In situ thermal measurements were successfully conducted within Hole 1109C using the Adara tool on Cores 180-1109C-3H, 5H, 7H, and 9H at 26.4, 45.4, 64.4, and 83.4 mbsf, respectively (Fig. F111). An additional temperature measurement was obtained before Core 180-1109C-19X using the DVTP at a probe-tip depth of 170.8 mbsf (Fig. F112).
Equilibrium formation temperatures were estimated using the TFIT program for Adara runs and the CONEFIT program for the DVTP run (see "Data Reduction" in "In Situ Temperature Measurements" in the "Explanatory Notes" chapter). The estimates of equilibrium temperature used the thermal conductivity determined by core measurements (see "Thermal Conductivity"), rounded to the nearest 0.1 W·m-1·ºC-1. Linear regression of the temperatures as a function of depth yields an estimated thermal gradient of 0.031ºC·m-1 (31ºC·km-1). The intercept was specified to be the mudline temperature (2.6ºC). Core measurements suggest an average thermal conductivity of 0.9 W·m-1·ºC-1 above 170 mbsf (see "Thermal Conductivity"), yielding a heat flow of 28 mW·m-2 (Fig. F113).