Complex sentence: Evidence suggests that Portus Adurni was built during the time of Carausius, of the coinage uncovered at the site a large portion were minted by Carausius acting as emperor during the time of his revolt.
Split into simpler sentences: Evidence suggests that Portus Adurni was built during the time of Carausius. Of the coinage uncovered at the site, a large portion were minted by Carausius acting as emperor during the time of his revolt.