Two out of four research grants go to the Department of Earth Science

Madeleine Bohlin, researcher in geochemistry, has received 2193 796 SEK for her project and Thomas Stevens, researcher in physical geography, has received 1780 900 SEK from The Geological Survey of Sweden, SGU, the expert agency for issues relating to bedrock, soil and groundwater in Sweden. 

Project explanation

Madeleine Bohlin´s project

"The geochemical cycle of lithium and lithium isotopes in Swedish catchments: Can Li isotopes in river waters be used as a tool for Li exploration?"

This project has two main aims, the first is to constrain the geochemical cycle of lithium (Li) in the Swedish landscape to study chemical weathering processes, and the second is to investigate whether dissolved Li in river waters can be used to trace Li-rich minerals in the bedrock, and use river waters as an initial low-resolution exploration tool. Li is an incredibly interesting element. As a technologically important element it will play a key role as we transition to a greener economy, and scientifically, the interest in using Li as an environmental tracer has grown rapidly in the last decades.

The Li isotopic signature of river waters and sediments provide a type of fingerprint of the weathering reactions that occur in a river catchment. Rivers are constantly shaping our landscape by cutting through and eroding the bedrock. Chemical erosion, or weathering, is a very important process as it uses atmospheric CO₂ to slowly dissolve the rock, and in doing so, regulates the global climate over geological time scales. The Li isotopic fingerprint can provide unique information on weathering reactions that are occurring in a catchment, and the intensity of weathering in different types of environments. So far, most studies have focused on tropical rivers such as the Amazon or the Ganges. In this project I’ll take advantage of the large climate gradient in Sweden and the exceptionally high resolution of surveying and monitoring programmes from a range of Swedish agencies to constrain the biogeochemical cycling of Li in the Swedish landscape.

The headwaters of the Ganges in Northern India. The river is cutting through the sedimentary rock sequences of the Lesser Himalayas, integrating the weathering signal from the whole drainage basin. Weathering of rocks controls the climate on geological timescales and the Li isotopic signature of rivers can help us understand these processes better.

For information contact:
Madeleine Bohlin:
madeleine.bohlin@geo.uu.se

Thomas Stevens project

"Swedish loess: a unique past dust-climate record and natural resource."

This SGU-funded project focusses on layers of fine-grained (dominantly silt-sized) mineral dust called ‘loess’ that were deposited over Sweden following the end of the last Ice Age. Deposits of loess cover more than 10% of the Earth’s land, forming some of the best agricultural soils in the world. Unfortunately, these soils are highly sensitive to erosion and soil loss. Furthermore, loess deposits hold excellent past climate records, and contain records of past atmospheric dust activity. Dust is a critical and poorly understood component of the climate system, both responding to climate shifts and also driving climate changes. Reconstructing past changes in dust activity is one of the great challenges in understanding the global climate system.

Thin (generally < 1m) loess deposits are also found in Sweden (often referred to as ‘flygmo’), yet there has been very little research conducted on how widespread they are, as well as on their formation, age, agricultural importance and sensitivity, and the potential climate and dust record they contain. This project aims firstly to constrain the distribution and properties of loess in Sweden, and in doing so aims to enable better land use and sustainable agriculture practice in loess areas. Secondly, the project aims to test the potential of loess in Sweden as a dust and climate record. This will be achieved through detailed dating of the time the loess was deposited, and through testing the chemical, physical and mineralogical properties of loess material.

Loess in Värmland showing the typical yellow coloured and structureless features of loess. The white upper part of the loess reflects the fact that the cool wet climate of western Sweden has leached iron and clays from the top of the sediment, moving them down profile to the orange-red sediment layer below. Photo: T. Stevens.


Loess from the Chinese Loess Plateau in north central China. Loess sediments here reach hundreds of metres thickness and reflect changes in dust and climate over millions of years. Photo: T. Stevens

For more information contact Thomas Stevens:
thomas.stevens@geo.uu.se