Axes have a primary purpose of chopping or pounding.  The 1/2 groove is used to attach the handle.  Handles were likely attached using pliable wood to wrap around the groove to form a handle, and securing the handle with rawhide wrapping.  Groundstone axes are made from a variety of stone materials, including quartzite, basalt, granite, slate, or sandstone.  The raw material (e.g., a stone slab or a cobble) is pecked to form the basic shape, ground with a coarse stone block to refine the shape, and sharpened by grinding with a finer stone.