Complex sentence: Test excavations at the site in 2004 by the University of Georgia Archaeology Field School resulted in evidence that the sites was occupied during the Early Middle Woodland Cartersville Phase and most intensively during the Mississippian period from 1350 to 1600 CE during the Lamar Phase.
Split into simpler sentences: Test excavations at the site in 2004 by the University of Georgia Archaeology Field School resulted in evidence that the sites was occupied during the Early Middle Woodland Cartersville Phase. It was most intensively occupied during the Mississippian period, from 1350 to 1600 CE during the Lamar Phase.