Here's why:
* Bermuda is a volcanic island: It formed from volcanic activity millions of years ago.
* Limestone formation: Over time, the volcanic rocks eroded and the resulting sediment, including calcium carbonate, settled and accumulated on the ocean floor. This sediment eventually hardened into limestone.
* Cave formation: The caves in Bermuda were formed through a process called karst topography. Rainwater, slightly acidic due to dissolved carbon dioxide, reacts with the limestone, dissolving it over time. This creates the caves and other karst features like sinkholes.
So, the crystal caves in Bermuda are not related to intrusive or extrusive igneous rocks. They are formed within sedimentary limestone through a process of dissolution by acidic rainwater.
