Examination of the chart from the sonar
survey reveals details of a structure that we propound as being that
of a harbour. The positioning is in keeping with other harbours on this
coast and would have given excellent protection from the tide and sea,
before ancient quarrying activities removed much of the Brigg.
Placed in the location of the Spittals such
a harbour would also have had the advantage of not drying out at low tide.
The geological survey rules out the
possibility that the structure is a glacial moraine. The photographic
survey shows the uniformity of rock sizes and that no rock sizes were
larger than could be handled by men
Due to protection afforded by Filey Bay,
the likelihood of the structure being a tidal collection of boulders is
negligible. The rock sizes are too uniform to support the theory that
rocks were washed over the brigg and channeled into a line by its shape.
If the structure was the remains of the
ancient coastline before the erosion of the clay, it too would have been
eroded and would not have remained the massive structure it is today