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.
Wilson Cycles. The earth is 30% continental crust. There isn't a great deal of room for pieces to move before they collide. The bigger a continent gets through collisions, the larger a target it becomes and the more likely it is that it will grow still larger through more collisions. Chances are good that a large part of the continental crust will collect in one place as a supercontinent before it begins to break apart.