Earth's Crust
Earth's crust is the first layer of the four layers of the Earth. The crust is about 50-70 km thick and is made of hard rock. In the deepest parts of the crust, it's 1600 degrees Fahrenheit, which is the temperature rock begins to melt. The Earth's crust is mostly of igneous rock along with smaller amounts of metamorphic and sedimentary rock. The crust and the attached solid upper mantle are in turn broken up into a series of individual pieces called tectonic plates.
The crust consists of the following elements and percentages:
The crust consists of the following elements and percentages:
- Oxygen--47%
- Silicon--28%
- Aluminum--8%
- Iron--5%
- Calcium--4%
- Sodium--3%
- Potassium--3%
- Magnesium--2%
- Titanium--0.5%
- All others--<1%