Final answer:
The type of convergent boundary without a subduction zone is the continental-continental boundary, where thick continental plates collide and create mountains rather than subducting.
Step-by-step explanation:
The type of convergent boundary that does not have a subduction zone is the continental-continental boundary. Unlike oceanic plates, thick continental plates are generally too buoyant to be forced deep into the mantle to create a subduction zone. Instead, when they collide, they tend to crumple and form mountains, such as the Himalayas, where the ancient oceanic crust between them, known as ophiolites, are found uplifted into these mountain ranges.
This process transforms the boundary into what is known as a suture zone. In contrast, subduction zones are associated with oceanic-continental and oceanic-oceanic convergences, where a denser oceanic plate is more likely to be subducted beneath another plate, forming deep trenches and leading to volcanic activity, marked by deep earthquakes along the zone.