Aske Lohse Sørensen

New method for more precise dating of soil layers

Geochronology

Aske Lohse Sørensen has developed a new method that allows for more precise dating of soil layers, which can help shed light on early human history and the climate.

Geologist and PhD Aske Lohse Sørensen and his research group have developed a novel method for dating soil layers. It is called CosmoChron. His PhD supervisor suggested developing a modelling method based on deposits created after cosmic radiation, and Aske Lohse Sørensen managed to create such a model through hard work and with help from geologists and archaeologists from five different countries. “In a large-scale project in Tajikistan, we studied dust deposits, which were around a hundred metres thick and contained stone tools used by some of the first human species. However, we did not have a method that allowed for precise dating of the layers and thus for determining when these people had inhabited the area,” says Aske Lohse Sørensen. What they did have were huge amounts of data produced in connection with the project. Aske Lohse Sørensen used the data to create a more sophisticated model. “Based on several types of geological data, CosmoChron produces a timeline for a series of layers. A main element is cosmogenic nuclides, which are found in minerals and created when the Earth is subjected to cosmic radiation. When the material is buried, the production of nuclides stops, and the deposits thus act as a geological clock.” Aske Lohse Sørensen was able to date the interglacial period in Central Asia to 400,000-600,000 years ago. Since then, he has contributed to several projects, and CosmoChron has proven highly useful, not least for dating the now oldest glacial deposits in Europe. Aske Lohse Sørensen continues to research geochronology, now as a postdoc at the University of Copenhagen.