Complex sentence: For "The Songlines," Chatwin went to Australia to develop the thesis that the songs of the Aborigines are a cross between a creation myth, an atlas and an Aboriginal man's personal story.
Split into simpler sentences: For "The Songlines," Chatwin went to Australia. He studied the culture to express how the songs of the Aborigines are a cross between a creation myth, an atlas and an Aboriginal man's personal story.