| The island contains a suite of rocks deposited in a forearc setting to the west of a magmatic arc, formed as the Pacific plate was subducted beneath Antarctica. |
| The plate carrying the Afro-Arabian continent began to be subducted beneath the oceanic crust of the Tethys at a deep ocean trench. |
| It is therefore likely that the radiogenic lead content in these rocks is also the result of a contribution from a subducted sedimentary component. |
| Pacific type margins have a trench at the foot of the slope, many earthquakes and volcanoes, and an ocean plate being subducted under a continent. |
| Is the whole crustal section exhumed, or is only part of the subducted crust exhumed? |
| Since Hadean times, nearly all of this original crust has subducted from the movements of tectonic plates, and thus few rocks and minerals remain from the interval. |
