2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 11
Presentation Time: 8:00 AM-12:00 PM

THE "LOCHNESS MONSTER" AS AN EXEMPLARY PSEUDOFOSSIL, MANCHURIOPHYCUS


RAUB, Timothy D. and RAUB, Theresa M.D., Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Caltech 170-25, Pasadena, CA 91125, timraub@caltech.edu

Transitional braidplain facies of ~1760 Ma Lochness Formation at Seymour River, Northern Territory, Australia expose sinuous sedimentary structures resembling sand-filled burrow casts or redeposited fecal trails, in positive epirelief and negative hyporelief occupying interference ripple troughs. We refer these to the seudofossil, Manchuriophycus, of purported syneresis-crack origin. Subcrop mapping of spatially heterogenous lithologies asssociates Manchuriophycus with normal dessication cracks as well as in situ, trellis-structure syneresis cracks, adjacent to sand-stromatolites on the beach of a playa lake margin. The Lochness outcrops at Seymour River present an unusually good opportunity to track pervasive microbial binding in Precambrian siliciclastics from inference to exposure.