Geomagnetic excursions. A tribute to Norbert Bonhommet for his discovery of the Laschamp event
Convener: Roperch  | Co-Conveners: A. Chauvin , N. Thouveny 
Oral Programme
 / Mon, 20 Apr, 10:30–12:00  / Room 37
Poster Programme
 / Attendance Mon, 20 Apr, 17:30–19:00  / Halls X/Y

In the 1960s, Norbert Bonhommet discovered the Laschamp excursion while he was undertaking a detailed study of the paleosecular variation of the earth’s magnetic field recorded by young lava flows from the Chaîne des Puys (France).
The Laschamp and Olby flows recorded paleomagnetic directions of nearly reverse polarity and the Laschamp event was initially thought to be the youngest geomagnetic reversal. Nearly four decades after its discovery and with the passing of Norbert Bonhommet this is an appropriate time to have a detailed overview of the impact of this discovery.
Apart from our better understanding of the earth’s magnetic field, the Laschamp event with its related peak in cosmogenic isotopes is also becoming an important marker in paleoclimate studies.
To honor the legacy of Norbert Bonhommet, we invite contributions that :
- provide new evidences for the occurrence of the Laschamp excursion and discuss its age and its duration.
- address the nature of the geomagnetic field during excursions with data and/or models.
- discuss the impact of excursions and low-intensity geomagnetic fields in the production of cosmogenic nuclides
- use excursions as a chronological tool and accurate markers for dating and global intercorrelation of paleoclimatic archives.