Idea of Spread Icon
Consider a circle to which an arrow mark is attached. There will be two circles separated by some distance to for which one arrow is towards the north-east direction and other is towards exactly opposite to it on the adjacent circle pointing towards south west direction. These two circles lie on an imaginary line which is at 45 degrees to the horizontal.
This is a Spread icon. It is available in PNG and vector. Downloading is free for PNGs up to 100x100px.