Thanks Brent, started in1969 with my 1st detector/ found my first drill hole in 1987, found that they were for real in1990/ started trying to get them figured out in 1995, still trying to get them figured out, 1/2 marble deep seems to indicate a map, 1/4 th inch wide seems to indicate direction when theres two, usually theres something else to indicate distance one was unusual in that it was 8 inches across and 4 inches deep with a shoulder 1/2 way down that made a horseshoe type symbol on the bottom 1/2, which indicated 2.5 cordell = 454 feet which a Bible verse / a carved initial / other carved letters on the site to verify 454 grams or = 1 pound bars, when you find a yard there should an upside down V on the " yard " which indicates something buried in a nearby land mark, ther will also a V horzional at the site, you must Read the carvings to figure out what they say, some sites may be 1/2 pound or 1/4 pound or possibly 2 pound bars or 1008 grams