What does «sima» mean in Spanish?
- Abyss, very deep cavity in the earth.
- An intermediate zone of the Earth's crust, between the nife and the sial, in which ferromagnesian silicates are assumed to predominate. The chasm is the name of the lower layer of the Earth's crust. This layer is made of rocks rich in magnesium silicate minerals. Usually when the chasm comes to the surface it is made of basalt, so sometimes this layer is called the basalt layer of the crust.