Andesite can be considered as the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic.
Who We Represent. The International Brotherhood of Teamsters (IBT) represents more than 1.4 million active members employed in a wide range of industries in the United States, Canada and Puerto Rico.he IBT negotiated the freight industry's first national agreement in 1964 and began its efforts to unionize the airline industry in 1966 with employees of Western Airlines. The International Brotherhood of Teamsters is the only union that represents every craft of workers in the airline industry.
North America's Strongest Union. Contact the Teamsters. Please be advised that if you have a matter of importance that you would like addressed in an official manner you need to write a letter to the address provided below. When communicating with the IBT, please be sure to include a return address so that a reply can be made.