Sedimentology
Long (1993) recognises three lithofacies in the Burgsvik beds; a poorly exposed silty/sandy mudstone facies dominant in the lower beds, appearing as interbeds in the middle beds; a fine to very fine sandstone; and a "biofacies" consisting of ooids, oncolites and bioclasts. He challenges three interpretations of the sub-aerial sandstone facies. Contrary to Gray et al.'s (1974) tidal mud flat interpretation, Long surmises that it may represent locally emergent offshore bars, near-shore sands or beach deposits. Tides cannot be a dominant factor, as cross-stratification is abundant; storm beds, recognised by hummocky cross-stratification, are also common, suggesting that storms were important in shaping the landscape. Irregularly aligned prod and scour marks on the sea floor shows that waves also played a role. The most favourable conclusion appears to be that the facies represents a shoaling sequence — the migration of sand wave complexes, detached offshore bars (Swift & Field 1981, Brenner et al.. 1985) or isolated mid-shelf bars (La Fon 1981).
Read more about this topic: Burgsvik Beds