Please help date this US Combat boot sole

[reefwreck]

Perhaps an unusual request. I'm interested in dating this US combat boot sole. I found it mostly buried alone on a sandbank off a beach in Saipan.
The sole has a visible marking which is the letters "US" which seem to be inside a circle. The visible sole pattern seems to be many small, rough, diamonds. It has remnants of what seem to be small nails or similar still embedded around the edge of the sole.
It seems that the heel has disappeared. But, under where the heel likely was located, there appears the following: "11 Style 502 12 IRON Made in USA"
Any insight on what era it is from would be appreciated.
Photos attached.
Thanks.
Michael.