Is the source of the mississippi river the gulf of mexico or a lake in northern minnesota answer?

The Mississippi river leads into the gulf of mexico and it is called the Mississippi Delta. Hopes this helps ;)

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.