Quantitative Revolution - Time in the history (after 1950) of physical geography when measurement became the central focus of research. This measurement was used primarily for hypothesis testing. With measurement came mapping, models, statistics, and mathematics. Researchers began investigating process rather than mere description of the environment.
Quarrying - Erosive process of particle detachment by moving glacial ice. In this process, basal ice freezes in rock surface cracks. As the main body of the glacial ice moves material around the ice in the cracks is pulled and plucked out. Also called plucking.
Quartz - Mineral with the chemical formula SiO2. Quartz is common in continental crust but rare in oceanic crust.
Quartzite - Metamorphic rock rich in quartz created by the recrystallization of sandstone.
Quaternary - Geologic period that occurred roughly 1.6 million years ago to today. During much of this period continental glaciers in the Northern Hemisphere covered large regions of land surface in the high and mid-latitudes. Homo sapiens appear about 200,000 years BP (before present) and become the first species to alter the Earth's environment on a large-scale.