PMT - different plate boundaries destructive oceanic and oceanic

Question 1

explain the process of a destructive oceanic and oceanic plate boundary?

Answer 1

• Heavier plate subducts leaving an ocean trench
• Fold mountains will also occur
• Built up pressure causes underwater volcanoes bursting through oceanic plate
• Lava cools and creates new land called island arcs

Question 2

what can form because of a destructive purely oceanic plate boundary?

Answer 2

fold mountains

underwater volcanoes

(when lava cools) island arcs