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.
Skateboards consist of three parts: the deck (the actual board), the truck (a component usually made of metal that holds the wheels to the deck), and the wheels. The average skateboard deck is about 32 in (81.3 cm) long, 8 in (20.3 cm) wide, and is a little less than 0.5 in (1.3 cm) thick.The deck has a defined nose and tail with a concave in the middle. Skateboard wheels are usually made of polyurethane and range in width from about 1.3-1.5 in (3.3-3.8 cm).While nearly all skateboards have similar shapes and characteristics, their dimensions vary slightly based on use.he deck has a defined nose and tail with a concave in the middle. Skateboard wheels are usually made of polyurethane and range in width from about 1.3-1.5 in (3.3-3.8 cm). While nearly all skateboards have similar shapes and characteristics, their dimensions vary slightly based on use.