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Garnet amphibolite
About a billion years ago, a collision between North American and another continent formed this metamorphic rock. The dark red areas are huge garnet crystals, mined to make abrasives like sandpaper or emery boards.
The minerals in this metamorphic rock record the following temperature (T) and pressure (P) conditions within the Earth:
T = 750°C, P = 8,000 atm. |
