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2025,
50(3):
815-829.
doi: 10.3799/dqkx.2024.113
Abstract:
Earth system science becomes one of the most important themes of geosciences in modern days, featured by the investigations on interactions among Earth spheres. Meanwhile, Chinese governments are paying great attention to the societal development of some typical regions. Integration of the scientific frontiers of geosciences with regional societal development thus leads to the proposal of Earth system science in drainage regions in connection with the regional societal development, exemplified by the Yangtze drainage regions in which two national developmental strategies including the Yangtze economic belt, and the economic integration of the lower Yangtze regions are being constructed. Earth system science in drainage regions deals with the geological processes, evolution and effects prior to, during and after the origin of the large river systems. Three issues are in particular discussed here; they include the interactions between surface and deep Earth and their effects on mineral resources, interactions and coevolution between life and environments, and the relationship between the environments and cultures and civilization in the drainage regions. Some important scientific achievements related to the three issues are summarized here, with the proposal of some critical points left to be deciphered. To further understand the evolution of the system in drainage regions in geological history, one of the most important linkages to deal with would be the coupling and co-evolution among water, carbon and heat, in particular the relationship between hydrothermal dynamics and carbon cycles. This linkage shows close connection with the regional resources, ecological environmental conditions, geohazards, the culture and civilization, understanding of which plays important roles on the regional societal development.
Earth system science becomes one of the most important themes of geosciences in modern days, featured by the investigations on interactions among Earth spheres. Meanwhile, Chinese governments are paying great attention to the societal development of some typical regions. Integration of the scientific frontiers of geosciences with regional societal development thus leads to the proposal of Earth system science in drainage regions in connection with the regional societal development, exemplified by the Yangtze drainage regions in which two national developmental strategies including the Yangtze economic belt, and the economic integration of the lower Yangtze regions are being constructed. Earth system science in drainage regions deals with the geological processes, evolution and effects prior to, during and after the origin of the large river systems. Three issues are in particular discussed here; they include the interactions between surface and deep Earth and their effects on mineral resources, interactions and coevolution between life and environments, and the relationship between the environments and cultures and civilization in the drainage regions. Some important scientific achievements related to the three issues are summarized here, with the proposal of some critical points left to be deciphered. To further understand the evolution of the system in drainage regions in geological history, one of the most important linkages to deal with would be the coupling and co-evolution among water, carbon and heat, in particular the relationship between hydrothermal dynamics and carbon cycles. This linkage shows close connection with the regional resources, ecological environmental conditions, geohazards, the culture and civilization, understanding of which plays important roles on the regional societal development.
2025,
50(3):
830-845.
doi: 10.3799/dqkx.2024.130
Abstract:
The Paleo-Yunmeng Lake Group (PYMLG) in the Jianghan Plain has been significant of historical, geographical, cultural, and ecological environment research since the Xia and Shang Dynasties. Owing to rare historical records and limited borehole surveys, the cause and spatiotemporal pattern of the PYMLG remain ambiguous. Based on previous historical documents and borehole survey, this paper first conducted high resolution research on the boreholes sedimentary environment and reconstructed a 4 000-year evolution history of PYMLG. This study systematically revealed the relationship among the PYMLG sedimentary landform process and regional neotectonic movement, climate change, river channel migration and human activities. Multiple borehole analyses revealed the diverse sedimentary environments including riverbed, floodplain, lake, and delta facies, indicating a composite sedimentary system marked by a composite sedimentary system of "river-lake-delta". The distribution of sedimentary facies from west to east shows a certain pattern: the west is mainly floodplain and delta facies, the central part is mainly floodplain, delta and lake facies, and the east is dominated by lake facies. Paleogeographic reconstruction indicated that the PYMLG is always a landscape of changeable lake group developed in the interriver depressions in the Interior of Jianghan Plain. A 4 000-year evolution history of the PYMLG experienced four stages ranging from a peak period (Xia and Shang Dynasties) to a siltation period (Zhou, Qin, and Han Dynasties), a shrinkage period (Wei, Jin, and Southern and Northern Dynasties), and a breakup period (Tang and Song Dynasties). Our results indicate that the PYMLG is jointly influenced by the superposition of neotectonic movements, climate change, river flooding and migration of the ancient Yangtze River channels, and human activities: (1) The neotectonic subsidence created space conditions for the distribution of the PYMLG, and the main water and sand of the Yangtze River created the emergence of the PYMLG, but the subsequent southward migration of dominant channels of ancient Yangtze River determines the evolutionary process of the PYMLG; (2) the ENSO-related abnormal precipitation and river flooding have promoted the rise of PYMLG, and the expansion of the Jingjiang Delta has been the driver of the siltation and shrinkage of the PYMLG; (3) since the Tang and Song Dynasties, the shaping of the unified riverbed of the Jingjiang River and increasing embankments and reclamations of lakes accelerated the breakup of the PYMLG. This study first systematically reveal the spatiotemporal pattern of the PYMLG and its complex influencing mechanism, providing reliable answers to long-standing controversies and important references for the protection of current Jianghan Lake Group.
The Paleo-Yunmeng Lake Group (PYMLG) in the Jianghan Plain has been significant of historical, geographical, cultural, and ecological environment research since the Xia and Shang Dynasties. Owing to rare historical records and limited borehole surveys, the cause and spatiotemporal pattern of the PYMLG remain ambiguous. Based on previous historical documents and borehole survey, this paper first conducted high resolution research on the boreholes sedimentary environment and reconstructed a 4 000-year evolution history of PYMLG. This study systematically revealed the relationship among the PYMLG sedimentary landform process and regional neotectonic movement, climate change, river channel migration and human activities. Multiple borehole analyses revealed the diverse sedimentary environments including riverbed, floodplain, lake, and delta facies, indicating a composite sedimentary system marked by a composite sedimentary system of "river-lake-delta". The distribution of sedimentary facies from west to east shows a certain pattern: the west is mainly floodplain and delta facies, the central part is mainly floodplain, delta and lake facies, and the east is dominated by lake facies. Paleogeographic reconstruction indicated that the PYMLG is always a landscape of changeable lake group developed in the interriver depressions in the Interior of Jianghan Plain. A 4 000-year evolution history of the PYMLG experienced four stages ranging from a peak period (Xia and Shang Dynasties) to a siltation period (Zhou, Qin, and Han Dynasties), a shrinkage period (Wei, Jin, and Southern and Northern Dynasties), and a breakup period (Tang and Song Dynasties). Our results indicate that the PYMLG is jointly influenced by the superposition of neotectonic movements, climate change, river flooding and migration of the ancient Yangtze River channels, and human activities: (1) The neotectonic subsidence created space conditions for the distribution of the PYMLG, and the main water and sand of the Yangtze River created the emergence of the PYMLG, but the subsequent southward migration of dominant channels of ancient Yangtze River determines the evolutionary process of the PYMLG; (2) the ENSO-related abnormal precipitation and river flooding have promoted the rise of PYMLG, and the expansion of the Jingjiang Delta has been the driver of the siltation and shrinkage of the PYMLG; (3) since the Tang and Song Dynasties, the shaping of the unified riverbed of the Jingjiang River and increasing embankments and reclamations of lakes accelerated the breakup of the PYMLG. This study first systematically reveal the spatiotemporal pattern of the PYMLG and its complex influencing mechanism, providing reliable answers to long-standing controversies and important references for the protection of current Jianghan Lake Group.
2025,
50(3):
846-856.
doi: 10.3799/dqkx.2024.119
Abstract:
Peatlands play a crucial role in the global carbon cycle by storing carbon, but they are also a major source of methane emissions. Understanding how climate change affects the stability of carbon stores in peatlands is a key area of research. This review examines the effects of factors such as warming and fluctuations in water levels on the stability of carbon stores in peatlands, as well as the role of plants in responding to warming and drought. Research indicates that peatland carbon stocks are highly sensitive to warming, with decomposition rates increasing significantly in the aerobic layer with even slight temperature increases. The anaerobic layer requires greater temperature increases and longer periods to show significant decomposition. Warming also leads to an increase in the CH4/CO2 ratio, which can enhance the global warming potential of peatlands. Changes in water levels are a key factor affecting peatland carbon cycling, as drought events not only directly result in enhanced CO2 emissions but can also indirectly impact carbon store stability through wildfires. Studies have shown that vascular plants can also play a role in releasing old carbon. Future research should focus on developing in-situ observation techniques for metabolic products, examining geological records of extreme climate events, and understanding the response and feedback mechanisms of peatland carbon stores under changing climate conditions.
Peatlands play a crucial role in the global carbon cycle by storing carbon, but they are also a major source of methane emissions. Understanding how climate change affects the stability of carbon stores in peatlands is a key area of research. This review examines the effects of factors such as warming and fluctuations in water levels on the stability of carbon stores in peatlands, as well as the role of plants in responding to warming and drought. Research indicates that peatland carbon stocks are highly sensitive to warming, with decomposition rates increasing significantly in the aerobic layer with even slight temperature increases. The anaerobic layer requires greater temperature increases and longer periods to show significant decomposition. Warming also leads to an increase in the CH4/CO2 ratio, which can enhance the global warming potential of peatlands. Changes in water levels are a key factor affecting peatland carbon cycling, as drought events not only directly result in enhanced CO2 emissions but can also indirectly impact carbon store stability through wildfires. Studies have shown that vascular plants can also play a role in releasing old carbon. Future research should focus on developing in-situ observation techniques for metabolic products, examining geological records of extreme climate events, and understanding the response and feedback mechanisms of peatland carbon stores under changing climate conditions.
2025,
50(3):
857-876.
doi: 10.3799/dqkx.2025.013
Abstract:
Are we alone in the Universe? How and where did life on Earth arise? These are the fundamental questions that we assiduously seek to solve and the core questions of astrobiology. With the significant advances in deep space exploration technology, we are much closer than ever before to answering these questions. Since Earth is the only planet known to has been supporting life with a history spanning over 3.5 billion years, the study of geobiology can effectively promote the development of astrobiology. In order to speed up the development of astrobiology, this paper first introduces the connotations and brief development histories of geobiology and astrobiology and demonstrates the two core scientific issues of astrobiology, namely habitability and the origin and evolution of life. The following session discusses the four components of the habitability of celestial bodies and how to determine whether the habitable environment produces life. The paper proposes three aspects that require further enhancement to connect geobiology and astrobiology: the evolution of early Earth's habitable environment, the features of life in extreme environments, and the identification of biosignature.
Are we alone in the Universe? How and where did life on Earth arise? These are the fundamental questions that we assiduously seek to solve and the core questions of astrobiology. With the significant advances in deep space exploration technology, we are much closer than ever before to answering these questions. Since Earth is the only planet known to has been supporting life with a history spanning over 3.5 billion years, the study of geobiology can effectively promote the development of astrobiology. In order to speed up the development of astrobiology, this paper first introduces the connotations and brief development histories of geobiology and astrobiology and demonstrates the two core scientific issues of astrobiology, namely habitability and the origin and evolution of life. The following session discusses the four components of the habitability of celestial bodies and how to determine whether the habitable environment produces life. The paper proposes three aspects that require further enhancement to connect geobiology and astrobiology: the evolution of early Earth's habitable environment, the features of life in extreme environments, and the identification of biosignature.
2025,
50(3):
877-886.
doi: 10.3799/dqkx.2024.138
Abstract:
Exploring the mechanisms of microbial regulation of carbon and nitrogen cycling in saline lakes and their response to salinity is of great scientific importance for understanding the global carbon and nitrogen cycles. In response to cutting-edge scientific questions related to the carbon and nitrogen cycle in saline lakes, the authors conducted a comprehensive study on the impact mechanism and environmental effects of climate and environmental changes such as increased organic matter input, increased temperature, and reduced salinity on the microbial activity of the carbon and nitrogen cycles in saline lakes, and obtained a series of research findings. Finally, a summary of the microbial effects on carbon and nitrogen cycling in lakes is presented, and prospects for future development directions are proposed.
Exploring the mechanisms of microbial regulation of carbon and nitrogen cycling in saline lakes and their response to salinity is of great scientific importance for understanding the global carbon and nitrogen cycles. In response to cutting-edge scientific questions related to the carbon and nitrogen cycle in saline lakes, the authors conducted a comprehensive study on the impact mechanism and environmental effects of climate and environmental changes such as increased organic matter input, increased temperature, and reduced salinity on the microbial activity of the carbon and nitrogen cycles in saline lakes, and obtained a series of research findings. Finally, a summary of the microbial effects on carbon and nitrogen cycling in lakes is presented, and prospects for future development directions are proposed.
2025,
50(3):
887-907.
doi: 10.3799/dqkx.2024.055
Abstract:
Lake, as an important part of inland water bodies, is a key site of action for the cycling of material elements by linking the atmosphere, rocks and hydrosphere. Iron, the fourth most abundant element in the Earth's crust, is prevalent in various mineral phases, and sulfur exists in various inorganic/organic compounds in a variety of valence states. The mutual transformation and interaction between iron and sulfur in different valence states in lakes constitute the process of iron and sulfur cycling in lakes, in which microorganisms play a dominant role and become an indispensable part of the cycle. This review summarizes the types of microorganisms, metabolic pathways and environmental influences involved in the iron and sulfur cycles in lakes, focusing on the current status of microbial research related to the iron and sulfur cycles in lakes on the Qinghai-Xizang Plateau, and presenting the future direction of microbial-driven iron and sulfur cycling research in lakes on the Qinghai-Xizang Plateau.
Lake, as an important part of inland water bodies, is a key site of action for the cycling of material elements by linking the atmosphere, rocks and hydrosphere. Iron, the fourth most abundant element in the Earth's crust, is prevalent in various mineral phases, and sulfur exists in various inorganic/organic compounds in a variety of valence states. The mutual transformation and interaction between iron and sulfur in different valence states in lakes constitute the process of iron and sulfur cycling in lakes, in which microorganisms play a dominant role and become an indispensable part of the cycle. This review summarizes the types of microorganisms, metabolic pathways and environmental influences involved in the iron and sulfur cycles in lakes, focusing on the current status of microbial research related to the iron and sulfur cycles in lakes on the Qinghai-Xizang Plateau, and presenting the future direction of microbial-driven iron and sulfur cycling research in lakes on the Qinghai-Xizang Plateau.
2025,
50(3):
908-917.
doi: 10.3799/dqkx.2024.132
Abstract:
Single framboid size and deviation of pyrites in marine sediments or strata have been widely used as a useful proxy to indicate the seawater redox environment. However, our recent data about pyrite framboid size from the modern sediments bearing nature gas hydrate show a tremendous increasing trend in pyrite framboid size within the sulfate-methane transition zone (SMTZ), indicating the anaerobic oxidation of methane (AOM) dominated in SMTZ might play a key role to enhance the enlargement of pyrite framboid size. In case of large methane release caused by dissociation of gas hydrate (so called methane event), the rising SMTZ position would move up to shallow sediment or near seafloor and even into bottom seawater, most likely resulting into some anaerobic and acid environmental changes in bottom seawater. Meanwhile, the enhancing AOM coupled with the methane event will still greatly enlarge the pyrite framboid size in sediments. So in this situation, the traditional critical relationship between the pyrite framboid size and seawater redox environment will be no longer functional and need to be modified. It is proposed that the coupling of average framboid size > 20 μm or core size > 12 μm and deviation > 3 μm might be used as a critical proxy to indicate the environment of marine methane event.
Single framboid size and deviation of pyrites in marine sediments or strata have been widely used as a useful proxy to indicate the seawater redox environment. However, our recent data about pyrite framboid size from the modern sediments bearing nature gas hydrate show a tremendous increasing trend in pyrite framboid size within the sulfate-methane transition zone (SMTZ), indicating the anaerobic oxidation of methane (AOM) dominated in SMTZ might play a key role to enhance the enlargement of pyrite framboid size. In case of large methane release caused by dissociation of gas hydrate (so called methane event), the rising SMTZ position would move up to shallow sediment or near seafloor and even into bottom seawater, most likely resulting into some anaerobic and acid environmental changes in bottom seawater. Meanwhile, the enhancing AOM coupled with the methane event will still greatly enlarge the pyrite framboid size in sediments. So in this situation, the traditional critical relationship between the pyrite framboid size and seawater redox environment will be no longer functional and need to be modified. It is proposed that the coupling of average framboid size > 20 μm or core size > 12 μm and deviation > 3 μm might be used as a critical proxy to indicate the environment of marine methane event.
2025,
50(3):
918-933.
doi: 10.3799/dqkx.2024.139
Abstract:
The Philippine Sea is an important sink area for eolian dust from the Asian interior carried by East Asian winter monsoon (EAWM), and its continuous sedimentary sequences provide important geological archives for studying the variation of the EAWM and the history of aridification of the Asian interior. However, environmental magnetic records over long time scales with a reliable chronological framework from this area are scarce. In this study, we conducted detailed rock magnetic and paleomagnetic studies on deep-sea sediments of a 5.12 m core (QYZ01) recovered from the eastern West Philippine Sea Basin, Philippine Sea. Our aims are to establish a reliable Quaternary chronological framework, and to reveal the Asian eolian dust input and the evolution of the intensity of EAWM according to the changes of the environmental magnetic characteristics of sediments. Rock magnetic results show that low-coercivity magnetite with SSD magnetic behavior is the dominant magnetic carrier in the sediments, and it may mainly originate from detrital sources. The paleomagnetic result suggest that the sequence recorded the early Matuyama reverse chron to the Brunhes normal chron, including the Jaramillo, Olduvai and Réunion normal subchrons, and the basal age was estimated to be ~2.43 Ma. The Matuyama/Brunhes boundary was found at the core depth of ~200 cm. The environmental magnetic proxy (χARM/SIRM) indicates that the EAWM intensity and the Asian eolian dust input of the area around the QYZ01 core have shown an overall increasing trend since 2.43 Ma, and further divided into four phased variation patterns. The changes in χARM/SIRM ratio reflect the glacier expansion in the high latitudes of the northern Hemisphere and the phased uplift of the Qinghai-Xizang Plateau since the Quaternary, which led to the intensified aridification in the Asian interior and strengthened EAWM. This study provides new insights into understanding the paleoclimate changes in Asian interior and the evolution process of East Asian monsoon during the Quaternary.
The Philippine Sea is an important sink area for eolian dust from the Asian interior carried by East Asian winter monsoon (EAWM), and its continuous sedimentary sequences provide important geological archives for studying the variation of the EAWM and the history of aridification of the Asian interior. However, environmental magnetic records over long time scales with a reliable chronological framework from this area are scarce. In this study, we conducted detailed rock magnetic and paleomagnetic studies on deep-sea sediments of a 5.12 m core (QYZ01) recovered from the eastern West Philippine Sea Basin, Philippine Sea. Our aims are to establish a reliable Quaternary chronological framework, and to reveal the Asian eolian dust input and the evolution of the intensity of EAWM according to the changes of the environmental magnetic characteristics of sediments. Rock magnetic results show that low-coercivity magnetite with SSD magnetic behavior is the dominant magnetic carrier in the sediments, and it may mainly originate from detrital sources. The paleomagnetic result suggest that the sequence recorded the early Matuyama reverse chron to the Brunhes normal chron, including the Jaramillo, Olduvai and Réunion normal subchrons, and the basal age was estimated to be ~2.43 Ma. The Matuyama/Brunhes boundary was found at the core depth of ~200 cm. The environmental magnetic proxy (χARM/SIRM) indicates that the EAWM intensity and the Asian eolian dust input of the area around the QYZ01 core have shown an overall increasing trend since 2.43 Ma, and further divided into four phased variation patterns. The changes in χARM/SIRM ratio reflect the glacier expansion in the high latitudes of the northern Hemisphere and the phased uplift of the Qinghai-Xizang Plateau since the Quaternary, which led to the intensified aridification in the Asian interior and strengthened EAWM. This study provides new insights into understanding the paleoclimate changes in Asian interior and the evolution process of East Asian monsoon during the Quaternary.
2025,
50(3):
934-950.
doi: 10.3799/dqkx.2025.001
Abstract:
Plants enhance their nutrient and water uptake and improve resilience to extreme climates through mutualism with microorganisms, including mycorrhizal fungi and nitrogen-fixing bacteria. Despite the ecological significance of plant-microbe interactions, direct evidence of such symbioses during critical climate transitions in Earth's history remains limited due to the lack of relevant fossil records. This study adopts a modern-analogue approach, focusing on extant relatives of plants that survived the Permian-Triassic mass extinction, including Araucaria heterophylla, Cycas revoluta, and Ginkgo biloba. Using artificial climate chambers with temperature gradients, these plants were cultivated for one year, and high-throughput amplicon sequencing was employed to analyse the composition and relative abundance of root-associated microbial communities. The findings were then compared to plant fossil evidence to explore the impact of plant-microbe symbioses on plant survival under the extreme greenhouse climates of the Triassic. Preliminary results indicate that increasing the temperature by 10 ℃ above 25 ℃ resulted in a higher relative abundance ratio of beneficial and harmful microorganisms in the rhizosphere of Araucaria compared to Cycas and Ginkgo. This may explain why coniferous plants like Araucaria became dominant during the high-temperature conditions of the Early Triassic. However, at lower temperatures (30 ℃ and 25 ℃), the microbial communities associated with Cycas and Ginkgo exhibited greater adaptive advantages, consistent with their later dominance in cooler Late Triassic and post-Triassic ecosystems. This study provides microbial-based insights into the mechanisms by which plants adapted to extreme greenhouse climates following the Permian-Triassic mass extinction and contributes valuable data for understanding deep-time plant-microbe-environment interactions.
Plants enhance their nutrient and water uptake and improve resilience to extreme climates through mutualism with microorganisms, including mycorrhizal fungi and nitrogen-fixing bacteria. Despite the ecological significance of plant-microbe interactions, direct evidence of such symbioses during critical climate transitions in Earth's history remains limited due to the lack of relevant fossil records. This study adopts a modern-analogue approach, focusing on extant relatives of plants that survived the Permian-Triassic mass extinction, including Araucaria heterophylla, Cycas revoluta, and Ginkgo biloba. Using artificial climate chambers with temperature gradients, these plants were cultivated for one year, and high-throughput amplicon sequencing was employed to analyse the composition and relative abundance of root-associated microbial communities. The findings were then compared to plant fossil evidence to explore the impact of plant-microbe symbioses on plant survival under the extreme greenhouse climates of the Triassic. Preliminary results indicate that increasing the temperature by 10 ℃ above 25 ℃ resulted in a higher relative abundance ratio of beneficial and harmful microorganisms in the rhizosphere of Araucaria compared to Cycas and Ginkgo. This may explain why coniferous plants like Araucaria became dominant during the high-temperature conditions of the Early Triassic. However, at lower temperatures (30 ℃ and 25 ℃), the microbial communities associated with Cycas and Ginkgo exhibited greater adaptive advantages, consistent with their later dominance in cooler Late Triassic and post-Triassic ecosystems. This study provides microbial-based insights into the mechanisms by which plants adapted to extreme greenhouse climates following the Permian-Triassic mass extinction and contributes valuable data for understanding deep-time plant-microbe-environment interactions.
2025,
50(3):
951-963.
doi: 10.3799/dqkx.2025.022
Abstract:
The Permian-Triassic (P-Tr) mass extinction, which occurred approximately 252 million years ago, represents the largest ecological crisis in Earth's geological history and is often regarded as a reference case for modern ecological crises. However, studies that integrate multiple taxa and systematically characterize the overall evolutionary trajectory of food web structures in communities remain scarce. In particular, the incompleteness of fossil records and their low temporal resolution within stratigraphic records pose significant challenges to using deep-time crises as analogs for modern ecological crises. This study focuses on the fossil-rich Meishan Section in Zhejiang Province, the global stratotype section and point (GSSP) for the P-Tr boundary. Using Bayesian modeling with the PyRate method, we recalculated the true first and last appearances of all fossil species within this section. The results reveal a three-phase decline in species diversity: rapid drops in the first and third phases, with a gradual decline in the second phase. Building on these results, we explored schemes for delineating paleocommunities at varying temporal resolutions, ranging from 50 ka per community down to 1 ka per community. We then analyzed species composition similarity between adjacent communities under each scheme. As the temporal resolution increases, adjacent communities exhibit increasingly similar species compositions. Notably, for resolutions of 1-4 ka years per community, over 5% of adjacent communities show identical species compositions. Adopting a temporal resolution of 5 ka per community, we constructed a continuous sequence of paleocommunities and quantitatively assessed the evolutionary dynamics of community composition, simulated food web stability, and resistance across the P-Tr boundary. The results indicate minimal changes in ecological structure and community stability during the first and second phases, followed by abrupt shifts in the third phase. Communities in the first and second phases retained relatively high resistance, likely due to the loss of redundant species that did not compromise the integrity of ecological structure and function. In contrast, the third phase witnessed the collapse and reorganization of ecological structures as multiple functional groups disappeared. This study provides a detailed examination of paleocommunity delineation at varying temporal resolutions and reconstructs the evolutionary trajectory of paleoecological structures at a resolution of 5 ka. These findings offer a novel approach for investigating high-resolution deep-time ecosystem evolution and facilitate comparative studies between ancient and modern ecological systems.
The Permian-Triassic (P-Tr) mass extinction, which occurred approximately 252 million years ago, represents the largest ecological crisis in Earth's geological history and is often regarded as a reference case for modern ecological crises. However, studies that integrate multiple taxa and systematically characterize the overall evolutionary trajectory of food web structures in communities remain scarce. In particular, the incompleteness of fossil records and their low temporal resolution within stratigraphic records pose significant challenges to using deep-time crises as analogs for modern ecological crises. This study focuses on the fossil-rich Meishan Section in Zhejiang Province, the global stratotype section and point (GSSP) for the P-Tr boundary. Using Bayesian modeling with the PyRate method, we recalculated the true first and last appearances of all fossil species within this section. The results reveal a three-phase decline in species diversity: rapid drops in the first and third phases, with a gradual decline in the second phase. Building on these results, we explored schemes for delineating paleocommunities at varying temporal resolutions, ranging from 50 ka per community down to 1 ka per community. We then analyzed species composition similarity between adjacent communities under each scheme. As the temporal resolution increases, adjacent communities exhibit increasingly similar species compositions. Notably, for resolutions of 1-4 ka years per community, over 5% of adjacent communities show identical species compositions. Adopting a temporal resolution of 5 ka per community, we constructed a continuous sequence of paleocommunities and quantitatively assessed the evolutionary dynamics of community composition, simulated food web stability, and resistance across the P-Tr boundary. The results indicate minimal changes in ecological structure and community stability during the first and second phases, followed by abrupt shifts in the third phase. Communities in the first and second phases retained relatively high resistance, likely due to the loss of redundant species that did not compromise the integrity of ecological structure and function. In contrast, the third phase witnessed the collapse and reorganization of ecological structures as multiple functional groups disappeared. This study provides a detailed examination of paleocommunity delineation at varying temporal resolutions and reconstructs the evolutionary trajectory of paleoecological structures at a resolution of 5 ka. These findings offer a novel approach for investigating high-resolution deep-time ecosystem evolution and facilitate comparative studies between ancient and modern ecological systems.
2025,
50(3):
964-982.
doi: 10.3799/dqkx.2024.156
Abstract:
Humanity is facing global warming driven by large-scale anthropogenic carbon emissions, alongside a series of global climate changes and ecological crises. Throughout geological history, several hyperthermal events triggered by massive volcanic activity have occurred, often accompanied by mass extinctions. These geological events provide important analogs for modern global warming. The Permian-Triassic mass extinction (~252 Ma), the largest mass extinction event of the Phanerozoic, is widely attributed to massive volcanisms and the resulting environmental changes. This review examines recent research on volcanism during the Permian-Triassic mass extinction and summarizes the types and magnitudes of volcanic degassing, including CO2, SO2, halogens, and metals. We also summarize the environmental impacts of global warming, ocean acidification, volcanic winter, acid rain, ozone depletion, and metal poisoning directly triggered by volcanic degassing, and assess how these changes drove mass extinctions in both marine and terrestrial ecosystems. This review aims to provide a comprehensive understanding of the relationship between volcanism and mass extinction. A comparison of Permian-Triassic carbon emissions with modern anthropogenic carbon emissions reveals that modern carbon emission and warming rates may be unprecedented in the past 252 million years.
Humanity is facing global warming driven by large-scale anthropogenic carbon emissions, alongside a series of global climate changes and ecological crises. Throughout geological history, several hyperthermal events triggered by massive volcanic activity have occurred, often accompanied by mass extinctions. These geological events provide important analogs for modern global warming. The Permian-Triassic mass extinction (~252 Ma), the largest mass extinction event of the Phanerozoic, is widely attributed to massive volcanisms and the resulting environmental changes. This review examines recent research on volcanism during the Permian-Triassic mass extinction and summarizes the types and magnitudes of volcanic degassing, including CO2, SO2, halogens, and metals. We also summarize the environmental impacts of global warming, ocean acidification, volcanic winter, acid rain, ozone depletion, and metal poisoning directly triggered by volcanic degassing, and assess how these changes drove mass extinctions in both marine and terrestrial ecosystems. This review aims to provide a comprehensive understanding of the relationship between volcanism and mass extinction. A comparison of Permian-Triassic carbon emissions with modern anthropogenic carbon emissions reveals that modern carbon emission and warming rates may be unprecedented in the past 252 million years.
2025,
50(3):
983-999.
doi: 10.3799/dqkx.2024.140
Abstract:
The duration for the End-Permian mass extinction has been estimated as about 30 to 60 kyr. However, an ever-expanding body of papers has revealed that the evolution of Late Permian ecosystems possibly involved some yet under-studied 'early warning signals' prior to the End-Permian mass extinction. The study on the pre-extinction 'warning signals' is still limited. In order to understand the process of marine ecosystem collapse specifically the 'early warning signals' pointing to the approaching of a global ecosystem regime shift (tipping point), 30 marine Permian-Triassic Boundary sections from different palaeogeographic settings were selected globally to investigate the spatiotemporal biodiversity changes of different taxa and the spatiotemporal redox conditions. The results reveal that: (1) The marine ecosystem collapsed first in deep waters and then in shallow waters (first in offshore pelagic settings, then in moderately deep waters and deep-water basins and shelves and finally in shallow water environments); (2) in the same environments (in deep or moderately deep waters), a similar differential temporal pattern is also apparent in that the planktonic ecosystems were devastated earlier than benthic ecosystems. To account for the spatiotemporal and ecological (taxonomic) differences in extinction timing, we propose that the formation and expansion of an OMZ (oxygen minimum zone) and the related anoxia (or oxygen depletion), were most likely responsible for the differential temporal patterns of marine ecosystem collapses between deep and shallow waters, and between planktonic and benthic communities during the Late Permian.
The duration for the End-Permian mass extinction has been estimated as about 30 to 60 kyr. However, an ever-expanding body of papers has revealed that the evolution of Late Permian ecosystems possibly involved some yet under-studied 'early warning signals' prior to the End-Permian mass extinction. The study on the pre-extinction 'warning signals' is still limited. In order to understand the process of marine ecosystem collapse specifically the 'early warning signals' pointing to the approaching of a global ecosystem regime shift (tipping point), 30 marine Permian-Triassic Boundary sections from different palaeogeographic settings were selected globally to investigate the spatiotemporal biodiversity changes of different taxa and the spatiotemporal redox conditions. The results reveal that: (1) The marine ecosystem collapsed first in deep waters and then in shallow waters (first in offshore pelagic settings, then in moderately deep waters and deep-water basins and shelves and finally in shallow water environments); (2) in the same environments (in deep or moderately deep waters), a similar differential temporal pattern is also apparent in that the planktonic ecosystems were devastated earlier than benthic ecosystems. To account for the spatiotemporal and ecological (taxonomic) differences in extinction timing, we propose that the formation and expansion of an OMZ (oxygen minimum zone) and the related anoxia (or oxygen depletion), were most likely responsible for the differential temporal patterns of marine ecosystem collapses between deep and shallow waters, and between planktonic and benthic communities during the Late Permian.
2025,
50(3):
1000-1022.
doi: 10.3799/dqkx.2025.030
Abstract:
The ichnoecological variations across the Permian⁃Triassic mass extinction have been well studied, but most studies focused on shallow marine environments. The ichnological characteristic and its evolution in deep marine remain unclear across the mass extinction. This paper investigates abundant ichnofossils in three deep marine sections from the West Qinling area of North China, and systematically describes 18 ichnogenera. The study shows that the diversity of ichnofossil in deep marine did not change across the mass extinction, but a large number of graphoglyptid trace fossils appeared in the Early Triassic. Further quantitative analysis by using ecospace utilization and ecosystem engineering methods reveals that ecospace utilization and ecosystem engineering parameters of trace-making organisms apparently declined after the mass extinction, especially in the deep tier. Unlike the siliciclastic nearshore 'habitable zone' refuges, the feedback effects of ecosystem engineers on the recovery of in deep marine ecosystem after the mass extinction is relatively weak. The deep marine environmental setting is unfavourable to the colonization of shallow-sea opportunistic organisms and may not have acted as a refuge after the mass extinction.
The ichnoecological variations across the Permian⁃Triassic mass extinction have been well studied, but most studies focused on shallow marine environments. The ichnological characteristic and its evolution in deep marine remain unclear across the mass extinction. This paper investigates abundant ichnofossils in three deep marine sections from the West Qinling area of North China, and systematically describes 18 ichnogenera. The study shows that the diversity of ichnofossil in deep marine did not change across the mass extinction, but a large number of graphoglyptid trace fossils appeared in the Early Triassic. Further quantitative analysis by using ecospace utilization and ecosystem engineering methods reveals that ecospace utilization and ecosystem engineering parameters of trace-making organisms apparently declined after the mass extinction, especially in the deep tier. Unlike the siliciclastic nearshore 'habitable zone' refuges, the feedback effects of ecosystem engineers on the recovery of in deep marine ecosystem after the mass extinction is relatively weak. The deep marine environmental setting is unfavourable to the colonization of shallow-sea opportunistic organisms and may not have acted as a refuge after the mass extinction.
2025,
50(3):
1023-1036.
doi: 10.3799/dqkx.2024.145
Abstract:
There are relatively abundant ostracod fossils remaining when the most critical mass extinction in the Phanerozoic occurs during the Permian-Triassic. These fossils provide an important carrier for studying the adaptive evolution of organisms undergoing the extinction and recovery. This research focuses on four ostracod species widely distributed in shallow marine environment during this period and measured and analyzed 1 172 valves/carapaces for length and height. The results display certain degree of abnormal variations take place in the ostracod instar structure, growth rate and body size following the mass extinction, but the changes vary among different sedimentary facies, species and ontogeny stages. This indicates that ostracods may have adopted proactive, diverse, and complex survival strategies in response to the mass extinction.
There are relatively abundant ostracod fossils remaining when the most critical mass extinction in the Phanerozoic occurs during the Permian-Triassic. These fossils provide an important carrier for studying the adaptive evolution of organisms undergoing the extinction and recovery. This research focuses on four ostracod species widely distributed in shallow marine environment during this period and measured and analyzed 1 172 valves/carapaces for length and height. The results display certain degree of abnormal variations take place in the ostracod instar structure, growth rate and body size following the mass extinction, but the changes vary among different sedimentary facies, species and ontogeny stages. This indicates that ostracods may have adopted proactive, diverse, and complex survival strategies in response to the mass extinction.
2025,
50(3):
1037-1047.
doi: 10.3799/dqkx.2024.118
Abstract:
An extreme greenhouse interval existed in the Norian of Late Triassic, lasted from the Middle Norian to the early Late Norian. The maximum sea surface temperature in low latitudes can reach 35 ℃ during the extremely high temperature interval occurred in the lower part of the conodont Mockina bidentata Zone. The extreme greenhouse interval of the Norian was accompanied by important biological evolution events in the ocean and land. The changes of dry and wet climate were not completely consistent in different regions. Many events occurred in this interval, such as global plate movement, igneous province activity, bolide and significant changes of geochemical indexes. The global significance of these events, their potential causality, and the response in the East Tethys need to be further studied. China has a good Norian stratigraphic sequence, which is an ideal area to study the climate change and biological evolution of this extreme greenhouse interval in the East Tethys region.
An extreme greenhouse interval existed in the Norian of Late Triassic, lasted from the Middle Norian to the early Late Norian. The maximum sea surface temperature in low latitudes can reach 35 ℃ during the extremely high temperature interval occurred in the lower part of the conodont Mockina bidentata Zone. The extreme greenhouse interval of the Norian was accompanied by important biological evolution events in the ocean and land. The changes of dry and wet climate were not completely consistent in different regions. Many events occurred in this interval, such as global plate movement, igneous province activity, bolide and significant changes of geochemical indexes. The global significance of these events, their potential causality, and the response in the East Tethys need to be further studied. China has a good Norian stratigraphic sequence, which is an ideal area to study the climate change and biological evolution of this extreme greenhouse interval in the East Tethys region.
2025,
50(3):
1048-1065.
doi: 10.3799/dqkx.2025.006
Abstract:
Two global-scale Snowball Earth events occurred during the Cryogenian period of the Neoproterozoic era (ca. 720‒635 Ma), representing a crucial transition period for the Earth's biological systems and environmental evolution. An increasing amount of evidence indicates that there are spatio-temporal fluctuations in the climate and marine redox state during the Snowball glaciation. However, the driving mechanisms of the carbon cycle-land-ocean system interaction and glacial climate fluctuations during this period remain largely unclear. Continental weathering is a key process linking snowball development, ocean chemistry, and biological evolution, but existing research has been unable to effectively characterize continental weathering during the Snowball period. This paper summarizes the current status of proxies for chemical weathering intensity during the Cryogenian period, and statistically analyzes the major-element data of 867 clastic rock samples from 28 Cryogenian sections (including drill cores) worldwide. Using the index of ln(Al2O3/Na2O), the evolutionary trend of the global average chemical weathering intensity from the Late Tonian period to the Early Ediacaran period is quantitatively reconstructed. Three fluctuations in chemical weathering intensity are discovered, indicating that the onset and termination of glaciation are closely related to chemical weathering. In addition, the average weathering intensity during the Marinoan glaciation is significantly higher than that during the Sturtian glaciation, possibly suggesting the existence of a certain degree of hydrological circulation during the Marinoan glaciation. Future research can further apply the comprehensive application of multiple proxies to deepen the understanding of the chemical weathering mechanisms during the Cryogenian period, and provide more in-depth perspectives and evidence to support the exploration of global environmental evolution.
Two global-scale Snowball Earth events occurred during the Cryogenian period of the Neoproterozoic era (ca. 720‒635 Ma), representing a crucial transition period for the Earth's biological systems and environmental evolution. An increasing amount of evidence indicates that there are spatio-temporal fluctuations in the climate and marine redox state during the Snowball glaciation. However, the driving mechanisms of the carbon cycle-land-ocean system interaction and glacial climate fluctuations during this period remain largely unclear. Continental weathering is a key process linking snowball development, ocean chemistry, and biological evolution, but existing research has been unable to effectively characterize continental weathering during the Snowball period. This paper summarizes the current status of proxies for chemical weathering intensity during the Cryogenian period, and statistically analyzes the major-element data of 867 clastic rock samples from 28 Cryogenian sections (including drill cores) worldwide. Using the index of ln(Al2O3/Na2O), the evolutionary trend of the global average chemical weathering intensity from the Late Tonian period to the Early Ediacaran period is quantitatively reconstructed. Three fluctuations in chemical weathering intensity are discovered, indicating that the onset and termination of glaciation are closely related to chemical weathering. In addition, the average weathering intensity during the Marinoan glaciation is significantly higher than that during the Sturtian glaciation, possibly suggesting the existence of a certain degree of hydrological circulation during the Marinoan glaciation. Future research can further apply the comprehensive application of multiple proxies to deepen the understanding of the chemical weathering mechanisms during the Cryogenian period, and provide more in-depth perspectives and evidence to support the exploration of global environmental evolution.
2025,
50(3):
1066-1081.
doi: 10.3799/dqkx.2024.135
Abstract:
This study investigates the environmental context for the rapid evolution of crown-group eukaryotes during the Late Mesoproterozoic, focusing on sedimentological and mineralogical analyses of clastic rocks from the Changlongshan Formation across four sections of the North China Craton. In the Huailai section, fine-to-coarse sandstones from the deep-to-shallow subtidal zones are dominated by chamosite, indicating an anoxic, ferruginous marine environment. Conversely, glauconite dominates silty mudstone and muddy siltstone in the deep subtidal zone, reflecting suboxic conditions. In the Mentougou section, medium-to-coarse sandstones from the shallow subtidal zone are rich in chamosite, suggesting persistent anoxic, ferruginous conditions. In the Jixian and Lulong sections, deep subtidal zone sandstones are dominated by glauconite, indicative of suboxic environments. These results reveal pronounced spatiotemporal variations in redox conditions across the shallow seas of North China during the deposition of the Changlongshan Formation. While oxygenation facilitated the emergence of Longfengshania algae, the spatiotemporal discontinuity in the distribution of oxic water bodies may have limited the sustained evolution and widespread distribution of eukaryotes.
This study investigates the environmental context for the rapid evolution of crown-group eukaryotes during the Late Mesoproterozoic, focusing on sedimentological and mineralogical analyses of clastic rocks from the Changlongshan Formation across four sections of the North China Craton. In the Huailai section, fine-to-coarse sandstones from the deep-to-shallow subtidal zones are dominated by chamosite, indicating an anoxic, ferruginous marine environment. Conversely, glauconite dominates silty mudstone and muddy siltstone in the deep subtidal zone, reflecting suboxic conditions. In the Mentougou section, medium-to-coarse sandstones from the shallow subtidal zone are rich in chamosite, suggesting persistent anoxic, ferruginous conditions. In the Jixian and Lulong sections, deep subtidal zone sandstones are dominated by glauconite, indicative of suboxic environments. These results reveal pronounced spatiotemporal variations in redox conditions across the shallow seas of North China during the deposition of the Changlongshan Formation. While oxygenation facilitated the emergence of Longfengshania algae, the spatiotemporal discontinuity in the distribution of oxic water bodies may have limited the sustained evolution and widespread distribution of eukaryotes.
2025,
50(3):
1082-1104.
doi: 10.3799/dqkx.2024.144
Abstract:
To reveal the silicon cycling and potential mechanism of chert deposition in Mesoproterozoic shallow seas, an integrated study of sedimentology, mineralogy, geobiology and geochemistry was conducted on the Wumishan cherts (~1.48 Ga) using multiple techniques. The results show that the cherts are predominated by microquartz (~90%) in composition, with some silica-replaced carbonate (~5%) and minor pyrite (~1%) grains, indicating that the cherts largely originated from primary silica precipitation. High Ge/Si molar ratios (~8.83 μmol/mol) and positive Eu anomalies (~1.41) in the cherts suggest silica largely deriving from seawater (~94%), with a small contribution of thermally derived Si (~6%). Diverse microbial components (e.g., microbial filaments, EPS (extracellular polymeric substances) relics, mat fragments) and picocyanobacterian fossils were closely associated with organominerals, suggesting that microbial activities played important roles in silica precipitation. The Si liberated from degraded EPS and organo-Si complexes locally increased the dissolved Si concentrations and changed the chemical conditions in shallow substrate and pore-waters, promoting silica precipitation. The flourishing picocyanobacteria and certain prokaryotes that can accumulate silica in their cells or EPS may have changed the Si-cycling in Mesoproterozoic ocean, and the biogenic silica released from the microbial biomass may have promoted the silica precipitation in the Mesoproterozoic shallow-sea environments.
To reveal the silicon cycling and potential mechanism of chert deposition in Mesoproterozoic shallow seas, an integrated study of sedimentology, mineralogy, geobiology and geochemistry was conducted on the Wumishan cherts (~1.48 Ga) using multiple techniques. The results show that the cherts are predominated by microquartz (~90%) in composition, with some silica-replaced carbonate (~5%) and minor pyrite (~1%) grains, indicating that the cherts largely originated from primary silica precipitation. High Ge/Si molar ratios (~8.83 μmol/mol) and positive Eu anomalies (~1.41) in the cherts suggest silica largely deriving from seawater (~94%), with a small contribution of thermally derived Si (~6%). Diverse microbial components (e.g., microbial filaments, EPS (extracellular polymeric substances) relics, mat fragments) and picocyanobacterian fossils were closely associated with organominerals, suggesting that microbial activities played important roles in silica precipitation. The Si liberated from degraded EPS and organo-Si complexes locally increased the dissolved Si concentrations and changed the chemical conditions in shallow substrate and pore-waters, promoting silica precipitation. The flourishing picocyanobacteria and certain prokaryotes that can accumulate silica in their cells or EPS may have changed the Si-cycling in Mesoproterozoic ocean, and the biogenic silica released from the microbial biomass may have promoted the silica precipitation in the Mesoproterozoic shallow-sea environments.
2025,
50(3):
1105-1121.
doi: 10.3799/dqkx.2024.155
Abstract:
Among the many branches of geobiology, molecular palaeontology integrates multidisciplinary theories and methods, and plays an important role in exploring the speciation and evolution of organisms as well as the interaction between organisms and the environment in the geological history. Ancient DNA is one of the main carriers of molecular palaeontology research. It can reflect the genetic differences between individuals and provide irreplaceable real-time genetic information from ancient organisms for phylogeny and phylogeography. The genetic components legacy from some extinct groups to living populations not only reflect the history of gene flow between these groups and the ancestral populations of extant species, but also provide reference for protection of their living counterparts. In recent years, with the advancement of high-fragmented and trace amount DNA extraction and enrichment technologies, ancient DNA from sediments that does not rely on biological body fossils has become a rapid developing research direction, highlighting its importance in the reconstruction of ancient ecosystems and the ecological adaptation of organisms under the pressure of climate and environmental changes. This article focuses on the typical application examples and important significance of ancient DNA in geobiological fields in terms of phylogenetics, phylogeography, conservation biology, and Quaternary paleoenvironment and paleoclimate reconstruction, and looks forward to the application prospects of ancient DNA and ancient genomes in geobiology.
Among the many branches of geobiology, molecular palaeontology integrates multidisciplinary theories and methods, and plays an important role in exploring the speciation and evolution of organisms as well as the interaction between organisms and the environment in the geological history. Ancient DNA is one of the main carriers of molecular palaeontology research. It can reflect the genetic differences between individuals and provide irreplaceable real-time genetic information from ancient organisms for phylogeny and phylogeography. The genetic components legacy from some extinct groups to living populations not only reflect the history of gene flow between these groups and the ancestral populations of extant species, but also provide reference for protection of their living counterparts. In recent years, with the advancement of high-fragmented and trace amount DNA extraction and enrichment technologies, ancient DNA from sediments that does not rely on biological body fossils has become a rapid developing research direction, highlighting its importance in the reconstruction of ancient ecosystems and the ecological adaptation of organisms under the pressure of climate and environmental changes. This article focuses on the typical application examples and important significance of ancient DNA in geobiological fields in terms of phylogenetics, phylogeography, conservation biology, and Quaternary paleoenvironment and paleoclimate reconstruction, and looks forward to the application prospects of ancient DNA and ancient genomes in geobiology.
2025,
50(3):
1122-1141.
doi: 10.3799/dqkx.2025.004
Abstract:
Conodonts, serving as a feeding apparatus in oral cavity of an extinct and taxonomically ambiguous group of marine chordates, are phosphatic microfossils composed of carbonate fluorapatite (typically around 0.5 mm in size, with a maximum of 3 mm). They exhibit strong resistance to diagenesis, which is beneficial for preserving primary seawater information. Their elemental and isotopic composition is considered a reliable carrier of paleoceanographic chemical records. Geochemical systems represented by rare earth elements and oxygen, strontium, and calcium isotopes in conodonts have played a key role in revealing seawater redox conditions, acidity and alkalinity of paleooceans, surface seawater temperature, continental weathering, and paleoclimates. Conodont geochemical studies have been not only focusing on its application in the field of paleoenvironment and paleoclimatology, but also continuously delving into the microstructure of conodonts, especially the accurate extraction, evaluation, and screening of various elemental and isotopic information, with the aim of further improving the accurate application of conodont geochemistry. This paper reviews the morphology, structure, and paleoecological characteristics of conodonts, and on this basis, summarizes the study progress of rare earth elements and oxygen, strontium, and calcium isotope geochemistry of conodonts, in order to provide reference and inspiration for the development of conodont geochemistry and its application in paleoenvironmental and paleoclimatic studies.
Conodonts, serving as a feeding apparatus in oral cavity of an extinct and taxonomically ambiguous group of marine chordates, are phosphatic microfossils composed of carbonate fluorapatite (typically around 0.5 mm in size, with a maximum of 3 mm). They exhibit strong resistance to diagenesis, which is beneficial for preserving primary seawater information. Their elemental and isotopic composition is considered a reliable carrier of paleoceanographic chemical records. Geochemical systems represented by rare earth elements and oxygen, strontium, and calcium isotopes in conodonts have played a key role in revealing seawater redox conditions, acidity and alkalinity of paleooceans, surface seawater temperature, continental weathering, and paleoclimates. Conodont geochemical studies have been not only focusing on its application in the field of paleoenvironment and paleoclimatology, but also continuously delving into the microstructure of conodonts, especially the accurate extraction, evaluation, and screening of various elemental and isotopic information, with the aim of further improving the accurate application of conodont geochemistry. This paper reviews the morphology, structure, and paleoecological characteristics of conodonts, and on this basis, summarizes the study progress of rare earth elements and oxygen, strontium, and calcium isotope geochemistry of conodonts, in order to provide reference and inspiration for the development of conodont geochemistry and its application in paleoenvironmental and paleoclimatic studies.
Geobiological Perspective for the Formation of Manganiferous Deposit: Principle, Evidence, and Model
2025,
50(3):
1142-1161.
doi: 10.3799/dqkx.2025.002
Abstract:
Manganese (Mn) is a crucial transition metal element within the Earth system, whose geochemical behavior is predominantly influenced by the synergistic interaction of biological and environmental factors. In sedimentary and diagenetic environments, redox conditions and pH levels play a pivotal role in controlling the processes of manganese precipitation and enrichment. Over geological history, the formation of large-scale manganese deposits has been closely linked to oxidation in Earth's surface systems. The fundamental research significance and considerable economic value of manganese deposits have driven a sustained focus on the relationship between the geochemical cycling of manganese and the mechanisms underlying ore formation. Recent advances in studies on the geobiological enrichment mechanisms and cycling processes of manganese have highlighted the critical role of microbial activity in manganese enrichment within sediments. Research on manganiferous sediments in representative modern sedimentary environments indicates that the enrichment of manganese is jointly governed by microbial processes and sedimentary environmental factors. Nevertheless, studies on the geobiological aspects of ancient manganese deposits have been fragmented, and comprehensive reviews of research methods and ore-forming mechanisms remain inadequate. This study systematically reviews current research cases and progress on microbial mineralization in sedimentary manganese deposits worldwide, identifying four key analytical technology modules: (1) microscopic observation, (2) spectroscopic analysis, (3) isotopic signal analysis, and (4) integrative analysis. These modules collectively enable the effective extraction of evidence related to microbial mineralization processes. Key evidence includes microstructures and textures of microbial origin, extensively developed biogenic authigenic minerals, stable isotopic characteristics (e.g., carbon-sulfur isotopes) with distinct biological signals, elemental or compositional enrichment associated with microbial activity, and organic geochemical signatures such as biomarkers. A geobiological synthesis of the ore-forming processes in sedimentary manganese deposits reveals a two-stage ore-forming mechanism involving microbial participation. This mechanism comprises an initial oxidation-enrichment stage (Stage 1) and a subsequent preservation stage under reducing conditions (Stage 2). Manganese-oxidizing microbes likely function within complex microbial mat systems, interacting with iron-oxidizing microbes and photosynthetic microbes to facilitate manganese deposition.
Manganese (Mn) is a crucial transition metal element within the Earth system, whose geochemical behavior is predominantly influenced by the synergistic interaction of biological and environmental factors. In sedimentary and diagenetic environments, redox conditions and pH levels play a pivotal role in controlling the processes of manganese precipitation and enrichment. Over geological history, the formation of large-scale manganese deposits has been closely linked to oxidation in Earth's surface systems. The fundamental research significance and considerable economic value of manganese deposits have driven a sustained focus on the relationship between the geochemical cycling of manganese and the mechanisms underlying ore formation. Recent advances in studies on the geobiological enrichment mechanisms and cycling processes of manganese have highlighted the critical role of microbial activity in manganese enrichment within sediments. Research on manganiferous sediments in representative modern sedimentary environments indicates that the enrichment of manganese is jointly governed by microbial processes and sedimentary environmental factors. Nevertheless, studies on the geobiological aspects of ancient manganese deposits have been fragmented, and comprehensive reviews of research methods and ore-forming mechanisms remain inadequate. This study systematically reviews current research cases and progress on microbial mineralization in sedimentary manganese deposits worldwide, identifying four key analytical technology modules: (1) microscopic observation, (2) spectroscopic analysis, (3) isotopic signal analysis, and (4) integrative analysis. These modules collectively enable the effective extraction of evidence related to microbial mineralization processes. Key evidence includes microstructures and textures of microbial origin, extensively developed biogenic authigenic minerals, stable isotopic characteristics (e.g., carbon-sulfur isotopes) with distinct biological signals, elemental or compositional enrichment associated with microbial activity, and organic geochemical signatures such as biomarkers. A geobiological synthesis of the ore-forming processes in sedimentary manganese deposits reveals a two-stage ore-forming mechanism involving microbial participation. This mechanism comprises an initial oxidation-enrichment stage (Stage 1) and a subsequent preservation stage under reducing conditions (Stage 2). Manganese-oxidizing microbes likely function within complex microbial mat systems, interacting with iron-oxidizing microbes and photosynthetic microbes to facilitate manganese deposition.
2025,
50(3):
1162-1200.
doi: 10.3799/dqkx.2024.147
Abstract:
The Qinghai-Xizang Plateau orogenic domain has experienced the formation, distribution, and multi-stage ocean-continent transformation of the Proto-Tethys, Paleo-Tethys, and Neo-Tethys oceans, making it a favorable area for polymetallic mineralization such as copper, gold, niobium, and tantalum. Throughout the Phanerozoic evolution of the Tethys Ocean, unique oceanic plate stratigraphy (referred to as OPS) was formed during each evolutionary stage. Reconstructing the OPS sequences of various tectono-stratigraphic units in different evolutionary stages of the Qinghai-Xizang Plateau orogenic domain, as well as establishing a comparative framework, is an essential foundation for polymetallic mineral exploration and major engineering construction in the orogenic domain. This paper systematically reviews and analyzes the composition of ophiolitic mélange and other remnants of oceanic crust from over 130 exposure points in various geological periods of the Qinghai-Xizang Plateau, 256 dating data of ophiolitic remnants, and accompanying siliceous rock radiolarian fossils. Based on the tectonic environment and temporal distribution, three OPS tectono-stratigraphic mega-regions and nine districts have been delineated, namely the Bayankala-Sanjiang, Longmu Co-Shuanghu-Bangong-Nujiang-Changning-Menglian, and Gangdise-Yarlung Zangbo mega-regions. The Bayankala-Sanjiang mega-region includes the Xijinwulan, Ganzi-Litang, Jinsha River, and Ailao Mountain districts; the Longmu Co-Shuanghu-Bangong-Nujiang-Changning-Menglian mega-region includes the Longmu Co-Shuanghu, Bangong-Nujiang, and Changning-Menglian districts; the Gangdise-Yarlung Zangbo mega-region includes the Shiquanhe-Jiali and Yarlung Zangbo districts. Based on the three mega-regions and nine districts, two major types of OPS, namely suture zone type and subordinate suture zone type, and five subcategories of OPS, including oceanic ridge, oceanic island-seamount, oceanic arc, forearc, and trench sedimentary construction, have been identified. Using isotopic dating, paleontological fossil sequence division and correlation, the first Phanerozoic OPS stratigraphic framework and spatiotemporal evolution model for the Qinghai-Xizang Plateau orogenic domain have been constructed, and a discussion on the Tethyan evolution model of the Qinghai-Xizang Plateau has been conducted.
The Qinghai-Xizang Plateau orogenic domain has experienced the formation, distribution, and multi-stage ocean-continent transformation of the Proto-Tethys, Paleo-Tethys, and Neo-Tethys oceans, making it a favorable area for polymetallic mineralization such as copper, gold, niobium, and tantalum. Throughout the Phanerozoic evolution of the Tethys Ocean, unique oceanic plate stratigraphy (referred to as OPS) was formed during each evolutionary stage. Reconstructing the OPS sequences of various tectono-stratigraphic units in different evolutionary stages of the Qinghai-Xizang Plateau orogenic domain, as well as establishing a comparative framework, is an essential foundation for polymetallic mineral exploration and major engineering construction in the orogenic domain. This paper systematically reviews and analyzes the composition of ophiolitic mélange and other remnants of oceanic crust from over 130 exposure points in various geological periods of the Qinghai-Xizang Plateau, 256 dating data of ophiolitic remnants, and accompanying siliceous rock radiolarian fossils. Based on the tectonic environment and temporal distribution, three OPS tectono-stratigraphic mega-regions and nine districts have been delineated, namely the Bayankala-Sanjiang, Longmu Co-Shuanghu-Bangong-Nujiang-Changning-Menglian, and Gangdise-Yarlung Zangbo mega-regions. The Bayankala-Sanjiang mega-region includes the Xijinwulan, Ganzi-Litang, Jinsha River, and Ailao Mountain districts; the Longmu Co-Shuanghu-Bangong-Nujiang-Changning-Menglian mega-region includes the Longmu Co-Shuanghu, Bangong-Nujiang, and Changning-Menglian districts; the Gangdise-Yarlung Zangbo mega-region includes the Shiquanhe-Jiali and Yarlung Zangbo districts. Based on the three mega-regions and nine districts, two major types of OPS, namely suture zone type and subordinate suture zone type, and five subcategories of OPS, including oceanic ridge, oceanic island-seamount, oceanic arc, forearc, and trench sedimentary construction, have been identified. Using isotopic dating, paleontological fossil sequence division and correlation, the first Phanerozoic OPS stratigraphic framework and spatiotemporal evolution model for the Qinghai-Xizang Plateau orogenic domain have been constructed, and a discussion on the Tethyan evolution model of the Qinghai-Xizang Plateau has been conducted.
2025,
50(3):
1201-1219.
doi: 10.3799/dqkx.2025.016
Abstract:
Mineral-microbe interaction (MMI) is one of the most dynamic geological processes driving the evolution of Earth's system, profoundly influencing Earth life's evolutionary processes. MMIs are also a key research focus in mineralogy and geomicrobiology. To fully understand the interactions between microbes and minerals, one of the critical areas is to decode how microorganisms affect the structural and compositional changes on mineral surfaces at an ultra-microscopic scale. Although significant progress has been made in the MMI studies in recent years, major challenges still remain due to the microscopic processes occurring at nanoscale and even sub-nanoscale levels. Simultaneous characterization of mineral structures, chemical compositions, and microbial remnants at these scales remains difficult, leaving many fundamental mechanistic questions unresolved. The emerging three-dimensional atom probe technology (APT) overcomes these limitations. APT enables near-atomic scale imaging and quantitative analysis of nearly all elements/isotopes simultaneously, with a detection limit as low as 10⁻⁶. This provides near-atomic scale, high-sensitivity analysis for research into mineral-microbe interactions. Originally developed and widely applied in materials science, APT has attracted increasing attention in the field of Earth sciences in recent years. This paper provides an overview of the principles, development, and sample preparation involved in APT, introduces the concept of biomineralization and related studies, and focuses on the key applications of APT technology in fields such as microbial mineralization, identifying geological microbial remnants, and biomaterials related to mineral-microbe interactions. Finally, we objectively summarize the current limitations and challenges of APT technology in the study of mineral-microbe interactions and explore the future development directions of this advanced in-situ micro-area technique in the field of mineral-microbe research.
Mineral-microbe interaction (MMI) is one of the most dynamic geological processes driving the evolution of Earth's system, profoundly influencing Earth life's evolutionary processes. MMIs are also a key research focus in mineralogy and geomicrobiology. To fully understand the interactions between microbes and minerals, one of the critical areas is to decode how microorganisms affect the structural and compositional changes on mineral surfaces at an ultra-microscopic scale. Although significant progress has been made in the MMI studies in recent years, major challenges still remain due to the microscopic processes occurring at nanoscale and even sub-nanoscale levels. Simultaneous characterization of mineral structures, chemical compositions, and microbial remnants at these scales remains difficult, leaving many fundamental mechanistic questions unresolved. The emerging three-dimensional atom probe technology (APT) overcomes these limitations. APT enables near-atomic scale imaging and quantitative analysis of nearly all elements/isotopes simultaneously, with a detection limit as low as 10⁻⁶. This provides near-atomic scale, high-sensitivity analysis for research into mineral-microbe interactions. Originally developed and widely applied in materials science, APT has attracted increasing attention in the field of Earth sciences in recent years. This paper provides an overview of the principles, development, and sample preparation involved in APT, introduces the concept of biomineralization and related studies, and focuses on the key applications of APT technology in fields such as microbial mineralization, identifying geological microbial remnants, and biomaterials related to mineral-microbe interactions. Finally, we objectively summarize the current limitations and challenges of APT technology in the study of mineral-microbe interactions and explore the future development directions of this advanced in-situ micro-area technique in the field of mineral-microbe research.
2025,
50(3):
1220-1233.
doi: 10.3799/dqkx.2025.021
Abstract:
NanoSIMS (nanoscale secondary ion mass spectrometry) technology, with its high spatial resolution and chemical sensitivity, demonstrates significant potential for implications in researches of geomicrobiology. This technology enables in-situ analysis of elemental and isotopic distributions at the nanoscale, offering a revolutionary tool for uncovering interactions between microorganisms and their environments. This article reviews the applications and advancements of NanoSIMS technology in the field of geomicrobiology. It provides a detailed overview of the principles of NanoSIMS and its applications in areas such as identifying biogenic minerals from ancient microorganisms, exploring extraterrestrial life, carbonate mineral precipitation, biogeochemical cycles, and functional studies of modern microbial communities. The development of NanoSIMS has propelled geomicrobiology towards greater precision and resolution, presenting unprecedented opportunities to study the origin of life, microbial activity in extreme environments, and global biogeochemical cycles. At the same time, this article identifies challenges related to sample preparation, signal-to-noise ratio, and quantitative analysis, while also suggesting directions for optimization, such as technological upgrades, multi-technique integration, and algorithmic improvements. In the future, the continued evolution of NanoSIMS will provide critical support for investigating early life on Earth, global elemental cycles, and extraterrestrial life, further advancing geomicrobiology and its related interdisciplinary fields.
NanoSIMS (nanoscale secondary ion mass spectrometry) technology, with its high spatial resolution and chemical sensitivity, demonstrates significant potential for implications in researches of geomicrobiology. This technology enables in-situ analysis of elemental and isotopic distributions at the nanoscale, offering a revolutionary tool for uncovering interactions between microorganisms and their environments. This article reviews the applications and advancements of NanoSIMS technology in the field of geomicrobiology. It provides a detailed overview of the principles of NanoSIMS and its applications in areas such as identifying biogenic minerals from ancient microorganisms, exploring extraterrestrial life, carbonate mineral precipitation, biogeochemical cycles, and functional studies of modern microbial communities. The development of NanoSIMS has propelled geomicrobiology towards greater precision and resolution, presenting unprecedented opportunities to study the origin of life, microbial activity in extreme environments, and global biogeochemical cycles. At the same time, this article identifies challenges related to sample preparation, signal-to-noise ratio, and quantitative analysis, while also suggesting directions for optimization, such as technological upgrades, multi-technique integration, and algorithmic improvements. In the future, the continued evolution of NanoSIMS will provide critical support for investigating early life on Earth, global elemental cycles, and extraterrestrial life, further advancing geomicrobiology and its related interdisciplinary fields.
2025,
50(3):
1234-1249.
doi: 10.3799/dqkx.2022.237
Abstract:
Fossil spores and pollen are important indicators for stratigraphic age determination and paleoclimate recovery. In this paper, we first reported the palynological assemblage in the middle part of the Lower Cretaceous Chijinbao Formation in the Zhongkouzi basin of the Beishan area. A total of 56 genera and 84 species of spores and pollens were obtained from the deposits, including 29.3% of fern spores, 62.6% of gymnosperm pollens, and 8.1% of angiosperm pollens. Based on the significant spore and pollen components in the palynological assemblage, we assigned the middle part of the Chijinbao Formation to the middle Early Cretaceous Hauterivian-Aptian. We divided three sequences based on palynological assemblage characteristics, with Ephedripites-Pterisisporites-Retitricolpites assemblage at the bottom, Classopollis-Cicatricosisporites-Tricolpites assemblage at the middle, and Triporoletes-Laricoidites assemblage at the top. Three Palynological assemblages from old to new respectively represent the vegetation of southern subtropical semi-dry and semi-humid coniferous forests, scrubs to subtropical semi-arid coniferous forests, northern subtropical semi-humid coniferous forests. The climate shows a characteristic of first becoming dry and hot and then becoming hot and humid.
Fossil spores and pollen are important indicators for stratigraphic age determination and paleoclimate recovery. In this paper, we first reported the palynological assemblage in the middle part of the Lower Cretaceous Chijinbao Formation in the Zhongkouzi basin of the Beishan area. A total of 56 genera and 84 species of spores and pollens were obtained from the deposits, including 29.3% of fern spores, 62.6% of gymnosperm pollens, and 8.1% of angiosperm pollens. Based on the significant spore and pollen components in the palynological assemblage, we assigned the middle part of the Chijinbao Formation to the middle Early Cretaceous Hauterivian-Aptian. We divided three sequences based on palynological assemblage characteristics, with Ephedripites-Pterisisporites-Retitricolpites assemblage at the bottom, Classopollis-Cicatricosisporites-Tricolpites assemblage at the middle, and Triporoletes-Laricoidites assemblage at the top. Three Palynological assemblages from old to new respectively represent the vegetation of southern subtropical semi-dry and semi-humid coniferous forests, scrubs to subtropical semi-arid coniferous forests, northern subtropical semi-humid coniferous forests. The climate shows a characteristic of first becoming dry and hot and then becoming hot and humid.
2025,
50(3):
1250-1262.
doi: 10.3799/dqkx.2024.129
Abstract:
U isotope carriers undergo significant fractionation during sedimentation and diagenesis, often leading to misinterpretations of paleoocean redox conditions. This study systematically reviews the fractionation mechanisms of U isotopes, detailing their behavior during the sedimentation and diagenesis of carbonates, black shales, and ferromanganese crusts. It also proposes characteristics of ideal carriers and techniques to mitigate diagenetic effects. Overall, U isotope fractionation mechanisms are diverse, influenced by factors such as reaction rates, electron flux, and ionic strength. Sedimentation and diagenesis in carbonates and black shales typically result in heavier isotope compositions, while ferromanganese crusts exhibit fractionation in the opposite direction. The extent of fractionation is controlled by depositional environments and lithological composition. In practical applications, marine carbonates with low diagenetic alteration and primarily aragonitic mineralogy are recommended. Advanced techniques, such as ion-exchange chromatography, should be employed to accurately reconstruct the redox conditions of paleooceans.
U isotope carriers undergo significant fractionation during sedimentation and diagenesis, often leading to misinterpretations of paleoocean redox conditions. This study systematically reviews the fractionation mechanisms of U isotopes, detailing their behavior during the sedimentation and diagenesis of carbonates, black shales, and ferromanganese crusts. It also proposes characteristics of ideal carriers and techniques to mitigate diagenetic effects. Overall, U isotope fractionation mechanisms are diverse, influenced by factors such as reaction rates, electron flux, and ionic strength. Sedimentation and diagenesis in carbonates and black shales typically result in heavier isotope compositions, while ferromanganese crusts exhibit fractionation in the opposite direction. The extent of fractionation is controlled by depositional environments and lithological composition. In practical applications, marine carbonates with low diagenetic alteration and primarily aragonitic mineralogy are recommended. Advanced techniques, such as ion-exchange chromatography, should be employed to accurately reconstruct the redox conditions of paleooceans.
