The mixture of molten rock, crystals and dissolved gases from the mantle is called magma. When magma erupts to the Earth's surface, it is called lava. Not all volcanic eruptions happen near the boundaries of tectonic plates. Some eruptions happen in the middle of the plates.These eruptions are caused by mantle streams called plumes. Mantle plumes are formed when hot magma rises beneath the thinner, or weaker, areas of the Earth's crust, creating 'hot spots'. Volcanic islands are formed when mantle plumes form at the bottom of the ocean.ome eruptions happen in the middle of the plates. These eruptions are caused by mantle streams called plumes. Mantle plumes are formed when hot magma rises beneath the thinner, or weaker, areas of the Earth's crust, creating 'hot spots'. Volcanic islands are formed when mantle plumes form at the bottom of the ocean.
Burst Fracture of the Lumbar Spine. General Considerations. Burst fractures result from axial loading most often secondary to motor vehicle accidents and falls. The axial load drives the intervertebral disk into vertebral body below. Usually produces a comminuted, vertical fracture through the vertebral body.
(A) Lateral view of this fracture caused by a flexion-rotation mechanism shows that it is stable. Anterior displacement of spine is less than one half of the diameter of a vertebral body. (B) Anteroposterior view shows disruption of a line connecting spinous processes at the level of the dislocation.