lichenometry
Lichenometry is a geochronological dating method used in geomorphology and archaeology that estimates the age of exposed rock surfaces by measuring the size of lichens, typically crustose forms, growing on them. The approach relies on the approximate constancy of lichen growth rates for a given climate and substrate, so the maximum observed lichen size on a surface can be related to time since exposure using species-specific growth curves.
Practically, researchers identify the lichen species with a reliable growth record (most often Rhizocarpon geographicum) and
Applications include dating moraines and other glacial landforms, rockfalls and rock avalanches, shoreline retreat, and some
Limitations include potential changes in growth rates over time, post-exposure colonization, and local microclimate effects that
History: Lichenometry was developed in the early 20th century and has since become a standard tool in