Rupelian
/rʊˈpiːlɪən/Geology
adjective
Designating the lower (older) stage of the Oligocene series, exemplified by certain clays and shales in Belgium and Germany; of or relating to this stage.
noun
The Rupelian stage; the strata collectively dating from this time.
Origin
Mid 19th century. From French Rupelien from Rupel, the name of a small tributary of the river Scheldt in Belgium + -ien.