How do you use stratum in a sentence?

Here are a few examples of how to use "stratum" in a sentence:

* Scientific: "The researchers studied the different strata of rock to understand the geological history of the region."

* Social: "The wealthy stratum of society often has different political views than the working class."

* Figurative: "He rose from the lower strata of society to become a successful businessman."

Note: "Stratum" is singular. The plural is "strata."