The Fossil Record 73of deposition of the Grand Canyon Series sediments (along with long erosion between them,
when the Galeros lavas flowed across the landscape), then the hardening of these soft sedi-
ments into sedimentary rock layers, then tilting, then erosion, then another long sequence that
makes up the higher part of the Grand Canyon. All of this is supposedly formed in a single
large flood event?
And so it goes, layer by layer, right up through the rest of the Grand Canyon. The first
unit above the tilted Grand Canyon Series rocks is the Tapeats Sandstone (figs. 3.4 and 3.7C),
a classic beach and nearshore deposit. It is chock-full of trackways and burrows of trilobites,
worms, and other invertebrates, layer after layer. When would these animals have had any
time to crawl across the bottom and leave tracks or burrow through the sediment if it had
been rapidly dumped by a flood? Above the Tapeats is the Bright Angel Shale, which real
geologists interpret as deposited on a shallow marine shelf below the action of storm waves.
It too is full of tracks and burrows, but of the types that today occur in the deeper part of the
ocean. How did these tracks and burrows get there, layer after layer, if all the deposits of the
Grand Canyon are a single flood deposit that drowned and buried all the marine life before
it had a chance to begin burrowing?
The Bright Angel Shale has a complex interfingering relationship with the next unit
above, the Muav Limestone. These types of relationships, where a thin layer of limestone
alternates with a thin layer of shale, are very typical of deposits we find today when sea
level slowly fluctuates back and forth—but it is impossible to explain such a complex
relationship by a single flood dumping these sediments in a flat “layer cake.” The Muav
Limestone is one of three consecutive limestones forming the steepest cliffs in the Grand
Canyon. Above the Muav is a sharp erosional surface with deeply eroded collapse fea-
tures (from ancient collapsed caves that slowly dissolved out of the Muav), into which the
much younger Temple Butte Limestone is deposited. The Temple Butte was then eroded
away in most places (except the remnant fillings of those collapse features), and above it
is deposited the big cliff of the Redwall Limestone. All three limestones have the features
typical of modern limestones, made largely of the delicate remains of fossils. Today, we
find such sediments forming in tropical, clear-water lagoons or shallow seas, such as
those in the Bahamas or Yucatan or the South Pacific. In no case do these sediments form
where there is the huge energy of floods or lots of mud stirred up by floodwaters. Par-
ticularly diagnostic is the fact that many of the fossils are extremely delicate (such as the
lacy “moss animals,” or bryozoans), yet they are intact and undisturbed, which proves
the flood cannot have occurred. Even more evocative are the delicate animals such as the
sea lilies (crinoids) and lamp shells (brachiopods), which are sitting just as they sat in life,
layer after layer growing over and over, undisturbed by high-energy currents and buried
by lime mud (not flood-type mud) that gently filtered in around them without disturb-
ing them. This is true of limestones like this around the world and in the geologic past,
so the Grand Canyon is not a special case—and definitely not evidence of a supernatural
flood. The same is true of the Toroweap and Kaibab Limestones, which form the rim of
the Grand Canyon.
Above the Redwall Limestone are the alternating sandstones and shales of the Supai
Group, followed by the red Hermit Shale. The sandstones of the Supai Group are full of
small ripples and small cross-beds, features of gentle deposition in rivers, not raging flood-
waters or muds settling out after flood movement has stopped. The Supai Group and Her-
mit Shale not only contain layer after layer of mudcracks (fig. 3.7D), clearly demonstrating