This picture shows the grid reference from the map, and the outline of
the rock and cut.
This is a view of the top of the section, the top of the anasibirites
beds, the cut was made through the shell of one of the visible
specimens of Anasibirites, ammonoid #33, 115mm Diameter. The cut
goes through a smaller ammonoid partially visible just north of, and
partially under, #33, and barely through a Wasatchites, just north of
and under it (it has an arrow drawn on it).
of the Anasibirites Beds.
for a larger view (about 2x actual size), without all the annotation
Ammonoids are outlined in black. The rocks were collected
and cut, then an acetate peel was taken. I soaked the cut
in 5% hydrochloric acid for about 20 seconds then flooded the
surface with acetone and applied a cut sheet of cellulose acetate, this
could be peeled off in a few minutes. The acetate peels were then
scanned on a flat bed scanner.
The spaces in between the cut sections were filled with soft fissle
shale, so they could not be sectioned with an acetate peel.
The thicknesses shown on the right were measured in the field,
and adjusted on the image. The location of the base of the
Anasibirites Bed was located and measured from the acetate peel and
field data (an
older section showed it 65-105mm lower, but after new evidence from the
field, the base of the anasibirites beds is revised upwards in between
two middle sections). Only the top 150-200mm or so of the
beds were sectioned just so I could find the base of the Anasibirites
The bottom three sections came from a location about 200 meters
north of the mapped area where they were easier to obtain. The
orientation of the cut lines up fairly close (not exact).
Thanks go to Gene Boardman of U-Dig
Fossils for a great job
of cutting the rocks for me.