Abstract
Twelve postdepositional, nontectonic pillow-shaped structures, present in the Panther Sandstone Member of the Star Point Formation in east-central Utah, are larger than any previously reported. Six pillows show primary lamination that can be traced along the bottoms and sides. Primary physical and biogenetic structures are preserved in the distorted primary lamination and on the bedding planes. Smaller ball-shaped structures 1 ft to 7 feet in diameter comprise the matrix between and above the large pillows. These were formed from a sandy-silt which was compressed by the subsidence of the pillow structures and flowed as a viscous fluid. Both the balls and the pillows are considered to have formed in place due to a fortuitous set of depositional conditions, which brought together beds of sand and sandy-silt of the proper thickness.
