downgoing slab造句

• At times some of the metamorphosed downgoing slab may be thrust up or obducted onto the continental margin.
• The volcanic arc is the surface expression of the magma that is generated by hydrous melting of the mantle above the downgoing slab.
• A study reported in 2016 found that the largest megathrust quakes are associated with downgoing slabs with the shallowest dip, so-called " flat slab subduction ".
• The volcanism associated with these islands occurs at the northeast closure of the downgoing slab and began approximately during the late Pliocene to early Pleistocene ( 1.5-1.7 Ma ).
• Mineralogy may also play a role, as locally metastable olivine will form areas of positive buoyancy, even in a cold downgoing slab, and this could cause slabs to'stall out'at the increased density of the 660-km phase transition.