A study of the historical development of the Earth from the examination of its rocks: In historical geology, the rocks are analyzed in order to determine their structure, composition, and interrelationships and are examined for remains of past life.

Historical geology includes paleontology, the systematic study of past life forms, stratigraphy, layered rocks and their interrelationships, as well as the locations of ancient land masses and their boundaries, and geologic mapping, the superimposing of geologic information upon existing topographic maps.