Why would Alfred wegener consider the presence of coal in Pennsylvania evidence of continental drift?

Alfred Wegener would consider the presence of coal in Pennsylvania as evidence of continental drift because coal forms in tropical, swampy environments, indicating that the region was once located near the equator. The existence of coal deposits in such a temperate location suggests that continents have shifted over geological time. This supports Wegener's theory that continents were once part of a supercontinent, allowing for the migration of ecosystems and climates across different latitudes. Thus, the presence of coal provides insight into the historical arrangement of landmasses.