The study of landforms and the evolution of the Earth's surface can be dated back to scholars of Classical Greece. In the 5th century BC, Greek historian Herodotus argued from observations of soils that the Nile delta was actively growing into the Mediterranean Sea, and estimated its age.Bierman, Paul R., and David R. Montgomery. Key Concepts in Geomorphology. Macmillan Higher Education, 2014.Rafferty, John P. (2012). Geological Sciences; Geology: Landforms, Minerals, and Rocks. New York: Britannica Educational Publishing, pp. 8–9. In the 4th century BC, Greek philosopher Aristotle speculated that due to sediment transport into the sea, eventually those seas would fill while the land lowered. He claimed that this would mean that land and water would eventually swap places, whereupon the process would begin again in an endless cycle. The Encyclopedia of the Brethren of Purity published in Arabic at Basra during the 10th century also discussed the cyclical changing positions of land and sea with rocks breaking down and being washed into the sea, their sediment eventually rising to form new continents. The medieval Persian Muslim scholar Abū Rayhān al-Bīrūnī (973–1048), after observing rock formations at the mouths of rivers, hypothesized that the Indian Ocean once covered all of India. In his De Natura Fossilium of 1546, German metallurgist and mineralogist Georgius Agricola (1494–1555) wrote about erosion and natural weathering.
