Geology 1 (The Science of Geology)

Geology is subdivided into physical geology (examining Earth's materials and processes operating beneath and on the surface) and historical geology (understanding Earth's origin and development through time). This course focuses on physical geology, which asks what materials compose the Earth and what processes shape it (1:30).

Cultures throughout history estimated Earth's age differently — Sumerians and Babylonians said 200,000-400,000 years, Hindus suggested 4.3 billion years (remarkably close to modern science), while Archbishop Usher's influential 1650 biblical calculation placed creation at October 22, 4004 BC, establishing the widely-held Western belief of a ~6,000-year-old Earth (4:30).

Early Western geology was dominated by catastrophism — the idea that Earth's features were shaped by sudden, violent, often supernatural events like Noah's flood. This paradigm held sway for roughly 350 years, attributing rock strata and fossils to the biblical deluge and being taught in universities with clergy support until the mid-19th century (7:30).

A refined form of catastrophism holding that all rocks precipitated from a primordial ocean, with a classification system of primary (crystalline, unfossiliferous like granite), secondary (fossiliferous sedimentary like limestone), tertiary (younger sediments), and quaternary (most recent deposits). Notably, the terms tertiary and quaternary survive in modern geological time scales (11:00).