梦溪笔谈
It was also observed in the 11th century, by Chinese scholar Shen Kuo, in his work "Dream Pool Essays," that the existence of fossils of species that no longer lived in the area, showed that climates had changed in the past. He also inferred that the landscape evolved over time, due to erosion and uplift. This led him to believe that vast spans of time were needed to form China's geomorphology.