The cave has its own website :[www.riverbluffcave.com]

From the Dating page
"Cosmogenic (Burial) Dating
Over the last decade in-situ-produced cosmogenic nuclides such as 26Al, 10Be and 36Cl have been increasingly used to date glacial landforms. This method has been checked many times with other dating techniques (Grainger 1997 and 2001) and has been proven to be effective. As uses diversify for this technique applications were soon taken to the cave environment primarily because of the simple requirements and also because the range of accurate dates ranges from 100,000 years to 5 million years. There are two main requirements for this technique to be useful. First there must be quartz present because the nuclides are created by the neutron spallation of quartz and second the quartz must be buried deep enough for neutron spallation to stop. The depth the sample must be buried to be dependent on the density of the material above the sample site. Normally sediment above 5 meters in depth encounters too much error to be considered reliable. By measuring the different decay rates of 10 Be with a half life of 1.5 million years to 26Al with a half life of 700,000 years a date of burial (nuclide production ends) an approximate age of burial can be identified. This constant decay rate is also matched by a constant production ratio. The 26Al nuclide produces six times faster than 10Be nuclide which makes calculating decay rates less tenuous. The results of the cosmogenic testing resulted in a sequential set of dates. Starting from the bottom of the type section sediment column (L-8) is 0.83 m.y. + or- 0.70 m.y. which is a layer of grey clay. The overlying channel gravel (Mammoth Horizon)(L-6 and L-7) that is the same deposition feature dated at 0.63 m.y. + or – 0.60 m.y. The field work and laboratory preparation was performed by David Gaunt while isotope dating was conducted by Greg Balco at the University of Washington."

This looks like a very promising technique but I am curious why being buried more than 5 meters deep would cause errors? Could this technique be used to date sites such as Calico or Hueyatloco?