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Sulphide oxidation coupled to carbonate dissolution can provide a transient source of carbon dioxide to Earth's atmosphere and so balance the Cenozoic increase in carbon dioxide consumption by silicate weathering, reconciling this increase with the need for mass balance in the long-term carbon cycle. Balancing the Cenozoic carbon budget It is thought that mountain uplift stimulated carbon dioxide consumption by silicate mineral weathering during the Cenozoic era, roughly spanning the past 66 million years, but there are no signs of a corresponding increase in volcanic carbon dioxide emissions that could balance the carbon budget. This paper suggests that some of the missing carbon dioxide could have been produced by coupled sulphide oxidation and carbonate dissolution, a process that may also have been accelerated in response to uplift. This hypothesis is consistent with isotopic records and may help explain the interactions between the long-term carbon cycle, tectonics, and Earth's climate. The observed stability of Earth's climate over millions of years is thought to depend on the rate of carbon dioxide (CO.sub.2) release from the solid Earth being balanced by the rate of CO.sub.2 consumption by silicate weathering.sup.1. During the Cenozoic era, spanning approximately the past 66 million years, the concurrent increases in the marine isotopic ratios of strontium, osmium and lithium.sup.2,3,4 suggest that extensive uplift of mountain ranges may have stimulated CO.sub.2 consumption by silicate weathering.sup.5, but reconstructions of sea-floor spreading.sup.6 do not indicate a corresponding increase in CO.sub.2 inputs from volcanic degassing. The resulting imbalance would have depleted the atmosphere of all CO.sub.2 within a few million years.sup.7. As a result, reconciling Cenozoic isotopic records with the need for mass balance in the long-term carbon cycle has been a major and unresolved challenge in geochemistry and Earth history. Here we show that enhanced sulphide oxidation coupled to carbonate dissolution can provide a transient source of CO.sub.2 to Earth's atmosphere that is relevant over geological timescales. Like drawdown by means of silicate weathering, this source is probably enhanced by tectonic uplift, and so may have contributed to the relative stability of the partial pressure of atmospheric CO.sub.2 during the Cenozoic. A variety of other hypotheses.sup.8,9,10 have been put forward to explain the 'Cenozoic isotope-weathering paradox', and the evolution of the carbon cycle probably depended on multiple processes. However, an important role for sulphide oxidation coupled to carbonate dissolution is consistent with records of radiogenic isotopes.sup.2,3, atmospheric CO.sub.2 partial pressure.sup.11,12 and the evolution of the Cenozoic sulphur cycle, and could be accounted for by geologically reasonable changes in the global dioxygen cycle, suggesting that this CO.sub.2 source should be considered a potentially important but as yet generally unrecognized component of the long-term carbon cycle., Author(s): Mark A. Torres [sup.1] , A. Joshua West [sup.1] , Gaojun Li [sup.2] Author Affiliations: (1) Department of Earth Sciences, University of Southern California, Los Angeles, USA (2) Department [...]

Nd-Sr isotopic signatures of loess, modern dust, and their potential source materials are systematically investigated to discriminate the natural and anthropogenic sources of eastern Asian dust. Chinese loess is an eolian deposit that has accumulated over the past few million years, and is characterized by a negative Nd-Sr isotopic correlation that implies binary sources for the natural background of eastern Asian dust. Loess in northeastern China shows the highest [[epsilon].sub.Nd](0) value, while loess in western China has the lowest [[epsilon].sub.Nd](0). Considering the Nd-Sr isotopic signatures of the potential sources, we propose that the high [[epsilon].sub.Nd](0) end member is derived from the arid lands around the northern boundary of China while the low [[epsilon].sub.Nd](0) end member originates from the deserts on the northern margin of the Tibetan Plateau. Chinese Loess Plateau deposits are dominated by northern margin Tibetan Plateau dust, suggesting a strong link between the thick eolian deposit in this region and the evolution of the Tibetan Plateau. The long-range transported spring dust in both Nanjing (south China) and Japan has an Nd-Sr isotopic composition similar to that of loess. However, spring dust in Beijing (north China) has a much lower [[epsilon].sub.Nd](0) value, indicating an additional anthropogenic contribution of low [[epsilon].sub.Nd](0) material, possibly from the sandy lands in the adjacent north and west.

Earth's climate system has experienced substantial millennial‐scale oscillations characterized by abrupt changes superimposed on orbital‐scale changes. However, the dynamic connection between millennial and orbital timescales remains elusive. Here, we provide a summer monsoon precipitation δ18O record spanning from ∼8 to ∼60.5 ka based on the oxygen isotopic composition of microcodium from loess deposits on the Chinese Loess Plateau. This record shows distinct precessional variations (23 ka) punctuated by prominent millennial‐scale oscillations. It is generally consistent with speleothem δ18O and other loess‐based records, reflecting the East Asian summer monsoon changes. More importantly, our result also shows that large increases in the magnitude of millennial‐scale variability correspond to the Northern Hemisphere summer insolation minimum. We propose that precession‐induced low‐latitude summer insolation modulates the amplitudes of millennial‐scale summer monsoon variability by changing the mean monsoon state during the last glaciation. Plain Language Summary: Understanding the dynamic connections between different timescales is crucial to predicting future climate variability. Here, we provide a summer monsoon precipitation δ18O record based on the oxygen isotopic composition of microcodium from loess deposits on the Chinese Loess Plateau, showing that large increases in the magnitude of millennial‐scale variability correspond to Northern Hemisphere summer insolation minimum. We propose that low‐latitude summer insolation modulates the amplitudes of millennial monsoon variability during the last glaciation. Our work provides clues for deciphering the dynamic connections between orbital and millennial timescales. Key Points: A summer precipitation δ18O record on the Chinese Loess Plateau during the last glaciation was reconstructed based on microcodium δ18OThe record shows distinct precessional variations punctuated by millennial‐scale oscillations, consistent with other monsoon recordsThe magnitude of millennial‐scale East Asian summer monsoon variability was found to be modulated by low‐latitude insolation during the last glaciation [ABSTRACT FROM AUTHOR]

The observed stability of Earth's climate over millions of years is thought to depend on the rate of carbon dioxide (CO2) release from the solid Earth being balanced by the rate of CO2 consumption by silicate weathering. During the Cenozoic era, spanning approximately the past 66 million years, the concurrent increases in the marine isotopic ratios of strontium, osmium and lithium suggest that extensive uplift of mountain ranges may have stimulated CO2 consumption by silicate weathering, but reconstructions of sea-floor spreading do not indicate a corresponding increase in CO2 inputs from volcanic degassing. The resulting imbalance would have depleted the atmosphere of all CO2 within a few million years. As a result, reconciling Cenozoic isotopic records with the need for mass balance in the long-term carbon cycle has been a major and unresolved challenge in geochemistry and Earth history. Here we show that enhanced sulphide oxidation coupled to carbonate dissolution can provide a transient source of CO2 to Earth's atmosphere that is relevant over geological timescales. Like drawdown by means of silicate weathering, this source is probably enhanced by tectonic uplift, and so may have contributed to the relative stability of the partial pressure of atmospheric CO2 during the Cenozoic. A variety of other hypotheses have been put forward to explain the 'Cenozoic isotope-weathering paradox', and the evolution of the carbon cycle probably depended on multiple processes. However, an important role for sulphide oxidation coupled to carbonate dissolution is consistent with records of radiogenic isotopes, atmospheric CO2 partial pressure and the evolution of the Cenozoic sulphur cycle, and could be accounted for by geologically reasonable changes in the global dioxygen cycle, suggesting that this CO2 source should be considered a potentially important but as yet generally unrecognized component of the long-term carbon cycle. [ABSTRACT FROM AUTHOR]

Macropodus hongkongensis (Freyhof & Herder, 2002), is sparsely distributed in Hong Kong and Guangdong provinces. Recently, a new geographical population of M. hongkongensis was discovered in the Wanquan River in the Hainan province. Therefore, this study focused on sequencing the complete mitochondrial genome of the new geographical population of Macropodus hongkongensis from the Wanquan River. The circular mtDNA molecule was 16,492 bp in size, and the overall base compositions were A (30.30%), C (24.90%), T (29.80%), and G (15.00%), with a slight bias toward A + T. The complete mitogenome encoded 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a control region. Phylogenetic analysis indicated that M. hongkongensis of the Hainan Wanquan River was most closely related to the M. hongkongensis of the Gongdong population. These results provide useful genetic information for species identification and phylogenetic studies of Macropodus species., Competing Interests: No potential conflict of interest was reported by the authors., (© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Coal has long fueled human civilizations. The history of systematic coal fuel exploitation has been traced back to the late third millennium before present (post-2500 B.P.). Although sporadic combustion of coal for fuel was reported in some prehistoric archaeological sites, evidence for the systematic exploitation of coal for fuel before 2500 B.P. remains lacking. Here, we report comprehensive understanding for the earliest systematic exploitation of coal for fuel at the Jirentaigoukou site in Xinjiang, northwestern China, at ~3600 B.P. The main body of the site witnessed systematic exploitation of bituminous coals, illustrating a complete chaîne opératoire with selective mining, planned storage, and extensive combustion. Our results transform the knowledge of energy history by extending the upper limit of the systematic exploitation of coal for fuel by approximately a millennium, and provide a precedent of energy transition under intense conflict between social demand and environmental deterioration.