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.
Causes of Fractures. Often an avulsion fracture occurs when there is a sudden forceful pull on a tendon while the bone is moving in the opposite direction. An example is an injury to the fifth metatarsal, the bone on the outside of the midfoot. The peroneal tendon attaches to the base of this bone.