Steps. 1  1. Perform major pruning during the dormant season. The ideal time to prune a crabapple tree is late winter or in the cold days of early spring, before leaves appear. 2  2. Remove suckers. Suckers are additional branches that begin growing underground and sprout near the base of the tree. 3  3. Remove water sprouts.
The upper crust is 12.5 km thick in crust with an average total thickness of 40 km (ref. 3). If the upper crust is the product of 14% melting, the corresponding residue would be 77 km thick, resulting in a total crustal thickness of 100 km, including the middle crust.
The continental crust is made mostly of rocks with a composition similar to granite (a light-colored rock you would expect to find in the Sierra Nevada), whereas the oceanic crust is made mostly of rocks with a composition of basalt (a dark-colored rock, like the rocks that make up the Hawaiian volcanoes).ecause continental crust is less dense than oceanic crust it floats higher on the mantle, just like a piece of Styrofoam floats higher on water than a piece of wood does. The mantle, oceanic crust and continental crust have different densities because they are made of different kinds of rock with different densities.