U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary

For additional information                      Copies of this report can
be write to:                                    purchased from: 
                                                U.S. Geological Survey  
                                                Earth Science and Information Center 
District Chief                                  Open-File Reports Section 
U.S. Geological Survey                          Box 25286, MS 517 
3916 Sunset Ridge Road                          Denver Federal Center 
Raleigh, NC 27607                               Denver, CO 80225