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.
The Axial Age is defined by Jaspers as occurring in the interval from about 800 to 200, but a closer analysis suggests the need to modify and break up this interval. However, the basic point is clear. But the Axial phenomenon is evanescent and begins to wane rapidly by 400.