Most gold ore was mined by large companies rather than prospectors since their vast economical and financial resources permitted them to acquire expensive machinery, such as heavy trucks, bulldozers, rotary mechanical scrreening machines ( used for separating ore from other materials) , etc.; none of which was at the hand of prospectors.
I think it is the first one (shoppers find sushi...). Cultural diffusion refers to the spread of different cultures around the world. Finding Asian food in America definitely shows an example of cultural spread.
