Magmatic underplating

As magma rises up to the surface, some may get trapped at the crust-mantle boundary, accumulating and eventually solidifying, thickening the crust.

Magmatic underplating occurs when basaltic magmas are trapped during their rise to the surface at the Mohorovičić discontinuity or within the crust.[1] Entrapment (or 'stalling out') of magmas within the crust occurs due to the difference in relative densities between the rising magma and the surrounding rock. Magmatic underplating can be responsible for thickening of the crust when the magma cools.[1] Geophysical seismic studies (as well as igneous petrology and geochemistry) utilize the differences in densities to identify underplating that occurs at depth.[1]

  1. ^ a b c Cox, K.G. (1993). "Continental Magmatic Underplating". Philosophical Transactions of the Royal Society A. 342 (1663): 155–166. Bibcode:1993RSPTA.342..155C. doi:10.1098/rsta.1993.0011. JSTOR 54188. S2CID 83865999.