Sial

     What is Sial? Sial in Geology, refers to the upper layer of the Earth's crust with rocks rich in silicates and aluminum minerals. Sial is usually associated with Continental Crusts because they can't be found in Oceanic Crusts, but the word Sial is a Geochemical term rather than a tectonic term.

     Rocks found in the Sial layer are called Felsic, because they contain high levels of Feldspar, which is an aluminum silicate mineral series. But, on the other hand, Sial can also contain a large mixture of different minerals, including Basaltic rocks.

(https://upload.wikimedia.org/wikipedia/commons/thumb/b/b1/Eduard_Suess_1869.jpg/800px-Eduard_Suess_1869.jpg)

     Sial is the contrast of Sima, the next lower layer, These names were proposed by Eduard Suess during the 19th century. It was later proven by modern scientific methods that his model of the outer layers of Earth were correct.

Properties

• Density: 2700-2800 kg/m³ (lower than Sima)
• Depth: 5-70 km

(https://upload.wikimedia.org/wikipedia/commons/3/3c/Precambrian_Granite_St_Francis_Mountains_Missouri.jpg)