Project

Discipline

Quaternary; glaciations; sediments; dating; luminescence; cosmogenic nuclides; Switzerland; Alps; chronostratigraphy

Lead
Lay summary
Deciphering the past dynamics of circulation systems and its impact on continental environments is a fundamental requirement for understanding the presently observed climate change and its possible consequences for human societies. In particular, it is still poorly understood how the geosphere responded to Quaternary climate change on different temporal as well as spatial scales. Within this context, we propose to reconstruct the glaciation history of the northern Swiss lowlands, where a variety of proglacial sedimentary sequences are well exposed in different gravel pits and natural outcrops. Recent research has shown that the Quaternary record of the region is much more complex than previously assumed. Investigating this geological record will allow a detailed reconstruction of the geological past, where and when glaciers advanced into the Swiss lowland. However, until recently, the lack of an independently dated chronological framework prevented the placement of this exceptional geological archive within a global context. We will use state-of-the-art approaches of both luminescence dating for determining the Quaternary deposition history of the area. The project is subdivided into two linked work packages (WP) that will focus on different time slices.WP 1 will focus on the number of glacial advances during the Late Pleistocene. Detailed sedimentological logging and Optically Stimulated Luminescence (OSL) dating of quartz will be used to establish an independent chronological framework for the deposits. Prior to dating a detailed testing program will be carried out to characterise the OSL properties of the investigated samples and find the optimal measurement conditions. This work will be done within a PhD project.WP 2 will concentrate on establishing the chronology of the Middle Pleistocene deposits of the area. We will use conventional OSL and Infrared Stimulated Luminescence (IRSL) dating and compare the results with those determined by cutting edge techniques such as thermally transferred OSL, IR radiofluorescence and red IRSL emissions from K-feldspar. Using these approaches it should be possible to date sediments as old as 500 ka. Due to the innovative character of these techniques, this WP will comprise a detailed experimental part. Considering the complexity of different dating techniques, this part of the project will by carried out by a person with experience in the field (postdoc).

Direct link to Lay Summary

Last update: 21.02.2013

Number	Title	Start	Funding scheme

Deciphering the past dynamics of circulation systems and its impact on continental environments is a fundamental requirement for understanding the presently observed climate change and its possible consequences for human societies. In particular, it is still poorly understood how the geosphere responded to Quaternary climate change on different temporal as well as spatial scales. Within this context, we propose to reconstruct the glaciation history of the northern Swiss lowlands, where a variety of proglacial sedimentary sequences are well exposed in different gravel pits and natural outcrops. Recent research has shown that the Quaternary record of the region is much more complex than previously assumed. Investigating this geological record will allow a detailed reconstruction of the geological past, where and when glaciers advanced into the Swiss lowland. However, until recently, the lack of an independently dated chronological framework prevented the placement of this exceptional geological archive within a global context. We will use state-of-the-art approaches of both luminescence as well as cosmogenic nuclide dating for determining the Quaternary deposition history of the area. The project is subdivided into three linked work packages (WP) that will focus on different time slices.WP 1 will focus on the number of glacial advances during the Late Pleistocene. Detailed sedimentological logging and Optically Stimulated Luminescence (OSL) dating of quartz will be used to establish an independent chronological framework for the deposits. Prior to dating a detailed testing program will be carried out to characterise the OSL properties of the investigated samples and find the optimal measurement conditions. This work will be done within a PhD project.WP 2 will concentrate on establishing the chronology of the Middle Pleistocene deposits of the area. We will use conventional OSL and Infrared Stimulated Luminescence (IRSL) dating and compare the results with those determined by cutting edge techniques such as thermally transferred OSL, IR radiofluorescence and red IRSL emissions from K-feldspar. Using these approaches it should be possible to date sediments as old as 500 ka. Due to the innovative character of these techniques, this WP will comprise a detailed experimental part. Considering the complexity of different dating techniques, this part of the project will by carried out by a person with experience in the field (postdoc).WP 3 will use cosmogenic isotopes 10Be and 26Al for the dating of Early and Middle Pleistocene deposits of the so-called ‘Deckenschotter’ as well as deeply buried sediments recovered from sediment sequences from overdeepend valleys. Previous experiences with this recently developed dating technique are very promising and it appears appropriate to move forward to an extended field study with this method. We will start with investigating the properties modern sediments, then date deposits of known age and continue to date samples of unknown age. Age control is available for old deposits by vertebrate palaeontology and, for younger (late Middle Pleistocene) deposits, through luminescence dating.The different WP’s will be linked and there will be several opportunities to cross-check the dating results. We expect that the proposed project will result in an important step forward to establishing directly dated chronostratigraphies for Quaternary proglacial deposits.