Sample Essay on Geology

Question 1

To understand the relationship between Plate Tectonic boundaries and igneous rock formation it is necessary to define some concepts. A plate tectonic boundary is a boundary between two or more plates where plates converge, whereas igneous rocks result from the cooling or solidification of lava.Lava is a term given to magma that which reaches the surface of the earth(Wicander, James and Peters 18). From a geological perspective igneous rocks often form at the points of convergence or divergence of tectonic plates,which create perfect conditions for the solidification of magma and pave the way for the formation of igneous rocks. The earth’s crust rests on tectonic plates which float on hot magma.This sets the stage for magma formation. Magma formation occurs in the molten subterranean sections of the earth.As plates move on top of the magma they interact with each other by moving closer together or farther apart.This provides the conditions for the formation of igneous rocks (Wicander, James, and Peters 19).

Question 2

A volcanic eruption often results in the flow of lava.Lava is magma that is expelled from underground to flow on the surface (Wicander, James, and Peters 97). The viscosity of the lava produced during volcanic eruptions determine how the lava flows and various forms of lava flow.More fluid and less viscous lava can be produced by the same eruption.Thistype of lavaflows at a slightly fast rate and produces thinner flows.This is often referred to as the “pahoehoe” type of lava flow. The same volcanic eruption can also produce highly viscous and slowly moving lava with thicker flows. This is known as ‘aa’ lava flow.


Work Cited

Wicander, Reed, James S. Monroe, and E K. Peters. Essentials of Geology. Belmont, CA: Thomson Brooks/Cole, 2006. Print.