Skolithos in a Permian braided river deposit, southern Victoria Land, Antarctica

Abstract

Skolithos burrows have been found in a Permian braided river deposit, the lower Feather Conglomerate of southern Victoria Land, Antarctica. They are straight, vertical, 1 cm in diameter and up to 30 cm deep. The host sediment varies from fine to very coarse sandstone, and even in places fine conglomerate. They are most abundant in coarse sandstone, where they form densely packed clusters and have destroyed virtually all stratification. They are less common in fine and medium sandstone and fine conglomerate. They appear to be identical to Skolithos linearis. The sedimentary facies, paleocurrent measurements and especially the well-developed paleosols of the lower Feather Conglomerate, provide a clear and consistent picture of rapid but intermittent deposition in relatively small shallow river channels in a high plains setting and a temperate sub-humid to humid climate. It is thought that the burrows are dwelling structures of worm-like organisms that responded to a fluctuating water table in the same way that polychaetes in a modern coastal setting respond to tidal changes in water level. We conclude that Skolithos can no longer be used, as it has in the past, as an unequivocal indicator of coastal deposition.