Neogene tectonic evolution of the Celebes-Sulu basins: new insights from Leg 124 drilling

Abstract

The Neogene tectonic evolution of the Celebes-Sulu basins is discussed on the basis of representative seismic profiles, published industrial wells, and Leg 124 drilling results. The study is also based on geological data collected all around the margins of these basins. A synthetic cross section was built from the South China Sea to Sulawesi, and correlation of the major magmatic and tectonic events was attempted. It is suggested that these basins and their margins (Celebes-Sulu block) collided with the rifted margin of China (Reed Bank) around 16 Ma. A main event of submarine pyroclastic emplacement coincided with this collision. The Sulu Basin probably opened in a back-arc position for the Cagayan volcanic arc in early Miocene time. Incipient closing of the Sulu and Celebes basins, still presently active, is documented within their sedimentary cover. -Authors