Pyroclastic Breccia Patterns 4 – Angular rock fragments embedded in a volcanic ash matrix from a pyroclastic flow in Cape Breton Island near Louisbourg Lighthouse, with my foot shown to give a scale to the image. I’m not certain but the largest piece of rock shown in this image looks a bit like a volcanic bomb – these form when globs of molten lava are expelled from the vent of the volcano and solidify as they fly through the air before landing in the ash.
Jessica's Nature Blog 