Tectono-thermal modeling of the Yinggehai Basin, South China Sea

Based on the observed data, the average value of surface heat flow in the Y inggehai Basin is calculated and it turns out to be 84.1 mW/m(2). The therm al evolution of the basin since the Cenozoic era has been attempted by tect ono-thermal modeling. Three-phase extension made the basin become hotter an d hotter, reaching its climax in paleo-temperature history since 5.2 Ma. An d nowadays, the basin is in the heat flow decreasing period. During the Cen ozoic era, the basement heat flow remained at 50-70 mW/m(2) all the time. T his is related to the degree of each extension phase, stretching rate mode and also the limited basin scale. Modeling results also show that, the surf ace heat flow is controlled mainly by the basement heat flow, and less than 20% comes from radiogenic heat production in the sediments of the basin.