What materials primarily compose tectonic plates?

Tectonic plates are primarily composed of silicate minerals, which are abundant in the Earth’s crust and upper mantle. These silicate minerals include a variety of rocks, such as granite in continental crust and basalt in oceanic crust. The lithosphere, which comprises the tectonic plates, is defined by its rigid nature and encompasses the crust as well as the uppermost portion of the mantle, where these silicate minerals are prevalent.

The plates consist of different types of rocks; continental plates are generally thicker and composed largely of granitic rocks, while oceanic plates are thinner and consist predominantly of basaltic rocks. This composition is crucial to the dynamics of plate tectonics as it influences the behavior of the plates, their interactions at plate boundaries, and the geological phenomena that arise from these interactions, such as earthquakes and volcanic activity.

In contrast, the other options reflect materials that do not primarily constitute tectonic plates. The metals from the Earth's core are located far beneath the crust and are not part of the plate structure. Liquid magma is found beneath the plates and is involved in volcanic activity but does not make up the solid plates themselves. Organic materials from the Earth's surface have no role in forming tectonic plates since they are composed of biological matter, which