Old blocks rarely read like blank ground. Fence lines move, sheds disappear, fill is added, drains are rerouted and small metal fragments can remain where no current plan shows them.
The practical decision was simple: scan the accessible area before the heavier work began. The aim was not to “hunt treasure”, but to identify persistent metal responses worth marking before digging or machinery disturbed the soil. That distinction matters. A detector cannot tell you the story of an object; it can only help indicate that a conductive target may be present.
Nothing dramatic happened in the first passes. There were short, broken responses near old fasteners and scraps that behaved like ordinary shallow iron. Then one patch produced a stronger, repeatable response from more than one sweep direction.
