Thanks Eighty for the link, this one will do me!
France: Tools in Rock
Extensive quarrying was done near the city of Aixen -Provence, France between 1786 and 1788, to provide the large quantities of limestone needed for the rebuilding of the Palace of Justice. In the quarry from which the limestone was taken, the rock strata were separated from each other by layers of sand and clay, and by the time the workmen had removed 11 layers of rock they had found they had reached a depth of some 40 feet or 50 feet from the original level of the area.
Beneath the 11th layer of limestone they came to a bed of sand and began to remove it to get at the rock underneath. But in the sand they found the stumps of stone pillars and fragments of half worked rock, the same stone and rock that they themselves had been excavating. they dug further and found coins, the petrified wooden handles of hammers, and pieces of other petrified wooden tools. Finally they came to a large wooden board, seven or eight feet long and an inch thick. like the wooden tools, it had also been petrified into a form of agate and it had been broken into pieces. When the pieces were reassembled, the workmen saw before them a quarryman's board of exactly the same kind they themselves used, worn in just the same way as their own boards were, with rounded, wavy edges.
How a stonemason's yard equipped with the kind of tools used in France in the late18th century, had come to be buried 50 feet deep under layer of sand and limestone 300 million years old is a question even more vexing today than at the time of the original discovery. For we now know, thanks to advances in geological and anthropological dating, that such a thing is absolutely impossible. And yet it does seem to have happened.