Tectonic–climatic interaction have sculpted their local and regional environments. Aside from admiring their majestic beauty, one might wonder how these geologic wonders work and what role they play in changing the landscape and atmosphere. Principally, volcanoes are geologic features that exude magmatic material from below Earth's surface onto the surface. Upon reaching the surface, the term "magma" disappears and "lava" becomes the common nomenclature. This lava cools and forms igneous rock. By examining igneous rocks, it is possible to derive a chain of events that led from the original melt of the magma to the crystallization of the lava at Earth's surface.
Lava delta Lava delta Lava deltas, similar to river deltas form wherever sufficient sub-aerial flows of lava enter standing bodies of water. The lava cools and breaks up as it encounters the water, with the resulting fragments filling in the adjacent seabed topography such that the flow can move further offshore sub-aerially. Lava deltas are generally associated with large-scale, effusive type basaltic volcanism. Lava deltas are found mainly associated with volcanic islands, particularly those formed at hotspots as they produce the necessary effusive basaltic flows. The largest lava delta systems known are associated with formation of volcanic type passive margins. Just prior