Oceanic Oceanic Convergent Boundary

Name 2 oceanic plates that are moving towards each other

The South American Plate is moving westwards due to sea floor spreading at the Mid Atlantic Ridge. Where it meets the Caribbean Plate, it descends (________) beneath it.

subduction causes low density ocean floor sediment to be ​ (a)   off the surface of the South American Plate and thrust onto the Caribbean Islands as ​ (b)   wedges, in a process called ​ (c)   . The line of subduction is marked by the deep sea Puerto Rico ​ (d)  

• scraped
• accretionary
• obduction
• Trench

As the ​ (a)   descends, it drags against the overlying plate, causing both to fracture and deform. This results in frequent ​ (b)   focus earthquakes that get deeper as the ocean plate descends further, defining a zone of earthquake foci known as a ​ (c)   zone.

• shallow
• superficial
• surface
• minor
• Benioff
• Obduction
• Milankovitch
• South American Plate
• Caribbean
• less dense

What is the name of the magma produced at an oceanic-oceanic convergent boundary?

• basalmic

• andesitic

• rhyolitic

• basaltic

What happens to the melting point of the plate as it descends into the mantle?

Andesitic magma is less dense than the surrounding material, and can have a temperature of ​ (a)   . It is ​ (b)   , trapping gases as it rises. The water and gases in andesitic magma account for the ​ (c)   activity of andesitic volcanoes, which typically lie ​ (d)   for many hundreds or thousands of years. These volcanoes typically produce ash and ​ (e)   flows, as well as small amounts of andesitic lava.

• 1000oC
• viscous
• dormant
• pyroclastic
• explosive

Name a volcano and volcanic island arch found at a convergent oceanic oceanic plate boundary

• Ben Nevis

• Caribbean Islands

• Montserrat

• The Phillipines

• Mount Vesuvious