Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: An anticline is a fold that arches upward. The rocks dip away from the center of the fold ( Figure below ). The oldest rocks are found at the center of an anticline. The youngest rocks are draped over them at the top of the structure. When upward folding rocks form a circular structure, that structure is called a dome . If the top of the dome is eroded off, the oldest rocks are exposed at the center. Answer: anticline
Solution:
What is the term for a fold that arches upward?