Late Quaternary tectonic movements and sea-level changes at Timor and Atauro Island

Flights of raised coral terraces on the north coast of East Timor and at Atauro Island, north of Timor, are described stratigraphically and dated by Th230-U234 determinations. The exposures at southern Atauro enable detailed reconstruction of the history of transgressions and regressions, especially for the period 140,000 to 105,000 yr B.P. Sea-level changes identified in Barbados and New Guinea are closely confirmed. The Atauro uplift rate is 0.47 m/1,000 yr, as estimated from the highest position of shallow-water coral faunas in the reef, which is dated as 120,000 old. The extrapolated rate is used to estimate ages of higher reefs; these ages correlate quite well with periods of major glacio-eustatic rise indicated by the O18 record of Pacific cores back to 700,000 yr B.P. Reefs from three sites along the north coast of Timor have been dated within the 84,000, 105,000, and 120,000 yr B.P. high sea-level periods and indicate uplift at 0.5 m/1,000 yr. A 120,000-yr-old reef from a fourth north Timor site, near Dili, indicates much slower uplift, about 0.03 m/1,000 yr. © 1978 Geological Society of America.