Li Siguang (1889-1971) was a Chinese geologist who contributed to the sciences of paleontology (study of fossils), glaciology (study of glaciers), and seismology (study of earthquakes). Li Siguang founded geological mechanics, the branch of geology that deals with stresses and strains. His theories of geological mechanics played a vital part in the discovery of several large oil fields in China. His main works included Quaternary Glaciation in the Lushan Area, Central China (1947), and Introduction to Geomechanics (1962).