Glacial geography features several types of plains, but the Outwash Plain is the most extensive depositional form. As a glacier melts, the resulting water carries a massive load of debris. As this water spreads out over a flat area, it loses energy and drops the sediment, creating a vast, level plain. These plains are distinct from “Till Plains,” which consist of unsorted material dropped directly by the ice. Outwash plains are common in formerly glaciated regions like the Northern USA, Germany and Poland and they often contain unique features like “kettles” (small lakes) formed by buried ice blocks.

The Columbia Plateau is a “Flood Basalt” province in the Pacific Northwest of the USA. Geographically, it is a vast, relatively level upland created by successive layers of cooling lava, some reaching thousands of feet in thickness. Unlike the jagged Rockies nearby, this plateau features wide, sweeping plains and deep canyons where rivers (like the Columbia and Snake) have cut through the basalt layers. This region is a prime example of “constructive” volcanic geography, where internal forces added massive amounts of new rock to the continental surface, creating fertile volcanic soil that supports major agriculture today.

There is a strong correlation between geology and mineral distribution. Plateaus, being stable “shields” or lava tablelands, are prime locations for metallic minerals and coal (in Gondwana-type plateaus). However, petroleum is a liquid hydrocarbon that migrates through porous rocks and gets trapped in specific “folds” of young sedimentary layers, usually in offshore areas or coastal plains. Therefore, while you find gold in the Canadian Shield or iron in Chota Nagpur, you look to the North Sea, the Gulf of Mexico or the Mumbai High (marine/sedimentary areas) for oil.