The two principal abiogenic petroleum hypotheses, the deep gas hypothesis of Thomas Gold and the deep abiotic petroleum hypothesis, have been scientifically reviewed without confirmation. Scientific opinion on the origin of oil and gas is that all natural oil and gas deposits on Earth are fossil fuels and are, therefore, biogenic.
In short a Thru Axle design incorporates a solid rod or hollowed shaft that passes directly through the hub and both legs of the fork or rear frame members. It is then secured to one side of the fork leg or rear frame member (typically on the brake rotor side) by a threaded mechanical connection.
A train wheel or rail wheel is a type of wheel specially designed for use on rail tracks. A rolling component is typically pressed onto an axle and mounted directly on a rail car or locomotive or indirectly on a bogie, also called a truck.