Removing the bones of long dead animals from their rocky tombs is never an easy task, but sometimes the magnitude of what we’re doing really hits home. On May 24th we met up with our friends and colleagues at Colorado Northern Community College (CNCC) to excavate a rather difficult site: a duck bill dinosaur buried in the middle of a 20 foot channel sandstone in the Upper Cretaceous Mesa Verde Group. We teamed up with CNCC to lend them a helping hand since they had a summer field course they wanted to run at this site and in order for the students to actually dig up bone, we had to first plow through a 10 foot ledge of sandstone overburden.
Typically removing overburden only requires hand tools (picks and shovels). Sometimes we speed things up with a jackhammer, especially when the surrounding matrix gets too hard to pick through. With sandstone, there aren’t many options, power tools are the only real way to go. In this case, we used a jackhammer to plow through the ledge about 1-2 feet per day.
The other useful technique, especially when we get closer to the bone bearing layer, is using a rock saw to cut blocks and chiseling or picking them out. This reduces the vibration on the bone as we get closer.
At the end of week 1, we’re still only half way there!