British Columbia: Peach plum fruit tree puzzle

Peach plum fruit tree puzzle??
A 7yr. Tree, which has produced mega quantities of fruit annually, this year, after a 'heavy flowering' in the spring, all the flowers and new leaves wilted and turned black, (but only on the 2yr. And older branches) ---also, approx. 70% of all the fruiting spurs blackened and died. Tree 'sap', resin? Liquid also formed in drops on the affected areas, and eventually hardened and turned amber-colored. (see pics)
however, all the top, new growth (approx. 2 ft.) was untouched. Also, there are new leaves sprouting in the affected areas, which look perfectly healthy.
A prune plum tree 30ft away was not affected, and is a heavy bearer every year.

 

Bacterial or fungal problem due to cool damp spring. Stone fruits are the least easy type to manage in the home orchard, blights like this being one of the main reasons. Start by reading about Brown Rot of Stone Fruits, it may be that.