If you see a very tall, rock feature that looks like a jagged, rectangular block sticking out of the ground, you're probably observing a
-lava dome
-geyser
-volcanic neck
-flood basalt plateau

If you see a very tall, rock feature that looks like a jagged, rectangular block sticking out of the ground, you're probably observing a volcanic neck. Also known as a lava neck or volcanic plug, a volcanic neck is formed when magma solidifies within a vent of an active volcano. This can harness great amounts of pressures which could lead to an explosive eruption.