Why can't geologists isotopically date a clastic sedimentary rock?
A) They do not contain the appropriate minerals.
B) These types of rocks do not contain enough of the appropriate minerals to date.
C) The minerals would yield the date of when they crystallized in a metamorphic or igneous rock.
D) The minerals would yield the date of when they weathered from their source material.

Question

Quizplus · Accepted Answer

Clastic sedimentary rocks are made up of fragments of pre-existing rocks. Therefore, the minerals in these rocks would yield the date of when they crystallized in a metamorphic or igneous rock which was the source for the fragment, rather than the date of deposition of the sedimentary rock itself.

Why Can't Geologists Isotopically Date a Clastic Sedimentary Rock