Another early theory of geomorphology was devised by Song dynasty Chinese scientist and statesman Shen Kuo (1031–1095). This was based on his observation of marine fossil shells in a geological stratum of a mountain hundreds of miles from the Pacific Ocean. Noticing bivalve shells running in a horizontal span along the cut section of a cliffside, he theorized that the cliff was once the pre-historic location of a seashore that had shifted hundreds of miles over the centuries. He inferred that the land was reshaped and formed by soil erosion of the mountains and by deposition of silt, after observing strange natural erosions of the Taihang Mountains and the Yandang Mountain near Wenzhou.Sivin, Nathan (1995). Science in Ancient China: Researches and Reflections. Brookfield, Vermont: VARIORUM, Ashgate Publishing. III, p. 23Needham, Joseph. (1959). Science and Civilization in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth. Cambridge University Press. pp. 603–618.Rafferty, John P. (2012). Geological Sciences; Geology: Landforms, Minerals, and Rocks. New York: Britannica Educational Publishing, pp. 6–8. Furthermore, he promoted the theory of gradual climate change over centuries of time once ancient petrified bamboos were found to be preserved underground in the dry, northern climate zone of Yanzhou, which is now modern day Yan'an, Shaanxi province.Chan, Alan Kam-leung and Gregory K. Clancey, Hui-Chieh Loy (2002). Historical Perspectives on East Asian Science, Technology and Medicine. Singapore: Singapore University Press. p. 15. .Rafferty, John P. (2012). Geological Sciences; Geology: Landforms, Minerals, and Rocks. New York: Britannica Educational Publishing, p. 6. Previous Chinese authors also presented ideas about changing landforms. Scholar-official Du Yu (222–285) of the Western Jin dynasty predicted that two monumental stelae recording his achievements, one buried at the foot of a mountain and the other erected at the top, would eventually change their relative positions over time as would hills and valleys.Rafferty, John P. (2012). Geological Sciences; Geology: Landforms, Minerals, and Rocks. New York: Britannica Educational Publishing, p. 9. Daoist alchemist Ge Hong (284–364) created a fictional dialogue where the immortal Magu explained that the territory of the East China Sea was once a land filled with mulberry trees.Schottenhammer, Angela. "The 'China Seas' in world history: A general outline of the role of Chinese and East Asian maritime space from its origins to c. 1800," Journal of Marine and Island Cultures, (Volume 1, Issue 2, 2012): 63-86. ISSN 2212-6821, p. 72. https://doi.org/10.1016/j.imic.2012.11.002.
