Here's a breakdown:
* Volcanoes: Volcanoes are surface expressions of volcanic activity, where magma erupts onto the Earth's surface as lava.
* Intrusive Features: These are formed when magma cools and solidifies underground. They are often exposed later by erosion.
Here are some of the major intrusive features:
1. Batholiths: These are the largest intrusive bodies, often covering hundreds of square kilometers. They are typically made up of granite and are often found in the cores of mountain ranges.
2. Stocks: Smaller, irregularly shaped bodies of intrusive rock, often associated with batholiths.
3. Dikes: Tabular, sheet-like intrusions that cut across existing rock layers. They are often formed by magma injected into fractures.
4. Sills: Tabular intrusions that are parallel to existing rock layers. They are often formed when magma is injected along bedding planes.
5. Laccoliths: Dome-shaped intrusions that uplift the overlying rock layers. They are formed by the injection of magma into a relatively soft layer.
6. Volcanic Necks: The solidified remnants of the conduit that fed a volcano. They are often exposed after erosion has removed the surrounding volcanic material.
7. Plutons: A general term for any intrusive igneous body, regardless of size or shape.
In summary: Volcanoes are surface manifestations of volcanic activity, while intrusive features are formed by magma cooling and solidifying underground. These underground formations contribute to the formation of mountains and play a significant role in the Earth's geological processes.
