Marian Iconography

"... the beautiful alabaster carving of the Assumption in the church of Sandford-on-Thames suggests that this may once have been the dedication there. The present title of the church is St. Andrew; but at the time of the Norman Conquest Sandford was in the possession of the Abbey of St. Mary at Abingdon, and it is noteworthy that the Abbey seal, like the alabaster, carries the relatively rare device of our Lady both crowned and in an aureole. A review of the monastic seals in Birch's Catalogue of Seals in the British Museum shows that whilst our Lady either crowned or in a nimbus or aureole is a very common device, the combination of crown and nimbus is uncommon. The angels supporting the aureole in the Sandford alabaster make it quite clear that the Assumption is the the subject of the carving. It should be added that the Sandford alabaster may have originally adorned not the parish church but one or other of the the two monastic chapels which formerly existed in the parish. Each of these was dedicated to our Lady ..."

Sic Bishop Kirk, 1946. The Bishop is mistaken in describing the statue as alabaster; Pevsner made exactly the same mistake ... I wonder ... does the error have a common source ...

Given that Sandford Church is within feet of the ancient flood-plain of the Thames, in my view the statue could have been transported aquatically for miles.

What I am wondering is: "Crown+nimbus/aureole=Assumption." Is this correct as an account of the symbolism of representations of the Mother of God in the later medieval period? Especially when the nimbus-encircled Figure is represented as being physically lifted aloft by angels?