Terrestrial selenium distribution in China is potentially linked to monsoonal climate

Area of Science:

• Geochemistry
• Paleoclimatology
• Environmental Science

Background:

• Terrestrial environments globally exhibit low selenium (Se) concentrations, leading to widespread Se deficiency.
• The processes driving Se depletion in environments remain largely unknown.
• The Chinese Loess Plateau (CLP) is a Se-depleted region with a history of Se deficiency-related diseases.

Purpose of the Study:

• To investigate the role of climatic factors in selenium distribution within the Chinese Loess Plateau over the past 6.8 million years.
• To elucidate the processes contributing to Se-depleted environments in monsoonal regions.

Main Methods:

• Analysis of geochemical data from loess-paleosol sequences in the CLP.
• Integration of paleoclimate data, focusing on East Asian monsoon variations.
• Correlation of Se concentration variations with climatic factors during interglacial periods.

Main Results:

• Climatic factors have been a key driver of Se distribution in the CLP over the last 6.8 million years.
• Se concentrations in the CLP between 2.30 and 0.16 Ma correlated with Se input via precipitation.
• Precipitation variability is identified as a critical factor controlling Se distribution in monsoonal China.

Conclusions:

• Climatic factors, especially precipitation, are crucial for understanding Se distribution in Se-depleted regions.
• Atmospheric Se input via precipitation may be a significant factor in global Se distribution.
• This research provides insights into the historical dynamics of essential trace element availability.