Shan Hai Jing is an ancient mystery book in the pre-Qin period, mostly fairy tales, but also an encyclopedia of human geography. Sima Qian thinks this book is "ridiculous"! Therefore, Tan Shan Hai Jing can also be regarded as nonsense, talking about absurd remarks!
In contrast, both of them have the meaning of "absurdity", but in daily life, "talking about heaven and earth" pays more attention to the friendship between friends! I think this is the biggest difference and difference!