File:Brooch, plate, enamelled (FindID 538560).jpg

English: Cast copper alloy plate brooch, rectangular with concave sides, on its face is an image of a small bird with a rounded body, wedge-shaped wings, a large head with a circular eye and a short beak. Below the bird is arch motif. On the underside of the plate are two fittings, the details of which were not recorded but appear to have consisted of a ring which held the pin and a catch plate. Trace of iron corrosion products are present on the back..The object appears to have been recently damage by the plough. Length 27.8mm, Width 18.5mm, Mass 5.17g.

Barry Ager writes:

This brooch is Carolingian, the British Museum acquired a matching pair of these brooches, with exactly the same bird design, as Carolingian items in 1991 (registration nos. 1991,0605.1 and 2; there is an image on the online database). These show definite arched motifs above the birds' heads (at least half an arch seems to be there on the PAS illustration, but only very faintly, unless I'm looking at it with the eye of faith).

They are a 9^th-century type, belonging to Frick's rectangular plate brooch type 2, variant 2, which occurs rather sporadically from northern France, the southern Netherlands around the lower Rhine and mouth of the Schelde, and across northern Germany to Hedeby. The 'new' find appears to be the first one from England, although the latest distribution map is from 1992/3 and needs a bit of updating, certainly to include Mablethorpe and Sutton.

You may be interested to know there's an article I published the BM pair in:-

"Recent acquisitions of late Merovingian and Carolingian metalwork in the Department of Medieval and Later Antiquities in the British Museum", Archäologisches Korrespondenzblatt, 25, 1995, pp. 253-263, at pp. 257-8, fig. 6a-b.