dendrochronology
noun [ U ] uk/ˌden.drəʊ.krəˈnɒl.ə.dʒi/ us/ˌden.droʊ.krəˈnɑː.lə.dʒi/
树木年代学，树龄学
a way of calculating dates and the age of objects by counting the rings that appear inside tree trunks
Dendrochronology of timbers from the present mansion showed that the roof and part of one wing were built around 1623. 通过树木年代学检测现存大宅的木料显示，屋顶和部分侧翼建于1623年左右。