What had happened at Marabar caves?

The caves are a surreal experience for Adela and Mrs. Moore. Both women experience some inner fright from some part of life that they had not considered before. Mrs. Moore sees the emptyness of her Christian faith while Adela feels the reality of lacking love for Ronny and then the reflection of her assault. It is probable the assault is merely in her mind: a reflection of her tormented psyche.