|Spreading center type:||Back-arc or intra-oceanic spreading center|
|Time of cessation:||Ca. 39 Ma (Beiersdorf et al., 1997)|
|Subsequent active spreading center:||None in immediate area|
The Celebes Sea is situated within tectonically complex south east Asia and is to the north of Sulawesi (Indonesia), east of Borneo and south of the Philippine Islands. The Sea is ringed by subduction zones, with the Cotabato-West Sangihe and East Sangihe trenches to the northeast and the North Sulawesi trench to the south (Hamilton, 1979). The Sulu Trench border the Sea on the northwest found and the inactive Neogene Sulu Island Arc is also present (Hamilton, 1979), suggesting that the Celebes Sea most likely formed as a back-arc basin during the Neogene. The Celebes Sea ocean crust is thought to be of early Tertiary or late Cretaceous age, inferred from depth and heat flow (Hamilton, 1979).
Two interpretations have been made of the magnetic anomalies measured within the Celebes Sea from shiptrack data (Beiersdorf et al., 1997; Weissel, 1980). Beiersdorf et al. (1997) interpreted magnetic anomalies and obtained an absolute date for the oceanic crust of 43 Ma. Beiersdorf et al. (1997) propose that the basin was formed at an extinct ridge until chron C18 and place the former spreading axis at 4° N and a spreading rate of 20 mm/yr is inferred (Beiersdorf et al., 1997). An alternative interpretation is proposed by Weissel (1980), who suggests anomaly sequence C18 to C20 may be present. From our review of global datasets and available data, we find that there is insufficient information available to constrain the location of the extinct spreading center and do not include this ridge in our statistical analysis.
Beiersdorf, H., Bach, W., Delisle, G., Faber, E., Gerling, P., and Hinz, K., 1997, Age and possible modes of formation of the Celebes Sea basement and thermal regimes within the accretionary complexes off SW Mindanao and N. Sulawesi, Iin Dheeradilok, P., et al., eds., Proceedings of the International Conference on Stratigraphic and Tectonic Evolution of Southeast Asia and the South Pacific, Integrated Ocean Drilling Program, p. 369–387.
Hamilton, W., 1979, Tectonics of the Indonesian region, USGS Professional Paper, 1078. 345 pp.
Weissel, J. K., 1980, Evidence for Eocene oceanic crust in the Celebes Basin, in, The Tectonic and Geological evolution of the Southeast Asian Seas and Islands. Geophysical Mongraph Series, v. 23, p. 37 - 47.