If you count my airplane flying days I have no idea as well. I can say I buried planes so deep in the ground you could not see the prop tips.
Back to the flint. I knocked the chalk off the outside of another nodule. Things were going well until I started thinning the the base and snapped off the tip.
Now, after fighting my way almost to a point, I can say that English concrete is the equal of the concrete in our flint. I could not thin through the concrete spots on this chunk. I did OK with regular percussion, but when I went to indirect I could not hit it hard enough. It's sort of a point, but too thick to haft at the base.
Not my best effort.
I'll clean it up a little more and let Neil take it back with him.
I learned something important tonight. If it's over 100 degrees in your shop and you knapp in just a swim suit so you can jump in the pool when you're done, you get to pull flint shards out of your chest for quite awhile.
Won't do that again.
George