Roman Group L. Layer I (cont. 59-64) Pre-Herulian second half of 3rd c. (bottom, 15.95-13.90). Layer II (cont. 42-58) 4th c.-first quarter of 4th c. (11.90-13.90). Layer III (cont. 17-41) -4th c. (10.00 ... Second half 3rd c.-early 5th c. A.D.