Project Details
Projekt
Provenance of Miocene siliciclastic turbidites of the Celebes and Sulu seas of ODP Leg 124
Applicant
Dr. Hans Tim Breitfeld
Subject Area
Geology
Mineralogy, Petrology and Geochemistry
Mineralogy, Petrology and Geochemistry
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 565636534
This project aims to study ages and provenance of quartzose sand intervals, which are interpreted as turbidites found in the Celebes and Sulu Seas in sites 767 and 768, and volcaniclastic sediments of sites 767, 769, 770 and 771 of ODP Leg 124 to determine their sources and obtain further insights into the magmatic and tectonic history of the region. The northern Borneo and Philippines area comprises a complex Neogene to Quaternary tectonic history. Subduction and rift processes and their associated magmatism are relatively poorly studied. The Proto-South China Sea (PSCS) was subducted beneath northern Borneo and the Cagayan Arc in the Oligocene to Early Miocene. Subsequently the PSCS was eliminated with the collision of the Palawan terrane with the arc in the upper Early Miocene followed by the emergence of extensive areas in Sabah and Palawan. In the Middle Miocene an opposite-directed subduction zone formed the Sulu Arc with the subduction of the Celebes Sea and subsequent extension lead to the opening of the Sulu Sea. The quartzose turbidites were interpreted as multiple reworked successions from older basement, based on their quartz-rich character. Volcanic-derived quartz that might have been derived from nearby volcanic arcs was not regarded. The Sabah-Cagayan Arc in the Late Oligocene to Early Miocene, associated with the Proto-South China Sea (PSCS) subduction could be a potential source for directly-derived volcanic material/quartz. Detrital zircons could be derived either by reworking of the Miocene arcs or by reworking of successions of uplifted NW Borneo/Palawan and could give a better time constrain on the arc activity. Miocene ash intervals in the cores can also be used to correlate the volcanic activity in the Celebes and Sulu Arcs and basins. The cores of Leg 124 have so far not been analysed with modern analytical methods. A characterisation of the intervals with a combination of single-grain and whole-rock methods, investigating provenance, geochronology, stratigraphy and geochemistry would help to identify source areas and to reconstruct uplift and subsidence periods and associated climate changes. The acquired data would also help to constrain the timings of the different subduction and rift phases associated with the basin development. The region is tectonically active at present, and also contains natural resources. To understand the present-day tectonics, it is important to increase our knowledge of the directly preceding situation and reconstruct the tectonic history. The cores were already sampled by the applicant in Kochi, Japan.
DFG Programme
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