Mr McLennan found a cross among dozens of silver armrings and ingots some 24 inches below the ground - well beyond the depth his machine should have been able to register.
When the hole was fully excavated, Mr McLennan picked up another signal at its base, further digging revealed a second level hoard. That find included what is possibly the largest silver Carolingian pot ever discovered, with its lid still in place.
The pot is likely to have been around 100 years old when the hoard was buried in the mid 9th or 10th centuries.
"We still don't know exactly what is in the pot, but I hope it could reveal who these artefacts belonged to, or at least where they came from."
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