Heating or cooling? Minerals against the thermometer

An invented well: a core from 1,700 m, where the recovered measured temperature is 180 °C. Its minerals are well-formed epidote, albite and prehnite, replacing crystals of plagioclase, set in fine-grained chlorite around them. So is the rock there heating up, cooling down, or stable? By the end, you can compare a well's minerals with its measured temperature, give a verdict, and say how far to trust it. 0:00 The question 0:32 Key terms 0:56 Minerals against the thermometer 1:45 A clearer sign of heating 2:00 Veins add time 2:32 Worked example: Well X 3:41 Recap 4:07 Your turn #geothermal #geology #earthscience