5.1.2. Temperature History of Model 1

Model 1 is modeled with and without salt structures. The first model follows the evolution of salt structures of Figure 11. The second model has continuous sedimentary units and a uniformly thin salt unit at the base throughout the geohistory. Figure 16 shows the reconstructed geometries at two time steps (20 Ma and 60 Ma) and the temperature difference between these two models.

**Figure 16.** (**<sup>a</sup>**–**d**) Reconstructed geometries at 20 Ma (**<sup>a</sup>**,**<sup>c</sup>**) and 60 Ma (**b**,**d**) without and with salt structures, Figure (**<sup>e</sup>**,**f**) shows the temperature differences between the two models; temperature cooling in blue colous and temperature increase as pink to red colors.

At 60 Ma the salt structure is still continuous and a strong vertical cooling effect is seen along the salt. At 20 Ma the salt balloon is broken free from its stem and the vertical cooling is less. The relatively hotter, isolated, salt balloon volume leaks heat upward into the shallow sediment section above. The temperature differences in these two models could be up to +5–10 ◦C above the salt at 20 Ma and −35–40 ◦C in the salt stem. The paleo heat flow was constant across the profile and calculated by two tectonic events in the area: A Permo–Triassic event and an Earliest Cretaceous event.

In the model, the entire width of the profile is affected by the temperature change. Deeper than 2 km, the temperatures are generally lowered with the existence of salt, increasingly towards the stem of the salt structure. Increased temperature due to the salt structure is only seen in the upper part of the salt balloon and directly above it. The largest difference in the sediments is found around the stem of the salt balloon during Latest Cretaceous time (75 Ma) (see Figure 17), whereas maximum heating of the area above salt occurred in Miocene time. The maximum modeled temperature reduction was between 84.7 ◦C at 75 Ma (Point 3 in Figure 17). A maximum positive temperature difference of only 5.8 ◦C was modeled directly above the highest point of the salt structure at base Miocene time (point 1 in Figure 17). An intermediate point in the chalk unit (point 2) shows a maximum temperature reduction in the salt model of 24 ◦C at 75 Ma.

**Figure 17.** Temperature history difference in models with and without the growth of a salt balloon structure. The curves show temperature history of the points 1, 2, and 3 given on the two model profiles. The temperature of point 1 above the salt increases by 5.8 ◦C in the salt balloon model, whereas the lowest point below salt shows a decrease of more than 84 ◦C in salt model.
