How could glacial marks on one continent be similar to glacial marks on another continent far away?

Plate Tectonics

Explanation:

Plate tectonics is the scientific theory that the continents move around due to due plate tectonics and the movement of magma under the crust. This explains why some fossils of the same kind are found on other continents, and same goes for the Glacial Marks.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.

your answer is, orbit around the nucleus