Curious rock shelter find

[1320]

This could be nothing at all but in it's context with other artifacts and a depth of nearly three feet makes me wonder. The rock type is also unique to this shelter. Is it possible that a point or knife created these marks? The lines don't appear to be artwork but more like sharpening marks maybe?

[1320]

After reviewing the post, the photos don't clearly show that the marks extend over the "lip" on the rock on the right side, and I think I see an arrow form on the "back" side.....lol....

[PrimitiveOne]

If it is sandstone it may been used for burnishing the edge of points and tools for the flaking process>------->

[1320]

If it is sandstone it may been used for burnishing the edge of points and tools for the flaking process>------->

It is sandstone. I tried in vain to get a good picture of the edges but I can't pull it off. All four edges are cut up, even more so than the surface. Many thanks for the reply.