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地球上最活动的火山带沿全球性大洋中脊系出现,该处岩石圈被拉开而新的洋壳以10和200公里/百万年的速度增长。火山作用具有分段性,並集中分布於快、慢扩张洋脊顶、底轴上;转换断层带将每个洋脊隔开、并通常将它们错断。在慢扩张脊水平错断的转换交叉处,火山活动几乎可能不存在;而在快扩张脊水平错断处火山活动普遍减少,说明这些地区地壳较薄。沿大洋脊喷发的岩浆源是下部地幔。地幔在上升过程中,充填扩张板块之间的空隙时经受了不完全的熔融作用。由此引起的岩浆聚合在上地幔,以及由于岩浆的密度比原始地幔岩石的低而上升到地表。熔体被认为集中在地壳岩浆房中,从那里它分期地喷发到地表。典型地,沿大洋中脊岩浆的形成、上升和聚合作用被认为是两维空间的;模拟这一过程可横
The most active volcanic belt on Earth appears along the global mid-ocean ridge where the lithosphere has been opened up and new ocean shells have been growing at 10 and 200 km / million years. The volcanism is segmental and concentrated on fast and slow dilatations of the oceanic crest and basement; the transgressive fault zone separates each ocean ridge and usually breaks them. Volcanic activity is almost impossible to absent at the transitional intersections where the slow dilatancy level is at a wrong level, while volcanic activity generally decreases at the level of rapid dilapidation ridge, indicating a thin crust in these areas. The magma source erupted along the ocean ridge is the lower mantle. Mantles experience incomplete melting during their ascent, filling the interstices between the expanded plates. The resulting magma aggregates in the upper mantle and rises to the surface as the magma is denser than the original mantle rocks. The melt is thought to concentrate in the crustal magma chamber, from where it erupts to the surface in phases. Typically, formation, ascending and polymerisation along the mid-ocean ridge magma are considered two-dimensional; simulating this process can be horizontal