The highest social class or group.
Crust and the upper mantle
Upper Crust Pizzeria was founded in 2001 in Boston, Massachusetts.
Upper Crust - restaurant chain - was created in 1986.
If you are using the term 'upper crust' euphemistically and not to refer to bread or pies, then the upper crust is made of aristocrats. If you mean the upper part of the earth's crust, then it is made of the lightest elements from which the planet is made (silicon, aluminum etc).
lithosphere
For the Upper Crust - 1903 was released on: USA: April 1903
The crust is the layer at the surface that forms the upper part of the plates. The plates also include a portion of the upper mantle just beneath the crust. Together, the crust and this upper portion of the mantle form the lithosphere.
The lower crust is denser and more mafic in composition compared to the upper crust, which is less dense and more felsic. The lower crust is also usually deeper in the Earth's crust compared to the upper crust.
The Upper Crust - 1917 was released on: USA: 25 June 1917
Earth's crust and brittle upper mantle is called the lithosphere.
It is called the lithosphere.
Large segments of the crust and upper mantle known as the Lithospheric plates.