analogues for future warmer climate scenarios. Here, we present paleoclimate, productivity, and biome reconstructions of 108 globally distributed Miocene leaf megafloras using a standardized method based on leaf physiognomy. Our results show that the Miocene had higher than modern zonal temperature, precipitation and net primary productivity (NPP) averages, especially for precipitation at latitudes >30°N/°S, suggesting enhanced poleward moisture transport in both hemispheres and a greener biosphere. There is a dearth of Miocene data in the tropics and notably an absence of data points in equatorial localities that have high modern NPP (rainforests), which makes a direct comparison complicated. 89% of investigated sites underwent a precipitation decrease from the Miocene to modern, whereas 66% underwent a temperature decrease, and 60% underwent both a precipitation and a temperature decrease. 67% of sites had more productive biomes during the Miocene than today. Most notably, forested biomes were replaced by more open woodland/shrubland or grassland biomes. Correspondingly, the average NPP decrease from the Miocene to today of our investigated localities was conservatively ∼250 gC m<sup>−2</sup> yr<sup>−1</sup> or ∼450 gC m<sup>−2</sup> yr<sup>−1</sup> by comparison of zonal averages. Considered collectively, leaf megafloras reveal an overall greener Miocene world that appears to be largely driven by greater moisture availability.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100058"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097917","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 : 2025-01-01DOI: 10.1016/j.eve.2025.100063
Susan M. Rimmer , Lois E. Yoksoulian , Darren R. Gröcke
Four transects of coal were studied to determine petrographic, geochemical, and δ13C changes due to contact with thin sills. Approaching the sills, vitrinite and coke reflectance increases from ∼0.75% to ∼7%, while volatile matter (VM) and H/C decrease. Despite extensive VM loss, the coals do not follow normal burial maturation pathways. Alteration above the sills exceeds that below, and the width of the contact aureole is large compared to that of the sills. This may suggest prolonged magma transport within the sills. Additionally, multiple fractures contain coke, pyrolytic carbon, and minerals, which suggests migration of fluidized coal, VM, and hot fluids. Incipient mosaic and anisotropic coke structures (fine-grained circular mosaic, with minor medium-grained circular mosaic) are observed within the aureole, consistent with intrusion of a high volatile bituminous coal. Devolatilization vacuoles, more abundant in altered collodetrinite than collotelinite, increase in number and size approaching the sills. Pyrolytic carbon occurs as fracture fills, spherulites, and botryoidal aggregates; spherulitic forms are more abundant at higher maturation levels. δ13C of the altered coal/coke varies only minimally from that of the unaltered coal and overall trends are ambiguous. Factors affecting δ13C may include maceral composition, rank at the time of intrusion, extent of alteration, size of the carbon reservoir, redeposition of pyrolytic carbon, and openness of the system. It is possible that the rapid heating and high temperatures associated with contact metamorphism limit carbon isotopic fractionation. In turn, this may imply that the intrusion of coal results in minimal liberation of isotopically light CH4.
{"title":"Contact metamorphism of coals in the Southern Piceance Basin, USA: Volatile matter generation, pyrolytic carbon accumulation, and δ13C trends","authors":"Susan M. Rimmer , Lois E. Yoksoulian , Darren R. Gröcke","doi":"10.1016/j.eve.2025.100063","DOIUrl":"10.1016/j.eve.2025.100063","url":null,"abstract":"<div><div>Four transects of coal were studied to determine petrographic, geochemical, and δ<sup>13</sup>C changes due to contact with thin sills. Approaching the sills, vitrinite and coke reflectance increases from ∼0.75% to ∼7%, while volatile matter (VM) and H/C decrease. Despite extensive VM loss, the coals do not follow normal burial maturation pathways. Alteration above the sills exceeds that below, and the width of the contact aureole is large compared to that of the sills. This may suggest prolonged magma transport within the sills. Additionally, multiple fractures contain coke, pyrolytic carbon, and minerals, which suggests migration of fluidized coal, VM, and hot fluids. Incipient mosaic and anisotropic coke structures (fine-grained circular mosaic, with minor medium-grained circular mosaic) are observed within the aureole, consistent with intrusion of a high volatile bituminous coal. Devolatilization vacuoles, more abundant in altered collodetrinite than collotelinite, increase in number and size approaching the sills. Pyrolytic carbon occurs as fracture fills, spherulites, and botryoidal aggregates; spherulitic forms are more abundant at higher maturation levels. δ<sup>13</sup>C of the altered coal/coke varies only minimally from that of the unaltered coal and overall trends are ambiguous. Factors affecting δ<sup>13</sup>C may include maceral composition, rank at the time of intrusion, extent of alteration, size of the carbon reservoir, redeposition of pyrolytic carbon, and openness of the system. It is possible that the rapid heating and high temperatures associated with contact metamorphism limit carbon isotopic fractionation. In turn, this may imply that the intrusion of coal results in minimal liberation of isotopically light CH<sub>4</sub>.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100063"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488232","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 : 2025-01-01DOI: 10.1016/j.eve.2024.100052
M. Sol González Estebenet , M. Verónica Guler , Edgardo L. Navarro , Luis Palazzesi , Viviana D. Barreda , Juan P. Pérez Panera , Andrea Caramés
The Península Valdés es-1 well exhibits the most complete stratigraphic record of an important Danian Atlantic marine event in Patagonia, Argentina. Biostratigraphic analysis of organic-walled dinoflagellate cysts (dinocysts) along with sporomorphs, calcareous nannofossils and foraminiferal complementary data allowed the identification of three stratigraphic intervals of earliest Danian, early to middle Danian and late Danian ages. Diagnostic palynomorph events were recognized including the highest occurrences of the dinocysts Danea californica and Senoniasphaera inornata; the highest common occurrences of Trithyrodinium evittii and Trithyridinium verrucosum. A basal spike of the Cheirolepidiaceae pollen Classopollis provides further evidence of the flourishing of this opportunistic taxon in disturbed ecosystems related to the K/P mass extinction event. The nannofossil zones NP1 to NP4 were identified throughout the section, as well as the foraminifera zones P1b–P1c in the middle and upper part. The microfossil composition reveals fluctuating proximal and neritic environments, as well as a maximum flooding episode; the latter, indicated by the outer neritic Spiniferites, the oceanic taxa Impagidiniumr, along with a glauconitic level. Two warm-sea surface temperature episodes were identified; the oldest, in the early Danian, indicated by the thermophilic dinocysts Trithyrodinium, Hafniasphera and Cordospheridium; and the youngest, in the late Danian, marked by Glaphyrocysta, Hafniasphaera, Tectatodinium pellitum and Pierceites spp. together with frost-intolerant sporomorph taxa and the warm-water foraminifer Boltovskoyella paleocenica. This study contributes to the Argentina paleogeography, achieving a refined marine reconstruction model for the early Paleocene.
{"title":"Biostratigraphy, paleoenvironment and paleoclimate in northeastern Patagonia during the early Paleocene based on the micropaleontological record","authors":"M. Sol González Estebenet , M. Verónica Guler , Edgardo L. Navarro , Luis Palazzesi , Viviana D. Barreda , Juan P. Pérez Panera , Andrea Caramés","doi":"10.1016/j.eve.2024.100052","DOIUrl":"10.1016/j.eve.2024.100052","url":null,"abstract":"<div><div>The Península Valdés es-1 well exhibits the most complete stratigraphic record of an important Danian Atlantic marine event in Patagonia, Argentina. Biostratigraphic analysis of organic-walled dinoflagellate cysts (dinocysts) along with sporomorphs, calcareous nannofossils and foraminiferal complementary data allowed the identification of three stratigraphic intervals of earliest Danian, early to middle Danian and late Danian ages. Diagnostic palynomorph events were recognized including the highest occurrences of the dinocysts <em>Danea californica</em> and <em>Senoniasphaera inornata</em>; the highest common occurrences of <em>Trithyrodinium evittii</em> and <em>Trithyridinium verrucosum</em>. A basal spike of the Cheirolepidiaceae pollen <em>Classopollis</em> provides further evidence of the flourishing of this opportunistic taxon in disturbed ecosystems related to the K/P mass extinction event. The nannofossil zones NP1 to NP4 were identified throughout the section, as well as the foraminifera zones P1b–P1c in the middle and upper part. The microfossil composition reveals fluctuating proximal and neritic environments, as well as a maximum flooding episode; the latter, indicated by the outer neritic <em>Spiniferites</em>, the oceanic taxa <em>Impagidinium</em>r, along with a glauconitic level. Two warm-sea surface temperature episodes were identified; the oldest, in the early Danian, indicated by the thermophilic dinocysts <em>Trithyrodinium</em>, <em>Hafniasphera</em> and <em>Cordospheridium</em>; and the youngest, in the late Danian, marked by <em>Glaphyrocysta</em>, <em>Hafniasphaera</em>, <em>Tectatodinium pellitum</em> and <em>Pierceites</em> spp. together with frost-intolerant sporomorph taxa and the warm-water foraminifer <em>Boltovskoyella paleocenica.</em> This study contributes to the Argentina paleogeography, achieving a refined marine reconstruction model for the early Paleocene.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100052"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140536","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 : 2025-01-01DOI: 10.1016/j.eve.2024.100053
Eduardo Guareschi Müller , Rodrigo Scalise Horodyski , Karlos Guilherme Diemer Kochhann , Gerson Fauth , Leslie Marcela Elizabeth Manríquez , Rodrigo do Monte Guerra , Hugo Schimidt Neto , Cristine Trevisan , Marcelo Adrian Leppe Cartes
Foreland basins are tectonically active, and the accommodation for sediment deposition in shallow marine environments is continuously altered due to rapid variations in the proximal area, influencing fossil concentration. The middle Eocene Man Aike Formation in the northwest region of the retroarc foreland Magallanes/Austral Basin, Chilean Patagonia, is represented by coarse siliciclastic deposits interbedded with dense fossil concentrations. To better understand the depositional and paleoenvironmental context recorded by these strata and fossil concentrations, this study presents a multi-proxy characterization, based on facies analysis, taphonomy and geochemical analysis of bulk sediments. In the study area, the base of the sedimentary succession is interpreted as stacked transgressive facies deposits of the shoreface zone. Taphonomic features as articulation, fragmentation, orientation and bioincrustation suggests that shell concentrations were influenced by fair weather and storm waves (mass flows started by gravitational effects) in three types. The fossil concentrations that characterize episodic deposits, we interpreted as proximal and distal tempestites. The Lowest shell fossil concentrations are interpreted as fossiliferous lags, suggesting the onset of a transgression in the Magallanes Basin. The fossil concentrations composed of closed and articulated bivalves, observed in the middle portion of succession, were interpreted as event concentrations. Results of geochemical analyses (terrigenous elements/Ca, Al/Ca, Ti/Al and Sr/Ca ratios) support the occurrence of a deepening trend towards the top of the sedimentary succession. Taphonomic control related to the low accommodation of the foreland basin, combined with relatively high sea-level, was a determining factor in the genesis of the middle Eocene fossil concentration.
{"title":"Genesis of fossil concentrations in foreland basins: A case study of the middle Eocene Man Aike Formation, Magallanes Basin, Chilean Patagonia","authors":"Eduardo Guareschi Müller , Rodrigo Scalise Horodyski , Karlos Guilherme Diemer Kochhann , Gerson Fauth , Leslie Marcela Elizabeth Manríquez , Rodrigo do Monte Guerra , Hugo Schimidt Neto , Cristine Trevisan , Marcelo Adrian Leppe Cartes","doi":"10.1016/j.eve.2024.100053","DOIUrl":"10.1016/j.eve.2024.100053","url":null,"abstract":"<div><div>Foreland basins are tectonically active, and the accommodation for sediment deposition in shallow marine environments is continuously altered due to rapid variations in the proximal area, influencing fossil concentration. The middle Eocene Man Aike Formation in the northwest region of the retroarc foreland Magallanes/Austral Basin, Chilean Patagonia, is represented by coarse siliciclastic deposits interbedded with dense fossil concentrations. To better understand the depositional and paleoenvironmental context recorded by these strata and fossil concentrations, this study presents a multi-proxy characterization, based on facies analysis, taphonomy and geochemical analysis of bulk sediments. In the study area, the base of the sedimentary succession is interpreted as stacked transgressive facies deposits of the shoreface zone. Taphonomic features as articulation, fragmentation, orientation and bioincrustation suggests that shell concentrations were influenced by fair weather and storm waves (mass flows started by gravitational effects) in three types. The fossil concentrations that characterize episodic deposits, we interpreted as proximal and distal tempestites. The Lowest shell fossil concentrations are interpreted as fossiliferous lags, suggesting the onset of a transgression in the Magallanes Basin. The fossil concentrations composed of closed and articulated bivalves, observed in the middle portion of succession, were interpreted as event concentrations. Results of geochemical analyses (terrigenous elements/Ca, Al/Ca, Ti/Al and Sr/Ca ratios) support the occurrence of a deepening trend towards the top of the sedimentary succession. Taphonomic control related to the low accommodation of the foreland basin, combined with relatively high sea-level, was a determining factor in the genesis of the middle Eocene fossil concentration.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100053"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140567","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}
The diminishing high-quality groundwater reservoirs have sparked significant interest in hard-rock aquifers, especially in active mining and raw material exploration areas. This paper aims to forecast the quantity and quality of alternative water resources in the area, thus facilitating the planning and design of the existing water resource systems. The focal point is the groundwater accommodated within basement-type alternative igneous aquifers nestled within an active mining and exploration province belonging to the Carpathian-Balkan fold-and-thrust belt (Banat-Timok Province/Banatitic Belt, sector in eastern Serbia). Despite their lower water-bearing capacity, we underscore the significant hydrogeological potential of natural water igneous-type aquifers, such as the Variscan Gornjane massif.
For the first time, this research identifies different reservoirs across the granite massif, providing a fresh perspective on the regional water resource systems. By categorizing reservoirs based on porosity type, flow rates, depth of reservoir rocks (in the depth range of 50 m), and distribution, this study significantly enhances the forecasting of the new water resource system, underlining the importance of this research in the field of water resources and mining. In addition to faulted sections of granite, aquifers are formed in the area characterized by weathered and decomposed granite fragments, often referred to as gruss deposits. The gruss layer has a flow rate reaching up to 0.01 l/s. In terms of the water quality, the groundwaters of the Gornjane granite massif mostly do not contain elements that are above the maximum permitted concentrations for drinking water. However, the occurrence of the elements Fe Mn in some water samples and the presence of Al Pb in one sample, as well as Se, As, Cu, Zn, Ag, Cd, Ga, and Bi, suggest the contact of water with sulfide mineralization detected in granite rocks of Rudna Glava-Tanda-Luka area, raising concerns about potential water quality issues.
{"title":"Variscan Gornjane granitoid as an alternative cold-water reservoir in the ore-baring and mining area of eastern Serbia: Quantitative-qualitative characterization (Carpathian-Balkan belt, Getic unit)","authors":"Goran Marinković , Marina Magazinović , Darko Spahić , Nataša Obradović , Maja Poznanović Spahić , Ivana Jovanić , Bogdan Kuzmanović","doi":"10.1016/j.eve.2024.100045","DOIUrl":"10.1016/j.eve.2024.100045","url":null,"abstract":"<div><div>The diminishing high-quality groundwater reservoirs have sparked significant interest in hard-rock aquifers, especially in active mining and raw material exploration areas. This paper aims to forecast the quantity and quality of alternative water resources in the area, thus facilitating the planning and design of the existing water resource systems. The focal point is the groundwater accommodated within basement-type alternative igneous aquifers nestled within an active mining and exploration province belonging to the Carpathian-Balkan fold-and-thrust belt (Banat-Timok Province/Banatitic Belt, sector in eastern Serbia). Despite their lower water-bearing capacity, we underscore the significant hydrogeological potential of natural water igneous-type aquifers, such as the Variscan Gornjane massif.</div><div>For the first time, this research identifies different reservoirs across the granite massif, providing a fresh perspective on the regional water resource systems. By categorizing reservoirs based on porosity type, flow rates, depth of reservoir rocks (in the depth range of 50 m), and distribution, this study significantly enhances the forecasting of the new water resource system, underlining the importance of this research in the field of water resources and mining. In addition to faulted sections of granite, aquifers are formed in the area characterized by weathered and decomposed granite fragments, often referred to as gruss deposits. The gruss layer has a flow rate reaching up to 0.01 l/s. In terms of the water quality, the groundwaters of the Gornjane granite massif mostly do not contain elements that are above the maximum permitted concentrations for drinking water. However, the occurrence of the elements Fe Mn in some water samples and the presence of Al Pb in one sample, as well as Se, As, Cu, Zn, Ag, Cd, Ga, and Bi, suggest the contact of water with sulfide mineralization detected in granite rocks of Rudna Glava-Tanda-Luka area, raising concerns about potential water quality issues.</div></div>","PeriodicalId":100516,"journal":{"name":"Evolving Earth","volume":"3 ","pages":"Article 100045"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097470","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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