At first glance these look like shapeless lumps of lead. However, the indented ridge around their edges says that they are in fact very welcome finds, as they indicate the presence of an early human settlement.

When a cooking or storage pot develope a hole, molten lead would be poured onto it to form a plug - hence the indent. These are therefore not likely to be 'casual loss' material which could be found in almost any field simply as a result of people wandering across them over hundreds of years. They are clear indications of habitation, and therefore a very encouraging sign to anyone who comes across them with a metal detector.