The volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.This process continues today in such places as Hawaii.he volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.
608 STANDARD. The most common bearing size is the â608.â Characterized by an 8mm core, a 22mm outer diameter and a 7mm width, these bearings are the industry standard and match up with nearly every skate wheel out there. NON-STANDARD Of course, there are exceptions to every rule.
The radius of hollow can be varied from Â¼-inch to 1 Â½-inch, however most players will chose a hollow between 3/8-inch and 5/8-inch. Radius of hollow is the most important aspect of skate sharpening to understand. Itâs really pretty simple. The bigger the radius, the shallower the hollow on the blade will be.tâs pretty obvious when youâre falling down that your skates arenât sharp enough. But beyond that, skate sharpening is as confusing as the workings of spray cheese in a can is to the average hockey player. (Donât take that as a jibe, I have no idea how that stuff works).