The end of moai quarrying and its effect on Lake Rano Raraku, Easter Island

We reconstruct aspects of the history of Easter Island over the last 4-5 ce nturies based on the study of a core from Rano Raraku Lake, situated in the crater that contains the quarry of the island's giant statues or moai. We use microfossils of plants and animals to identify five zones. The last thr ee of these are separated by waves of immigration from South America and fr om the subantarctic. We argue that the first or South American wave, dated to the second half-of the 14th century, may represent a visit by South Amer ican Indians. Magnetic information, pollen, diatoms, chrysophyte stomatocys ts and fossil plant pigments reveal a synchronism between the South America n contact and the cessation of moai quarrying. We therefore suggest that Am erindians contributed to the cultural collapse of the island. The second or subantarctic wave may reflect an early European Visit to the island, possi bly by Cpt. James Cook in 1774, or by Jacob Roggeveen in 1722.