12:00 PM - 12:15 PM
[MIS32-12] High paleo-heat flow in Costa-Rica seismogenic zone, off Osa peninsula (CRISP Exp344)
Keywords:IODP, Seismogenic zone drilling, CostaRica, Heat flow, Vitrinite reflectance
In the results, 11 and 13 samples of the vitrinite reflectance are obtained at site U1380 (500-800 mbsf) and U1413 (0-600 mbsf) respectively. The value of the vitrinite reflectance increases with depth from 0.15 to 0.60 %. The average increase rate of 0.51 %/km at site U1380 and 0.53 %/km at site U1413 correspond to the heat flow of 115-123 mW/m2. This heat flow is two times higher than the present heat flow of 44.2-56.2 mW/m2 obtained from borehole temperature measurement (Harris et al., 2013). Pore-fluid chemistry found fluid seepage from deep level within middle slope sediment (Harris et al., 2013). Such fluid flow from deep portion can transfer heat and possibly have caused high thermal-event.