Cenotypal Rocks

magmatic rocks that preserve a freshappearance despite their age. Cenotypal rocks are distinguished from paleotypal rocks, which are much decayed and there fore appear ancient. This terminology arose in the second half of the19th century (W. C. Brògger, F. J. Levinson-Lessing) in connection with the refutation of the previously held but mistaken idea that fresh-looking cenotypal rocks are young and decayed(paleotypal) rocks are ancient.