At the listing co-ordinates you should be able to see a slab of red sandstone which has some fossil dinosaur footprints raised above the general surface.
Dinosaurs were reptiles that were the major animal life form on Earth during the Carboniferous period. Although there were mammals living then, these were mostly small and nocturnal. The first Human-like apes did not evolve until a million or so years ago and Modern humans (Homo sapiens) have been on earth for only the last 40,000 years or so no human ever came into contact with a living dinosaur in spite of what you might see in comics, films or Creationist museums!
Sandstone — a rock made of grains of quartz and sediments of sand — seems to be the best type of environment for preserving organic material in fossils, although in this block there are just the impressions of the animal and no organic remains. There are 5 large prints and one smaller one.
HOW FOSSILS MAY FORM
When animals, plants and other organisms die, they typically decay completely. But sometimes, when the conditions are just right, they're preserved as fossils. The heat and pressure from being buried in sediment can sometimes cause the tissues of organisms — including plant leaves and the soft body parts of fish, reptiles and marine invertebrates — to release hydrogen and oxygen, leaving behind a residue of carbon. This process — which is called carbonization, or distillation — yields a detailed carbon impression of the dead organism in sedimentary rock.
The most common method of fossilization is called permineralization, or petrification. After an organism's soft tissues decay in sediment, the hard parts — particularly the bones — are left behind. Water seeps into the remains, and minerals dissolved in the water seep into the spaces within the remains, where they form crystals. These crystallized minerals cause the remains to harden along with the encasing sedimentary rock.
In another fossilization process, called replacement, the minerals in groundwater replace the minerals that make up the bodily remains after the water completely dissolves the original hard parts of the organism.
Fossils also form from molds and casts. If an organism deforms the sediments when it is alive (e.g. by walking across the surface) or when it is dead its remains completely dissolve in the sedimentary rock, it can leave an impression of its exterior in the rock, called an external mold. If that mold gets filled with other minerals, it becomes a cast. An internal mold forms when sediments or minerals fill an internal cavity, such as a shell or skull, of an organism, and the remains dissolve.
To log this earthcache you must email me the answers to the following questions, ensuring your message contains a reply email address, or send me the answers via the geocaching message board:-
1) What was the likely weight and length of the dinosaur that made these prints and was he/she a carnivore or herbivore? (a nearby sign should help with this)
2) Tell me the width (in inches or centimetres) of the top left print and describe any feature that seems to relate to the way of life of the creature.
3) How come the prints are raised above the surface of the sandstone when the dinosaur that made them was very heavy?
4) Approximately how long ago did the dinosaur that made these prints live?
Once you have email me the answers to these questions you may log a "Find" and I will get back to you as soon as possible to confirm whether your answers are correct or not and whether your 'find' is legitimate.
My grateful thanks to the folk at the Interpretation, Partnerships and Education section at the Glen Canyon National Recreation Area & Rainbow Bridge National Monument for giving permission for this earthcache to be listed on the geocaching website.