You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Bermuda

Context:
The archipelago is formed by high points on the rim of the caldera of a submarine volcano that forms a seamount. The volcano is one part of a range that was formed as part of the same process that formed the floor of the Atlantic, and the Mid-Atlantic Ridge. The top of the seamount has gone through periods of complete submergence, during which its limestone cap was formed by marine organisms, and during the Ice Ages the entire caldera was above sea level, forming an island of approximately two hundred square miles.

Question:
What type of volcano forms the archipelago?

a submarine volcano