A new volcanic arc forms at the site of the easternmost transform, and many complications develop in SE Asia (Philippines, etc.) because of transforms turning into arcs, and various subduction-flips as thick (plateau-type) ocean crust refuses to subduct. A new subduction zone develops north of Australia.
Some of the causes of the European voyages of exploration were: 1  Alternate trade routes: Europe was dependent on Middle East countries for the import of spices and was looking for alternate trade routes to Asia and Africa to obtain spices (ginger, nutmeg, clove, cinnamon, etc.) and luxury goods (silk, gold, ivory, etc.) cheaply.
Negative Effects of Imperialism. Negative Effects of Imperialism: Africans lost control of their land and independence and were placed under the indirect rule of the British. Many of the Africans died of new diseases, such as small pox, that were brought over by the British.