Long-Term Surface Uplift History of the Active Banda Arc-Continent Collision: Depth and Age Analysis of Foraminifera from Rote and Savu Islands, Indonesia
Analysis of foraminifera for synorogenic pelagic units of Rote and Savu Islands, Indonesia, reveals high rates of surface uplift in the past 1.5 Ma of the incipient Banda arc-continent collision. Paleodepth estimates are derived from benthonic forams and ages from planktonic forams. But estimates are complicated, however, by abundant reworking; yet several distinctive species have been found. Synorogenic deposits in western Rote yield forams of biozone Neogene (N) 18 and depths from 5000-5700 meters at the base of the section, and 3600 meters at the top of the section. Eastern Rote yields forams of N 19/20 - N 22 and depths from 5400-5700 meters. Central Rote yields N 21 and depths from 5000-5700 meters. Because all of the sections are presently about the same elevation (~200 m), long-term surface uplift rates are slightly higher (1.84-3.29 m/yr) in eastern and central Rote than those in western Rote. Forams from Savu yield ages of N19/20 - N 22. Across Savu depth estimates range from 3200-5700 meters, which yields a range of uplift rates from 1.86 mm/yr in SE Savu to 3.25 mm/yr in Central Savu. These results indicate the Banda arc-continent collision caused uplift of Rote and Savu at rates of 1-2 mm/yr over the past 3 Ma.
Foraminifera, uplift, synorogenic, depth analysis, age analysis, Banda arc, Rote, Savu, Timor, reworked fossil, plankton, benthic, collision, progressive, Indonesia, Geology
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