What are some possible effects of the migrations on the changes in the structure of population within a country (age, gender, economic, education, religious, national, etc.) and the future of the population growth in the country?

Tectonically stable means that this part of the continent has not moved for billions of years. The rock formation is important understanding the history of Earth since its unmoved and untouched state can provide ideas about how the Earth looked like as seen on the layers of the rock formation.