Article
Environmental Sciences
Butsawan Bidorn, Kimhuy Sok, Komkrit Bidorn, William C. Burnett
Summary: Deltas are facing threats such as sea level rise and erosion, with many retreating shorelines attributed to decreased sediment supply from upstream dam construction. Despite the presence of two large dams in the Chao Phraya River and Delta, sediment accumulation has actually increased in recent decades, mainly due to expansion of activities in the delta since the 1970s. Shoreline erosion in the Chao Phraya Delta is primarily caused by subsidence induced by groundwater withdrawal and global sea level rise, rather than mangrove removal for development purposes.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Zhouqiao Zhao, Bing Shen, Jian-Ming Zhu, Xianguo Lang, Guangliang Wu, Decan Tan, Haoxiang Pei, Tianzheng Huang, Meng Ning, Haoran Ma
Summary: The deglaciation of the Marinoan snowball Earth ice age was associated with intense continental weathering, recovery of primary productivity, transient marine euxinia, and potentially extensive CH4 emission. It is proposed that the deglacial CH4 emissions may have provided positive feedbacks for ice melting and global warming. The study suggests that active methanogenesis was fueled by methyl sulfides produced in sulfidic seawater during the deglacial recovery of marine primary productivity.
NATURE COMMUNICATIONS
(2021)
Article
Meteorology & Atmospheric Sciences
Nicholas J. Edkins, Roger Davies
Summary: This study explores the impact of increased CO2 levels in the atmosphere on the expansion of the Earth's thermal layer in two directions. It is found that the expansion downward has a more significant effect on surface temperature, aiding in the deglaciation of a "Snowball Earth".
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Geology
D. O. Zakharov, D. R. Zozulya, D. P. Colon
Summary: Given the scarcity of reliable paleoclimate record, this study shows how analyzing the oxygen isotope values of surface precipitation recorded in Archean igneous and hydrothermal formations can help to understand the climate of early Earth.
Article
Physics, Fluids & Plasmas
Maura Brunetti, Charline Ragon
Summary: The climate is a complex system that tends towards a steady state under solar radiation and dissipative mechanisms. Bifurcation diagrams are useful tools for understanding the possible steady states, but constructing them can be time-consuming. Researchers tested two techniques for constructing bifurcation diagrams in a climate model, one involving random fluctuations in forcing and the other using estimates of internal variability and surface energy imbalance to find tipping points more precisely.
Article
Geosciences, Multidisciplinary
Benjamin W. Johnson, Colin Mettam, Simon W. Poulton
Summary: The history of the nitrogen cycle on Earth is closely linked to the redox evolution of the surface environment. Interpretation of nitrogen isotopic analyses in past environments requires linking with redox-sensitive proxies. Combining N isotope and redox analyses is essential to interpret biologic isotopic signals during times of dynamic redox in the ocean-atmosphere system.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geography, Physical
Zhouqiao Zhao, Yonggang Liu, Haijin Dai
Summary: This study uses a model to evaluate the rate and timescale of marine ice deglaciation, finding that it takes at most 300 to 1500 years and results in the formation of a freshwater lid.
GLOBAL AND PLANETARY CHANGE
(2022)
Review
Mathematics, Interdisciplinary Applications
Thomas E. Mulder, Heiko Goelzer, Fred W. Wubs, Henk A. Dijkstra
Summary: This study utilizes a novel fully-implicit Earth System Model of Intermediate Complexity (I-EMIC) to investigate transitions to Snowball Earth (SBE) states, revealing a complex bifurcation structure associated with the ice-albedo feedback. High-dimensional branches of the SBE bifurcation diagram are obtained through parameter continuation, allowing for the identification of stable and unstable equilibria. Additionally, large-scale linear stability analyses near major bifurcations uncover the spatial nature of destabilizing perturbations.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2021)
Article
Biodiversity Conservation
Huw J. Griffiths, Rowan J. Whittle, Emily G. Mitchell
Summary: The timing of the first appearance of animals is crucial for understanding the evolution of life on Earth. The fossil record suggests a relatively recent origin, while molecular clock studies suggest a much earlier origination. Little attention has been given to how animal life would have survived during global glacial periods. Recent research on polar biota offers insights into the survival strategies and habitats of modern marine organisms in environments similar to those during Neoproterozoic glaciations.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Biology
Hao Zhang, Ying Sun, Qinglu Zeng, Sean A. Crowe, Haiwei Luo
Summary: Prochlorococcus, the most abundant photosynthetic organisms in the modern ocean, experienced a massive genome reduction in their early evolutionary history during the Neoproterozoic Snowball Earth event. The lethally low temperature and exceedingly dim light during this period inhibited their growth and caused severe population bottlenecks, leading to an excess of deleterious mutations accumulated across genomic regions. Adaptations to extreme environmental conditions during the Snowball Earth intervals can be inferred by tracing the evolutionary paths of genes encoding key metabolic potential.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
T. M. Vandyk, C. Kettler, B. J. Davies, G. A. Shields, I Candy, D. P. Le Heron
Summary: This passage discusses the importance of ancient glacial deposits in understanding Earth's climate during the Cryogenian Period, as well as the challenges in determining the past positions of grounded ice, its thermal regime, and flow direction. The study found that Cryogenian subglacially striated surfaces are globally rare but are crucial indicators of the presence of ice and thermal regime.
PRECAMBRIAN RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Yongjing Mao, Daniel L. Harris, David P. Callaghan, Stuart Phinn
Summary: This study compared and evaluated large-scale shoreline retreat rate (SRR) in Australia using Discrete and Hybrid Bayesian networks. It was found that Hybrid BNs outperformed in predicting continuous variables and provided a more realistic assessment of the range of SRR, while both BNs gave consistent qualitative findings for Australia's SRR. Sediment sink/source was identified as the most informative parameter in indicating shoreline retreat.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2021)
Article
Geochemistry & Geophysics
Daniel Garduno Ruiz, Colin Goldblatt, Anne-Sofie Ahm
Summary: A one-dimensional atmospheric photochemical model is used to study the effect of temperature and humidity variations on the evolution of O2 and O3 during the Great Oxidation Event (GOE). It is found that changes in temperature and humidity can significantly impact the levels of O2 and O3, with higher temperatures and humidity leading to higher levels of these gases.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geology
Min Ren, Brian Jones
Summary: The study focuses on the global Ediacaran cap dolostones to understand the Earth's conditions after the Marinoan period, assuming that the original environmental features have not been altered. The Doushantuo cap dolostones in southeast China exhibit distinct petrographic, stoichiometric, and crystal architectural features that indicate their formation and evolution. Analysis of these dolostones shows that they are composed of near-stoichiometric dolomite and have experienced various processes such as cementation, dolomitization, fracture filling, recrystallization, and dolomite precipitation. The homogeneity in the dolomite populations and crystal architecture suggests extensive recrystallization in the Doushantuo cap dolostones. (c) 2023 Elsevier B.V. All rights reserved.
SEDIMENTARY GEOLOGY
(2023)
Article
Geography, Physical
Atena Shizuya, Kunio Kaiho, Jinnan Tong
Summary: This study used biomarker evidence to reveal the evolutionary processes during the late Neoproterozoic from the Marinoan glaciation to the early Ediacaran period. The results show the presence of photosynthetic activity, low productivity, and the expansion of eukaryotes during different stages of this transition.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geosciences, Multidisciplinary
Maximilian Droellner, Milo Barham, Christopher L. Kirkland
Summary: This study reconstructs the sediment routing system of the Canning Basin during the Early Cretaceous and reveals its response to the supercontinent dispersal using multi-proxy analysis. The majority of the detrital grains are sourced from the crystalline basement in central Australia, indicating the negligible influence of proximal sediment supply. Central Australia acted as a major drainage divide during the Early Cretaceous, and a sediment pathway from Antarctica provided a template for drainage in this period.
Article
Geochemistry & Geophysics
Andreas Zametzer, Christopher L. Kirkland, Milo Barham, Nicholas E. Timms, Michael I. H. Hartnady, Aaron J. Cavosie, Bryant Ware, William D. A. Rickard, Timmons Erickson
Summary: Hypervelocity impacts have had a significant impact on the evolution of Earth's continental crust. The use of accessory minerals and rock-forming minerals like zircon and quartz, respectively, has been common in dating impact events and measuring shock-induced deformation. However, feldspar group minerals, which are major components of most crustal rocks, have not been extensively utilized in documenting impact-induced deformation and alteration. This study explores the potential of using Pb isotope analysis in alkali feldspar to identify impact-related modifications and estimate their timing.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Janne Liebmann, Milo Barham, Christopher I. L. Kirkland
Summary: The Grenville Orogen in North America contains Proterozoic anorthosite massifs that were emplaced episodically. These magmas were formed through fractional crystallization of plagioclase from mafic magma. U-Pb geochronology and Zr-in-rutile analyses of the Lac Malbaie complex in Quebec provide information on the tectonothermal history of anorthosite emplacement. The rutile ages obtained suggest variable modification of cooling ages during later intrusion and fluid mobilization events.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geology
Maximilian Drollner, Milo Barham, Christopher L. Kirkland, Malcolm P. Roberts
Summary: Dating of xenotime outgrowths (XOs) showed that they were detrital and transported with the zircon. Integration of geochronology and geochemistry linked XOs to intermediate geological events in the source area. These findings emphasize the importance of evaluating a potential detrital origin for XOs.
Article
Geosciences, Multidisciplinary
Maximilian Drollner, Milo Barham, Christopher L. Kirkland, Martin Danisik, Julien Bourdet, Maike Schulz, Mehrooz Aspandiar
Summary: Accurate dating of continental climate change is challenging due to the lack of dateable terrestrial products. In this study, ferruginous indurations from the Nullarbor Plain in Australia were used to determine the timing of Plio-Pleistocene aridification. The results suggest that the formation of ferruginous indurations was linked to a decline in the groundwater table caused by a rapid climatic shift. This finding highlights the importance of ferruginous indurations as targets for obtaining absolute ages on landscape evolution and improving understanding of environmental drivers of species diversification and extinction.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Ross N. Mitchell, Uwe Kirscher
Summary: This study analyzes observational constraints on the Precambrian length of day and finds that the day length stalled at about 19 h for about 1 billion years during the mid-Proterozoic. It suggests that the accelerative torque of atmospheric thermal tides from solar energy balanced the decelerative torque of lunar oceanic tides, temporarily stabilizing Earth's rotation. This stalling coincides with a period of relatively limited biological evolution known as the boring billion.
Article
Multidisciplinary Sciences
Ruimin Wang, Bing Shen, Xianguo Lang, Bin Wen, Ross N. Mitchell, Haoran Ma, Zongjun Yin, Yongbo Peng, Yonggang Liu, Chuanming Zhou
Summary: A Great Ediacaran Glaciation, lasting for 20 million years, occurred globally from mid-to-high latitudes, witnessing the evolution of the Ediacara biota. The timing of Ediacaran glaciation remains controversial due to limited age constraints and a lack of convincing evidence for low-latitude glaciations. However, recent studies using carbon isotope excursions and paleomagnetic evidence suggest that the Ediacaran glaciation occurred diachronously but continuously from ca. 580-560 Ma as different continents migrated through polar-temperate latitudes.
NATIONAL SCIENCE REVIEW
(2023)
Review
Environmental Sciences
Shujuan Jiao, Michael Brown, Ross N. Mitchell, Priyadarshi Chowdhury, Chris Clark, Lin Chen, Yi Chen, Fawna Korhonen, Guangyu Huang, Jinghui Guo
Summary: Ultrahigh-temperature (UHT) metamorphism occurs in the continental crust at depths of 15-55 km and requires unusually high thermal conditions. This review explores the tectonic settings of UHT metamorphism, which are commonly associated with convergent plate margins, supercontinent assembly, arc-backarc systems, thinned lithosphere, orogenic plateaus, and orogenic collapse. Geophysical mapping reveals the occurrence of UHT metamorphism in present-day orogens such as the Tibetan Plateau and the North American Cordillera. Further research should focus on improved geodynamic modelling to establish quantitative correlations between heat sources and the spatial extent of UHT metamorphism.
NATURE REVIEWS EARTH & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Igor K. Nikogosian, Antoine J. J. Bracco Gartner, Paul R. D. Mason, Douwe J. J. van Hinsbergen, Klaudia F. Kuiper, Uwe Kirscher, Sergei Matveev, Araik Grigoryan, Edmond Grigoryan, Arsen Israyelyan, Manfred J. van Bergen, Janne M. Koornneef, Jan R. Wijbrans, Gareth R. Davies, Khachatur Meliksetian
Summary: This study presents new geochronological, palaeomagnetic, and geochemical constraints to understand the geodynamic evolution of the South Armenian Block (SAB) and its Gondwanan origin. It reveals the timing of rifting and provides insights into the geological history of the SAB since the Permian.
Article
Multidisciplinary Sciences
Heng-Ci Tian, Chi Zhang, Wei Yang, Jun Du, Yi Chen, Zhiyong Xiao, Ross N. Mitchell, Hejiu Hui, Hitesh G. Changela, Tian-Xin Zhang, Xu Tang, Di Zhang, Yangting Lin, Xianhua Li, Fuyuan Wu
Summary: This study investigates the mineralogy and geochemistry of lunar basalts from the Chang'e-5 mission, revealing limited magma recharge or shallow-level assimilation in most crystals. Thermal modeling shows an enhanced magmatic flux around 2 billion years ago, suggesting episodic eruptions at the final stage could have above average eruptive fluxes, revising models of lunar thermal evolution.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Gisela Gartmair, Milo Barham, Christopher L. Kirkland
Summary: Provenance studies in sediment commonly use isotopic signatures to identify the sources of detrital minerals. However, similar ages and geochemical characteristics in different geographical regions can lead to ambiguities in mineral provenance interpretations. In this study, new Hf isotope data and zircon grain shape data are used to investigate the effectiveness of grain shape analysis in resolving mineral provenance in the Eucla Basin.
GEOSCIENCE FRONTIERS
(2023)
Article
Multidisciplinary Sciences
Qing Zhang, Lei Zhao, Dawn Zhou, Allen P. Nutman, Ross N. Mitchell, Yu Liu, Qiu-Li Li, Hui-Min Yu, Billy Fan, Christopher J. Spencer, Xian-Hua Li
Summary: Studying silicon and oxygen isotopes in the oldest rocks on Earth helps understand crustal recycling and the geological evolution of early Earth.
Article
Environmental Sciences
Dongfang Song, Ross N. Mitchell, Wenjiao Xiao, Qigui Mao, Bo Wan, Songjian Ao
Summary: The study reveals a method to record Late Palaeozoic climate change and constrain tectonic-climate interaction, based on the analysis of sediments in North China. It suggests the existence of an orogenic plateau that played a significant role in triggering Permian aridification.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Environmental Sciences
Bin Su, Yi Chen, Zongyu Yue, Lin Chen, Ross N. Mitchell, Ming Tang, Wei Yang, Guangyu Huang, Jinghui Guo, Xian-Hua Li, Fu-Yuan Wu
Summary: Partial remelting of KREEP basalts on the Moon could explain the occurrence of highly silicic volcanic constructs without the need for water and plate tectonics. The origin of lunar silicic magmatism remains enigmatic, but phase equilibrium simulations suggest that silicic volcanic constructs can be produced by partial melting of KREEP basalts. This finding may reshape our understanding of early planetary crust formation.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)