Combine blackberries, sugar and 1/4 c flour. Stir well and spoon into an 8-in baking dish, dot with butter. Combine 1 cup flour with salt. Cut in the shortening with a pastry blender until mixture resembles coarse meal. Sprinkle ice water evenly over suface, stirring with a fork until all dry ingredients are moistened. Shape the dough into a ball and roll pastry out on a lightly floured surface, into an 8-in square. Place over the blackberries, sealing the edges to the side of the dish. Cut slits in the top and bake at 375 F for 45 mins or until golden brown. Serve. warm.