Figure 2.06. Continental geotherms. Gulf of Mexico drill hole bottom temperatures (Tetrahedron, Inc., 2017) are shown with a blue curve labeled GM. Also shown are average continental model geotherms based on heat flow data by Pollack and Chapman (1977) (purple curve labeled PC) and by Hasterok and Chapman (2011) (green curve labeled HC). Pressure is based on a uniform crustal density of 2830 kg/m³.

To put these data into the context of regional metamorphism, click on the "Show Als" button to view the stabilities of the 3 aluminosilicate (Als) minerals: andalusite (And), kyanite (Ky), and sillimanite (Sil). Neither the trajectory of the Gulf of Mexico measured temperatures nor the continental geotherm models (based on heat flow measurements) pass very close to the Als triple point. Return to Previous View