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.
Axial T2-weighted MRI image in a patient with a burst fracture injury to the upper lumbar spine. The posterior margin of the vertebral endplate has been displaced into the spinal canal (arrow). Cerebrospinal fluid is seen as bright signal anterior to the conus and upper cauda equina.umbar spine trauma. Axial CT images of an L2 compression burst fracture after posterior fusion with pedicle screws (yellow arrow) joined by a posterior bar (white arrow). The pedicle screws should be entirely within the bone of the body and pedicle of the vertebral bodies.