Lab - The rocks constituting the Earth's crust

Official Extract:
First S - Plate Tectonics: The Story of a Model (1B)

Scientific Issue:
Based on the bimodal distribution of Earth's altitudes, Alfred WEGENER suggests in his theory of continental drift the existence of distinct oceanic and continental domains.
Measurements of seismic wave propagation through the crust indeed suggest different types of rocks in these domains. What are the characteristics of crust rocks?

Operational Procedure:
The study involves examining rocks representative of the continental crust and oceanic crust, both on a macroscopic scale (texture, minerals visible to the naked eye) and microscopic scale (texture, minerals identified in LPNA and LPA).
Observations are conducted simultaneously on rock samples and high-resolution photographs of corresponding thin sections.
The latter, from the IDOL database, are accessible via the Jeulin Digital Platform: plateformenum.jeulin.fr