Late Miocene?Pliocene development of Asian aridification as recorded in the Red-Earth Formation in northern China

Abstract. The Late Miocene (11.6–5.3 Ma) is a crucial period in the history of the Asian monsoon. Significant changes in the Asian climate regime have been documented for this period, which saw the formation of the modern Asian monsoon system. However, the spatiotemporal structure of these changes is still ambiguous, and the associated mechanisms are debated. Here, we present a simulation of the average state of the Asian monsoon climate for the Tortonian (11–7 Ma) using the regional climate model CCLM3.2. We employ relatively high spatial resolution (1° × 1°) and adapt the physical boundary conditions such as topography, land-sea distribution and vegetation in the regional model to represent the Late Miocene. As climatological forcing, the output of a Tortonian run with a fully-coupled atmosphere-ocean general circulation model is used. Our regional Tortonian run shows a stronger-than-present East Asian winter monsoon wind as a result of the enhanced mid-latitude westerly wind of our global forcing and the lowered present-day northern Tibetan Plateau in the regional model. The summer monsoon circulation is generally weakened in our regional Tortonian run compared to today. However, the changes of summer monsoon precipitation exhibit major regional differences. Precipitation decreases in northern China and northern India, but increases in southern China, the western coast and the southern tip of India. This can be attributed to the changes in both the regional topography (e.g. the lower northern Tibetan Plateau) and the global climate conditions (e.g. the higher sea surface temperature). The spread of dry summer conditions over northern China and northern Pakistan in our Tortonian run further implies that the monsoonal climate may not have been fully established in these regions in the Tortonian. Compared with the global model, the high resolution regional model highlights the spatial differences of the Asian monsoon climate in the Tortonian, and better characterizes the convective activity and its response to regional topographical changes. It therefore provides a useful and compared to global models, a complementary tool to improve our understanding of the Asian monsoon evolution in the Late Miocene.

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High-Resolution Carbonate Variability in Red Earth Deposits: Implications for Water Cycling Dynamics during the Late Miocene

10.5194/egusphere-egu21-2962 ◽

2021 ◽

Author(s):

Tong He

Keyword(s):

High Resolution ◽

Late Miocene ◽

Water Availability ◽

Asian Monsoon ◽

Chinese Loess Plateau ◽

Time Interval ◽

Terrestrial Environment ◽

Ice Volume ◽

Red Earth ◽

The Antarctic

<div>The late Miocene provides the chance to assess the changing boundary conditions on a warmer world than present. While the climate variability is well understood for the oceanographic records, the water availability and dynamics in terrestrial environment in the densely populated East Asian remains enigmatic. Little is known about the precipitation response to the Antarctic ice-sheets during this time interval. To understand this critical relationship between low- and high-latitude climates, we use a new indicator based on the carbonate variability in Red Earth on the northern Chinese Loess Plateau to reconstruct water availability throughout the interval (7.5&#8211;6.9 Ma). Our high-resolution reconstructions show that the carbonate leaching/reprecipitation cycle is dominantly forced by the astronomical parameter obliquity (40-kyr) that is in accord with the Antarctic ice-volume controlled oceanography records at ~7 Ma. Supported by goethite and hematite records in the same site, soil temperatures and precipitations are fully coupled, interpreted as marking the climate pattern of Asian monsoon during the late Miocene. Cyclic correlation between the carbonate variability and the goethite, hematite data, reveal that the obliquity controlled precipitation oscillations were superimposed on a long-term increase of the Asian monsoon, which was synchronous with intensifification of climate cooling, the declining of partial pressure of carbon dioxide, and the growing of Antarctic ice-volume. Combined with the atmospheric- and oceanic-adjustments, we suggest that the cross-equatorial pressure gradient has led to the rise of Asian monsoon.</div>

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Millennial resolution late Miocene northern China precipitation record spanning astronomical analogue interval to the future

Geophysical Research Letters ◽

10.1029/2021gl093942 ◽

2021 ◽

Author(s):

Peng Gao ◽

Junsheng Nie ◽

Qing Yan ◽

Xu Zhang ◽

Qingsong Liu ◽

...

Keyword(s):

Late Miocene ◽

Northern China ◽

Precipitation Record ◽

The Future

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Geologic-seismic models, prediction of shallow-water lacustrine delta sandbody and hydrocarbon potential in the Late Miocene, Huanghekou Sag, Bohai Bay Basin, northern China

Journal of Palaeogeography ◽

10.1016/j.jop.2017.11.001 ◽

2018 ◽

Vol 7 (1) ◽

pp. 66-87 ◽

Cited By ~ 6

Author(s):

Hao Liu ◽

Qing-Long Xia ◽

Xin-Huai Zhou

Keyword(s):

Shallow Water ◽

Late Miocene ◽

Northern China ◽

Hydrocarbon Potential ◽

Bohai Bay ◽

Bohai Bay Basin ◽

Lacustrine Delta ◽

Seismic Models

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Phylogenomics, biogeography, and clade diversification of Paris (Melanthiaceae)

10.21203/rs.2.12669/v1 ◽

2019 ◽

Author(s):

Yunheng Ji ◽

Lifang Yang ◽

Mark W. Chase ◽

Changkun Liu ◽

Zhenyan Yang ◽

...

Keyword(s):

Late Miocene ◽

Phylogenetic Relationships ◽

Northern China ◽

Molecular Dating ◽

Nuclear Ribosomal Dna ◽

Tibet Plateau ◽

Climatic Fluctuations ◽

Difficult Genus ◽

Ancestral Area Reconstruction ◽

Inference Methods

Abstract Background Paris (Melanthiaceae) is an economically important but taxonomically difficult genus, which is unique in angiosperms because some species have extremely large nuclear genomes. Phylogenetic relationships within Paris have long been controversial. Based on complete plastomes and nuclear ribosomal DNA (nrDNA) sequences, this study aims to reconstruct a robust phylogenetic tree and explore historical biogeography and clade diversification in the genus. Results All 29 species currently recognized in Paris were sampled. Complete plastomes and nrDNA sequences were generated by the genome skimming approach. Phylogenetic relationships were reconstructed using the maximum likelihood and Bayesian inference methods. Based on the phylogenetic framework and molecular dating, biogeographic scenarios and historical diversification of Paris were explored. Significant conflicts between plastid and nuclear datasets were identified, and the plastome tree is highly congruent with past interpretations of the morphology. Ancestral area reconstruction indicated that Paris may have originated in northeastern Asia and northern China, and has experienced multiple dispersal and vicariance events during its diversification. The rate of clade diversification has sharply accelerated since the late Miocene. Conclusions Our results provide important insights for clarifying some of the long-standing taxonomic debates in Paris. Cytonuclear discordance may have been caused by ancient and recent hybridizations in the genus. The climatic and geological changes since the late Miocene, such as the intensification of Asian monsoon and the rapid uplift of Qinghai-Tibet Plateau, as well as the climatic fluctuations during the Pleistocene, played essential roles in driving range expansion and radiative diversification in Paris. Our findings challenge the theoretical prediction that large genome sizes may limit speciation.

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