the lower boundary of earth’s crust is called the oceanic trench.
the lower boundary of earth’s crust is called the?
oceanic trench
Na
Na
bullet::::- harrisonian: lower boundary 24.8 ma. upper boundary 20.43 ma.





























bullet::::- monroecreekian: lower boundary 26.3 ma. upper boundary 24.8 ma.





























bullet::::- geringian: lower boundary 30.8 ma. upper boundary 26.3 ma.





























bullet::::- whitneyan: lower boundary 33.3 ma. upper boundary 30.8 ma.





























bullet::::- orellan: lower boundary 33.9 ma. upper boundary 33.3 ma.





























bullet::::- chadronian: lower boundary 37.2 ma. upper boundary 33.9 ma.





























bullet::::- duchesnean: lower boundary 40.4 ma. upper boundary 37.2 ma.





























bullet::::- uintan: lower boundary 46.2 ma. upper boundary 40.4 ma.





























bullet::::- bridgerian: lower boundary 50.3 ma. upper boundary 46.2 ma.





























bullet::::- wasatchian: lower boundary 55.8 ma. upper boundary 50.3 ma.
north american land mammal age