What kind of air mass can from over the cold icy north pacific, and even in summer can cool the west coast of the usa?

Cold and warm air masses sometimes meet, but neither can move the other. ... Many summer showers and thunderstorms in the eastern United States develop in air ... Cool, humid air masses form over the icy cold North Pacific and North Atlantic. Maritime Polar air masses affect the West Coast more than the East Coast.

the precambrian aged rocks could be found in australia. australia is a region that has a lot of ancient civilization history from million years ago. in this region, there are a lot of recognizable fossils buried in its land which is considered a precambrian-aged rocks