> "This and similar fossil 'forests' must be taken into account in
>reconstructing the paleoecology of the Navajo. it is possible the scattered
>ponds and small groves of trees provided food and perches for the pterosaurs
>known to have left trackways in nearby localities."
>"Silicified wood fragments as much as 20 cm. in diameter are widespread in
>outcrops of the Triassic-Juraswsic Navajo Sandstone near Moab, Utah. The
>is typically found in indistinctly crossbedded sandstone peripheral to thin,
>discontinuous carbonate beds. some trunks are in nearly vertical position
>suggesting in situ preservation. Smooth, fluted surfaces on some fragments
>indicate abrasion before burial.
> "Diverse tubular and cylindrical structures, typically in diameter are
>also abundant in the Navajo. They occur just below horizontal truncation
>planes which separate sets of crossbeds. Crossbedding is indistinct below
>truncation planes, and distinct and undisturbed above. Tubes are composed of
>an outer sheath of well-cemented sand surrounding a core of calcite spar;
>cylindrical features consist entirely of sand. These structures have many
>similarities with root casts in Holocene dunes at Arches National Park, near
>Moab, and have important implications concerning depositional environments of
>the Navajo Sandstone."
Interesting stuff. I predict a careful examination will demonstrate, as it
did in Yellowstone that the trunks are transported, that the limestone will
reveal fossils incompatible with sanddunes, and that the root casts are