Abstract:

Based on the terrestrial heat flow and crustal structure data, this paper calculates the temperature and the thermal structure of lithosphere in the South China Sea. The result shows that there is a larger change of temperature along vertical direction in the central basin, which is caused by the uplifting of mantle. Mantle uplifting in local areas would cause seabed outspread in multi periods and multi aspects.As a result, different areas of heat flow value in the central basin are formed. The percentage of heat flow from mantle is bigger than 80% in terrestrial heat flow, whereas the percentage of lower crustal heat flow is smaller than 20% in terrestrial heat flow. We argue that two factors might produce the thinning of layer 3 in central basin crust. One factor is the lower original crustal temperature, the other is the slowly cooling process after late heating event.

Key words: central basin in South China Sea, terrestrial heat flow, thermal structure of oceanic crust, seabed outspread