Explain how coal forms, what conditions are needed to form coal, the differences between the types of coals (peat, lignite, bituminous, anthracite) and what causes the changes. Use sketch(es) to aid your explanation. Also, describe the age and factors that helped create the vast amounts of coal during the Carboniferous in places like the U.S. and U.K., including the role of Pangea

Depending the conditions are the stages of coal that are presented, the greater the pressure and heat, the higher rank appears (from peat, lignite, bituminous until anthracite).

During the Carboniferous period, in the Paleozoic Era, there were a collision among Laurasia (present day Europe, Asia and North America) with Gondwana (present day Africa), both part of the Pangea. As a result of the collision, Appalachian Mountain appears in North America and Hercynian Mountains in the UK. Giving a separation of both continents.

During this period, the mild temperatures, increases the tree ferns, plus the increases of the tetrapods, produce coal areas in both countries.

Hope this info is useful.