Lawsonite is known to form in high pressure, low temperature conditions, most commonly found in subduction zones where cold oceanic crust subducts down oceanic trenches into the mantle (Comodi et al., 1996).

How does blueschist come to the surface?

Blueschists and other high-pressure subduction zone rocks are thought to be exhumed rapidly by flow and/or faulting in accretionary wedges or the upper parts of subducted crust, or may return to the Earth's surface in part owing to buoyancy if the metabasaltic rocks are associated with low-density continental crust ( ...

How is epidote formed?

It forms when basalts in sheeted dikes and ophiolites are transformed by hydrothermal activity or metasomatism. Unakite is a rock that forms from the metamorphism of granite. Less-resistant minerals in the granite are altered to epidote or replaced by epidote, with the orthoclase and quartz remaining.