The dust bowl can be associated with: a. terrible storms that plagued the Great Basin. b. the blowing away of millions of acres of topsoil. c. a famous movie made by the Works Progress Administration filmmaker Ansel Adams. d. a severe blow to farmers in Illinois, Ohio, and Wisconsin. e. large migrations from the impacted area to the Atlantic coast.

The oldest rocks in the south atlantic ocean, immediately adjacent to the african and south american continental shelves, are 120,000,000 years old (time). calculate the average rate of seafloorspreading for the south atlantic ocean over its entire existence (hint: use formula: velocity = distance/time): /yr (velocity). now convert that to: cm/yr: