The development of archaeological geology, a combination of geology and archaeology, is surveyed. Examples of this new discipline include: reconstruction of past landscapes; reconstructing coastlines; reconstruction of geological, and where possible, ecological environments. Techniques used in provenance studies include: provenance of lithic artifacts by mineral composition; petrographic studies of thin-sections of artifacts; trace element fingerprinting; study of isotopic variation. The effect of volcanic eruptions on early sites is noted. Archaeomagnetic dating is an example of cooperation between the two fields. It is pointed out that most archaeological geologists are trained as geologists, and are self-educated in the archaeological component of their work.