Drill cores of Miocene rocks in Brazil, which provided the only complete sequence of the change from reddish clays to the blue and brown sediments, further corroborated my conclusions.

• 巴西的中新世岩石钻探岩心，提供了淡红色黏土连续转变成蓝棕色沉积物的证据，更加支持了我的结论。