Geology (from the Greek γῆ, gê, "earth" and λόγος, logos, "study") is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates. In modern times, geology is commercially important for mineral and hydrocarbon exploration and for evaluating water resources; is publicly important for the prediction and understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change; plays a role in geotechnical engineering; and is a major academic discipline.

The study of the physical material of the Earth dates back at least to ancient Greece when Theophrastus (372-287 BCE) wrote the work Peri Lithon (On Stones). In the Roman period, Pliny the Elder wrote in detail of the many minerals and metals then in practical use, and correctly noted the origin of amber.

James David Head is a Canadian television director.

Head began his career as a cameraman on various film crews. In 1985, he was a second assistant camera for the concert film 9012Live by Yes. In 1987, he was a second assistant camera for the movie Stakeout. He then worked as a first assistant camera on Beyond the Stars (1989), The Fourth War (1990), Run (1991), And the Sea Will Tell (1991), and Bingo (1991).

Head made his directorial debut in 1991, directing at least one episode of TV's The Commish, but did not become a full-time director at that time. He was second unit director of photography for Man of the House (1995) and Fear (1996). He was back as a director in 1996, directing at least one episode of F/X: The Series. In 1997, he directed an episode of The Adventures of Sinbad, and during the 1996-97 season, he has directors credits for three episodes of Two. During the 1998-99 TV season, he directed two episodes of The Crow: Stairway to Heaven, an episode of Nothing Too Good for a Cowboy, an episode of Poltergeist: The Legacy, and five episodes of Earth: Final Conflict. Between 1998 and 2001, he directed six episodes of The Outer Limits . In 2000, he was second unit director on First Target and he directed a television movie remake of The Spiral Staircase. In 2001, he was second unit director on Just Cause and also directed at least one episode of Wolf Lake. In 2002, he was second unit director for two episodes of Jeremiah and then went on to direct two episodes of the series.