“…The sensitivity of the model overpressure to downward fluid flow into basement rock, was modelled using ranges in pre‐Messinian claystone permeabilities of 10 –17 –10 –22 m 2 at porosities of 2%–14% for a 4,000 m subsurface depth. To ground truth mineral dehydration as an overpressure mechanism in the region, heat flow of 80–120 m W/m 2 (Carballo et al, 2014), thermal conductivities for marlstone of 1.5–3.0 W/m K/m (Erickson & Von Herzen, 1978), thermal conductivities for gypsum of 1.0–1.3 W/m K/m (Balkan et al, 2017; Robertson & Geological Survey (U.S.), 1988), thick basin‐ward units and seabed temperature are used to estimate the thermal structure of the 1D sediment column. Combining these temperature data with pressure data we estimate the P‐T conditions of the Algero‐Balearic Upper Unit Gypsum relative to the boundaries of the dehydration reaction.…”